JP5156299B2 - Motorcycle tire pair - Google Patents

Description

  The present invention relates to a tire pair that is an optimal combination of a front wheel tire and a rear wheel tire of a motorcycle.

  In motorcycle tires, the roles of front wheel tires and rear wheel tires are clearly different, front wheel tires have the role of manipulating the vehicle body by the steering angle as steering wheels, and rear wheel tires have a steering angle of It is necessary to change it according to the required performance so that it has the role of advancing the vehicle body as a drive wheel and can sufficiently generate each function.

  The front wheel tires function to contact the road surface in the center area of the tread, including the tire equator when traveling straight, and to transmit braking force to the road surface. Functions on the road surface to generate a lateral force that opposes the centrifugal force acting on the motorcycle. When cornering is performed with a particularly large camber angle, the shoulder region including the tread grounding end contacts the ground and functions to generate a greater lateral force.

  The rear wheel tire functions so that the central area of the tread, including the tire equator, touches the road surface when driving straight, and transmits the driving force and braking force to the road surface. The shoulder region including the end functions to contact the road surface and generate a lateral force that opposes the centrifugal force acting on the motorcycle. The intermediate region located in the middle of these regions generates a lateral force that counteracts the centrifugal force during cornering while transmitting driving force and braking force to the road surface by, for example, corner rising traveling, slalom traveling, etc. It will work as well.

  Therefore, the tread rubber disposed in the tread portion contact area of the motorcycle tire can be selected in each contact area only by selecting a single rubber type, a single rubber hardness, etc. The function of could not be fully demonstrated.

  Therefore, the present invention particularly provides a motorcycle tire pair that enables safer and more comfortable driving by using an optimum combination according to the respective roles of the front wheel tire and the rear wheel tire. provide.

The motorcycle tire pair according to the present invention comprises a front wheel tire mounted on a front wheel of a motorcycle and a rear wheel tire mounted on a rear wheel, the front wheel tire and the rear wheel tire. Each of the contact areas is composed of five regions, a central region including the tire equatorial plane, a pair of shoulder regions including the tread ground contact edge, and a pair of intermediate regions located between the central region and the shoulder region, The middle region of the front wheel tire is a region that is attached to the rim and applied with a load corresponding to a specified air pressure and a specified mass, and is grounded with a camber angle of 35 to 45 °, and a rear wheel tire. The intermediate region is assembled to the applicable rim and a load corresponding to the prescribed air pressure and the prescribed mass is applied to make a grounding region with a 20-30 ° camber angle applied. The tread rubber having at least one layer structure having different physical properties in each region is used , and in the front wheel tire, the rubber hardness of the tread rubber is set to at least a portion of the central tread rubber disposed over the central region to form the ground contact surface. Rubber hardness, the rubber hardness of the intermediate tread rubber disposed over the entire intermediate region, at least the portion of the shoulder tread rubber disposed over the entire shoulder region, and the rubber of the portion of the shoulder tread rubber disposed over the entire shoulder region. In the rear wheel tire, the rubber hardness of the intermediate tread rubber disposed over the entire intermediate region is at least the portion of the central tread rubber disposed over the entire central region. At least the rubber hardness of the part that forms the ground plane and the entire shoulder area. Shoulder tread rubber disposed I, characterized in that it is greater than any of the rubber hardness of the portion forming at least a ground plane.

  Here, the “at least one-layer tread rubber” means not only a case where the tread rubber of the tread portion has a single layer structure but also a tread rubber having a laminated structure such as a cap-and-base structure.

  Here, the “applicable rim”, “specified air pressure”, and “load corresponding to the specified mass” are respectively JATMA (THE Japan Automobile Tires Association, Inc.) YEAR BOOK, ETRTO (European Tire Tyre). Organization) STANDARD MANUAL, TRA (THE TIRE and RIM ASSOCATION INC.) YEAR BOOK, the rim used for the application size, the air pressure corresponding to the prescribed load of the single wheel at the application size, and the single wheel at the application size The load corresponding to the mass shall be said.

  Here, the rubber hardness is a hardness measured under a room temperature condition of 20 ° C. using a type A tester in a durometer hardness test according to JIS K6253.

  More preferably, in the tire for the rear wheel, the rubber hardness of the central tread rubber is made larger than that of the shoulder tread rubber.

  Preferably, in the front wheel tire, the central tread rubber has a rubber hardness of 54 to 60, the intermediate tread rubber has a rubber hardness of 51 to 57, and the shoulder tread rubber has a rubber hardness of 48 to 54. The rubber hardness of the central tread rubber is 50 to 56, the rubber hardness of the intermediate tread rubber is 55 to 61, and the rubber hardness of the shoulder tread rubber is 49 to 55.

