JP2002178713A - Installing method of pneumatic tire and pneumatic tire for front wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an installing method of a pneumatic tire capable of improving braking performance. SOLUTION: When setting a negative rate of an installing inside area of a tread 12 of this pneumatic tire 10 of a front wheel smaller than an outside area, the grounding area of the inside area can be increased at braking time, and average ground pressure of the inside area can be reduced. Thus, in the pneumatic tire 10, an extreme ground pressure increase at braking time of the inside area of the tread 12 can be restrained, and braking force can be efficiently generated by restraining reduction in a friction coefficient. Since a load of the front wheel increases at braking time of a vehicle, when using such an installing method of the pneumatic tire, the braking performance of the vehicle can be improved in an installing method of a conventional pneumatic tire.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of mounting a pneumatic tire capable of improving braking performance and a pneumatic tire for a front wheel.

[0002]

2. Description of the Related Art Hitherto, in order to improve braking performance particularly on a wet road surface, a technique of changing a tread rubber or increasing a rigidity of a block provided on a tread has been used.

Further, when the vehicle is mounted on the vehicle using an asymmetrical pattern for improving the steering stability, the side rigidity is generally set to the side force input side at the time of turning on the outside of the mounting, so that the block rigidity is set to be large. However, the negative rate is inevitably reduced, and conversely, the negative rate is set to be large in order to improve drainage inside the mounting.

[0004]

However, in order to improve braking performance on wet road surfaces, changing the tread rubber or making the lateral grooves shallow in order to increase the block rigidity increases the rolling resistance and the like. In many cases, it has a drawback that the hydroplaning property is deteriorated.

The conventional asymmetrical pattern designing method and the mounting method on a vehicle in consideration of the steering stability have almost no advantage in terms of braking performance.

The present invention has been made in consideration of the above-described facts, and solves the above-mentioned problems of the prior art described above, and a method of mounting a pneumatic tire capable of improving braking performance and a pneumatic tire for a front wheel. The purpose is to provide.

[0007]

SUMMARY OF THE INVENTION It is known that a braking vehicle generates a moment about the center of gravity of the vehicle due to the braking force generated by the tires, so that the front load increases and the rear load decreases. ing.

[0008] At this time, the suspension expands and contracts in response to the front and rear load fluctuations, and the front corresponds to the contraction (bump) side and the rear corresponds to the extension (rebound) side.

On the other hand, in order to ensure steering stability during turning, the alignment of a general vehicle (the angle at which the wheels are attached to the vehicle) is such that the front is toe-out (ToeOut) + negative camber (Negative-Camber) at the time of bumping.
(See FIG. 10A), the rear is Toe In
It is set to change to + Negative-Camber (see FIG. 10B).

Conversely, at the time of rebound, the front is toe-in + positive camber, and the rear is toe-out +
It is set to change to positive camber.

Therefore, at the time of braking, the alignment of the vehicle is changed in a sense different from the intended purpose, whereby the tires are directed obliquely with respect to the vehicle and the road surface. And the braking force generated when the vehicle is viewed as a whole decreases accordingly.

That is, at the time of braking, since the front wheel changes to the toe-out + negative camber side due to the bump, the ground pressure inside the mounting is relatively high and the ground pressure outside the mounting is relatively low.

On the other hand, the rear wheel changes to the toe-out + positive camber side due to the rebound, and the influence of the change in the camber is large. The ground pressure of the battery becomes low.

Here, the friction coefficient of rubber generally depends nonlinearly on the load applied per unit area, that is, the contact pressure.
It is known that when the contact pressure increases, it rapidly decreases.

Therefore, it is not preferable to have an extremely high contact pressure area in the contact surface because the frictional force generated in that area is lost by that amount.

A change in the ground pressure distribution due to a change in alignment due to the behavior of the vehicle at the time of braking reduces the friction coefficient on the inside of the front wheel and on the outside of the rear wheel, so that the braking force is lost. Will be.

