JPH06183210A - Pneumatic tire - Google Patents

Abstract

PURPOSE:To secure traction performance while improving wandering performance on a snow road or the like. CONSTITUTION:In a pneumatic tire 1, a lateral groove 5 opening on a buttress surface 4 continuing to the tread end 3 is arranged in a recessed shape in a tread part 2, and juxtaposed shoulder blocks 6 are formed in a circumferential direction along the tread end 3 between the lateral groove 5, and locking parts 9 which have projecting parts 12 projecting in a tire shaft direction from the buttress surface 4 and also having a taper surface 11 continuing to ground contact surfaces 10 of the shoulder blocks 6 on the ground contact side and have small width groove parts 13 opening on the buttress surface 4 between the projecting parts 12, are formed in the shoulder blocks 6. Step shape square parts 15 are formed in front and in rear in a circumferential direction of the tread end 3 in the shoulder blocks 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic tire, and more particularly to a pneumatic tire having improved shoulder block wandering performance and improved traction performance by improving the shape of a shoulder block. .

[0002]

2. Description of the Related Art The profile of a snow tire has a shoulder block which is shown in FIG. 3 in order to prevent skidding on a snowy road.
Basically, it is a square-shaped block V as shown in (A). In this case, since the wandering performance deteriorates, in recent years, the round shoulder block V1 shown in FIG. 3 (B) or the semi-square shoulder block V2 shown in FIG. 3 (C) is being adopted.

However, these have merits and demerits, in the round shoulder block V1, side slip on snow and ice becomes worse, and in the semi-square square shoulder block V2, it is good at the beginning of riding in the round part but on the way up Since many square parts hit the road surface at one time, the reaction force is large and the wandering performance is not so good. Therefore, if the square part is reduced, the sideslip will be worse.

From this point of view, a plurality of locking portions each having a narrow groove opening on the buttress surface and a raised portion protruding from the buttress surface are formed on the shoulder block to generate a traction effect and to run on a snowy road. As a pneumatic tire having improved performance, there is a technique disclosed in JP-A-2-182503.

[0005]

In the prior art disclosed in the above-mentioned publication, a scratching or scraping effect on the rut wall surface formed on the snow-compacted road surface by the side surface of the protruding portion protruding from the buttress surface facing the traveling direction is newly added. However, since the connecting edge of the tapered surface formed on the raised portion with the ground contact surface of the shoulder block is located inward of the tread edge in the tire axial direction, the wandering performance and edge effect are halved. There was a problem.

Therefore, according to the present invention, by forming a stepped square portion on a tread edge of a shoulder block having a tapered surface of a raised portion, the wandering effect is ensured by utilizing the wandering effect of the tapered surface. The purpose is to improve.

[0007]

SUMMARY OF THE INVENTION The present invention is a tread portion 2
By forming a lateral groove 5 that opens at the buttress surface 4 connected to the tread edge 3, a shoulder block 6 is formed between the lateral grooves 5 along the tread edge 3 in the circumferential direction, and the buttress surface 6 is formed. An engaging portion having a raised portion 12 projecting in the axial direction of the tire from 4 and having a tapered surface 11 connected to the contact surface 10 of the shoulder block 6 on the contact side and a narrow groove portion 13 opened between the raised portions 12 at the buttress surface 4.
9 is the pneumatic tire 1 formed on the shoulder block 6, and the following technical measures are taken to achieve the above-mentioned object.

That is, the present invention according to claim 1 is characterized in that a square-shaped square portion 15 is formed in the shoulder block 6 in front of and behind the tread edge 3 in the circumferential direction. Further, in the present invention according to claim 2, in addition to the above-mentioned claim 1, the narrow groove portion is located more inward in the tire axial direction than the connecting edge between the tapered surface 11 and the ground contact surface 10.
The groove bottom 14 of 13 is formed.

[0009]

When the vehicle travels on a flat road, the taper surface 11 formed on the raised portion 12 does not come into contact with the road surface and secures a lateral grip (axial direction of the tire) at the square portion. In particular, a large grip is secured by the stepped square portion 15. On the other hand, when running on a rut such as a snowy road, the reaction force is reduced by the taper surface 11 following the rut road surface first, and scratches are generated by the side surface 12A of the protruding portion 12 protruding from the buttress surface 4 in the traveling direction. A new traction effect is generated by the scraping effect, and a traction effect is also generated by the stepped square portion 15. Furthermore, since the square portion 15 is formed in a staircase shape, the square portion 15 is formed while riding over the rut.
Many 15 do not hit the road surface at one time, so the reaction force is small and wandering performance can be secured. In the present invention according to claim 2, in addition to the above, the groove bottom of the narrow groove portion 13 is provided.
Since 14 is located inward in the tire axial direction, traction performance by the side surface 12A is enhanced.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 (A) is a perspective view showing a tread portion 2 of a pneumatic tire 1 according to the present invention of claim 1.
2 is provided with a lateral groove 5 which is open at the buttress surface 4 connected to the tread edge 3 so that a shoulder block 6 is formed between the lateral grooves 5 along the tread edge 3 in the circumferential direction. , The inner side of the shoulder block 6 in the axial direction of the tire is provided with a side block 8 through a vertical groove 7 or the like.
And a center block (not shown) is formed.