The front wheel tire has a role as a steered wheel that operates the vehicle body by the rudder angle, so it is necessary to ensure that the response to the rudder angle change is reasonably good in the central area where it touches down straightly. In the middle region of the tire tread that is sometimes grounded, the rudder angle is fixed, so that it is necessary to ensure not a responsiveness but a grip force that can withstand a large lateral force.
Further, the shoulder region that contacts the ground when a large camber angle is applied needs to generate a greater lateral force.

  Therefore, in the motorcycle tire pair of the present invention, the contact region of the front wheel tire is located between the central region including the tire equatorial plane, the pair of shoulder regions including the tread ground contact edge, and the central region and the shoulder region. By forming the five regions including the pair of intermediate regions, the region to be grounded when the camber angles of the front wheel tires are applied is effectively separated. In addition, by using a tread rubber having at least one layer structure having different physical properties for each region, it is possible to efficiently improve the running performance required when each camber angle is given.

  In addition, since the tire for the rear wheel does not have a rudder angle and plays a role as a driving wheel for advancing the vehicle body, the central region that contacts the ground during straight traveling must efficiently transmit driving force and braking force to the road surface. In addition, the shoulder region that contacts the ground during cornering needs to be suitable for generating a large lateral force. In addition, it is necessary to generate sufficient lateral force in the intermediate region of the tread part between these two regions in addition to efficient road surface transmission of driving force and braking force at the corner rising etc. become.

  Therefore, in the motorcycle tire pair of the present invention, the contact area of the tire for the rear wheel is divided between a central region including the tire equator plane, a pair of shoulder regions including the tread ground contact edge, and the central region and the shoulder region. By forming the five regions including the pair of intermediate regions positioned, the region to be grounded when the camber angles of the rear wheel tires are applied is effectively separated. In addition, by using a tread rubber having at least one layer structure having different physical properties for each region, it is possible to efficiently improve the running performance required when each camber angle is given.

  Moreover, here, by forming the contact regions of the front wheel tire and the rear wheel tire together in five regions, and by using a tread rubber having at least one layer of physical properties different from each other, Since the front-wheel tire and the rear-wheel tire travel at substantially the same camber angle, the performance improvement effects of each can be synergized.

The motorcycle tire pair of the present invention will be described below in detail with reference to the drawings.
FIG. 1 (a) is a meridian cross-sectional view showing one embodiment of a front tire of a motorcycle tire pair of the present invention, and FIG. 1 (b) is a rear wheel of the motorcycle tire pair of the present invention. It is a meridian cross-sectional view showing one embodiment of the tire for use.
In addition, about the structure of the tire for front wheels and the tire for rear wheels, a common part is demonstrated collectively below.

  In FIGS. 1 (a) and 1 (b), 11 and 21 are tread portions, 12 and 22 are a pair of sidewall portions extending radially inward continuously to the respective side portions of the tread portions 11 and 21, and Reference numerals 13 and 23 denote bead portions that are continuous on the radially inner side of the sidewall portions 12 and 22, respectively.

  These tires have carcass plies 15 and 25 which are turned around the bead cores 14 and 24 of the bead portions 13 and 23 from the tread portions 11 and 21 through the sidewall portions 12 and 22. In the drawing, the carcass is constituted by one carcass ply 15, 25, but a carcass can also be constituted by a plurality of carcass plies.

Belts 16 and 26 each including at least one circumferential reinforcing cord layer extending in the tire width direction are disposed on the outer peripheral side of the crown regions of the carcass plies 15 and 25. A so-called spiral belt structure in which one or a plurality of cords are continuously wound in an extending posture in the tire circumferential direction can be obtained.
On the further outer peripheral side of the belts 16 and 26, tread rubbers 17 and 27 that extend in an arc shape up to the maximum width position of the tire and form contact areas of the tread portions 11 and 21 are provided. Further, side rubbers 18 and 28 that form side portions are provided on both sides of the tread rubbers 17 and 27.
Further, although omitted in FIG. 1, required grooves are formed on the surfaces of the tread rubbers 17 and 27 at a required negative rate.

  Further, in the tire shown here, the contact areas of the tread portions 11 and 21 are center areas 1A and 2A located including the tire equator plane in the center, and shoulder areas 1C and 2C located including the tread ground contact edge, It is formed by five regions, an intermediate region 1B, 1B located between the central region 1A, 2A and the shoulder region 1C, 2C. The shoulder region 1C, 2C and the intermediate region 1B, 1B sandwich the equator plane, respectively. A pair is formed at symmetrical positions.

In addition, here, the tread rubbers 17 and 27 disposed in the respective regions have a single-layer structure, and the physical properties are made different in each region.
As the physical properties that differ from region to region, rubber hardness is preferred.

  Further, the intermediate region 1B of the front wheel tire is a region that is attached to the applicable rim and applied with a load corresponding to a specified air pressure and a specified mass and is grounded with a camber angle of 35 to 45 °. Thus, the responsiveness and lateral force of the role of the front wheel tire can be improved according to each camber angle.