In the conventional method of mounting a pneumatic tire, the pneumatic tire having the same negative ratio of the tread in one region and the other region with respect to the equatorial plane of the tire is mounted on the front and rear wheels of the vehicle. Or use a pneumatic tire in which the negative rate of the tread is different between one area and the other area across the tire equatorial plane, using the pneumatic tire on the front and rear wheels of the vehicle so that the area with a small negative rate faces the outside of the vehicle. There was no idea to reverse the setting of the negative rate for the front wheels and the rear wheels.

The method of mounting a pneumatic tire according to claim 1 has been made in view of the above facts, and at least the front wheel of the vehicle has a negative tread ratio in one region with respect to the tire equatorial plane. It is characterized in that a pneumatic tire set smaller in the other area is used so that the area having a lower negative rate faces the inside of the vehicle.

Next, the operation of the pneumatic tire mounting method according to the first aspect will be described.

According to the present invention, by setting the negative ratio of the inner region of the front tread with respect to the tire equatorial plane to be smaller than that on the opposite side, the contact area of the inner region of the tread during braking can be increased. It is possible to reduce the average ground pressure in the inside area of the mounting.

[0021] Therefore, it is possible to suppress an extreme increase in the contact pressure during braking of the inner mounting area, and it is possible to suppress a decrease in the friction coefficient and efficiently generate a braking force.

Since the load on the front wheels increases during braking of the vehicle, using such a pneumatic tire mounting method,
The braking performance of the vehicle can be improved as compared with the conventional pneumatic tire mounting method.

According to a second aspect of the present invention, in the method for mounting a pneumatic tire according to the first aspect, the negative ratio of the tread is set to be smaller on one side of the rear wheel of the vehicle than on one side of the tire equatorial plane. Is characterized in that a pneumatic tire set small in the region is used so that the region with a small negative rate faces the outside of the vehicle.

Next, the operation of the method for mounting a pneumatic tire according to the second aspect will be described.

As described in the present invention, by setting the negative ratio of the rear wheel tread outside mounting area to the tire equatorial plane smaller than that on the opposite side, it is possible to increase the contact area of the outside mounting area during braking. In addition, it is possible to reduce the average contact pressure in the outer mounting region.

Therefore, in the pneumatic tire of the rear wheel, an extreme increase in the contact pressure at the time of braking in the outer mounting region can be suppressed, and a reduction in the coefficient of friction can be suppressed to efficiently generate a braking force. .

Therefore, the braking performance of the vehicle can be further improved.

The pneumatic tire mounting method according to claim 3, wherein the negative rate of the tread is set to be smaller on one side of the front wheel of the vehicle than on one side of the tire equatorial plane. Is used so that the area with a low negative rate faces the outside of the vehicle, and the rear wheels of the vehicle are pneumatically set so that the negative rate of the tread is the same in one area and the other area across the tire equatorial plane. It is characterized by using tires.

Next, a method of mounting the pneumatic tire according to claim 3 will be described.

In the pneumatic tire for the rear wheel, the negative rate of the tread is set to be the same in one area and the other area with respect to the tire equatorial plane. For pneumatic tires whose negative rate is set smaller than the negative rate in the area outside the vehicle, the ground contact area inside the vehicle can be increased during braking, and the average contact pressure in the area inside the vehicle decreases. Can be done.

Accordingly, a pneumatic tire having the same negative ratio on the left and right of the tire equatorial plane is set to have a smaller negative rate on the inner side of the vehicle than the pneumatic tire set on the inner side of the vehicle when braking in the region inside the vehicle. It is possible to suppress an increase in the ground pressure and suppress a decrease in the coefficient of friction, thereby efficiently generating a braking force.

Thus, the braking performance of the vehicle can be further improved.

According to a fourth aspect of the present invention, in the pneumatic tire mounting method, the negative rate of the tread is set to be equal in one area and the other area on the front wheel of the vehicle with respect to the tire equatorial plane. Using tires, the rear wheels of the vehicle are pneumatic tires in which the negative rate of the tread is set smaller in one area than the other area across the equatorial plane of the tire, and the area with the lower negative rate faces the outside of the vehicle. It is characterized by being used for the rear wheel of a vehicle.

Next, the operation of the pneumatic tire mounting method according to the fourth aspect will be described.

