JP2002274108A - Wheel with tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a treading property at the time of turning and improve steering stability. SOLUTION: Peripheral length Li of an inward rim sheet is made larger than peripheral length Lo of an outward rim sheet directed to the car body outside, and peripheral length Ti of an inward bead sheet is made larger than peripheral length To of an outward bead sheet directed to the car body outside. Additionally, a peripheral length difference (Ti-To) of the bead sheets is made 0.5-1.5 times of the peripheral length difference (Li-Lo) of the rim sheets.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called outset wheel in which a disk portion is offset to the outside of a vehicle body, and more particularly to a wheel with a tire in which a ground contact property of a turning tire is enhanced to improve steering stability.

[0002]

2. Description of the Related Art FIG.
1 shows a cross-sectional view of a conventional wheel with a tire mounted on a vehicle. Reference numeral b1 in the drawing is a rim for mounting and holding the automobile tire a, and includes a rim seat c for seating a bead portion of the tire a. Reference numeral b2 denotes a disk portion for attaching the wheel b to the axle, and is integrally connected to the rim b1.

[0003] In the wheel b, generally, the mounting surface s2 of the disk portion b2 is attached to the tire axle of the rim b1 so that members such as a brake and a suspension provided on the axle side can be accommodated inside the wheel b. A so-called outset that is offset (displaced) to the outside of the vehicle body with respect to the intermediate position s1 in the direction is often used.

[0004]

On the other hand, a large lateral force fy acts on a wheel with tires in addition to the vertical load fz during turning at high speed. At this time, in the wheel b of the outset, the torsional moment m in the direction of the arrow is generated by the forces fz and fy, and as shown by the dashed line in FIG. As a result, the wheel is deformed so as to rise from the road surface.

In particular, in recent years, as the speed and performance of vehicles have increased, the diameter and width of the wheel b have been increasing, and the offset amount e has also increased with the increase in size of the brake. As a result, the deformation of the wheel becomes remarkable, for example, the torsional moment m becomes very large, and the tire comes into contact with the tire at the time of turning, so that the steering stability is deteriorated.

[0006] Therefore, the present invention is based on a so-called outset wheel, in which the peripheral length of the rim sheet facing the inside of the vehicle body is set to be larger in a predetermined range than the peripheral length of the rim sheet facing the vehicle body. It is an object of the present invention to provide a wheel with a tire that can improve the ground contact property and the steering stability.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the invention of claim 1 of the present application is directed to an automobile tire and a rim having a rim seat on which a bead seat of a bead seats is mounted on an axle for mounting to an axle. A wheel for an automobile having a disk portion, wherein the wheel is mounted on an outwardly directed rim sheet facing outwardly of the vehicle body by mounting and an inwardly directed rim sheet facing inwardly with respect to a tire axially intermediate position. , The disk mounting surface is offset to the outside of the vehicle body, and the circumferential length L of the outward rim sheet is adjusted.
The circumferential length Li of the inward rim sheet is made larger than o, and the tire has a circumferential length T of the outward bead seat facing outward of the vehicle body.
The circumferential length Ti of the inward bead sheet facing inward is larger than o, and the circumferential length difference (Ti-To) of the bead sheet is 0.5 to 1.5 of the circumferential length difference (Li-Lo) of the rim sheet. It is characterized by being doubled.

According to a second aspect of the present invention, the tire includes a breaker layer inside the tread portion, and the center of the breaker layer in the width direction is positioned on the inner side of the vehicle with respect to the width center line JJ of the tire cross section. Is shifted by a distance H of 1.0 to 10.0 mm.

According to a third aspect of the present invention, the rim sheet has a peripheral length difference (Li-Lo) of 1.0 to 10.0 mm.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of the present invention will be described.
This will be described together with the illustrated example. FIG. 1 is a cross-sectional view showing a wheel with a tire according to the present invention. In FIG. 1, a wheel 10 with a tire includes an automobile tire 20 and a wheel 1 to which the tire 20 is mounted.

