JP2008024271A - Traveling body with lug - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a traveling body with lugs capable of considerably enhancing the traction performance and the non-paved road performance. <P>SOLUTION: The traveling body 1 with lugs has a plurality of lugs 5 extending in an inclined manner to the circumferential direction of a tire toward a tread shoulder part S from a tread center part C of a tread part 3, and a shoulder end 5a is brought into ground contact in the rotational direction of the tire earlier than a center end 5b. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a traveling body with a lug having a plurality of lugs extending obliquely with respect to a tire circumferential direction from a tread center portion in a tread portion toward a tread shoulder portion.

  Conventionally, a traveling body with a lug such as a tire or a crawler that can travel on a non-paved road such as a wetland, a soft ground, and a muddy area (for example, a tire for a 4WD, a tire for an agricultural machine, an OR tire, a crawler for a four-wheel buggy, etc.) ) Is strongly required to have traction performance including running performance, running performance and escape performance on general and non-paved roads.

  In particular, in agricultural machinery tires, in addition to the above traction performance, mud removal performance that removes adhering mud, etc., flotation performance to prevent subsidence, anti-digging performance that does not dig up too much mud on unpaved roads, Various performances (hereinafter referred to as non-paved road performance) such as collapse prevention performance that does not break down are required.

  For example, the shape where the center end, which is the end located on the tread center portion side, comes in contact with the tire rotation direction earlier than the shoulder end, which is the end located on the tread shoulder portion side (that is, tire rotation) 2. Description of the Related Art A traveling body with a lug having a lug that is a C-shaped with respect to a direction is known.

Specifically, a lug traveling body that improves the traction performance by defining an angle with respect to the tire radial direction at the stepping side wall or the kicking side wall of the lug (for example, refer to Patent Document 1), or the tire radial direction at the stepping side wall A rugged traveling body (for example, see Patent Document 2 and Patent Document 3) that improves traction performance and non-paved road performance (particularly, mud performance) by increasing the angle, and a groove is formed at the top of the lug. A running body with a lug (see, for example, Patent Document 4) that improves the traction performance and the non-paved road performance (particularly, mud performance) is disclosed.
Japanese Patent No. 3315169 JP-A-8-34209 JP-A-8-34210 JP-A-10-119516

  By the way, in the above-mentioned conventional traveling body with a lug and the traveling body with a lug developed in recent years, the tread portion is not significantly improved, and the tread center end portion is more in the tire rotation direction than the shoulder end portion. A lug having a shape in which the tread shoulder end part comes in contact with the tire rotating direction later than the center end part is used.

  For this reason, in the above-described conventional traveling body with a lug, the tread center side wall and the kicking side wall of the lug are formed on the basis of the lug in which the tread center end comes in contact with the tire rotation direction earlier than the shoulder end. Since it is improved, the traction performance and non-paved road performance (mud removal performance, flotation performance, digging prevention performance and collapse prevention performance) cannot be significantly improved. That is, development of a traveling body with a lug that significantly improves the traction performance and the non-paved road performance has been desired.

  Then, this invention is made | formed in view of such a condition, and it aims at providing the traveling body with a lug which can improve a traction performance and an unpaved road performance remarkably.

  In order to solve the above situation, the present invention has the following features. First, the invention according to the first feature of the present invention is a traveling body with a lug having a plurality of lugs extending obliquely with respect to the tire circumferential direction from the tread center portion in the tread portion toward the tread shoulder portion, The gist is that the shoulder end portion, which is the end portion located on the tread shoulder portion side of the lug, contacts the tire rotation direction earlier than the center end portion, which is the end portion located on the tread center portion side of the lug. To do.

  According to such a feature, when the shoulder end comes in contact with the tire rotation direction earlier than the center end, mud or the like located on the stepping side wall at the moment when the lug touches the ground, the tread shoulder side on both sides As a result, the mud or the like located on the stepping side wall is applied not only with the compressive force in the tire radial direction due to the load but also with the compressive force in the tire width direction. As a result, the shear strength generated between the mud compressed in the gap between the lugs (hereinafter, between the lugs) and the ground can be increased, and the traction performance can be improved.