In the pneumatic tire for the front wheels, the negative rate of the tread is set to be the same in one region and the other region with respect to the tire equatorial plane. For a pneumatic tire in which the negative rate is set smaller than the negative rate in the area inside the vehicle, the ground contact area inside the vehicle can be increased during braking, and the average contact pressure in the area inside the vehicle decreases. be able to.

On the other hand, in the case of the rear pneumatic tire, the contact area of the outer area of the tread is increased during braking by setting the negative rate of the area outside the tread to the tire equatorial plane smaller than that on the opposite side. Therefore, it is possible to reduce the average contact pressure in the outer mounting area.

Therefore, when such a method of mounting a pneumatic tire is used, the braking performance of the vehicle can be improved as compared with the conventional method of mounting a pneumatic tire.

According to a fifth aspect of the present invention, there is provided a pneumatic tire for a front wheel in which a negative rate of a tread is different between left and right regions across a tire equatorial plane, wherein an inner region when the vehicle is mounted is an outer region when the vehicle is mounted. Is characterized in that the negative rate is smaller than that of the region.

Next, the operation of the pneumatic tire for a front wheel according to the fifth aspect will be described.

When the pneumatic tire for a front wheel is used for the front wheel of a vehicle, the negative rate of the inner area of the front wheel tread with respect to the tire equatorial plane is set to be smaller than that on the opposite side. Thus, it is possible to increase the ground contact area in the mounting inner region during braking, and to reduce the average ground pressure in the mounting inner region.

Therefore, it is possible to suppress an extreme increase in the contact pressure during braking of the inner mounting area, and to suppress the decrease in the friction coefficient, thereby efficiently generating the braking force.

Since the load on the front wheels increases during braking of the vehicle, the use of this pneumatic tire for the front wheels can improve the braking performance of the vehicle as compared with the prior art.

[0043]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] A first embodiment of a method for mounting a pneumatic tire according to the present invention will be described below in detail with reference to the drawings.

In this embodiment, a pneumatic tire 10 having the pattern shown in FIG. 1 and a pneumatic tire 30 having the pattern shown in FIG. 2 are used.

As shown in FIG. 1, the tread 12 of the pneumatic tire 10 has a narrow width extending along the tire circumferential direction (the direction of the arrow A and the direction of the arrow B) on the side of the tire equator plane CL in the direction of arrow L. A circumferential groove 14 and a narrow circumferential groove 16 are formed, and a circumferential groove 1 wider than the circumferential groove 14 and the circumferential groove 16 is provided on the tire equatorial plane CL in the direction of arrow R.
8. A wide circumferential groove 20 is formed.

Further, the tread 12 has a circumferential groove 16.
A narrow lateral groove 22 extending in the direction of arrow L from
A plurality of lateral grooves 24 which are set wider than the circumferential grooves 16 and extend in the direction of the arrow R from the circumferential grooves 16 are formed at intervals in the tire circumferential direction.

Therefore, in the tread 12 of the pneumatic tire 10, the negative ratio in the region on the tire L equatorial plane CL in the direction of the arrow L is smaller than the negative ratio in the region in the direction of the arrow R.

Incidentally, in the pattern shown in FIG. 1, the negative ratio of the region on the tire L equatorial plane CL in the direction of arrow L is 2
The negative rate in the region on the arrow R direction side of the tire equatorial plane CL is 37%.

Next, as shown in FIG. 2, the tread 32 of the pneumatic tire 30 extends in the tire circumferential direction (the direction of the arrow A and the direction of the arrow B) on the side of the tire equatorial plane CL in the direction of arrow L. Narrow circumferential groove 34, narrow circumferential groove 36
A circumferential groove 38 and a circumferential groove 40 wider than the circumferential groove 34 and the circumferential groove 36 are formed on the tire equatorial plane CL in the direction of the arrow R.

Further, the tread 32 has a circumferential groove 36.
A narrow lateral groove 42 extending in the direction of arrow L from
A plurality of lateral grooves 44 which are set wider than the circumferential grooves 38 and extend in the direction of arrow R from the circumferential grooves 38 are formed at intervals in the tire circumferential direction.

For this reason, in the tread 32 of the pneumatic tire 30, the negative rate in the area of the tire equatorial plane CL in the direction of the arrow L is smaller than the negative rate in the area of the tire R in the direction of the arrow R.

