JP2007021942A - Blade and pneumatic tire made using blade - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blade which improves stiffness of a block and makes an improvement of an edge effect on snow and ice and an improvement of a water absorbing effect on a snow road or a wet road with an improvement of handling stability on a dry road, and to provide a pneumatic tire made by using the blade. <P>SOLUTION: In a blade forming a sipe of the pneumatic tire having a block on a tread portion which is divided by a plurality of grooves and has a plurality of sipes formed thereon, the blade has an opening periphery made by hollowing a part of the blade, and the downward cross-section of the opening periphery is tapered toward the opening provided that the downward side is on the carcass layer side when the blade is embedded in the pneumatic tire. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pneumatic tire formed using a blade and a blade that forms a sipe of a pneumatic tire having a tread portion having a block that is partitioned by a plurality of grooves and formed with a plurality of sipes.

  Conventionally, a pneumatic tire having a corrugated sipe extending in the tire width direction while repeating the amplitude in the tire circumferential direction in a block formed in the tread portion is known (for example, Patent Document 1). By forming a plurality of such sipes in one block, it is possible to improve the ground contact with the road surface of the tread surface and the drainage effect.

In general, the sipe as described above has a corrugated shape, and is formed by pressing a flat plate having a certain thickness onto a pneumatic tire.
JP 11-310013 PR

  However, as described above, when a plurality of sipes are formed in one block using a blade having a certain thickness, the tire circumferential length between sipes is shortened, thereby reducing the rigidity of the block. There was a problem.

  When the rigidity of the block is lowered, the block collapses and the edge effect on ice and snow is reduced. Further, when the block collapses, the gap of the sipe is reduced, and the water absorption effect on ice and snow or on the WET road surface is also reduced. Furthermore, it is generally said that the steering stability on the DRY road surface and the like is lowered.

  Therefore, in view of the above-described problems, the present invention improves the rigidity of the block and achieves both an improved edge effect on ice and snow, an improved water absorption effect on ice and snow and a wet road surface, and improved steering stability on a DRY road surface. An object of the present invention is to provide a blade that can be used and a pneumatic tire formed using the blade.

  In order to solve the above-described problem, a first feature of the present invention is a blade that forms a sipe of a pneumatic tire having a block in which a plurality of sipe is formed in a tread portion and is partitioned by a plurality of grooves. If the carcass layer side when the blade is embedded in a pneumatic tire is down, the lower cross-section of the opening edge is at the opening. The gist is that the blade is characterized by being tapered toward the front.

  According to this feature, since the blade has an opening edge that is an edge of the opening formed by hollowing out a part of the blade, when the blade embedded in the pneumatic tire is pulled out, the opening edge below the blade is In order to cut the tread portion, when the blade is embedded in the pneumatic tire, a sipe close to 0 mm can be formed at the position corresponding to the opening in the tread portion. Thereby, even when the block falls down, the portions where sipes close to 0 mm are formed are used as supporting wands and the deformation of the block is suppressed, so that the rigidity of the block can be improved. Further, by improving the rigidity of the block, it is possible to improve both the edge effect on ice and snow, the water absorption effect on ice and snow and the WET road surface, and the steering stability on the DRY road surface.

  Moreover, since the cross section below the opening edge is tapered toward the opening, the blade can be easily pulled out from the pneumatic tire.

  Moreover, it is preferable that the angle of the front-end | tip below an opening part edge is 60 degrees or less. Since the angle of the tip below the opening edge is 60 ° or less, the blade can be more easily pulled out than the pneumatic tire.

  The opening edge is preferably polygonal. Specifically, the polygonal shape is preferably an elongated rectangle. Since the polygonal shape is an elongated rectangle, the blade can be more easily pulled out than the pneumatic tire.

  The polygonal shape is preferably tapered downward. Since the polygonal shape is tapered downward, when the blade is pulled out from the pneumatic tire, the resistance applied to the edge of the opening below the blade can be further reduced, and the pulling out can be further facilitated.

  Moreover, it is preferable that the opening edge is continuous. Since the opening edge is continuous, the strength of the blade itself can be improved.

  The position of the edge of the opening in the blade is preferably a position in contact with the ground contact surface when the blade is embedded in a pneumatic tire or in the vicinity of the ground contact surface. Since the position of the edge of the opening in the blade is in the vicinity of the contact surface or in the vicinity of the contact surface, which is particularly greatly deformed and has low rigidity in the block, the rigidity of the block can be effectively improved.

