WO2023223573A1

WO2023223573A1 - Tire for construction vehicle

Info

Publication number: WO2023223573A1
Application number: PCT/JP2022/037134
Authority: WO
Inventors: 玲王中里
Original assignee: 株式会社ブリヂストン
Priority date: 2022-05-19
Filing date: 2022-10-04
Publication date: 2023-11-23
Also published as: JP2023170402A

Abstract

A tread (20) of a tire (10) for a construction vehicle has formed therein: a width-direction narrow groove (100) that extends in the tire width direction (TW); a center circumferential direction groove (30) that connects to one end of the width-direction narrow groove (100), is formed in a position including a tire equator line (CL), and extends in the tire circumferential direction (TC); an outer circumferential direction groove (40, 50) that connects to the other end of the width-direction narrow groove (100), is formed outward in the tire width direction (TW) relative to the width-direction narrow groove (100), and extends in the tire circumferential direction (TC); a plurality of slope-like notch grooves (110, 210) that each connect to the width-direction narrow groove (100); and an intermediate circumferential direction groove (60) that extends in the tire circumferential direction (TC), intersects with the width-direction narrow groove (100), and is disposed between the notch grooves included in the plurality of notch grooves (110, 210) in the tire width direction (TW).

Description

construction vehicle tires

The present disclosure relates to a tire for a construction vehicle, which includes a tread in which a plurality of slope-shaped notch grooves are formed in narrow grooves in the width direction, and an intermediate circumferential groove is arranged between the notch grooves.

A tire for a construction vehicle is known that includes a tread in which a slope-shaped cutout groove is formed (for example, see Patent Document 1). The construction vehicle tire is said to be able to efficiently cool the entire tread while suppressing the effect on wear resistance, for example, by the action of the slope-shaped notch grooves formed in the tread.

Japanese Patent Application Publication No. 2018-130971

In recent years, there has been a strong demand for tires for construction vehicles such as those described above to be able to handle higher vehicle speeds and higher loads. In recent years, there has been a strong demand for construction vehicle tires such as those described above to be able to handle higher vehicle speeds and higher loads.

The present disclosure aims to provide a construction vehicle tire that can further improve the heat dissipation efficiency of the entire tread.

A construction vehicle tire according to an embodiment of the present invention includes a widthwise narrow groove extending in the width direction of the tire, and a center formed at a position including the tire equator line and communicating with one end of the widthwise narrow groove and extending in the tire circumferential direction. a circumferential groove, an outer circumferential groove that communicates with the other end of the widthwise narrow groove and extends in the tire circumferential direction and is formed on the outside of the widthwise narrow groove in the tire width direction; A plurality of slope-shaped notch grooves that communicate with each other, and a notch groove that extends in the circumferential direction of the tire, intersects with the narrow groove in the width direction, and is included in the plurality of notch grooves in the width direction of the tire. The tread is provided with a tread having an intermediate circumferential groove formed therein.

In the construction vehicle tire configured as described above, a plurality of slope-shaped notch grooves are formed in the tread, and an intermediate circumferential groove is provided between the notch grooves, so that outside air is introduced from the notch grooves. generates airflow that passes through the groove bottom side of the widthwise narrow groove and efficiently flows into the groove bottom side of the adjacent circumferential grooves (center circumferential groove, outer circumferential groove, intermediate circumferential groove), and Heat dissipation efficiency near the groove bottom can be improved over the entire width of the groove. Thereby, the heat dissipation efficiency of the entire tread can be improved.

FIG. 1 is a partially developed plan view of a tire 10 for a construction vehicle. 2(a) is a cross-sectional view of the widthwise narrow groove 100 and the notched groove 110 along the tire circumferential direction, and FIG. 2(b) is a perspective view of the notched groove 110. 3(a) is a cross-sectional view of the widthwise narrow groove 100 and the notched groove 210 along the tire circumferential direction, and FIG. 3(b) is a perspective view of the notched groove 210. FIG. 4(a) is a schematic plan view of the airflow generated in the tread having the configuration of this embodiment, and FIG. 4(b) is a schematic plan view of the airflow generated in the tread having the conventional configuration.