  In addition, when the lug comes into contact with the ground, mud or the like located on the kicking side wall flows from the tread center side to the tread shoulder side, thereby reducing unnecessary running force and reducing running resistance. it can. As a result, the traction force and the driving force can be increased, and the running resistance can be reduced, so that the non-paved road performance can be improved.

  Here, the traction performance includes traveling performance and running performance on general paved roads and non-paved roads, escape characteristics from non-paved roads, and the like. Non-paved road performance refers to mud removal performance that removes adhering mud, etc., flotation performance that prevents subsidence, anti-digging performance that does not dig up too much mud etc. on non-paved roads, Including prevention performance.

  The gist of the second aspect of the present invention is that the lug is curved at the tread surface of the tread portion.

  According to this feature, since the lug is curved at the tread surface, it is possible to secure a large volume between the lugs at the tread center, thereby improving non-paved road performance, particularly mud removal performance. Can be made.

  In the invention according to the third aspect of the present invention, in the tire circumferential cross section, at least one of the stepping side wall that is the side wall on the lug stepping side or the kicking side wall that is the side wall on the lug kicking side is The gist is to incline from the top toward the bottom.

  According to such a feature, at least one of the stepping side wall or the kicking side wall is inclined from the top part to the bottom part of the lug, so that mud or the like hardly collects on the kicking side wall, and the compressive force on the kicking side wall is reduced. Therefore, running resistance can be reduced. Moreover, the rigidity at the bottom of the lug can be increased, and the durability of the lug can be improved (the lug is difficult to chip).

  In the invention according to the fourth aspect of the present invention, in the tire circumferential cross section, the stepping side angle (α1) that is an angle with respect to the tire radial direction on the stepping side wall or the kicking that is an angle with respect to the tire radial direction on the kicking side wall The gist is that at least one of the side angles (α2) gradually increases from the bottom to the top of the lug.

  According to this feature, at least one of the depression side angle (α1) or the kicking side angle (α2) gradually increases from the bottom to the top of the lug, so that mud or the like hardly collects on the kicking side wall. Thus, since the compressive force on the kicking side wall can be reduced, the running resistance can be further reduced.

  In the invention according to the fifth feature of the present invention, the average depression side angle that is the average angle of the depression side angle (α1) in a part of the tire circumferential cross section gradually increases from the tread center portion toward the tread shoulder portion. This is the gist.

  According to such a feature, the step-side average angle gradually increases from the tread center portion toward the tread shoulder portion, thereby increasing the angle of the lug with respect to the tread width direction and the degree of bending of the lug that is curved on the tread surface. The same effect is obtained, it becomes easy to collect mud etc. on the tread center side on the stepping side wall, and the shear strength generated between the mud etc. compressed between the lugs and the ground can be further increased. .

  In the invention according to the sixth aspect of the present invention, the average kick-side angle, which is the average angle of the kick-side angles (α2) in a part of the tire circumferential cross section, gradually decreases from the tread center portion toward the tread shoulder portion. It is a summary.

  According to this feature, the average angle of the kicking side gradually decreases from the tread center portion toward the tread shoulder portion, thereby increasing the angle of the lug with respect to the tread width direction and the degree of bending of the lug that is curved on the tread surface. It is possible to obtain the same effect as above, to easily release mud etc. to the tread shoulder portion side on the kicking side wall, and to further reduce the running resistance without generating unnecessary compressive force.

  ADVANTAGE OF THE INVENTION According to this invention, the traveling body with a lug which can improve traction performance and non-paved road performance remarkably can be provided.

  Next, an example of a traveling body with a lug according to the present embodiment will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions are different from actual ones. Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, the part from which the relationship and ratio of a mutual dimension differ also in between drawings is contained.

