JPH03125604A - Motorcycle tire - Google Patents

Abstract

PURPOSE:To equalize wear of left and right shoulder portions to prevent partial wear for improvement of durability by respectively specifying loss modulus of elasticity and loss compliance of each of rubber which forms one shoulder area and the remainder area in a tread portion. CONSTITUTION:A tread portion 5 is formed by one shoulder area S from a particular boundary point P to one outer edge Q1 and the remainder area O from the boundary point P to the other outer edge Q2 via an equatorial line C of a tire. The shoulder area S is made of rubber which is set respectively within the limits of 6 - 15kg/cm of loss modulus of elasticity, and also within the limits of 3.5X10<-3> - 6X10<-3>cm/kg<2> of loss-compliance, under conditions that initial strain is 10% dynamic strain is 2%, frequency is 10Hz and a measuring temperature is 60 deg.C. The remainder area O is made of rubber which is set respectively within the limits of 1 - 10kg/cm of loss modulus of elasticity and also within the limits of 1X10<-3> - 5X10<-3>cm/kg<2> of loss compliance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a motorcycle tire that can equalize the amount of wear on the left and right sides of the tire and improve its durability when traveling on general roads.

[Conventional technology]

On general roads, it is shaped like a semicircle with a slightly higher center, and when driving on the left side of the road,
Affected by the bank angle, tires wear more on the right side than the left side in the direction of travel of the vehicle, causing uneven wear on the tires.

When such uneven wear occurs, the straight-line performance is lost even during running, the steering stability is impaired, and the durability of the tire is impaired. Furthermore, the tendency of uneven wear is remarkable in the rear wheels of motorcycles, which are subjected to a larger load than the front wheels.

The present invention divides the tread portion into one shoulder region and a residual region using a boundary point provided between the tire equator and one end edge as a boundary, and the rubber of each of the one shoulder region and the residual region has a loss elasticity. The present invention aims to provide a motorcycle tire that has a bank angle and can prevent the occurrence of uneven wear of the tread portion during driving on general roads and can improve the durability of the tire by regulating the ratio and loss compliance.

〔Example〕

The present invention provides a carcass that passes from the tread part through the sidewall part and folds around the bead core of the bead part, and is provided with a belt ply made of organic fiber cords, and a belt ply located inside the tread part and outside the carcass in the radial direction. , the tread portion includes a belt layer consisting of one or more belt plies, and the tread portion has one outer edge (Q
The tread width (
From the boundary point (P) that separates the tire equator (C) from the tire equator (C) to one outer edge (Q2) side by a distance of 0.15 times or more and 0.35 times or less of TW), One shoulder region (S) leading to the outer edge Q1, and the other outer edge (Q2) from the boundary point (P) through the tire equator (C).
and a residual region (O) leading to , and the one shoulder region (S) has an initial strain of 10%, a dynamic strain of 2%,
The loss modulus (E”S) is 6 kIr/a1 or more and 15 at a frequency of 10 Hz and a measurement temperature of 60°C.
kg/cs or less and loss compliance (
LC5) is made of rubber with a 3.5 x 10-'ts/ktr" or more and 6 x 10-'as/kg" or less, and the remaining area (O) is the one shoulder area (S).
The loss modulus E'O was measured under the same conditions as 1 kg.
/c11 or more and 10ksr/c11 or less, and the loss compliance (LCO) is I x 10-3
cs/kg or more and 5 X 10-”cs/k
This is a motorcycle tire made of rubber of less than

[Effect]

Since the tread part has a loss modulus of elasticity and a loss compliance within a certain range in one shoulder region S and the remaining region 0, the tire has directionality in the axial direction, and can be used to drive on the left or right side. Accordingly, even when the tire is mounted on a motorcycle running on a general road, the amount of wear on the left and right sides of the tire can be equalized, and the durability of the tire due to wear can be increased.

〔Example〕

An embodiment of the present invention will be described below based on the drawings.

In the figure, the motorcycle tire l of the present invention has bead portions 3.3 on both sides through which the bead core 2 passes, sidewall portions 4 extending outward in the tire radial direction from the bead portions 3, and a tread portion 5 joining the upper end thereof. and a carcass 6 that passes through the tread portion 5 and folds around the bead core 2 of the bead portion 3, and is arranged inside the tread portion 5 and outside the carcass 6 in the radial direction. A belt layer 7 is provided.

The carcass 6 is a single carcass ply made of a solid or radial structure in which carcass cords made of organic fibers such as nylon, polyester, and aromatic polyamide resin are arranged at an angle of 0° to 85° with respect to the tire equator C. Or have multiple pieces.

In this embodiment, the belt layer 7 includes two belt plies consisting of an inner belt ply 11 and an outer belt ply 12 radially outward from the carcass 6.
．． 12 is a belt cord made of nylon, polyester, aromatic polyamide resin, etc.
They are arranged at an angle of 30° to 85° relative to the surface.

The tread portion 5 has a distance 1gz, which is 0.15 times or more and 0.35 times or less of the tread width TW, which is the distance in the tire axial direction between one outer edge Ql and the other outer edge 02 of the tread portion 5, at the tire equator C. One shoulder region S extending from the boundary point P to the one outer edge Q1 with reference to the boundary point P separating from the boundary point P to the one outer edge Q1 side, and a tire equator C from the boundary point P to the tire equator C.
It is divided into a residual area O extending through the area to the other outer edge Q2.