  Moreover, it is preferable that an opening part becomes so large that the position of the opening part edge in a braid | blade is close to a groove | channel, when a braid | blade is embed | buried in a pneumatic tire. Since the opening becomes larger as the position of the opening edge of the blade is closer to the groove, the rigidity in the vicinity of the groove having a particularly large deformation and low rigidity can be effectively improved.

  A second feature of the present invention is a pneumatic tire having a tread portion including a block formed by a plurality of grooves and having a plurality of sipes in the tread portion. The sipes are openings that are edges of the openings. Using a blade having an edge and having a carcass layer side when embedded in a pneumatic tire as a lower side, at least a lower cross section at the edge of the opening is tapered toward the opening. The gist of the invention is that it is a pneumatic tire formed.

  According to such a feature, the sipe is formed by using a blade having an opening edge that is an edge of the opening that is partially hollowed, and at least a lower cross section of the opening edge is tapered toward the opening. Therefore, since the position corresponding to the opening in the sipe can be set to a sipe thickness as close as possible to 0 mm, deformation of the block can be suppressed and the rigidity of the block can be improved. Further, by improving the rigidity of the block, it is possible to improve both the edge effect on ice and snow, the water absorption effect on ice and snow and the WET road surface, and the steering stability on the DRY road surface.

  ADVANTAGE OF THE INVENTION According to this invention, the braid | blade and blade which can improve the rigidity of a block, and can make the improvement of the edge effect on ice and snow, the improvement of the water absorption effect on ice and snow and the WET road surface, and the improvement of the steering stability on a DRY road surface compatible. The pneumatic tire formed using can be provided.

(Composition of pneumatic tire)
Hereinafter, the pneumatic tire in the present embodiment will be described.

  FIG. 1 is a view showing a tread portion 10 of a pneumatic tire in the present embodiment.

  As shown in the figure, the tread portion 10 includes a block 3 that is partitioned by a plurality of grooves and in which a plurality of sipes 4 are formed.

  Specifically, the plurality of grooves are a circumferential groove 1 and a width direction groove 2.

  The circumferential groove 1 is a groove extending in the tire circumferential direction (arrow S direction) in the tread portion.

  The width direction groove | channel 2 is a groove | channel extended in a tire width direction (arrow W direction) in a tread part.

  A plurality of sipes 4 are formed in the block 3 that is partitioned by the circumferential groove 1 and the width groove 2 and protrudes from the circumferential groove 1 and the width groove 2.

  Specifically, the sipe 4 is a thin zigzag groove that repeats amplitude in the tire circumferential direction and extends in the tire width direction.

  This sipe 4 has an opening edge that is an edge of an opening that is partially hollowed out, and when the carcass layer side is embedded in a pneumatic tire, the sipe 4 has at least a lower cross section at the opening edge. Is formed using a blade that tapers toward the opening. This blade will be described in detail later.

(Blade configuration)
Hereinafter, the blade in this embodiment will be described.

  FIG. 2 is a diagram showing the blade 40 in the present embodiment.

  As shown in the figure, like the sipe 4 formed in the tread portion 10, the blade 40 has a zigzag shape that repeats amplitude in the tire circumferential direction and extends in the tire width direction when embedded in a pneumatic tire. have.

  The blade 40 has an opening edge 42 that is an edge of the opening 41 in which a part of the blade 40 is hollowed out.

  Specifically, the opening edge 42 is a frame that borders the opening 41.

  Since the blade 40 has the opening edge 42, when the blade 40 embedded in the pneumatic tire is pulled out, the opening edge 42 below the blade 40 cuts the tread portion, and the blade 40 is embedded in the pneumatic tire. In this case, a sipe close to 0 mm is formed at a position corresponding to the opening 41 in the tread portion.

  Further, when the carcass layer side in the case where the blade 40 is embedded in the pneumatic tire is downward, the lower section of the opening edge 42 is tapered toward the opening 41.

  FIG. 3 is a diagram showing a cross section below the opening edge 42 in the present embodiment.

  2 is an enlarged view showing a cross section A in FIG.

  As shown in FIG. 3A, the lower section of the opening edge 42 is tapered toward the opening 41. Specifically, the angle of the tip below the opening edge 42 (in the figure, one angle α) is preferably 60 ° or less.

