JP4037949B2 - Pneumatic tires for passenger cars - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a pneumatic tire for passenger cars, and in particular, a bead core provided on a pair of left and right bead parts, and extends from the crown part to both bead parts through both side parts and wound around the bead core. A carcass ply moored to the bead portion, a belt disposed radially outward of the crown portion of the carcass ply, and a tread disposed radially outward of the belt, wherein the tread includes a tire. A pair of left and right central circumferential grooves that extend in the tire circumferential direction or substantially circumferential direction, with the equator plane interposed therebetween, and a tire circumferential direction that is disposed adjacent to the central circumferential groove. The present invention relates to a pneumatic tire for a passenger car in which a tread pattern having a central circumferential rib extending is formed, and is inclined inward at a camber angle θ and is mounted on a vehicle in a C shape. .
[0002]
[Prior art]
Generally speaking, a pneumatic tire for a passenger car is not mounted straight in the vertical direction when the vehicle is mounted, but is usually mounted with a small angle in the vertical direction. This angle is called a camber angle or camber angle, and so-called high-performance sports cars are usually attached with a camber angle of about 1 to 3 degrees and tilted inward to be mounted on the vehicle in a C shape. . However, the conventional pneumatic tire has a camber angle of 1 to 3 degrees as described above, and the tread pattern is designed without considering that it is tilted inward and attached to the vehicle in a C shape. It had been. As a result, in the conventional pneumatic tire having the tread pattern as described above, the central circumferential rib is arranged at the center of the tread, in other words, the central line of the central circumferential rib is located on the tire equatorial plane. Thus, the central circumferential ribs are arranged symmetrically.
[0003]
[Problems to be solved by the invention]
A pneumatic tire having a conventional tread pattern with a central circumferential rib arranged at the center of the tread as described above is inclined inward with a camber angle of about 1 to 3 degrees and is shaped like a square When installed in a vehicle, there is a slight time difference in steering response performance at the beginning of turning the rudder, which may cause the driver to feel frustrated with a feeling of delay.
[0004]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to arrange a pair of left and right central circumferential directions extending in the tire circumferential direction or substantially circumferential direction, which are arranged on both left and right sides with the tire equatorial plane in between. A pneumatic tire with a tread pattern formed with a groove and a central circumferential rib that is arranged adjacent to the central circumferential groove and extends in the tire circumferential direction is inclined inward with a camber angle. It is an object of the present invention to provide a pneumatic tire for a passenger car that eliminates a delay in steering response performance that is likely to occur when mounted on a vehicle in a C shape.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a pneumatic tire for a passenger car according to the present invention includes a bead core provided in a pair of left and right bead portions, and extends from the crown portion to both bead portions via both sidewall portions. A carcass ply wound around a core and moored at a bead; and a belt and a tread arranged radially outward of the crown of the carcass ply. A pair of left and right central circumferential grooves that extend in the tire circumferential direction or substantially circumferential direction, and the tire circumferential direction that is disposed adjacent to the inside of the pair of left and right central circumferential grooves, disposed on both sides. continuous tread pattern with a central circumferential rib extending is formed, inclined inwardly camber angle θ is mounted on a vehicle in the form of a slanted roof, pneumatic tire for passenger cars of the outer diameter 2R , The central circumferential rib is asymmetrically arranged so that the center line of the central circumferential rib is located on the inner side of the vehicle when mounted on the vehicle by R · tan θ from the tire equator plane, and the central circumferential rib is unevenly distributed. It is characterized by being mounted on the vehicle so that the side is located inside the vehicle.
[0006]
Conventionally provided with a pair of left and right central circumferential grooves disposed on both left and right sides of the tire equatorial plane, and a central circumferential rib disposed adjacent to the inside of the pair of left and right central circumferential grooves In the tire, a central circumferential rib having a width of about 20 to 30 mm is arranged at the center of the tread. In other words, the central circumferential rib is positioned so that the center line of the central circumferential rib is located on the tire equatorial plane. It was arranged symmetrically. When a pneumatic tire having a conventional tread pattern as described above is attached to a vehicle with a camber angle of about 1 to 3 degrees and tilted inward, the center of contact is the tire equator. The surface is displaced by about 10 to 20 mm from the surface, and the grounding center is located not in the rib but in the groove. As a result, at the beginning of turning the rudder, it was found that there is a slight time difference in the steering response performance, which may cause the driver to feel dissatisfied with the feeling of delay.
[0007]
