JPS59227510A - Semiradial tire for motorcycle - Google Patents

Abstract

PURPOSE:To improve driving stability by having both ends of a carcass ply, rolling up a bead, overlapped each other in predetermined width right under the belt of a crown part. CONSTITUTION:Both ends of a carcass 4 made of one ply P-1 form turnup parts P-2 by rolling up beads 5 respectively. Further, both terminal parts P-E of said turnup parts overlap each other, right under a belt of a crown part, in width of overlapping less than the largest width TW of a tread and more than 1/5TW. Thus, rigidity of a tread part is improved so that driving stability of a car can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for improving the handling stability of a motorcycle tire, which is sensitively influenced by its rigidity.

As for passenger Ichikawa tires, radial/l/groove tires have already become mainstream due to their excellent handling stability, wear resistance, and high durability. Use U& fiber cord or steel cord, and the angle of the cord is 90 degrees with respect to the inner center line of the tire.
1 in the radial direction, 1 in the row of plies
Using 1 piece or 1 piece of heavy metal, attach 1 piece or 2 pieces of coarse cord with low elongation coefficient such as steel cord or rayon at an inclination angle of 15 to 60° to the circumferential center line of the tire. A bell made by using 1 piece and overlapping the 2 or more rows by crossing each other!・Although it is well-known that the tire has a structure with reinforced layers, this kind of lap/Ifff tire has a lower tire strength compared to the bias structure tire that was the mainstream before then. full
The walls (hereinafter referred to as sidewalls) are extremely flexible, providing a comfortable ride, and the highly rigid belt station is located directly under the tread, making it possible to maintain a high level of stability similar to that seen in bias tires. The pantograph effect of the tread contact surface does not occur, and the rigidity of the belt layer extends to the contact surface, resulting in high cornering characteristics, that is, excellent steering stability, and at the same time, there is less movement of the rubber on the contact surface. This means that it exhibits excellent properties in terms of resistance to magic wear and tear.

If you think about motorcycle tires at around 2,
The fact that the sidewall is flexible means that when the motorcycle turns or goes around a curve, it leans the heavy body toward the turning side, which gives the tire a camber angle. The fishing force acting as a protective force against the lateral deformation of the tire due to the presence of the Camper River, that is, the fishing force acting in the horizontal direction, that is, the Camper River
A strike occurs. The magnitude of this camber thrust is 2
UFI plays a very important role in the turning movement of the wheel load and the disturbance that occurs when the vehicle is moving directly.
：This is a well-understood theory, but the structure of a motorcycle tire that requires a curve or turning motion with a rough camber angle is as follows.
Tires with a flexible wall/I/structure are unstable due to lateral deformation, and this phenomenon is caused by the disturbance t in the straight line.
It also reacts sensitively to this. In addition, motorcycles, which are often driven at high speeds, have poor lateral stability as mentioned above, that is, poor handling stability, which can be fatal, unlike in the case of four-wheeled vehicles, as this entails the risk of rollover. There will be some defects.

The inventors of the present invention have conducted intensive research on the sidewall rigidity and contact surface rigidity required for motorcycle tires from the viewpoint of the carcass snowbelt structure.
1G construction and belt structure with unique ingenuity. -Thus, it not only eliminates the disadvantages of radial tires as mentioned above, but also exhibits effects that cannot be obtained with conventional bias tires in terms of +111 wear resistance and high-speed durability. found.

This invention relates to a carcass consisting of at least two or more plies in which cords are arranged at an angle of 70 to 85 degrees with respect to the circumferential center line of the tire, and a carcass consisting of at least two or more plies with cords arranged at an angle of 70 to 85 degrees with respect to the circumferential center line of the tire. From the above code,
In a two-wheeled vehicle tire having a round belt, both ends of the carcass ply are formed by rolling up one bead part to the other and overlapping each other directly under the round part belt. This is a pneumatic tire for two-wheel heavy use, which is characterized by the wrap width W being in the wide range of W=Tlv~'15TW, where the tread width is TV. is polyester or nylon aa ((I
: The cords of the belt layer are arranged parallel to each other, and are arranged at an angle of 15 to 50 degrees with respect to the center line of the tire direction. The material 'U' is a pneumatic tire for a motorcycle having a semi-radial-belted structure, characterized in that it is made of an organic fiber cord such as polyester, nylon, or aromatic polyamide, and a steel cord.

This will be explained below based on the drawings.

FIG. 1 is a cross-sectional view of a tire according to the present invention. In the figure, tire 1 has sidewall 2. Troy I to Trayed 3
It is constructed continuously in a round shape.