  Further, the cross section below the opening edge 42 is not limited to the shape shown in FIG. 3A, but may have a shape as shown in FIG.

  As shown in FIG. 2, the opening edge 42 is preferably a polygonal shape having an elongated rectangle, but is not limited thereto, and may be a shape that tapers downward.

  Specifically, as shown in FIG. 4, the shape that is tapered downward includes a trapezoid in which the lower opening edge 42 is shorter than the upper opening edge 42, a downward triangle, or the like. .

  Further, the opening edge 42 is not limited to a polygonal shape, and may be a circle or the like.

  Furthermore, the opening edge 42 is continuous as shown in FIG. Specifically, it is a state in which the opening 41 is closed.

  The opening edge 42 is not limited to being continuous, and may be discontinuous, that is, partially open as shown in FIG.

  Furthermore, the position of the opening edge 42 in the blade 40 is a position in contact with the ground contact surface G when the blade 40 is embedded in a pneumatic tire, or the vicinity of the ground contact surface G.

  Further, as shown in the figure, the opening 41 becomes larger as the position of the opening edge of the blade 40 becomes closer to the circumferential groove 1 or the width groove 2 when the blade 40 is embedded in a pneumatic tire. .

(Operation and effect of pneumatic tire formed using blades and blades)
According to the blade according to the present embodiment, since the blade 40 has the opening edge 42 which is the edge of the opening 41 obtained by hollowing out a part of the blade 40, when pulling out the blade 40 embedded in the pneumatic tire, Since the opening edge 42 below the blade 40 cuts the tread portion 10, when the blade 40 is embedded in a pneumatic tire, a sipe as close to 0 mm as possible is placed at a position corresponding to the opening 41 in the tread portion 10. Can be formed. Thereby, even when the block 3 falls down, the portion where the sipe close to 0 mm is formed is a supporting cane and the deformation of the block 3 is suppressed, so that the rigidity of the block 3 can be improved. Further, by improving the rigidity of the block 3, it is possible to simultaneously improve the edge effect on ice and snow, improve the water absorption effect on ice and snow and on the WET road surface, and improve the steering stability on the DRY road surface.

  Moreover, since the cross section below the opening edge 42 is tapered toward the opening 41, the blade 40 can be easily pulled out from the pneumatic tire.

  Further, since the angle of the tip below the opening edge 42 is 60 ° or less, the blade 40 can be more easily pulled out than the pneumatic tire.

  Further, since the opening edge 42 has a polygonal shape, particularly an elongated rectangular shape, the blade 40 can be more easily pulled out than the pneumatic tire.

  Further, since the polygonal shape is tapered downward, when the blade 40 is pulled out from the pneumatic tire, the resistance applied to the opening edge 42 below the blade 40 can be further reduced, and it is easier to pull out. can do.

  Further, since the opening edge 42 is continuous, the strength of the blade 40 itself can be improved.

  In addition, since the position of the opening edge 42 in the blade 40 is a position where the deformation is particularly large in the block 3 and is in contact with the ground plane G having low rigidity or in the vicinity of the ground plane G, the rigidity of the block 3 is effectively reduced. Can be improved.

  Further, since the opening 41 becomes larger as the position of the opening edge 42 in the blade 40 becomes closer to the groove, the deformation in the block 3 is particularly large and the rigidity in the vicinity of the groove having low rigidity can be effectively improved. it can.

  According to the pneumatic tire according to the present embodiment, the sipe has the opening edge 42 that is the edge of the opening 41 that is partially hollowed out, and at least the lower cross section of the opening edge 42 faces the opening 41. Since it is formed using the blade 40 which is tapered, the position corresponding to the opening 41 in the sipe 4 can be set to a sipe thickness as close to 0 mm as possible, so that the deformation of the block 3 is suppressed, and the block 3 The rigidity of can be improved. Further, by improving the rigidity of the block 3, it is possible to simultaneously improve the edge effect on ice and snow, improve the water absorption effect on ice and snow and on the WET road surface, and improve the steering stability on the DRY road surface.

  Examples of the blade according to the embodiment of the present invention will be described in detail below.

  The blade shown in FIG. 6 having the shape of the present invention (Example 1) was manufactured, and the rigidity of the block in the pneumatic tire manufactured using this blade, the braking distance on ice, and the steering stability on the DRY road surface The brake performance on the WET road surface was investigated. For comparison, unlike the present invention, a blade (Comparative Example 1) shown in FIG. 7 having no opening edge was manufactured, a pneumatic tire was manufactured using this blade, and the same conditions were investigated.