The wheel 1 is provided with an automobile tire 20.
And a disk portion 4 integrally connected to the rim 2 and attaching the wheel 1 to the axle 3. The wheel 1 may be a light alloy wheel in which the rim 2 and the disk portion 4 are integrally formed by casting, or a steel plate wheel 1 in which the steel plate rim 2 and the disk portion 4 are joined by welding. It may be.

As shown in FIG. 2, the rim 2 has a pair of rim seats 5 on which the bead portions 22 of the tire 20 are seated.
And a flange portion 6 rising radially outward from the tire axial outer end P of each rim sheet 5 and a well portion 7 provided between the inner ends of the rim sheet 5 and recessed radially inward. are doing. In this example, the case where the well 7 is a deep deep rim is illustrated, but the well 7 may be a shallow shallow rim or a flat flat rim.

As shown in FIG. 1, the disk portion 4 is a substantially disc-shaped body having a hole 9 at the center, and a disk mounting surface for mounting a hub of the axle 3 is provided on a side surface facing the inside of the vehicle body. 4S is formed. This disk mounting surface 4S
Is offset (outset) to the outside of the vehicle body with respect to the intermediate position C in the tire axial direction between the rim seats 5 on both sides, whereby each member (not shown) such as a brake and a suspension arranged on the axle side is provided. ), Wheel 1
Housed inside.

Here, as described with reference to FIG. 6, a lateral force fy acts on a wheel with tires in addition to a vertical load fz during a high-speed turning. A large torsional moment m in the direction of the arrow is generated by the forces fz and fy. Then, due to the torsional moment m, a wheel deformation occurs in which the rim sheet facing inward of the vehicle body rises from the road surface as compared with the rim sheet facing outward, thereby impairing the ground contact of the tire at the time of turning.

Therefore, in the present embodiment, the peripheral length Li of the inward rim sheet 5i that faces the inside of the vehicle body when the vehicle is mounted on the vehicle body.
Is formed to be larger than the circumferential length Lo of the outwardly directed rim sheet 5o to reduce the floating of the inwardly directed rim sheet 5i caused by the wheel deformation, and to enhance the contact property of the tire during turning.

At this time, the circumference difference Li-Lo is:
The range determined by the following formula can be preferably adopted. That is, 0.5Y ≦ Li−Lo ≦ 1.2Y— (1) Y = 2π × (r × Fy + e × Fz) × W / K −− (2) It is on the street. r: radius (unit: m) of the tire-equipped wheel when a standard inner pressure and a standard load Fz are applied by mounting the tire on a rim, Fy: maximum lateral force during turning (1.2 times the standard load Fz)
(Unit: N), e: offset amount (unit: m) between the intermediate position of the rim sheet and the disk mounting surface, Fz: standard load (unit: N), W: rim width (unit: m), K: twisting of the wheel Spring constant (unit: Nm / rad),

In the equation (2), "(r × Fy + e × F
z) "indicates the force F during turning, as shown in FIG.
y, Fz, which is a torsional moment M, and “(r × Fy + e × Fz) × W / K” in equation (2) is, as conceptually shown in FIG.
Sheets 5o, 5 generated by wheel deformation due to
represents the amount of displacement δy in the height direction (radial direction) between i. Therefore, the value Y in equation (2) is, in other words, the displacement amount δy
The difference in radius between the rim sheets 5o and 5i necessary to cancel the difference can be said to be a value converted into a difference in circumference.

That is, the value Y is set on the rim of the tire,
In the extreme turning state in which the vehicle travels in a standard state in which the standard internal pressure and the standard load Fz are applied, and the maximum turning force is applied at that time, the circumferential length difference means that the rim sheets 5o and 5i can be at the same height from the ground contact surface.

Therefore, by setting the perimeter difference Li-Lo in the actual wheel 1 in the range of 0.5 to 1.2 times the value Y, the inward rim sheet 5i when the wheel deformation occurs is obtained. Floating from the road surface is reduced. As a result, the contact property of the tire at the time of turning is enhanced, and steering stability can be improved.