The shoulder block 6 has a plurality of locking portions 9
The locking portion 9 is formed, and the protruding portion 12 has a tapered surface 11 that protrudes from the buttress surface 4 in the tire axial direction and that is connected to the ground contact surface 10 of the shoulder block 6 on the ground contact side via a connecting edge. Between the raised portions 12, there are narrow width groove portions 13 opening at the buttress surface 4. Tapered surface 11 is shown in Figure 1 (B)
The angle θ with the buttress surface 4 is 45 ° to 75 ° as shown in
In addition, a stepped squeeze portion 15 is formed before and after the tread edge 3 of the shoulder block 6 in the direction of rotation, which secures a lateral grip force in the block 6 and reduces traction. Performance is also secured.

In the embodiment of the present invention according to claim 2 shown in FIGS. 2A and 2B, in addition to the structure described with reference to FIGS. 1A and 1B, the groove of the narrow groove portion 13 is formed. The bottom 14 has a rising surface along the buttress surface 4 and is located inward in the tire axial direction as indicated by the symbol L in FIG. 2 (B), and is a raised portion protruding from the buttress surface 4.
The side surface 12A facing the traveling direction of 12 is at least enlarged by the reference numeral L in the narrow groove portion 13, so that a new traction action due to the scratching and scraping effect of the rut wall surface formed on the snow-compacted road surface can be greatly generated. Has become.

That is, if the connecting edge of the tapered surface formed on the raised portion is located more inward in the tire axial direction than the groove bottom of the narrow groove portion as in the above-mentioned prior art, the wandering performance and the edge effect are reduced by half. On the other hand, in the present invention, contrary to the prior art, the groove bottom 14 of the narrow groove portion 13 is located inward in the tire axial direction, so that the side surface 12A facing the traveling direction of the ridge 12 is large as indicated by the symbol L. Therefore, the traction performance can be greatly generated, and the traction performance is improved in combination with the above-described stepped square portion 15.

[0014]

According to the present invention described in detail above, since the ridge forming the engaging portion of the shoulder block has a tapered surface, the tapered surface does not come into contact with the road surface during traveling on general roads. Lateral grip can be exerted on the square portion, and by forming the square portion in a step shape before and after the shoulder block, the lateral grip performance and the traction performance can be improved together, while the taper on the snowy road surface etc. Since the surface follows the Wadachi road surface first, there is little reaction force and while maintaining wandering performance,
The stair-like squares formed before and after the shoulder block enhance the scratching and scraping effect on the wall surface of the wadachi formed on the snow-compacted road surface, thereby significantly improving the traction.

Further, since the groove bottom of the narrow groove portion which constitutes the locking portion together with the raised portion is located inward of the connecting edge of the tapered surface in the tire axial direction together with the stepped square portion, The side facing the direction of travel becomes larger,
The scratching and shaving effect on the wall surface of the wadachi formed on the snow-covered road surface is enhanced, and the traction performance is significantly improved.

Therefore, the present invention is particularly useful as a snow tire.

[Brief description of drawings]

1A and 1B show an embodiment of the present invention according to claim 1, wherein FIG. 1A is a perspective view of a tread portion, and FIG.

2A and 2B show an embodiment of the present invention according to claim 2, wherein FIG. 2A is a perspective view of a tread portion, and FIG.

FIG. 3 shows a conventional example, (A) shows a square shoulder block, (B) shows a round shoulder block, and (C) shows a semi-square shoulder block.

[Explanation of symbols]

 1 Pneumatic tire 2 Tread part 3 Tread edge 4 Buttress surface 5 Lateral groove 6 Shoulder block 9 Locking part 11 Tapered surface 12 Raised part 13 Narrow groove part 14 Groove bottom 15 Stepped square part

Claims (2)

[Claims] 1. The tread portion (2) is provided with a lateral groove (5) opening at a buttress surface (4) continuous with the tread edge (3), whereby the tread edge (3) is formed between the lateral grooves (5). ) Along with the shoulder blocks (6) arranged in the circumferential direction, and a taper surface protruding from the buttress surface (4) in the tire axial direction and connected to the ground contact surface (10) of the shoulder block (6) on the ground contact side. An engaging portion (9) having a raised portion (12) having (11) and a narrow groove portion (13) opening at the buttress surface (4) between the raised portions (12) is provided on the shoulder block (6). A pneumatic tire (1) being formed, characterized in that a stepped square portion (15) is formed in the shoulder block (6) at the front and rear in the circumferential direction of the tread edge (3). And pneumatic tires. 2. The tread portion (2) is provided with a lateral groove (5) which opens at a buttress surface (4) connected to the tread edge (3), whereby the tread edge (3) is formed between the lateral grooves (5). ) Along with the shoulder blocks (6) arranged in the circumferential direction, and a taper surface protruding from the buttress surface (4) in the tire axial direction and connected to the ground contact surface (10) of the shoulder block (6) on the ground contact side. An engaging portion (9) having a raised portion (12) having (11) and a narrow groove portion (13) opening at the buttress surface (4) between the raised portions (12) is provided on the shoulder block (6). A pneumatic tire (1) being formed, wherein a square-shaped square portion (15) is formed in the shoulder block (6) before and after the tread edge (3) in the circumferential direction. The groove bottom (14) of the narrow groove portion (13) is formed inward in the tire axial direction with respect to the connecting edge between the tapered surface (11) and the ground contact surface (10). A pneumatic tire which is characterized the door.