[First Embodiment]
First, the traveling body with a lug according to the first embodiment will be described with reference to FIGS. FIG. 1 is a development view showing a tread pattern of a traveling body with a lug according to the first embodiment, and FIG. 2 shows a stepping side wall of the lug provided in the traveling body with a lug according to the first embodiment. FIG. 3 is an enlarged top view (stepping side wall) of a lug provided in the traveling body with a lug according to the first embodiment, and FIG. 4 shows the first embodiment. FIG. 5 is a cross-sectional view in the tire circumferential direction showing a lug kicking side wall provided in the running body with lug, and FIG. 5 is an enlarged top view of the lug provided in the running body with lug according to the first embodiment. ).

  Here, the traveling body with a lug includes a 4WD tire, an agricultural machine tire, an OR tire, a 4-wheel buggy crawler, etc., but in the first embodiment, a wetland, a soft ground, a muddy ground, It is assumed that the tire is for agricultural machinery that can travel on a non-paved road (hereinafter, ground G) such as arable land.

  As shown in FIG. 1, the traveling body with lugs 1 includes a plurality of lugs 5 extending from the tread center portion C in the tread portion 3 toward the tread shoulder portion S in an inclined manner with respect to the tire circumferential direction.

  Specifically, the lug 5 has a shoulder end portion 5a, which is an end portion located on the tread shoulder portion S side, in a tire rotation direction more than a center end portion 5b, which is an end portion located on the tread center portion C side. On the other hand, it is a shape to ground first. That is, the center end portion 5b is grounded after the shoulder end portion 5a with respect to the tire rotation direction.

  The center end portions 5b are alternately arranged with respect to the center end portions 5b of the lugs 5 adjacent in the tread width direction and the tire circumferential direction. The lug 5 is curved so as to protrude to the opposite side of the tire rotation direction on the tread portion 3 tread surface.

  More specifically, as shown in FIG. 2, the stepping side wall 5 </ b> A that is the side wall on the stepping side of the lug 5 is inclined from the top 5 </ b> B to the bottom 5 </ b> C of the lug 5 in the tire circumferential cross section. Further, in the tire circumferential cross section, the depression side angle (α1), which is an angle with respect to the tire radial direction in the depression side wall 5A, gradually increases from the bottom portion 5C of the lug 5 toward the top portion 5B.

  Furthermore, as shown in FIG. 3, the depression side average angle, which is the average angle of the depression side angle (α1) in a part of the tire circumferential cross section, gradually increases from the tread center portion C toward the tread shoulder portion S. That is, the average depression angle on the X-ray parallel to the tire circumferential direction is smaller than the average depression angle on the Y line parallel to the tire circumferential direction and the depression average angle on the Z line parallel to the tire circumferential direction. Further, the stepping-side average angle on the Y line is smaller than the stepping-side average angle on the Z line.

  Further, as shown in FIG. 4, in the tire circumferential cross section, the kicking side wall 5 </ b> D that is the side wall on the kicking side of the lug 5 is inclined from the top 5 </ b> B to the bottom 5 </ b> C. Further, in the tire circumferential cross section, the kicking side angle (α2), which is the angle with respect to the tire radial direction in the kicking side wall 5D, gradually increases from the bottom 5C of the lug 5 toward the top 5B.

  Further, as shown in FIG. 5, the kicking-side average angle, which is the average angle of the kicking-side angle (α2) in a portion of the tire circumferential cross section, gradually decreases from the tread center portion C toward the tread shoulder portion S. Yes. That is, the average kick-out side angle on the X-ray parallel to the tire circumferential direction is larger than the average kick-out side angle on the Y-line parallel to the tire circumferential direction and the kick-side average angle on the Z line parallel to the tire circumferential direction. large. Further, the kick-side average angle on the Y line is larger than the kick-side average angle on the Z line.

[Second Embodiment]
Next, a lug traveling body according to a second embodiment will be described with reference to FIG. FIG. 6 is a development view showing a tread pattern of a traveling body with a lug according to the second embodiment. The difference from the lug traveling body according to the first embodiment described above will be mainly described.