[0020] The effect of improving the contact property is particularly that the nominal rim width W is 6 inches or more, the nominal rim diameter D is 15 inches or more, and the offset amount is 30 mm or more. Works more effectively for larger wheels.

Here, the above-mentioned "standard internal pressure" is the air pressure determined for each tire in the standard system including the standard on which the tire is based. Table "TIRE LOAD LIMITS AT
VARIOUS COLD INFLATION PRESSURES "
EINFTO means "INFLATION PRESSURE",
If the tire is for a passenger car, the pressure is 180 KPa.

The "standard load Fz" is a load defined by the standard for each tire. The maximum load capacity is JATMA, and the table "TIRE LOAD LIMITS A" is TRA.
The maximum value described in "T VARIOUS COLD INFLATION PRESSURES", or "LOADCAPACITY" for ETRTO.

The reason why the "maximum lateral force Fy" is adopted as the lateral force fy is that the contact with the ground is a problem when the vehicle is in a running state in which a large lateral force is generated, such as an extreme turning state. , In the case of a normal passenger car, in the extreme turning state,
A lateral acceleration of about 0.5 G to 1.2 G acts. Therefore, in the present invention, the value of 1.2 times the standard load Fz is adopted as the “maximum lateral force Fy”.

The "torsion spring constant K" is the value of the wheel 1
When a torsional moment m acts on the rim sheet 5o and 5i, and the rim width is W and the rim width is W, the following equation (3) is given. K = m × W / δy (3)

On the other hand, in the case of a normal passenger car, the vertical load fz applied to one tire is about 3 to 7 kN, the radius r of the tired wheel is about 250 to 350 mm, the offset amount e is about 30 to 60 mm, and the rim width W is 150-250m
m, torsional spring constant K is 400 to 800 kNm / ra
d.

Therefore, when the wheel with tire 10 is for a passenger car, the circumferential difference Li-Lo is expressed as
It is also preferable to adopt a range of 1.0 to 10.0 mm.

Note that the circumferential length difference Li-Lo is 0.5Y to
In the case of out of the range of 1.2Y, and 1.0 to 10.0 mm
When the angle is out of the range, the effect of improving the contact property during turning is too small. Also particularly larger than 1.2Y and 10.0mm
If it is larger, the contact property when going straight will be worse,
There is also a risk that steering stability will be adversely affected.

In this example, as shown in FIG. 2, since the rim sheets 5o and 5i are inclined with respect to the tire axial direction line J0, their circumferential lengths Lo and Li are set in the tire axial direction. Depends on location. Therefore, in the present specification, the circumferential lengths Lo and Li are defined as circumferential lengths at outer ends P (rim heel points P) of the rim sheets 5o and 5i in the tire axial direction. The intermediate position C between the rim sheets 5 and 5 is defined as the intermediate position C between the outer ends P and P in the tire axial direction. The rim diameter D is defined as the diameter at the outer end P of the smaller diameter side, that is, the outward rim sheet 5o.

In this embodiment, the rim sheets 5o, 5i
Are inclined inward in the radial direction with an angle α of, for example, 5 degrees with respect to the rim reference line J1 connecting between the outer ends P, P, and each flange portion 6 is also inclined to the rim reference line J1. On the other hand, a preferred case is shown, for example, in which it rises radially outward with an angle β of 90 degrees.

For example, as shown schematically in FIG. 4, when the rim sheets 5o, 5i and the flange portions 6, 6 are inclined at the angles α, β with respect to the tire axial line J0, the circumferential length is reduced. Due to the difference Li-Lo, there is a possibility that the tire 20 changes its shape from an original shape to an irregular shape. For this reason, the stress distribution inside the tire changes, and there is a concern that the durability of the tire may be reduced or the rim may be detached when the pressure is reduced. However, the structure shown in FIG.

Next, the tire 2 mounted on the wheel 1
If the conventional tire is used, the bead tightening force differs between the outside and the inside of the vehicle body, which may cause problems in the rim displacement resistance, the rim assembly performance, and the fitting when the rim is assembled. I am concerned.