In the present invention, the tread portion 5 is formed of rubber having different rubber characteristics in one shoulder region S and the remaining region O.

On the other hand, the rubber in the Schilder region S was measured using a viscoelastic spectrometer manufactured by Iwamoto Seisakusho at a frequency of 10 Hz, an initial strain of 10%, a dynamic strain of 2%, and a measurement temperature of 60°C.
Loss modulus E"S is 6 kg/cm or more and 15 kg/cm
cm or less, and loss compliance LC3
, that is, the ratio E"S/(E13)"-LC3 of the loss modulus E"S to the square of the complex modulus ESS is 3.5
10-3cs/kg” or more and 6X10-”mouth/
kg” or less.

In addition, in the residual region 0, under the same measurement conditions as one shoulder region S, as long as the loss modulus E'O is 1 kg/cm or more and 10 kr/cm or less, the loss compliance LCO-E"O/ ( 1 x 10
-“am/ni!r” or more and 5×10-cs/k
It is set to be less than g.

In this way, by making the loss elastic modulus E"0 and loss compliance LCO in the residual region 0 relatively lower than the loss elastic modulus E"S and loss compliance LC3 of one shoulder region S, the center of the tread portion 5 is This makes it possible to increase the wear resistance between the shoulder region S and the other shoulder region, and to balance the amount of wear in the one shoulder region S, which suffers relatively little wear.

It is preferable that the value of the loss elastic modulus E"O of the remaining region 0 is in the range of 0.5 times or more and 0.8 times or less of the value of the loss elastic modulus E"S of one shoulder region S. It is desirable that the value of the loss compliance LCO of the remaining region 0 be within the range of the value of the loss compliance LC3 of the one shoulder region S.

〔Concrete example〕

A tire with a tire size of 140/60R1864 having the structure shown in Figure 1 and the specifications shown in Table 1 was manufactured as a prototype, and the tire was installed on the rear wheel of a motorcycle with an exhaust capacity of 11409cc and 4 cycles, and a tire was installed on the front wheel. A test was carried out using conventional tires having a size of 110/70R53 and made of a single rubber shown in Table 1.

During the test, the vehicle was driven on a general road (left-hand traffic road) with the one shoulder region S facing left in the direction of vehicle travel.

After running for 5000k11, it was found that the difference in wear between the one and other shield parts was 0.98:1, indicating that the wear was uniform.

By the way, in a tire with a conventional structure in which the entire tread portion is made of rubber with the same value as the loss modulus E"S and loss compliance 1 LC3 of one shoulder region S, the difference in wear is 0.75:1 to 0.85:1. The amount of wear on the right side in the direction of travel was large.

〔Effect of the invention〕

Like soft soil, the motorcycle tire of the present invention has a bank angle because the loss elastic modulus and loss compliance are regulated for the rubber of the tread portion of one shoulder region and the remaining region of the tread portion. Even for motorcycles traveling on public roads, the amount of wear on the left and right shoulder parts can be equalized, and by preventing the occurrence of one-sided wear, the durability of the tire can be improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention. 2-...Bead core, 3...Bead part, 4-...
-Side wall part, 5...Tread part, 〇-Residual area, P-Boundary point, Ql, Q2-・Outer edge, S...One side Φ shield area, T W-) - Red width.

Claims (1)

[Scope of Claims] 1. A carcass that passes from the tread portion through the sidewall portion and is folded around the bead core of the bead portion, and is provided with a belt ply made of organic fiber cords, and a belt ply that extends from the tread portion to the sidewall portion and folds around the bead core of the bead portion, and a belt ply that extends from the tread portion to the side wall portion and folds around the bead core of the bead portion, and the belt ply that is formed from the inside of the tread portion and the outside of the carcass in the radial direction. The tread portion includes a belt layer consisting of one or more belt plies, and the tread portion is located at one outer edge of the tread portion and the other outer edge (Q1, Q
2) Tread width (TW), which is the axial distance between
A boundary point (P
) from the boundary point (P) to the one outer edge Q1
One shoulder region (S) leading to and the boundary point (P)
and a residual region (O) extending from the tire equator (C) to the other outer edge (Q2), and one shoulder region (S) has an initial strain of 10%, a dynamic strain of 2%, and a frequency. is 10 Hz and the measurement temperature is 60°C, the loss modulus (E”S) is 6 kg/cm or more and 15 kg/cm or less, and the loss compliance (LCS) is 3.
．． 5×10^-^3cm/kg^2 or more and 6×10^
- 3 cm/kg 2 or less rubber, and the remaining region (O) has a loss modulus E"O of 1 kg/cm or more and 10 kg/cm or less when measured under the same conditions as the one shoulder region (S). and a loss compliance (LCO) of 1 x 10^-^3 cm/kg^2 or more and 5 x 10^-^3 cm/kg^2 or less. 2. The residual area (O). E is the ratio of the loss modulus (E”O) of the shoulder region (S) to the loss modulus (E”S) of the shoulder region (S).
"O/E" S and LCO/LCS, which is the ratio of the loss compliance (LCO) of the residual area (O) to the loss compliance (LCS) of the shoulder area (S), are both 0.
The motorcycle tire according to claim 1, which has a particle diameter of 5 or more and 0.8 or less.