Hereinafter, embodiments will be described based on the drawings. Note that the same functions and configurations are given the same or similar symbols, and the description thereof will be omitted as appropriate.

(1) Schematic structure of construction vehicle tire FIG. 1 is a partially exploded plan view of a construction vehicle tire 10 according to the present embodiment. The construction vehicle tire 10 is a pneumatic tire mounted on a dump truck or the like that travels on rough terrain such as a mine.

The size of the construction vehicle tire 10 is not particularly limited, but tires that can be mounted on rims with a rim diameter of 49, 51, 57, or 63 inches are widely used. The construction vehicle tire 10 is sometimes called an ORR (off-the-road radial) tire or the like. However, it is not necessarily limited to radial tires.

As shown in FIG. 1, the construction vehicle tire 10 includes a tread 20 that comes into contact with the road surface. A plurality of

circumferential grooves

30, 40, 50, and 60 extending in the tire circumferential direction TC are formed in the tread 20. Moreover, a plurality of widthwise narrow grooves 100 extending in the tire width direction TW are formed in the tread 20.

The construction vehicle tire 10 has a generally symmetrical shape with respect to the tire equator line CL. However, the positions of the widthwise narrow grooves 100 on one side and the other side with respect to the tire equator line CL are slightly offset in the tire circumferential direction TC.

The circumferential groove 30 communicates with one end of the widthwise narrow groove 100. The circumferential groove 30 is formed at a position including the tire equator line CL. In this embodiment, the circumferential groove 30 constitutes a central circumferential groove.

The circumferential groove 40 communicates with the other end of the widthwise narrow groove 100. The circumferential groove 40 is formed outside the widthwise narrow groove 100 in the tire width direction TW.

The circumferential groove 50 is formed on the opposite side of the circumferential groove 40 with respect to the tire equator line CL, and has the same shape as the circumferential groove 40. In this embodiment, the

circumferential grooves

40 and 50 constitute an outer circumferential groove.

In this embodiment, each of the

circumferential grooves

30, 40, and 50 has a groove width of about 10 mm and a groove depth of about 100 mm (in the case of a tire that can be mounted on a rim with a rim diameter of 63 inches). Note that the groove width and groove depth can be changed as appropriate depending on the tire size or specifications, and in the case of tires that can be installed on rims with a rim diameter of 49 inches to 63 inches used for construction vehicle tires, the groove width The width is 3 to 10 mm, and the groove depth is 40 to 100 mm.

Furthermore, the

circumferential grooves

40 and 50 having approximately symmetrical shapes are formed to have the same groove width and groove depth, but the circumferential groove 30 and the

circumferential grooves

40 and 50 have the same groove width and groove depth. The values may be the same or different.

Since the construction vehicle tire 10 has a generally symmetrical shape with respect to the tire equator line CL, the configuration of the circumferential groove 40 side of the tread 20 with respect to the tire equator line CL will be described below.

A first shoulder lug groove 80 is formed in the tread 20. The first shoulder lug groove 80 is formed outside the widthwise narrow groove 100 in the tire width direction TW, and communicates with the widthwise narrow groove 100 via the circumferential groove 40 . The first shoulder lug groove 80 extends in the tire width direction TW.

A second shoulder lug groove 90 is formed in the tread 20. The second shoulder lug groove 90 is formed on the outer side of the widthwise narrow groove 100 in the tire width direction TW, opens into the circumferential groove 40, and extends outward in the tire width direction TW. Then, the second shoulder lug groove 90 is formed in a crank shape bent at two points on the outer side of the widthwise narrow groove 100 in the tire width direction TW. The second shoulder lug groove 90 terminates within a shoulder land portion located between the circumferential groove 40 and the tread end TE.

