JP2002274106A - Arrangement method of wheel with tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a treading property in 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. A peripheral length difference (Li-Lo)L on a wheel with a tire the tire load of which becomes large on a front wheel and a rear wheel is made more than a peripheral length difference (Li-Lo)S on the wheel with the tire the tire load of which becomes small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for arranging a wheel with a tire for improving the steering stability by improving the contact property of a turning tire in a so-called outset wheel in which a disk portion is offset to the outside of a vehicle body.

[0002]

2. Description of the Prior 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 wheel deformation becomes remarkable, for example, the torsional moment m becomes extremely large, and the tire's contact property during turning is impaired. Moreover, the magnitude of the wheel deformation differs between the front wheel side and the rear wheel side due to the load distribution of the vehicle and the like, so that the influence on the steering stability becomes more remarkable.

Accordingly, the present invention provides a so-called outset wheel in which the circumferential length of a rim sheet facing the vehicle body is set to be larger than the circumferential length of a rim sheet facing the vehicle body.
Based on the difference in circumference difference between the front wheel side and the rear wheel side according to the load distribution of the car, the method of arranging wheels with tires that can improve the ground contact during turning and improve steering stability It is intended to be provided.

[0007]

In order to achieve the above-mentioned object, according to the first aspect of the present invention, an automobile tire and a rim having a rim seat on which a bead portion is seated are provided with a disk portion for attachment to an axle. A method of arranging wheels with tires, comprising wheels provided for an automobile, at a front wheel position f and a rear wheel position r of the vehicle, the wheel comprising: The disk mounting surface is offset to the outside of the vehicle body with respect to the tire axially intermediate position between the inwardly directed rim sheet and the inwardly directed rim sheet, and the circumferential length Li of the inward rim sheet is greater than the circumferential length Lo of the outward rim sheet. And the tire wheels at the front wheel position f and the rear wheel position r acting on the tire wheels when the vehicle is stationary. In tyred wheels Ya load becomes larger, the circumferential length difference between the circumferential length Li of the circumferential length Lo and the inward rim seat outward rim seat of the wheel (Li-Lo)
_L is a wheel with a tire where the tire load is small,
A peripheral length difference (Li-Lo) _S between the peripheral length Lo of the outward rim sheet of the wheel and the peripheral length Li of the inward rim sheet is equal to or larger than _S.

[0008] In the invention of claim 2, the circumferential length difference (Li-Lo) _L on the side where the tire load becomes large is:
The circumference difference (Li-Lo) on the side where the tire load becomes smaller.
The ratio of _{S (Li-Lo) L /} (Li-Lo) S has a load W _L comprising the large ratio between the small consisting load W _S (W _L /
W _S ) is 0.7 to 1.3 times.

[0009] Further, in the invention according to claim 3, the circumferential difference (Li-Lo) between the respective rim sheets is 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 in which the steel plate rim 2 and the disk portion 4 are joined by welding. There 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, in the wheel with tires, as described with reference to FIG. 7, when turning at high speed, a lateral force fy acts in addition to the vertical load fz. 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, thereby reducing the lifting of the inwardly directed rim sheet 5i caused by the wheel deformation, and enhancing 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: wheel twist 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 magnitude of the wheel deformation differs between the front wheel side and the rear wheel side due to load distribution of the vehicle and the like. Therefore, in order to more effectively exert the effect of improving the steering stability by the wheel 1, in accordance with the load distribution and the like,
It is also important to provide a difference in the circumferential length difference Li-Lo between the front wheel side and the rear wheel side.

[0032] Thus, in the present invention, the front wheel position f, the tyred wheel 10 of the rear wheel position r, circumference of the tire wheel with the tire load acting on the tired wheel 10 in a stationary state of the automobile is large W _L Long difference (L
The i-Lo) _L, the circumferential length difference in the tyred wheel tire load is small W _S (above Li-Lo) _S, preferably is set to a large. Each (Li-Lo) _L , (Li
-Lo) Both _S are preferably in the range of 0.5Y to 1.2Y or in the range of 1.0 to 10.0 mm.

The circumference difference (Li-Lo)_LAnd circumference difference
(Li-Lo)_SAnd the ratio (Li-Lo)_L/ (Li-L
o)_SWith the large load W_LAnd a small load W_SWith
Ratio (W _L/ W_S) Is 0.7 to 1.3 times
Preferred. If it is out of this range, the front and rear wheels
There is no improvement in the grounding balance between
The effect is reduced. Therefore, preferably 0.8-1.
It is preferably 2 times, more preferably 0.9 to 1.1 times.

The "tire load when the vehicle is at rest" means a load acting on each wheel with tires in a vehicle with no occupants. Note that in the front wheel drive vehicle (FF vehicle), a tire load W is the front wheel is large W _L, the rear wheel side is small W _S, the ratio W _L / W _S is usually about 1.1 to 1.7. In a rear wheel drive vehicle (FR vehicle), the front wheel side and the rear wheel side have substantially the same load.