<Block rigidity>
The tires of Example 1 and Comparative Example 1 are mounted on a cantilevered shaft, and 80% of the maximum load of JATMA is applied to these tires, and the surface is pressed onto a road surface having a safety walk to rotate the shaft. The surface of the road was moved in the state of stopping and the reaction force transmitted to the shaft was measured. The reaction force of Comparative Example 1 is shown as an index with the reaction force being 100. This numerical value indicates that the larger the block, the greater the rigidity of the block.

<Brake distance on ice>
Mount the tires of Example 1 and Comparative Example 1 on the Toyota Mark II, apply a certain load (the load when two people are riding on the front), apply the specified vehicle internal pressure, and the initial speed on the mu ice is 20km / H It measured by the lock stop distance from running. In addition, the distance of the comparative example 1 was set to 100 and indicated as an index. This value indicates that the greater the distance, the shorter the distance and the better the braking performance.

<Operation stability on the DRY road>
The tires of Example 1 and Comparative Example 1 were mounted on a vehicle, and the time required for traveling on a test track of a handling track having a circumference of about 1200 m was measured. In addition, the time of the comparative example 1 was set to 100 and indicated as an index. This value indicates that the larger the time, the faster the time and the better the steering stability.

<Brake performance on WET road>
The tires of Example 1 and Comparative Example 1 were mounted on a vehicle, subjected to breaking from 80 km / h, and the average deceleration was measured. The water depth was 2 mm so that hydroplaning would not occur. The average deceleration of Comparative Example 1 was taken as 100 and displayed as an index. This value indicates that the larger the value, the better the braking performance.

  The tire of Example 1 and the tire of Comparative Example 1 differ only in the blades that form the sipe, and the other parts are all the same.

The obtained results are shown in Table 1.

  As shown in Table 1, Example 1 is improved in all of block rigidity, braking distance on ice, steering stability on the DRY road surface, and braking performance on the WET road surface as compared with Comparative Example 1. I understood.

It is a figure which shows the tread part which concerns on embodiment of this invention. It is a figure which shows the braid | blade which concerns on embodiment of this invention. It is a figure which shows the cross section of the opening part edge below the braid | blade which concerns on embodiment of this invention. It is a figure which shows the braid | blade which concerns on embodiment of this invention. It is a figure which shows the braid | blade which concerns on embodiment of this invention. It is a figure which shows the braid | blade of Example 1 of this invention. It is a figure which shows the braid | blade of the comparative example 1 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Circumferential groove | channel 2 ... Width direction groove | channel 3 ... Block 4 ... Sipe 10 ... Tread part 40 ... Blade 41 ... Opening part 42 ... Opening part edge

Claims (9)

In the blade forming the sipe of the pneumatic tire having a tread portion having a block formed by a plurality of grooves and formed with a plurality of sipes,
An opening edge that is an edge of an opening formed by hollowing out a part of the blade;
When the carcass layer side when the blade is embedded in a pneumatic tire is set downward,
The blade according to claim 1, wherein a cross section below the edge of the opening is tapered toward the opening.   The blade according to claim 1, wherein an angle of a tip below the edge of the opening is 60 ° or less.   The blade according to claim 1, wherein the opening edge has a polygonal shape.   The blade according to claim 3, wherein the polygonal shape is an elongated rectangle.   The blade according to claim 3, wherein the polygonal shape is tapered downward.   The blade according to claim 1, wherein the opening edge is continuous.   2. The blade according to claim 1, wherein a position of the opening edge of the blade is a position in contact with the ground contact surface when the blade is embedded in a pneumatic tire or in the vicinity of the ground contact surface.   2. The blade according to claim 1, wherein the position of the opening edge of the blade becomes larger as the position of the opening edge becomes closer to the groove when the blade is embedded in a pneumatic tire. In a pneumatic tire having a tread portion having a block formed by a plurality of grooves and formed with a plurality of sipes,
The sipe is
When the carcass layer side in the case of having an opening edge which is an edge of an opening part hollowed out and being embedded in a pneumatic tire is the lower side, at least the lower cross section at the opening edge is the opening A pneumatic tire formed by using a blade characterized by being tapered toward a portion.

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