By the way, in the pattern shown in FIG. 2, the negative rate in the region on the tire L equatorial plane CL in the direction of the arrow L is 1.
The negative rate in the region on the arrow R direction side of the tire equatorial plane CL is 39%.

Next, as shown in FIG. 3 (in the figure, "front" indicates the front side of the vehicle, "large" indicates an area where the negative rate is large, and "small" indicates an area where the negative rate is small). The pneumatic tires 10 are used on the left and right front wheels so that a region having a low negative rate is arranged inside the vehicle mounting, and the pneumatic tires 30 are negatively mounted on the left and right rear wheels outside the vehicle mounting. It is used so that the area with a small ratio is arranged.

The vehicle 50 is a general passenger vehicle, and the camber angle of both the front and the rear changes to the negative camber side at the time of bump and to the positive camber side at the time of rebound. (Operation) Next, the operation of the present embodiment will be described.

In the method of mounting the pneumatic tire of the present embodiment, the negative rate of the inner area of the tread 12 of the front pneumatic tire 10 is set smaller than that of the outer area. And the average contact pressure in the inner region can be reduced.

Therefore, in the pneumatic tire 10, an extreme increase in the contact pressure during braking of the inner region of the tread 12 can be suppressed, and a reduction in the coefficient of friction can be suppressed to efficiently generate a braking force. .

Further, by setting the negative rate of the outer region of the tread 32 of the pneumatic tire 30 of the rear wheel to be smaller than that of the inner region, it is possible to increase the contact area of the outer region at the time of braking. The average contact pressure can be reduced.

Therefore, in the pneumatic tire 30, an extreme increase in the contact pressure at the time of braking the outer region of the tread 32 can be suppressed, and a reduction in the coefficient of friction can be suppressed to efficiently generate a braking force. .

As described above, in the present embodiment, since the braking force can be efficiently generated in each of the front pneumatic tire 10 and the rear pneumatic tire 30, the braking performance of the vehicle can be improved. Can be.

In this case, the pneumatic tire 10 is used for the front wheel and the pneumatic tire 30 is used for the rear wheel of the vehicle 50. However, the pneumatic tire 30 is used for the front wheel with the smaller negative ratio being the inside of the vehicle. The pneumatic tire 10 may be used for the rear wheel with the negative rate being smaller as the vehicle outside. [Second Embodiment] In the above-described first embodiment, the pneumatic tire 10 is used for the front wheels so that the negative rate of the inner area of the tread 12 is smaller than that of the outer area.
The pneumatic tire 30 was used for the rear wheel so that the negative rate in the outer mounting area was smaller than that in the inner area. However, as shown in FIG. 4, the front wheel was adjusted so that the negative rate in the inner mounting area was smaller than that in the outer area. The pneumatic tire 10 may be used for the rear wheel, and the pneumatic tire 52 whose negative rate is set to be the same on the left and right of the tire equatorial plane CL as shown in FIG.

A pneumatic tire 52 having the same negative ratio for the front wheels on the left and right sides of the tire equatorial plane CL is used, and the pneumatic tires are mounted on the rear wheels so that the negative ratio in the outer region is smaller than that in the inner region. 30 may be used. [Third Embodiment] A third embodiment of the method for mounting a pneumatic tire according to the present invention will be described below in detail with reference to the drawings.

FIG. 6 shows a tread pattern of the pneumatic tire 60 used in the present embodiment.

Next, as shown in FIG. 6, the tread 62 of the pneumatic tire 60 extends in the tire circumferential direction (the direction of the arrow A and the direction of the arrow B) on the side of the tire equator plane CL in the direction of arrow L. Narrow circumferential groove 64, narrow circumferential groove 66
The circumferential groove 64 and the circumferential groove 70 which are wider than the circumferential groove 64 and the circumferential groove 66 are formed on the tire equatorial plane CL in the direction of the arrow R.

Further, the tread 62 has a circumferential groove 64.
A plurality of narrow lateral grooves 72 are formed at intervals in the circumferential direction between the tire and the circumferential groove 66, and are set wider than the lateral groove 72 and extend from the circumferential groove 66 in the direction of the arrow R from the circumferential groove 66. A plurality of 74 are formed at intervals smaller in the tire circumferential direction than at intervals of the lateral grooves 72.

