JPH0646722Y2 - Low noise tires - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a low noise tire having a block pattern, in which noise is reduced.

[Conventional technology]

In recent years, noise reduction of automobiles has been desired. In addition, engine noise, cooling fan for intake / exhaust noise, and tire noise are the main car noises. Especially, since tire noise increases with traveling speed, improvement of the noise is an important issue. In tire noise, air contained in the groove of the tire tread, which is formed as a repeating pattern, causes compression waves in the air around the air when it is compressed or released due to rolling of the tire, so-called pattern noise, road irregularities. , When the tire is rotated due to the unevenness of the tire (tread rubber thickness, change in circumferential curvature), elastic vibration sound caused by cyclic impact from the road surface and compression waves in the surrounding air, When a tire rolls, there is a noise due to slippage with the road surface due to movement of the tread portion at the tire contact surface, or a squeak noise due to slippage with the road surface due to deformation of the tread portion before and after the tire contact portion.

Conventionally, in order to reduce these noises, in a block pattern tire, blocks having different lengths are arranged in the circumferential direction (variable pitch method).

Reduce the groove area.

Although such a method has been adopted, it is desired to further reduce noise in a block pattern tire.

The present invention aims to provide a low noise tire having a block pattern.

[Technical means]

The present invention is a low-noise tire having a block pattern having a plurality of blocks in which blocks are arranged in the tire circumferential direction, wherein the crown portion of the tread is disposed on one side of the tire equatorial plane and the tire circumferential direction. A basic block group in which basic blocks having a constant length are juxtaposed at a constant interval, and arranged on the other side of the tire equator and having a constant length and the same number as the basic blocks and one of the basic blocks in the tire circumferential direction. Form a phase difference block group consisting of blocks in which the edges facing in the same circumferential direction are displaced from each other in the circumferential direction of the tire, and the number of blocks of the basic block group and the phase difference block group at the shoulders on both sides. The number of side blocks is smaller than that of the basic blocks, and the number of blocks is equal to the number of blocks on the shoulders on both sides. As well as formed, positional displacement amount of the positional deviation between the basic block and the phase difference blocks block is a low noise tire characterized by comprising a plurality of different lengths.

[Action]

As described above, since the basic block group arranged on one side of the tire equator, the phase difference block group arranged on the other side, and the two side block groups are composed of four block groups, the tire axial length is increased. In addition to increasing the block strength, noise is converted to white noise by a block group having a plurality of types of blocks on both sides of the tire equator. Moreover, these 2
The noise can be effectively reduced in combination with the fact that the load is equally applied to one block group.

Also, since the side block group is composed of a large number of blocks, the interval between the blocks,
That is, it is clear that the lateral groove width can be made small and the rigidity difference caused by the rotating block per rotation can be relatively averaged to reduce the impact and smooth the rotation. Property, wet grip property at the time of turning, and wear resistance can be improved.

Further, at the time of turning, the side block group having a large number of blocks and the basic or phase difference block group are grounded, so that white noise can be generated due to the positional deviation of the blocks.

Further, the blocks of the basic block group are arranged in the tire circumferential direction at the same length and at equal intervals, the blocks of the phase difference block group have a constant length, and the blocks of the side block group have the same length,
Since it is evenly spaced and the number of shoulders on both sides is the same,
It makes it easy to manufacture tire molds while reducing noise.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, the crown portion of the tread portion T is sandwiched by the tire equator C, and, for example, on the left side of FIG. 1, basic blocks B1 to B4 having a constant length L in the tire circumferential direction are provided at constant circumferential intervals. The basic block group P1 arranged in W is arranged. On the other hand, that is, on the right side of the tire equator C in FIG. 1, from the one edge in the circumferential direction of each of the basic blocks B1 to B4 of the basic block group P1, the edge facing in the circumferential direction is the same in the tire circumferential direction. A phase difference block group P2 in which the positional shift amounts E1 to E4 are displaced in the circumferential direction and the same number of blocks C1 to C4 as the basic block number of the basic block group P1 are arranged in the tire circumferential direction are arranged.

Here, the positional deviation amounts E1, E2, E3, and E4 are preferably different from each other, but in the present embodiment, E2 = E3, and therefore E1,
It consists of three different lengths, E2 (E3) and E4.

Table 1 shows an example of an arrangement method in the tire circumferential direction.

In Table 1, the positional shift amount of 5 mm and the number of 5 in the left column of the table mean that in the phase difference block group P2, five blocks having a positional shift amount of 5 mm are lined up. But
It means that two 10 mm blocks are lined up, and in the same way, the blocks having the positional deviation amounts described in the upper row are arranged in the lower row.