  That is, if it is less than 35 °, the effect of improving the tire response is small, whereas if it exceeds 45 °, the effect of improving cornering tends to be small.

  On the other hand, the middle region 2B of the rear wheel tire is a region that is attached to the rim and applied with a load corresponding to a specified air pressure and a specified mass and is grounded with a camber angle of 20 to 30 °. Thus, the driving force and cornering performance of the role of the rear wheel tire can be improved according to each camber angle.

  That is, if it is less than 20 °, the effect of improving the driving force is small, whereas if it exceeds 30 °, the effect of improving the cornering property tends to be small.

In the front wheel tire, the rubber hardness of the tread rubber is the same as the rubber hardness of the intermediate tread rubber 17b disposed over the entire intermediate region 1B and the shoulder region. By making it larger than any of the rubber hardnesses of the shoulder tread rubber 17c disposed over the entire 1C, it is possible to ensure responsiveness to changes in the steering angle.
By making the rubber hardness of the intermediate tread rubber 17b larger than the rubber hardness of the shoulder tread rubber 17c, the gripping force can be ensured.

  In the rear wheel tire, the rubber hardness of the intermediate tread rubber 27b disposed over the entire intermediate region 2B is equal to the rubber hardness of the central tread rubber 27a disposed over the entire central region 2A and the shoulder disposed over the entire shoulder region 2C. By making it larger than any of the rubber hardnesses of the tread rubber 27c, it is possible to transmit a driving force when the corner rises and generate a lateral force.

  By making the rubber hardness of the central tread rubber 27a larger than the rubber hardness of the shoulder tread rubber 27c, it is possible to improve the wear resistance of the central region where the wear occurs most.

  Further, in the front wheel tire, by setting the rubber hardness of the central tread rubber 17a in the range of 54 to 60, both moderate responsiveness and absorbability can be achieved. By setting the rubber hardness of the intermediate tread rubber 17b in the range of 51 to 57, it is possible to achieve both moderate responsiveness and lateral force. By setting the rubber hardness of the shoulder tread rubber 17c in the range of 48 to 54, an appropriate lateral force can be generated.

  In the rear wheel tire, by setting the rubber hardness of the central tread rubber 27a in the range of 50 to 56, it is possible to achieve both an appropriate driving force and absorbability. By setting the rubber hardness of the intermediate tread rubber 27b in the range of 55 to 61, the absorbability can be improved while improving the driving force and lateral force. By setting the rubber hardness of the shoulder tread rubber 27c in the range of 49 to 55, the grounding property and the rigidity are compatible, and the lateral force can be secured.

Next, Fig. 2 (a) shows that since a large lateral force is applied from the center to the shoulder side during cornering, the tread rubber for each region is inclined so as to ensure durability against peeling from the surface edge of each region. FIG. 6 is a cross-sectional view in the width direction showing another embodiment of the front tire of the motorcycle tire pair of the present invention provided as described above. Front tire size 120 / 70ZR17, steel monofilament spiral belt and two rayon carcasses having a structure as shown in FIG. 2 (a) are provided. The front wheel tire 1 to the front wheel tire 8 which were changed to the above were manufactured as prototypes. In addition, it mounted | worn to the rim | limb of rim size MT3.50, the internal pressure was 250 kPa, and the load was 150 kg.
In FIG. 2 (b), since a large lateral force is applied from the center to the shoulder side during cornering, the tread rubber for each region is provided to be inclined so that durability against peeling can be secured from the surface edge of each region. FIG. 6 is a cross-sectional view in the width direction showing another embodiment of a motorcycle tire pair and a rear wheel tire according to the present invention. The size of the rear wheel tire having the structure shown in FIG. 2 (b) is 190 / 50ZR17, the steel monofilament spiral belt and the nylon carcass are changed as shown in Tables 3 to 4. Rear wheel tires 1 to 8 were manufactured as prototypes. In addition, it mounted | worn to the rim | rim of rim size MT6.00, the internal pressure was 290 kPa, and the load was 150 kg.
The combination of the front wheel tire 1 and the rear wheel tire 1 is an example tire pair 1, and the combination of the front wheel tire 2 and the rear wheel tire 2 is a reference example tire pair 1 , for the front wheel tire 3 and the rear wheel The combination of tires 3 is a reference example tire pair 2 , the combination of front wheel tires 4 and rear wheel tires 4 is comparative example tire pair 1, and the combination of front wheel tires 5 and rear wheel tires 5 is a comparative example. The tire pair 2 is a combination of the front wheel tire 6 and the rear wheel tire 6 as the comparative example tire pair 3, and the combination of the front wheel tire 7 and the rear wheel tire 7 is the comparative example tire pair 4, and the front wheel tire. The combination of the tires 8 and 8 for the rear wheels was used as a comparative tire pair 5.
For each of Example tire pair 1 , Reference tire pair 1 to Reference tire pair 2, and Comparative tire pair 1 to Comparative tire pair 5, the responsiveness, drivability, and cornering properties were evaluated.
In the present invention, since the tire structure other than the tread portion does not require modification, the tire structure is almost the same as that of a conventional motorcycle tire.