The carcass 4 consists of one piece of braai P-1, and a pair of left and right beads 1 and 5 are wound around both ends of the braai. The Oparanor "llW" is the range of Arashi TW to T-Jl of the large tread amount i1 T W, and its 11α is the tire size, the tire installation l"L
An arbitrary 11] is determined depending on the model and required performance. The rigidity of the ground contact area increases in proportion to the size of the W,
Since the wheel rigidity also improves, the maneuverability of the city is improved, but ultimately, in relation to the tread pattern rigidity 2,
It is set so that the rigidity of the crown part is one product higher than the crown part, so that the rigidity gradually decreases. If there is a rigidity fault in the direction of the contact surface, it will become a fatal defect 2 for two-wheel heavy duty tires.

FIG. 2 is a cross-sectional view of a tire showing another embodiment of the present invention. In this example, the carcass uses two plies, a wide ply 4L of l] and a narrow ply 4S of 11,
1] The turn-up part terminal of the narrow ply 4S is hl
The end is at the height of → t1 The outer side of this terminal in the direction of the tire 1 is covered by the wide ply 4L Kuhnnup part,
The crown part forms an overlapping part of the W. 48 of the second braai is intended to improve the rigidity of the sidewall part 2, and its terminal height hl is 48, which is the position where it overlaps with the belt 5. It is also possible to increase the rigidity of the sidewall part 2 (within a range that does not affect performance). It is possible.

Father, carcass ply 4) The cord is a stepped fiber cord of polyester or nylon, and the cord of bells 1-5 is a polyester, nylon, aromatic polyamide fiber cord and O
- Steel cord. Of course, it is also n111hi to put together the belt 4A material of Kohachi and others. For example, the first belt is made of steel, and the second belt is made of nylon cord.

As shown in the second example, the test F was cut horizontally.
It's hard and it's this tongue.

The tire size is 4-ply rating for the front and rear wheels (1 < 1 ko 4.00-10), and the tread shown in the pattern development diagram in Fig. 3 is shared between the embodiment of the present invention and the conventional comparative example with a flat surface. . The main features of these test tires are shown in Table 1.

Table 1 The test results are shown in Table 2. The values in the table are conventional product viou
The f-direction is expressed as an index when

2nd S The above test result is ℃, which is the quadratic quotient to explain.

1) Steering stability Front and rear tires 4.00-10 4PR tires are stuck, internal pressure is 22~/d in front, 2,41 in rear. tl
/ d conducted an actual vehicle feeling test (stability, maneuverability) with 5 test drivers / (-, 5 points rating).
Results were tabulated using the ti method.

2) - Abrasiveness 1 lap 5.5 & 1 lap at an average speed of 120 m/h
A 500AJ vehicle was driven, and the crown groove surface was measured. The internal pressure at this time is 2.5 bx /
It was made into a CD.

6) A steel drum with a smooth surface and a diameter of 1.6 m is heated under the conditions of high internal pressure of 25 mq/c-0 and a tonne of 250 kq.
Start at a speed of 0.001 m/h, and after running for 60 minutes without any abnormalities, increase the speed in increments of 10 h/h and allow sex for 60 minutes each. And it was criticized for the speed at which the tire broke down.

As described in detail below, the semi-radial tire for heavy duty motorcycles according to the present invention not only provides superior longitudinal stability compared to conventional tires.

It can be seen that the abrasion resistance and high-speed 1ml durability are also significantly improved.

These excellent properties are brought about by the overlap of the turnply ply and the unique combination of the belt and the unique combination of the turnply and the belt.

[Brief explanation of the drawing]

FIGS. 1 and 2 are cross-sectional views showing examples of the present invention, and FIG. 6 is a developed pattern of a tire used as an IJli test tire. 2 fist...") I V wall, 5... Tread, 4.
O. Carcass, P-1...Ply, P-2...-Ply turn 1 nap part, P-B...Ply terminal, 5... Bead. 11...'tflj, 12...sub. Patent applicant: Sumitomo Rubber Industries, Ltd. 2

Claims (1)

[Scope of Claims] (1) A carcass consisting of at least one or more plies with seven rows of cords arranged at an angle of 70 to 85 degrees to the tire circumferential center, 115 degrees below the tread rubber. in,
2) In a wheeled tire having a belt layer consisting of two cords arranged adjacent to the carcass,
At both ends of the carcass ply, extend the capacity bead from one bead and overlap each other directly under the L-shaped round part belt as 'fH' (f-), and the width of the overlap is y+. If the tread width is T-AI, then W = T /
A semi-radial louvered groove pneumatic tire for two-wheel heavy duty, characterized by a wide range of / -Q T W. (2) The pneumatic tire according to claim 1, wherein the cord of the carcass ply is an organic fiber cord of polyester or nylon. (6) The cords of the belt layer are arranged parallel to each other at an angle of 15-30' to the circumferential center of the tire, and the material is polyester, nylon, aromatic polyamide, etc. The pneumatic tire according to claim 1, which is a cord and a steel cord.