In this way, by arranging blocks having a plurality of length displacement amounts in the tire circumferential direction in the basic block group, it is possible to prevent noise synchronization and reduce the noise level.

The circumferential lengths of the blocks C1 to C4 of the phase difference block group P2 are also constant.

The shoulder portion of the tread portion T is arranged along the vicinity of the tread edge and has a larger number of blocks than the basic block group P1 and the phase difference block group P2, and has the same number of blocks S1 to S4 juxtaposed on the shoulder portions on both sides. Block groups P3 and P4 are arranged.

Further, the blocks S1 to S4 have a constant length in the circumferential direction, and the intervals in the circumferential direction between the blocks S1 to S4 are also constant, and the intervals are also between the basic blocks B1 to B4. It is smaller than the circumferential distance W. Side block group P3, P4
Since the number of blocks of the basic blocks is larger than the number of basic blocks, the pitch length, which is the sum of the circumferential length of the blocks and the length of one interval, is the pitch length p1 of the basic block group P1 (phase difference The average pitch length of the block group P2) is smaller than the pitch length p2 of the side block groups P3 and P4.

As described above, the low noise tire of the present invention is composed of four block groups including a basic block group arranged on one side of the tire equator, a phase difference block group arranged on the other side, and two side block groups. It becomes possible to increase the axial length of the tire and increase the block strength, and the noise is converted to white noise by the block group having the blocks displaced in plural kinds on both sides of the tire equator. Moreover, the noise can be effectively reduced in combination with the equal load being applied to both blocks during straight traveling.

Also, since the side block group is composed of a large number of blocks, the interval between the blocks,
That is, in combination with the reduction of the width of the lateral groove, the rigidity difference caused by the rotating block per rotation can be relatively averaged to reduce the impact and smooth the rotation. As a result, it is possible to improve the turning property, the wet grip property at the time of turning, and the wear resistance. Further, at the time of turning, when the side block group having a large number of blocks and the basic or phase difference block group come into contact with the ground, white noise can be generated due to the positional deviation of the blocks.

Further, the blocks of the basic block group are arranged at the same length and at equal intervals in the tire circumferential direction, and the phase difference block group also uses blocks of the same length which are displaced only in the circumferential direction from the blocks of the basic block group, Moreover, since the blocks of the side block group have the same length, are equally spaced, and have the same number of shoulder portions on both sides, it is possible to reduce the noise while facilitating the manufacture of the tire mold.

Those skilled in the art can select specifications such as the circumferential length, width, height, number, and intervals of the blocks according to the purpose with reference to the drawings and the following specific examples.

〔Concrete example〕

A tire size of 4.60 was obtained for a tire of a tread pattern having five blocks including an example of the present invention shown in FIG. 1 and a comparative example shown in FIG. -18 motorcycle tires were prototyped according to the specifications in Table 2 and a noise test was conducted. Tested indoors with air pressure of 1.75kgf / cm ² and load of 100
Measurements were made at a position 50 cm lateral to the tire in accordance with JASO under the conditions of kgf / line, and the results are shown in FIG.

As is clear from FIG. 3, the embodiment of the present invention is recognized to reduce noise noise more than the comparative example.

[Effect of device]

As described above, the low-noise tire of the present invention has a block pattern, can effectively suppress noise synchronization, and can reduce the noise level.

[Brief description of drawings]

1 is a partial plan view of a tire tread portion of an embodiment of the present invention, FIG. 2 is a partial plan view of a tread portion of a comparative example, FIG.
The figure is a graph showing the relationship between the noise level and the traveling speed. P1 ... Basic block group, P2 ... Phase difference block group, P3, P4 ... Side block group, E1, E2, E3, E4 ... Positional shift amount.

Claims (1)

[Scope of utility model registration request] 1. A low noise tire having a block pattern having a plurality of blocks in which blocks are arranged in a tire circumferential direction, the tire being arranged on one side of a crown portion of a tread with a tire equatorial plane interposed therebetween. A basic block group in which basic blocks having a constant length are juxtaposed at regular intervals in a direction, and arranged on the other side of the tire equator and having a constant length and the same number as the basic blocks and in the tire circumferential direction of the basic block. A phase difference block group consisting of blocks whose one edge faces the same in the circumferential direction are displaced in the tire circumferential direction is formed from one edge, and the blocks of the basic block group and the phase difference block group are formed on both shoulders. The number of blocks is the same and the number of blocks is the same on both sides. Both low noise tire positional deviation amount of the positional deviation between the block of the basic block and the phase difference blocks is characterized by comprising a plurality of different lengths.