(responsiveness)
Example tire pair 1 , reference example tire pair 1 to reference example tire pair 2 , comparative example tire pair 1 to comparative example tire pair 5 are mounted on a 1000 cc motorcycle, and the vehicle body to steering when running slalom Table 5 shows the agility of the movement, and the responsiveness was evaluated by the feeling of the evaluation rider.

(Drivability)
Example tire pair 1 , reference tire pair 1 to reference tire pair 2 , comparative tire pair 1 to comparative tire pair 5 were each mounted on a 1000 cc motorcycle and cornered when cornering was started. Table 5 shows the behavior of the vehicle body, etc., with the responsiveness evaluated by the feeling of the evaluation rider.

(Cornering)
Example tire pair 1 , reference example tire pair 1 to reference example tire pair 2 , comparative tire pair 1 to comparative example tire pair 5, respectively, a round course with a test speed of 30 to 300 km / h and a travel distance of 4 km, Table 5 shows the cornering performance evaluated by the evaluation rider's feeling of traveling repeatedly at an angle of 0 to 45 °, especially at a camber angle of 45 to 50 °.

From the results of Table 5, Example tire pair 1 , Reference tire pair 1 to Reference example tire pair 2 have both responsiveness, drivability, and cornering performance compared to Comparative tire pair 1 to Comparative tire pair 5. be able to.

(A) It is width direction sectional drawing which shows one Embodiment of the tire for front wheels of the motorcycle tire pair of this invention, (b) One embodiment of the tire for motorcycles of this invention pair of rear-wheel tires FIG. (A) It is sectional drawing of the width direction which shows other embodiment of the front-wheel tire of the motorcycle tire pair of this invention, (b) Other embodiment of the rear-wheel tire of the motorcycle tire of this invention FIG.

Explanation of symbols

11, 21 Tread portion 12, 22 Side wall portion 13, 23 Bead portion 14, 24 Bead core 15, 25 Carcass ply 16, 26 Belt 17, 27 Tread rubber 17a, 27a Central tread rubber 17b, 27b Intermediate tread rubber 17c, 27c Shoulder Tread rubber 18, 28 Side rubber 1A, 2A Central area 1B, 2B Middle area 1C, 2C Shoulder area

Claims (3)

In a tire pair consisting of a front wheel tire mounted on a front wheel of a motorcycle and a rear wheel tire mounted on a rear wheel,
Each of the contact regions of the front wheel tire and the rear wheel tire includes a center region including a tire equatorial plane, a pair of shoulder regions including a tread ground contact edge, and a pair of intermediate positions located between the center region and the shoulder region. It consists of five areas with areas,
The middle region of the front wheel tire is a region that is attached to the rim and applied with a load corresponding to a specified air pressure and a specified mass, and is grounded with a camber angle of 35 to 45 °, and a rear wheel tire. The intermediate region of is attached to the applicable rim, a load corresponding to a specified air pressure and a specified mass is applied, and a region where the camber angle is applied at 20 to 30 ° is grounded,
In each region, tread rubber of at least one layer structure having different physical properties for each region is used ,
In the tire for the front wheel, the rubber hardness of the tread rubber is at least the rubber hardness of the central tread rubber disposed over the entire central region, at least the portion of the intermediate tread rubber disposed over the entire intermediate region. The rubber hardness of the portion forming the ground contact surface and the shoulder tread rubber disposed over the entire shoulder region are reduced in order of at least the rubber hardness of the portion forming the ground contact surface. The rubber hardness of at least the portion forming the ground contact surface of the intermediate tread rubber disposed over the entire region of the central tread rubber disposed over the entire central region and the rubber hardness of at least the portion forming the ground contact surface. Form at least the ground contact surface of the shoulder tread rubber Min either greatly tire pair for a motorcycle, characterized by comprising than the rubber hardness. The pair of motorcycle tires according to claim 1 , wherein in the rear wheel tire, the rubber hardness of the central tread rubber is larger than that of the shoulder tread rubber. In the front wheel tire, the central tread rubber has a rubber hardness of 54 to 60, the intermediate tread rubber has a rubber hardness of 51 to 57, and the shoulder tread rubber has a rubber hardness of 48 to 54. The tire pair for a motorcycle according to claim 1 or 2 , wherein the rubber hardness of the rubber is 50 to 56, the rubber hardness of the intermediate tread rubber is 55 to 61, and the rubber hardness of the shoulder tread rubber is 49 to 55.

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