Therefore, in the present invention, as the tire 20,
As schematically shown in FIG. 5, before the rim is assembled, the circumferential length Ti of the inward bead sheet 21i is set to be larger than the circumferential length To of the outward bead sheet 21o within a predetermined range.

More specifically, the tire 20 has a sidewall portion 23 extending radially outward from the left and right bead portions 22.
And a tread portion 24 connecting the outer ends thereof.

The bead portion 22 is provided with the rim sheet 5
i, 5o, a bead seat 21i, 21o is seated, and a bead reference line J2 connecting the outer ends Q, Q of the bead seats 21i, 21o in the tire axial direction is the rim reference with respect to the tire axial direction J0. It is inclined in the same direction as the line J1. That is, the circumferences Ti and To measured at the outer end Q are:
There is a relation of Ti> To, whereby the bead tightening force between the outside and the inside of the vehicle body is balanced. The cross-sectional shape of the tire is substantially symmetrical with respect to the vertical bisector JJ of the bead reference line J2.

At this time, the bead sheets 21i, 21
It is necessary that the circumferential difference (Ti-To) of o be 0.5 to 1.5 times the circumferential difference (Li-Lo) of the rim sheets 5i and 5o. In addition, smaller than 0.5 times, or 1.5
When it is larger than twice, the difference in bead tightening force is too large,
No improvement is seen in the rim displacement resistance, the rim assembling performance, and the fitting property when assembling the rim.

In the tire 20, the bead portion 22,
The carcass 26 includes a toroidal carcass 26 extending over the space 22 and a tough breaker layer 27 disposed outside the carcass 26 and inside the tread portion 2.

The carcass 26 is composed of one or more carcass plies in which carcass cords are arranged at an angle of, for example, 70 ° to 90 ° with respect to the tire circumferential direction. As the carcass cord, for example, an organic fiber cord such as nylon, polyester, rayon, or aromatic polyamide, or a steel cord is suitably used.

The breaker layer 27 is composed of two or more breaker cords arranged at an angle of, for example, 10 to 35 ° with respect to the tire circumferential direction (two or more breaker cords are usually used for tires for passenger cars and three to four for tires for heavy loads). ) Breaker ply. The breaker plies are superimposed with different inclinations so that the breaker cords cross each other between the plies, thereby increasing the rigidity and reinforcing the tread portion 24 with an excellent tagging effect. In addition, as the breaker code,
For example, a steel cord or a high-strength aromatic polyamide fiber cord comparable thereto is suitably used.

Here, in a wheel with a tire using the wheel 1, when the vehicle goes straight, a camber angle CA (unit degree) expressed by the following equation (4) is generated, and based on this, a lateral force called camber thrust is generated. . In the case of the present embodiment, a lateral force of 1 to 60 N is usually generated. CA = (δy / W) × (360 / 2π) --- (4) As a result, when a difference occurs in the load on the left and right wheels due to undulation on the road surface, a lateral force in one direction is suddenly generated. Therefore, the straightness of the vehicle tends to decrease.

Therefore, it is necessary to reduce the lateral force in order to maintain straightness, and therefore, in this embodiment, conicity in a direction opposing the camber thrust is intentionally generated, and the lateral force is reduced. We are trying to decrease.

In order to generate the conicity, in the present embodiment, the center 27M in the width direction of the breaker layer 27 is set to the width center line JJ of the tire section, which is the perpendicular bisector JJ of the bead reference line J2. On the other hand, the position is shifted by a predetermined distance H inside the vehicle.

The distance H of the positional deviation is 1.0 to 1
A range of 0.0 mm is preferable, and if it is less than 1.0 mm, the effect of reducing the lateral force is insufficient, and if it exceeds 10.0 mm, the lateral force in the opposite direction becomes large. Cannot be expected.

Although the preferred embodiment of the present invention has been described in detail above, the present invention is not limited to the illustrated embodiment, but may be implemented in various forms.