For this reason, in the tread 62 of the pneumatic tire 60, the negative ratio in the region of the tire equatorial plane CL in the direction of the arrow R is larger than the negative ratio in the region of the tire L in the direction of the arrow L.

In the pattern shown in FIG. 6, the tire equatorial plane C
The negative ratio of the region on the arrow L direction side of L is 22%, and the negative ratio of the region on the tire R equatorial plane CL in the arrow R direction is 4%.
3%.

As shown in FIG. 7, a pneumatic tire 60 is mounted on a front wheel of a vehicle 50 so that a region having a small negative rate is arranged in a vehicle, and a pneumatic tire 60 is mounted on a rear wheel. It is mounted so that a region with a small negative rate is arranged outside the vehicle. (Operation) Next, the operation of the present embodiment will be described.

In this embodiment, similarly to the first embodiment, the pneumatic tire 60 is used for the front wheels so that the negative rate in the inner area is smaller than that in the outer area, and the negative rate in the outer area is smaller than that in the inner area. As the pneumatic tire 60 is used for the rear wheel so as to reduce the frictional force, it is possible to suppress an extreme increase in the contact pressure when braking the inner area of the tread 62 with the front wheel, and to suppress a decrease in the coefficient of friction to reduce the braking force. Can be generated efficiently. In the rear wheel, the tread 62
It is possible to suppress an extreme increase in the contact pressure during braking of the outer region of the vehicle, to suppress a decrease in the friction coefficient, and to efficiently generate a braking force.

In this embodiment, since one type of pneumatic tire 60 is used for the vehicle 50, rotation (forward and backward) is possible by removing the tire from the wheel and changing the direction of the tire. [Other Embodiments] In the pneumatic tire of the above embodiment, a rectangular block is formed in the tread by the circumferential groove and the lateral groove, but the groove direction is inclined with respect to the tire circumferential direction and the tire axial direction. The shape of the block may be a shape other than a rectangle (a rhombus, a trapezoid, a polygon, or the like).

The pattern of the pneumatic tire may be of any type, such as a rib pattern, a pattern in which a rotation direction and / or a left-right mounting direction of the vehicle is specified.

The front and rear wheels do not necessarily have to be tires of different patterns as in the first embodiment. The tires of the same pattern are mounted on the wheels with the front and back reversed as in the third embodiment. It may be attached to.

Further, it is not always necessary that both the front wheel and the rear wheel have an asymmetric negative rate with respect to the tire equatorial plane, and it is sufficient that either one has a left-right asymmetric negative rate as in the second embodiment. . (Test Examples) In order to confirm the effects of the present invention, one type of vehicle to which the mounting method of the conventional example is applied, two types of vehicles to which the mounting method of the comparative example is applied, and four types of vehicles to which the mounting method of the present invention is applied are described. The braking distance was measured in each case. -Example 1: The mounting method of the first embodiment is applied. -Example 2: The mounting method of the second embodiment is applied. -Example 3: The mounting method of the third embodiment is applied. -Embodiment 4: The mounting method of claim 4 is applied. Comparative Example 1: The pneumatic tire 10 was used for the front wheel, and the pneumatic tire 30 was used for the rear wheel. The mounting direction was reversed from that of the first embodiment, as shown in FIG. Comparative Example 2: The pneumatic tire 10 was used for the front wheel, and the pneumatic tire 30 was used for the rear wheel. As shown in FIG. 9, the mounting direction of the front wheel was reversed from that of the first embodiment. Conventional Example 1: A pneumatic tire 52 is used in which the negative rate is the same for both the front and rear wheels on the left and right of the tire equatorial plane.