The width direction narrow groove 100 is a narrow groove extending in the tire width direction TW. A narrow groove is a groove in which at least the groove width is smaller than the groove depth. In this embodiment, the width direction narrow groove 100 constitutes a width direction narrow groove.

As shown in FIG. 1, the widthwise narrow groove 100 has one end (the end on the tire equator line CL side) communicating with the circumferential groove 30, and the other end (the end on the outside in the tire width direction TW) communicating with the circumferential groove 30. It is connected to 40. The widthwise narrow groove 100 is a curved groove portion 150 that extends from the one end to the outside in the tire width direction TW and to one side in the tire circumferential direction TC, and curves convexly to one side in the tire circumferential direction TC (upper side in FIG. 1). and a linear groove portion 170 that continues from the curved groove portion 150 and extends linearly outward in the tire width direction TW along the tire width direction TW.

In this embodiment, the groove width of the widthwise narrow grooves 100 is about 10 mm, and the groove depth is about 100 mm (in the case of a tire that can be mounted on a rim with a rim diameter of 63 inches). Note that the groove width and groove depth can be changed as appropriate depending on the tire size or specifications, and in the case of tires that can be installed on rims with a rim diameter of 49 inches to 63 inches used for construction vehicle tires, the groove width The width is 3 to 10 mm, and the groove depth is 40 to 100 mm.

Furthermore, a plurality of

cutout grooves

110 and 210 are formed in the tread 20, which communicate with the widthwise narrow grooves 100. In the tire width direction TW, a circumferential groove 60 that extends in the tire circumferential direction TC and intersects the widthwise narrow groove 100 is arranged between the

notch grooves

110 and 210.

Further, as shown in FIG. 1, among the plurality of

notch grooves

110 and 210, the notch groove 110 that communicates with the linear groove portion 170 of the widthwise narrow groove 100 has a rectangular shape when viewed from the tread surface. The notch groove 210 communicating with the curved groove portion 150 of the widthwise narrow groove 100 has a parallelogram shape when viewed from the tread surface.

As shown in FIGS. 2(a) and 2(b), the notch groove 110 has a slope shape that communicates with the widthwise narrow groove 100. In this embodiment, the notch groove 110 constitutes a first notch groove.

The notch groove 110 is formed at a distance of 1/4 of the width of the tread 20 (hereinafter referred to as tread width) from the tire equator line CL. Note that the width of the tread 20 is the ground contact width of the tread 20 when a regular load is applied to the construction vehicle tire 10 that is assembled to a regular rim wheel and set to a standard internal pressure specified by the vehicle.

The groove width w1 of the notch groove 110 in the tire width direction TW may be 2% or more and 4% or less of the tread width. By setting the groove width w1 to 2% or more, a sufficient effect of suppressing the temperature rise of the tread 20 can be obtained. Further, by setting the groove width w1 to 4% or less, it is possible to suppress a decrease in the rigidity of the tread 20.

Here, the description that "the notch groove 110 is formed at a distance of 1/4 of the tread width from the tire equator line CL" means that the central position of the notch groove 110 in the tire width direction TW is The notch grooves 110 are arranged in a range set to the groove width w1 of the notch grooves 110, which is about two times, centering on a reference position separated by a distance of 1/4 of the tread width from the equator line CL. is formed. For example, when the groove width w1 of the notch groove 110 is 2% of the tread width, the center position is arranged within a range of 4% (twice 2%) of the tread width around the reference position. A notch groove 110 is formed in the groove. Similarly, when the groove width w1 of the notch groove 110 is 4% of the tread width, the center position is arranged within a range of 8% (twice 4%) of the tread width around the reference position. A notch groove 110 is formed as shown in FIG.

For example, when a notch groove 110 with a width of about 50 mm is formed in a construction vehicle tire 10 that can be mounted on a rim with a rim diameter of 63 inches, "a distance of 1/4 of the tread width from the tire equator line CL is The notch groove 110 is arranged so that the center position of the notch groove 110 in the tire width direction TW is located within a range of approximately ±50 mm based on a position approximately 400 mm apart from the tire equator line CL. It is formed.

