JPH06183219A - Snow tire for motorcycle - Google Patents

Abstract

PURPOSE:To provide a snow tire for a motorcycle by which a slide slip can be prevented when riding across a weak bank while securing driving force and braking force on the ice or on the snow. CONSTITUTION:In a snow tire for a motorcycle having a block keynote tread pattern, lateral sipes 5 extending in a tire width direction are arranged in central area A extending to 1/8 of tread developing width on both respective left and right sides from the tire equator of a tread 1. Length of this lateral sipe 5 is set not less than 70% of actual ground contact width in the central area A, and longitudinal sipes 6 extending in a tire circumferential direction are arranged in an outside area B extending to the left and right shoulder sides from the central area A, and a rate of the longitudinal sipes 6 to the whole sipes in the outside area B is set not less than 70%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a snow tire for a motorcycle suitable for running on ice or running on snow, and more specifically, to prevent skidding during weak banking while securing driving force and braking force. Regarding snow tires for motorcycles.

[0002]

2. Description of the Related Art Conventionally, in a snow tire for a motorcycle having a block-based tread pattern, a large number of sipes are provided in the block. Among these sipes, the lateral sipes extending in the tire width direction mainly contribute to driving force and braking force on ice or snow, and the longitudinal sipes extending in the tire circumferential direction mainly contribute to skid prevention.

However, by providing the sipes as described above, it is difficult to ensure both the driving force and the braking force and the improvement of the skid prevention performance at the same time. Tilted to)
When driving or braking with, there is a problem that the balance is lost and skidding occurs.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a snow tire for a motorcycle capable of preventing skidding during weak banking while securing driving force and braking force on ice or snow. Especially.

[0005]

A snow tire for a motorcycle according to the present invention for achieving the above object is a snow tire for a motorcycle having a block-based tread pattern. A lateral sipe extending in the tire width direction is provided in a central region extending to ⅛ of the developed width, and the length of the lateral sipe is set to 70% or more of the actual ground contact width of the central region. A vertical sipe extending in the tire circumferential direction is provided in the outer region extending to the shoulder side, and the ratio of the vertical sipe to all the sipe in the outer region is 70% or more.

Thus, the lateral sipe extending in the tire width direction is provided in the central region of the tread, and the length of the lateral sipe is set to 70% or more of the actual ground contact width of the central region, so that the driving force on ice or snow and In addition to ensuring braking force, vertical sipe extending in the tire circumferential direction is provided in the outer region, and the ratio of the vertical sipe to all the sipe in the outer region is 70% or more to prevent skidding during weak banking. You can

In the present invention, the lateral sipe is defined as a narrow groove whose angle with respect to the tire circumferential direction is in the range of 75 ° to 105 °, and the longitudinal sipe has an angle with respect to the tire circumferential direction of ± 1.
It is defined as a narrow groove in the range of 5 °. Further, the actual ground contact width of the central area is the width of the land portion such as a block located in the central area. Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a development view showing a tread of a snow tire for a motorcycle according to an embodiment of the present invention.

In FIG. 1, a tread 1 is provided with a plurality of main grooves 2 extending in the tire circumferential direction and a lug groove 3 extending in the tire width direction. The main groove 2 and the lug groove 3 form a plurality of blocks. 4 are divided and formed. A plurality of lateral sipes 5 extending in the tire width direction are provided in the block 4 in the central region A extending from the tire equator of the tread 1 to the left and right sides of the tread 1 to the width W / 8. The length of the lateral sipe 5 is set to be 70% or more of the actual ground contact width of the central region, that is, 70% or more of the block width in the central region in this embodiment.

On the other hand, in the outer region B extending from the central region A to the left and right shoulders, the block 4 is provided with a plurality of vertical sipes 6 extending in the tire circumferential direction. Further, although the outer region B may include some lateral sipes,
The ratio of the vertical sipes 6 to the total sipes in the outer region B is 70.
% Or more is set. According to the present invention, in the snow tire for a motorcycle having the block-based tread pattern as described above, the lateral sipe 5 extending in the tire width direction is provided in the central region A of the tread 1, and the length of the lateral sipe 5 is set. By setting the actual ground contact width of the central region A to be 70% or more, it is possible to secure the minimum necessary driving force and braking force. Further, by providing the vertical sipe 6 extending in the tire circumferential direction in the outer region B and setting the ratio of the vertical sipe 6 to all the sipe in the outer region B to 70% or more,
Even if the vehicle is driven or braked in a weak bank state on ice or snow, skidding is less likely to occur.

That is, the central region A and the outer region B are divided from the tire equator of the tread 1 on the left and right sides respectively at the positions of W / 8, and the lateral sipe 5 is arranged in the central region A and the outside thereof. By arranging the vertical sipes 6 in the region B, it is possible to prevent skidding during weak banking while securing driving force and braking force on ice or snow.

[0011]

EXAMPLE Two types of snow tires for motorcycles having a tire size of 2.75-14 and having a block pattern were produced in which only the sipes provided on the blocks were changed as described below. Tires of the Present Invention As shown in FIG. 1, a lateral sipe is provided in a block that constitutes one central block row, and a vertical sipe is provided in a block that constitutes four outer block rows. Conventional tire As shown in FIG. 2, a lateral sipe is provided in a block forming the central three block rows, and a vertical sipe is provided in a block forming the outer two block rows.

With respect to these two types of tires, the side slip occurrence rate and the braking distance were measured by the following methods, and the results are shown in Table 1. Sideslip incidence: Attach the test tires to the front and rear wheels of the motorcycle, apply the rear brake from the condition of running on ice at a speed of 20 km / h, and stop. It was measured.

Braking distance: Test tires were attached to the front and rear wheels of a motorcycle, and the braking distance was measured when the vehicle was running on ice at a speed of 15 km / h and the rear brake was applied to stop. As is clear from Table 1, the tire of the present invention has a braking force equivalent to that of the conventional tire, but can reduce the side slip occurrence rate.

[0014]

As described above, according to the present invention, in a snow tire for a motorcycle having a block-based tread pattern, the center extending from the tire equator of the tread to the left and right sides to 1/8 of the tread deployment width, respectively. Provide a lateral sipe that extends in the tire width direction in the area,
The length of this lateral sipe is 70% of the actual contact width of the central area.
In addition to the above, a vertical sipe extending in the tire circumferential direction is provided in the outer region extending from the central region to the left and right shoulder sides, and the ratio of the vertical sipe to all the sipe in the outer region is 70% or more. It is possible to prevent skidding during weak banking while securing driving force and braking force on ice or snow.

[Brief description of drawings]

FIG. 1 is a development view showing a tread of a snow tire for a motorcycle according to an embodiment of the present invention.

FIG. 2 is a development view showing a tread of a conventional snow tire for a motorcycle.

[Explanation of sign]

 1 Tread 2 Main groove 3 Lug groove 4 Block 5 Horizontal sipe 6 Vertical sipe A Central area B Outside area

Claims (1)

[Claims] 1. In a snow tire for a motorcycle having a block-based tread pattern, a lateral sipe extending in the tire width direction is provided in the central region extending from the tire equator of the tread to the left and right sides to 1/8 of the tread deployment width, respectively. The length of the lateral sipe is 70% or more of the actual ground contact width of the central region, and a vertical sipe extending in the tire circumferential direction is provided in an outer region extending from the central region to the left and right shoulder sides. A snow tire for a motorcycle in which the ratio of the vertical sipe to all the sipes in the outer region is 70% or more.