Next, as the automobile tire 20 mounted on the wheel 1, a conventional tire can be used because the circumferential difference Li-Lo is relatively small. In other words, as schematically illustrated in FIG. 5, in a state before the rim assembly, the bead diameter of the bead portion 22 is substantially the same on the left and right, that is, the circumferential length To of the outward bead seat 21o facing the outside of the vehicle body, A tire in which the circumferential length Ti of the inward bead sheet 21i is substantially equal can be used. However, in such a tire, since the bead tightening force is different between the outside and the inside of the vehicle body, there is a concern that rim displacement resistance, rim assembling performance, and fitting during rim assembling may occur.

Therefore, as shown in FIG. 6, the circumferential length Ti of the inwardly facing bead sheet 21i is larger than the circumferential length To of the outwardly facing bead sheet 21o by a predetermined range before the rim is assembled, as schematically shown in FIG. It is preferable that

More specifically, the tire 20 includes 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 preferable 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. If it is out of this range, the difference in bead tightening force is too large, and no improvement is seen in the rim displacement resistance, the rim assembling performance, the fitting at the time of rim assembling, and the like.

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 comprises 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 has two or more breaker cords arranged at an angle of, for example, 10 to 35 ° with respect to the circumferential direction of the tire (usually two tires for passenger car tires and three to four tires for heavy load tires). ) 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 traveling 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. 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.

As the distance H of this positional deviation, 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.

[0048]

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. Also, a tire-equipped wheel obtained by mounting a passenger car tire (tire size 215 / 45ZR17) having the specifications shown in Table 1 on this aluminum wheel was mounted on a front-wheel-drive automobile with an internal pressure of 230 kPa and the arrangement shown in Table 2, and The steering stability was compared.

(1) Steering stability during turning: Wheels with tires are mounted on all wheels of an automobile (2000cc, front-wheel-drive), and high-speed running is performed on a high-speed circuit on a dry asphalt road. The steering stability was evaluated by a five-point method using Comparative Example 1 as 2.5 points by the sensory evaluation of the driver. The larger the value, the better.

[0050]

[Table 1]

[0051]

[Table 2]

[0052]

As described above, according to the present invention, in a so-called outset wheel, the circumferential length of the rim sheet facing the vehicle body is set to be larger than the circumferential length of the rim sheet facing the vehicle body. The groundability can be improved. Since there is a difference in the circumferential length between the front wheel side and the rear wheel side according to the load distribution of the vehicle, the balance of the improvement of the ground contact property is optimized, and the steering stability can be improved.

[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.

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

FIG. 6 is a sectional view showing another example of a tire that can be mounted on a wheel.

FIG. 7 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 part 4S disk mounting surface 5, 5i, 5o rim seat 20 tire 21, 21i, 20o bead seat 22 bead part C intermediate position

Claims (3)

[Claims] 1. A tire-equipped wheel comprising an automobile tire and a vehicle wheel having a rim having a rim seat for seating a bead portion thereof and having a disk portion for attachment to an axle mounted on a rim having a front wheel position f, A method of arranging wheels with tires arranged at a rear wheel position r, wherein the wheel has a disc with respect to an intermediate position in the tire axial direction between an outward rim sheet facing outwardly of a vehicle body and an inward rim seat facing inward by mounting. The mounting surface is offset to the outside of the vehicle body, the circumferential length Li of the inward rim sheet is made larger than the circumferential length Lo of the outward rim sheet, and the vehicle is stationary at the wheels with tires at the front wheel position f and the rear wheel position r. In a wheel with a tire, in which the tire load acting on the wheel with a tire in a state is large, outward of the wheel Circumferential length difference between the circumferential length Li of the circumferential length Lo and the inward rim seat of Mushito (Li-Lo)
_L is a wheel with a tire where the tire load is small,
A method of arranging wheels with tires, wherein a circumferential difference (Li-Lo) _S between a circumferential length Lo of an outward rim sheet of the wheel and a circumferential length Li of an inward rim sheet is equal to or larger than _S. 2. The ratio (Li-Lo) of the circumferential length difference (Li-Lo) _{S on} the side where the tire load is small to the circumferential length difference (Li-Lo) _L on the side where the tire load is large. Lo) _L /
Li-Lo) S has a load W _L comprising the large, according to claim 1, characterized in that 0.7 to 1.3 times the ratio between the small consisting load _{W S (W L / W S} ) How to arrange wheels with tires. 3. A circumferential difference (Li-Lo) between the rim sheets.
3. The method for arranging wheels with tires according to claim 1, wherein the diameter is 1.0 to 10.0 mm.