As shown in FIG. 1, the circumferential groove 60 is arranged inside the notch groove 110 in the tire width direction TW (tire equator line CL side). The circumferential groove 60 extends in the tire circumferential direction TC and intersects with the widthwise narrow groove 100. Note that the circumferential groove 60 may be arranged on the outer side in the tire width direction TW from a position separated by a distance of 1/10 of the tread width with respect to the tire equator line CL. In this embodiment, the circumferential groove 60 constitutes an intermediate circumferential groove.

In this embodiment, the circumferential groove 60 has a groove width of about 10 mm and a groove depth of about 100 mm (in the case of a tire that can be mounted on a rim with a rim diameter of 63 inches). Note that the groove width and groove depth can be changed as appropriate depending on the tire size or specifications, and in the case of tires that can be installed on rims with a rim diameter of 49 inches to 63 inches used for construction vehicle tires, the groove width The width is 3 to 10 mm, and the groove depth is 40 to 100 mm.

As shown in FIGS. 3(a) and 3(b), the notch groove 210 is arranged inside the circumferential groove 60 in the tire width direction TW (on the tire equator line CL side) and communicates with the widthwise narrow groove 100. It has a slope shape. In this embodiment, the notch groove 210 constitutes a second notch groove.

The notch groove 210 arranged inside the circumferential groove 60 in the tire width direction TW is located at a position where the circumferential groove 30 communicates with the widthwise narrow groove 100 and a position where the circumferential groove 60 intersects the widthwise narrow groove 100. is formed at the midpoint in the tire width direction.

The width w2 of the notch groove 210 in the tire width direction TW may be 2% or more and 4% or less of the tread width. By setting it to 2% or more, a sufficient effect of suppressing the temperature rise of the tread 20 can be obtained, and by setting it to 4% or less, a decrease in the rigidity of the tread 20 can be suppressed.

Here, the notch groove 210 intersects with the widthwise narrow groove 100, the midpoint between the position where the circumferential groove 30 communicates with the widthwise narrow groove 100 and the position where the circumferential groove 60 intersects with the widthwise narrow groove 100. The description "tire width direction position" means that the center position of the notch groove 210 in the tire width direction TW is the position where the circumferential groove 30 formed at a position including the tire equator line CL communicates with the width direction thin groove 100. The groove width w2 of the notch groove 210 is set to be about the width of the notch groove 210, centering on a reference position which is the midpoint in the tire width direction with the position where the circumferential groove 60 intersects the widthwise thin groove 100. This means that it is placed within the specified range. For example, if the width w2 of the notch groove 210 is 2% of the tread width, the notch groove 210 is formed such that the center position is located within a range of 2% of the tread width centered on the reference position. be done. Similarly, when the width w2 of the notch groove 210 is 4% of the tread width, the notch groove 210 is arranged so that the center position is located within a range of 4% of the tread width around the reference position. It is formed.

For example, a notch groove 210 with a width of about 50 mm is formed in a construction vehicle tire 10 that can be mounted on a rim with a rim diameter of 63 inches, and the circumferential groove 60 is located at a position separated by about 200 mm from the tire equator line CL. If so, the tire width direction position of "the midpoint between the position where the circumferential groove 30 communicates with the widthwise narrow groove 100 and the position where the circumferential groove 60 intersects the widthwise narrow groove 100" is at the tire equator. The notch groove 210 is formed such that the center position of the notch groove 210 in the tire width direction TW is located within a range of approximately ±25 mm based on a position approximately 100 mm apart from the line CL.

(2) Shape of Notch Groove FIG. 2(a) is a cross-sectional view of the widthwise narrow groove 100 and the notch groove 110 along the tire circumferential direction. FIG. 2(b) is a perspective view of the notch groove 110.