  As shown in FIG. 6, the lug-equipped traveling body 1 according to the second embodiment has a plurality of slanted extensions extending from the tread center portion C of the tread portion 3 toward the tread shoulder portion S with respect to the tire circumferential direction. It has a lug 5.

  The lug 5 has a shoulder end portion 5a that is an end portion located on the tread shoulder portion S side, and a ground end earlier than the center end portion 5b that is an end portion located on the tread center portion C side. Shape. Each center end 5b is connected to the center end 5b of the lug 5 adjacent in the tread width direction. Further, the lug 5 is curved so as to protrude to the opposite side of the tire rotation direction on the tread surface of the tread portion 3.

[Other Embodiments]
Although the contents of the present invention have been disclosed through the embodiments of the present invention as described above, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention.

  For example, in the above-described traveling body with a lug 1 according to the present invention, the lug 5 is described as being curved so as to protrude to the opposite side of the tire rotation direction on the tread surface of the tread portion 3, but is not limited thereto. Of course, as shown in FIG. 7, it may be inclined from the tread shoulder portion S toward the tread center portion without being curved.

  Moreover, in the traveling body 1 with a lug according to the present invention described above, the stepping side wall 5A and the kicking side wall 5D are described as being inclined from the top 5B to the bottom 5C of the lug 5, but the present invention is not limited thereto. Instead, at least one of the stepping side wall 5 </ b> A or the kicking side wall may be inclined from the top 5 </ b> B to the bottom 5 </ b> C of the lug 5.

  Further, in the above-described traveling body with a lug 1 according to the present invention, the step-side angle (α1) and the kicking-side angle (α2) are described as gradually increasing from the bottom 5C to the top 5B of the lug 5. However, the present invention is not limited to this, and at least one of the depression side angle (α1) and the kicking side angle (α2) may gradually increase from the bottom 5C of the lug 5 toward the top 5B.

  From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

(Action / Effect)
According to the lug-equipped traveling body 1 according to the present invention described above, the traction performance and the non-paved road performance are remarkably improved because the shoulder end portion 5a contacts the tire rotation direction earlier than the center end portion 5b. Can be made.

  Specifically, in order to improve the traction performance, as shown in FIG. 8, the mud or the like located in the gap between the lugs 5 and 5 (hereinafter, between the lugs 5) is compressed, and the compressed mud or the like is compressed. It is necessary to increase the shearing force (shear strength) generated between the ground and the ground G. Because, as shown in FIG. 9, the peak traction (that is, the maximum value of the driving force and the traction force) is substantially equal to the integral of the shearing force generated between the compressed mud and the like and the ground G, and It is considered that the shear force generated between the compressed mud soil and the ground G is proportional to the compressive force, and it is necessary to increase this shear force (the field of geotechnical engineering, soil mechanics and the field of vehicle and ground system mechanics). Mohr-Coulomb's fracture condition).

  In the traveling body with a lug of the present invention, as shown in FIG. 10 (a), the shoulder end portion 5a comes in contact with the ground rotation direction earlier than the center end portion 5b, so the lug 5 is in contact with the ground G. The mud or the like located on the stepping side wall 5A instantaneously flows from the tread shoulder portion S side on both sides to the tread center portion C side (that is, the inner side).

  On the other hand, in the conventional traveling body 100 with a lug, as shown in FIG. 10 (b), the tread center end portion 101a of the lug 101 comes in contact with the tire rotating direction earlier than the tread shoulder end portion 101b. At the moment when 5 comes into contact with the ground G, mud or the like located on the stepping side wall 5A flows from the tread center portion C side to the tread shoulder portion S side (that is, outside).

  As described above, in the traveling body with lugs 1 of the present invention, mud or the like located on the stepping side wall 5A flows from the tread shoulder portion S side to the tread center portion C side at the moment when the lug 5 contacts the ground G. Thus, mud or the like located on the stepping side wall adds not only the compressive force in the tire radial direction due to the load but also the compressive force in the tire width direction. As a result, the shear strength generated between the mud or the like compressed between the lugs 5 and the ground G can be increased, and the traction performance can be improved.