The pneumatic tire for a passenger car of the present invention is configured as described above, and in particular, the tread is disposed on the left and right sides of the tire equatorial plane, and a pair of left and right tires extending in the tire circumferential direction or substantially in the circumferential direction. A tread pattern including a central circumferential groove and a central circumferential rib disposed adjacent to the inside of the pair of left and right central circumferential grooves and continuously extending in the tire circumferential direction is formed. In a pneumatic tire for passenger cars with an outer diameter of 2R, which is inclined inward at an angle θ and mounted on the vehicle, the center line of the central circumferential rib is R · tanθ from the tire equator when the vehicle is mounted The central circumferential ribs are arranged asymmetrically so as to be located on the inner side of the vehicle, and the tire is attached to the vehicle so that the uneven side of the central circumferential rib is located on the inner side of the vehicle. Lean inward When mounted on the vehicle in a letter C shape, the ground contact center is located on the unevenly distributed rib without being located in the groove. As a result, even at the beginning of turning the rudder, there is no time difference in the steering response performance, and the conventional feeling of dissatisfaction such as a feeling of delay is eliminated.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a pneumatic radial tire for a passenger car according to an embodiment of the present invention and a pneumatic radial tire for a passenger car according to a conventional example will be described with reference to the drawings. The tire size is 245 / 45ZR17 in all cases.
[0009]
FIG. 1 is a partially enlarged schematic view of a tread pattern of a tire according to an embodiment of the present invention. The tire of the example has a bead core (not shown) provided on a pair of right and left bead parts, and extends from the crown part to both bead parts through both sidewall parts, and is wound around the bead core to bead parts. A pneumatic car for a passenger car comprising a carcass ply (not shown) made of moored radial cords, and a belt (not shown) and a tread (not shown) arranged radially outward of the crown of the carcass ply. It is a radial tire, tilted inward at a camber angle θ = 1.5 degrees, mounted on the vehicle in a C shape, and has an outer diameter of 2R = 326 mm. As shown in FIG. 1, the tread includes a pair of left and right central circumferential grooves 1 and 2 that are disposed on both left and right sides of the tire equatorial plane E, and a pair of left and right central circumferential grooves. A tread pattern including central circumferential ribs 3 extending in the tire circumferential direction and disposed adjacent to the inside of the directional grooves 1 and 2 is formed. In the tire according to the example, the central circumferential rib 3 is asymmetrically arranged so that the center line C of the central circumferential rib 3 is shifted from the tire equatorial plane E by a distance d in the tire axial direction. 3 is mounted on the vehicle such that the unevenly distributed side is located inside the vehicle. This distance d is calculated by R · tan θ, and since R = 163 mm and θ = 1.5 degrees, d = 8.5 mm.
[0010]
In the conventional tire, the center line C of the central circumferential rib 3 is positioned on the tire equatorial plane E, and the central circumferential rib 3 is arranged symmetrically in the left-right direction. It is almost the same as a tire.
[0011]
About the tire of the said Example based on this invention, and the tire of the said prior art, it rim-assembles to the rim | limb 9J-17, is filled with the internal pressure 2.4kg / cm < ² >, and is mounted | worn with a test vehicle. A feeling evaluation test was conducted by a test driver on a winding road that included running from a high speed to a high speed. The evaluation items are a straight traveling performance including a minute rudder angle response performance, a lane change performance, a cornering performance, and an overall performance thereof. As a result of this evaluation test, when displayed with a maximum of 10 points, the straight running performance, lane change performance, and cornering performance were 6.0, 6.0, and 6.5 in the conventional tires described above. The tires of the above examples based on the invention showed excellent results at 6.5, 7.5 and 7.0. Further, the overall performance of the tire of the above-mentioned conventional example was 6.0, whereas the tire of the above-mentioned example based on the present invention showed an extremely excellent result at 7.25.
[0012]
【The invention's effect】
From the above results, it can be seen that the present invention provides a pneumatic tire for a passenger car that is excellent in straight running performance including minute steering angle response performance, lane change performance, cornering performance, and overall performance thereof.
[Brief description of the drawings]
FIG. 1 is a partially enlarged front view of a tread pattern of a pneumatic tire for a passenger car according to the present invention.
[Explanation of symbols]
1 Central circumferential groove 2 Central circumferential groove 3 Central circumferential rib C Centerline E of central circumferential rib 3 Tire equatorial plane

Claims (1)

A bead core provided in a pair of left and right bead parts, a carcass ply extending from the crown part to both bead parts through both sidewall parts, wound around the bead core and anchored to the bead part, A belt and a tread disposed radially outward of the crown portion of the carcass ply, and the tread is disposed on the left and right sides of the tire equatorial plane and extends in the tire circumferential direction or substantially in the circumferential direction A tread pattern comprising a pair of central circumferential grooves and a central circumferential rib disposed adjacent to the inside of the pair of left and right central circumferential grooves and extending continuously in the tire circumferential direction is formed. In a pneumatic tire for a passenger car having an outer diameter of 2R, which is attached to a vehicle in a C shape inclined inward at a camber angle θ ,
The central circumferential rib is arranged asymmetrically so that the center line of the central circumferential rib is located on the inner side of the vehicle when mounted on the vehicle by R · tan θ from the tire equatorial plane, and the unevenly distributed side of the central circumferential rib is the vehicle A pneumatic tire for a passenger car, which is mounted on a vehicle so as to be located inside.

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