As shown in FIGS. 2(a) and 2(b), the notch groove 110 communicates with the widthwise narrow groove 100. Specifically, the notch groove 110 has a slope portion 120, and the slope portion 120 communicates with the widthwise narrow groove 100.

The slope portion 120 extends along the tire circumferential direction and slopes inward in the tire radial direction from the surface of the tread 20 toward the widthwise narrow groove 100.

As described above, in this embodiment, the width w1 of the slope portion 120 in the tire width direction, that is, the width w1 of the notch groove 110, is approximately 50 mm. Further, the inclination angle θ of the slope portion 120 with respect to the surface of the tread 20 is about 20 degrees.

Since the notched groove 110 has the slope portion 120, when the construction vehicle tire 10 rolls, air flows into the widthwise narrow groove 100 along the slope portion 120. Specifically, the air travels along the slope portion 120, collides with the groove wall 130 of the widthwise narrow groove 100, and spreads within the widthwise narrow groove 100.

3(a) is a cross-sectional view of the widthwise narrow groove 100 and the notched groove 210 along the tire circumferential direction, and FIG. 3(b) is a perspective view of the notched groove 210. The notch groove 210 has a slope portion 220, and the slope portion 220 communicates with the widthwise narrow groove 100.

The slope portion 220 extends along the tire circumferential direction and has a parallelogram shape when viewed from the tread surface, and is inclined inward in the tire radial direction TR as it goes from the surface of the tread 20 toward the widthwise narrow groove 100.

The width w2 of the slope portion 220 in the tire width direction TW, that is, the width w2 of the notch groove 210 in the tire width direction is approximately 50 mm. Further, the inclination angle θ of the slope portion 220 with respect to the surface of the tread 20 is about 20 degrees.

Similarly to the notched grooves 110, when the construction vehicle tire 10 rolls, air flows into the widthwise narrow grooves 100 along the slope portions 220. Specifically, the air travels along the slope portion 220, collides with the groove wall 230 of the widthwise narrow groove 100, and spreads within the widthwise narrow groove 100.

(3) Actions and Effects FIG. 4(a) is a plan view of airflow occurring in the tread 20 having the configuration of this embodiment, and FIG. 4(b) is a plan view of airflow occurring in the tread having the conventional configuration. .

As shown in FIG. 4(b), in the width direction narrow groove 1100 in the tread of the conventional configuration, by forming

notch grooves

1110 and 1210, the width direction narrow groove is formed when the tire rotates in the tire rolling direction TRD. Since the amount of air taken into the widthwise narrow grooves 1100 can be increased while allowing air to flow smoothly within the grooves 1100, the portion of the tread near the widthwise narrow grooves 1100 is efficiently cooled. However, in a tread with a conventional configuration, the air flowing into the widthwise narrow groove 1100 from the notched

grooves

1110 and 1210 is mainly guided to the circumferential groove 1030 and the circumferential groove 1040, so that the notched groove 1110 The heat dissipation efficiency between the notch groove 1110 and the notch groove 1210 is different from the heat dissipation efficiency of the width direction thin groove 1100 between the circumferential groove 1040 or between the notch groove 1210 and the circumferential groove 1030. It was relatively low. In other words, with a tread having a conventional configuration, cooling was not uniformly performed across the width of the tire, so there was room for further improvement in heat dissipation efficiency.

In this embodiment, the air flowing into the width direction narrow groove 100 from the

notch grooves

110 and 210 is guided to the circumferential groove 30 and the circumferential groove 40, so that the air flowing into the width direction narrow groove 100 is The parts are cooled evenly.

In this embodiment, since the circumferential groove 60 is further formed between the first notch groove 110 and the second notch groove 210, the flow of water from the

notch grooves

110 and 210 into the widthwise narrow groove 100 Since air is also guided to the circumferential groove 60, the widthwise narrow groove 100 can be effectively cooled even at the position in the tire width direction between the first notch groove 110 and the second notch groove 210. Therefore, the tread 20 can be efficiently cooled over the entire width of the widthwise narrow grooves 100.