[0044]

EXAMPLE An aluminum wheel (rim size: 17 × 7JJ) having the structure shown in FIG. 1 and having the specifications shown in Table 1 was prototyped. A passenger car tire (tire size: 215 / 45ZR17) having the specifications shown in Table 1 was attached to the aluminum wheel, and the steering stability when turning, the steering stability when traveling straight, and the fitting property when assembling the rim were compared.

(1) Steering stability during turning: A wheel (2000 kPa) was mounted on a tire (wheel) with an internal pressure (230 kPa).
cc, FR car), mounted at high speed on a high-speed circuit on dry asphalt road surface, driving stability at the time of turning at the time was 2.5 points in Comparative Example 1 by sensory evaluation of driver. The five-point method was used for evaluation. The larger the value, the better.

(2) Steering stability in straight running: In high-speed running in the high-speed circuit, the steering stability in straight running was determined by a sensory evaluation of the driver by a five-point method with Comparative Example 1 being 4.0 points. evaluated. The larger the value, the better.

(3) Fitting property when assembling the rim Cross-sectional images of the rim-assembled wheel with the tire were taken at four locations at equal intervals in the circumferential direction of the tire using a CT scan, and the gap between the rim and the tire bead was measured. Was measured. The larger the amount of the gap, the higher the degree of poor fitting, which has an adverse effect on force variations and the like.

[0048]

[Table 1]

[0049]

As described above, according to the present invention, in the so-called outset wheel, the circumferential length of the rim sheet facing the inside of the vehicle body is set to be larger in the predetermined range than the circumferential length of the rim sheet facing the outside of the vehicle body. In addition, the contact property at the time of turning can be improved, and the steering stability can be improved. Also, the circumferential length of the bead seat facing the inside of the vehicle body is made larger than the circumferential length of the bead seat facing the outside of the vehicle body, and the circumferential difference of the bead seat is set to 0.5 to 1.5 times the circumferential length difference of the rim sheet. While exhibiting the above advantages, it is possible to maintain the rim displacement resistance, the rim assembling performance, the fitting property when assembling the rim, and the like.

[Brief description of the drawings]

FIG. 1 is a sectional view of an automobile wheel according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing a rim.

3A is a schematic diagram illustrating a torsional moment acting on a wheel, and FIG. 3B is a schematic diagram illustrating a torsional spring constant of the wheel.

FIG. 4 is a sectional view showing another example of the wheel of the present invention.

FIG. 5 is a cross-sectional view showing an example of a tire that can be mounted on the wheel of the present invention.

FIG. 6 is a schematic view of a wheel with a tire illustrating a problem of the prior art.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 wheel 2 rim 3 axle 4 disk portion 4S disk mounting surface 5, 5i, 5o rim seat 20 tire 21, 21i, 20o bead seat 22 bead portion 24 tread portion 27 breaker layer C intermediate position

Claims (3)

[Claims] 1. A tire wheel comprising: a vehicle tire; and a vehicle wheel provided with a disk portion for mounting to an axle on a rim having a rim seat on which a bead seat of a bead seats is provided. The wheel offsets the disk mounting surface to the outside of the vehicle body with respect to the tire axial direction intermediate position between the outward rim sheet facing outwardly of the vehicle body and the inward facing rim sheet when mounted, and the circumferential length Lo of the outwardly facing rim sheet. In addition, the circumferential length Li of the inward rim sheet is larger than the circumferential length To of the outward bead seat facing the outside of the vehicle, and the circumferential length T of the inward bead seat is larger than the circumferential length To of the outward bead seat facing the vehicle body.
A wheel with a tire, wherein i is large and the circumferential difference (Ti-To) of the bead sheet is 0.5 to 1.5 times the circumferential difference (Li-Lo) of the rim sheet. 2. The tire has a breaker layer inside a tread portion, and the center of the breaker layer in the width direction is:
It is 1.0 inside the vehicle with respect to the width center line JJ of the tire section.
2. The tired wheel according to claim 1, wherein the wheel is displaced by a distance H of about 10.0 mm. 3. The rim sheet according to claim 1, wherein a peripheral length difference (Li-Lo) is 1.0 to 10.0 mm.
Or the wheel with a tire according to 2.