The size of each tire was 195.
/ 65R14, the test tire was mounted on a 5.5 J rim at an internal pressure of 220 KPa, and mounted on an actual vehicle. The test conditions are as follows.・ Vehicle: FF passenger car ・ Mounting position: 4 wheels ・ Front wheel load: 4.11KN ・ Rear wheel load: 3.34KN ・ Equivalent to 2 passengers ・ Speed: Initial speed 80km / h ・ Road surface: Dry asphalt road surface ・ ABS operation ・ Groove Depth: 8 mm The evaluation was expressed as an index with the braking distance (the distance traveled from the start to the stop of the braking) performed under the above conditions, with the braking distance of the vehicle to which the conventional mounting method was applied being taken as 100. In addition,
The numerical value indicates that the smaller the value is, the shorter the braking distance is, and the more excellent the braking performance is.

[0074]

[Table 1]

As a result of the test, Examples 1 to 4 to which the method for mounting a pneumatic tire according to the present invention were applied have shorter braking distances than Comparative Examples 1, 2 and the conventional example, and are excellent in braking performance. I understand.

[0076]

As described above, the method for mounting a pneumatic tire according to the present invention has an excellent effect that the braking performance of a vehicle can be improved.

The pneumatic tire for a front wheel according to the present invention has an excellent effect that the braking performance of the vehicle can be improved.

[Brief description of the drawings]

FIG. 1 is a plan view of a tread of a pneumatic tire for a front wheel according to a first embodiment.

FIG. 2 is a plan view of a tread of the pneumatic tire for a rear wheel according to the first embodiment.

FIG. 3 is an explanatory diagram showing a mounting mode of the pneumatic tire according to the first embodiment on a vehicle.

FIG. 4 is a plan view of a tread of a pneumatic tire for a rear wheel according to a second embodiment.

FIG. 5 is an explanatory diagram showing a mounting mode of a pneumatic tire according to a second embodiment on a vehicle.

FIG. 6 is a plan view of a tread of a pneumatic tire according to a third embodiment.

FIG. 7 is a plan view of a tread of a pneumatic tire for a rear wheel according to a third embodiment.

FIG. 8 is a plan view of a tread of a pneumatic tire for a rear wheel according to Comparative Example 1.

FIG. 9 is a plan view of a tread of a pneumatic tire for a rear wheel according to Comparative Example 2.

10A is a graph showing a change in front camber angle, and FIG. 10B is a graph showing a change in rear camber angle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Pneumatic tire 12 Tread 14 Circumferential groove 16 Circumferential groove 18 Circumferential groove 20 Circumferential groove 22 Lateral groove 24 Lateral groove 30 Pneumatic tire 32 Tread 34 Circumferential groove 36 Circumferential groove 38 Circumferential groove 40 Circumferential groove 42 Lateral groove 44 lateral groove 60 pneumatic tire 62 tread 64 circumferential groove 66 circumferential groove 68 circumferential groove 70 circumferential groove 72 horizontal groove 74 horizontal groove

Claims (5)

[Claims] 1. A pneumatic tire in which the negative rate of the tread is set to be smaller in one area than the other area with respect to the equatorial plane of the tire on at least the front wheel of the vehicle, and an area having a small negative rate is located inside the vehicle. A method for mounting a pneumatic tire, characterized in that it is used to face. 2. A pneumatic tire in which the negative rate of the tread is set smaller in one area than the other area with respect to the equatorial plane of the tire on the rear wheel of the vehicle. The method for mounting a pneumatic tire according to claim 1, wherein the pneumatic tire is used so as to face. 3. The pneumatic tire according to claim 1, wherein the negative ratio of the tread is set to be the same in one region and the other region across the tire equatorial plane for the rear wheels of the vehicle. The mounting method of the pneumatic tire described in 1. 4. A pneumatic tire in which the negative rate of the tread is set to be the same in one region and the other region with respect to the tire equatorial plane for the front wheels of the vehicle, and the tread is provided for the rear wheels of the vehicle. The pneumatic tire, the negative rate of which is set smaller in one area than the other area across the tire equatorial plane, is used for the rear wheels of the vehicle such that the area with a lower negative rate faces the outside of the vehicle. How to install pneumatic tires. 5. A pneumatic tire for a front wheel, wherein a negative rate of a tread is different in left and right regions across a tire equatorial plane, wherein a negative rate of an inner area when the vehicle is mounted is negative in an outer area when the vehicle is mounted. A pneumatic tire for a front wheel, which is smaller than the ratio.