In other words, in the case of the width direction narrow groove 100 of this embodiment, the two

notch grooves

110, 210 are formed to increase the amount of air flowing into the width direction narrow groove 100, and the

notch grooves

110, 210 are formed. By setting the position appropriately, and by the action of the circumferential grooves 60, the tread 20 can be effectively cooled over the entire width of the widthwise narrow grooves 100.

Note that if the notch groove is formed at a position shifted from the above-mentioned position, the smooth flow of air will be hindered, making it difficult to evenly cool the tread 20 in the tire width direction.

Further, according to the shape of the widthwise narrow groove 100, there is no need to form a large number of notched grooves, so that the influence on other performances such as wear resistance can be suppressed.

That is, according to the construction vehicle tire 10, the entire tread 20 can be efficiently cooled while suppressing other performance deterioration and deterioration. In particular, in the construction vehicle tire 10, the

notch grooves

110 and 210 are formed in the widthwise narrow groove 100 at appropriate positions according to the groove shape, and the circumferential groove is formed between the

notch grooves

110 and 210. 60, the entire tread 20 can be cooled more efficiently.

Note that as a measure against the temperature rise of the tread 20, it is easy to use rubber with high heat resistance. Generally, rubber with high heat resistance has poor abrasion resistance, but according to the construction vehicle tire 10, the structural characteristics can suppress the temperature rise of the tread 20, so it has excellent abrasion resistance. As a result, the wear resistance of the tire 10 can also be improved.

In this embodiment, the

notch grooves

110 and 210 have

slope portions

120 and 220. Since the

slope portions

120, 220 are inclined inward in the tire radial direction from the tread surface as they go toward the widthwise narrow grooves, the tread 20 of this embodiment allows air to flow smoothly into the widthwise narrow grooves. can promote the influx of Thereby, the tread pattern of this embodiment can cool the entire tread 20 more efficiently.

As described above, the embodiments of the present invention have been described, but the statements and drawings that form part of this disclosure should not be understood as limiting the present invention. Various alternative embodiments, implementations, and operational techniques will be apparent to those skilled in the art from this disclosure.

The entire contents of Japanese Patent Application No. 2022-082128 (filing date: May 19, 2022) are incorporated herein by reference.

Claims

Widthwise narrow grooves extending in the widthwise direction of the tire;
a central circumferential groove that communicates with one end of the widthwise narrow groove, is formed at a position that includes the tire equator line, and extends in the tire circumferential direction;
an outer circumferential groove extending in the tire circumferential direction and communicating with the other end of the widthwise narrow groove and formed on the outer side of the widthwise narrow groove in the tire width direction;
a plurality of slope-shaped notch grooves each communicating with the widthwise narrow groove;
A tread formed with: an intermediate circumferential groove extending in the tire circumferential direction, intersecting the widthwise narrow groove, and disposed between notched grooves included in the plurality of notched grooves in the tire width direction. Construction vehicle tires equipped with:
A first notch groove included in the plurality of notch grooves arranged on the outside in the tire width direction of the intermediate circumferential groove is formed at a position spaced apart from the tire equator line by a distance of 1/4 of the tread width. is,
A second notch groove included in the plurality of notch grooves arranged inside the intermediate circumferential groove in the tire width direction is located between a position where the central circumferential groove communicates with the widthwise thin groove and the intermediate groove. The tire for a construction vehicle according to claim 1, wherein the circumferential groove is formed at a position in the width direction of the tire that is midway between a position where the circumferential groove intersects with the narrow groove in the width direction.
The construction vehicle tire according to claim 1 or 2, wherein the notched groove has a slope portion that extends in the tire circumferential direction and slopes inward in the tire radial direction from the surface of the tread to the widthwise narrow groove.
The construction vehicle tire according to claim 1 or 2, wherein the notch groove extends along the circumferential direction of the tire.
The construction vehicle tire according to claim 3, wherein the notch groove extends along the circumferential direction of the tire.