  Moreover, in order to improve the non-paved road performance, it is conceivable to reduce the running resistance in addition to increasing the driving force by increasing the traction force. This running resistance occurs mainly on the top 5B and bottom 5C of the lug 5 and the kicking side wall 5D, and is governed by the shape of the tread portion 3 and the shape of the tread pattern (top 5B and bottom 5C of the lug 5). In particular, the running resistance generated on the kicking side wall 5D is easily affected by the shape of the tread pattern.

  In the traveling body with a lug of the present invention, as shown in FIG. 10 (a), the shoulder end portion 5a comes in contact with the ground rotation direction earlier than the center end portion 5b, so the lug 5 is in contact with the ground G. The mud or the like positioned on the kicking side wall 5D instantaneously flows from the tread center portion C side to the tread shoulder portion S side (that is, outside).

  On the other hand, in the conventional traveling body 100 with a lug, as shown in FIG. 10 (b), the tread center end portion 101a of the lug 101 comes in contact with the tire rotating direction earlier than the tread shoulder end portion 101b. At the moment when 5 comes into contact with the ground G, mud or the like located on the stepping side wall 5A flows from the tread shoulder portion S side to the tread center portion C side (that is, inside).

  Thus, in the traveling body with a lug of the present invention, when the mud or the like located on the kicking side wall 5D flows from the tread center portion C side to the tread shoulder portion S side at the moment when the lug 5 contacts the ground G, Travel resistance can be reduced without generating unnecessary compression force. As a result, it becomes possible to increase the traction force and the driving force, and the non-paved road performance can be improved. As the running resistance is reduced, it is possible to work at a low slip rate, which is suitable for economy and environmental performance.

  In addition, since the lug 5 is curved at the tread surface of the tread portion 3, the tread center portion C can secure a large volume between the lugs 5, thereby improving non-paved road performance, particularly mud removal performance. Can be made.

  Further, when the stepping side wall 5A and the kicking side wall 5D are inclined from the top part 5B to the bottom part 5C of the lug 5, mud or the like is hardly collected on the kicking side wall 5D, and the compressive force on the kicking side wall 5D is reduced. Therefore, running resistance can be reduced. Moreover, the rigidity at the bottom 5C of the lug 5 can be increased, and the durability of the lug 5 can be improved (the lug 5 is difficult to chip).

  Further, since the stepping side angle (α1) and the kicking side angle (α2) are gradually increased from the bottom 5C to the top 5B of the lug 5, it becomes difficult for mud to collect on the kicking side wall 5D. Since the compressive force on the exit wall 5D can be reduced, the running resistance can be further reduced.

  In addition, since the stepping-side average angle is gradually increased from the tread center portion C toward the tread shoulder portion S, the angle β1 (see FIG. 3) of the lug 5 with respect to the tread width direction and the lug curved at the tread surface. The same effect as increasing the degree of curvature can be obtained, making it easier to collect mud etc. on the tread center portion C side, and further increasing the shear strength generated between the mud etc. compressed between the lugs 5 and the ground G Can be made. Note that the angle β1 indicates an angle at which a straight line toward the shoulder end 5a with respect to the center of the center end 5b is inclined with respect to the tread width direction.

  Furthermore, since the average angle on the kicking side gradually decreases from the tread center portion C toward the tread shoulder portion S, the angle β2 (see FIG. 5) of the lug 5 with respect to the tread width direction and the lug that curves at the tread surface. The same effect as that of increasing the degree of bending is obtained, and it is easy to allow mud etc. to escape to the tread shoulder portion S side on the kick-out side wall 5D, and further reduces the running resistance without generating unnecessary compression force. be able to. The angle β2 indicates an angle at which a straight line toward the shoulder end portion 5a with respect to the center of the center end portion 5b is inclined with respect to the tread width direction.

  Next, in order to further clarify the effects of the present invention, test results performed using the traveling bodies with lugs according to the following comparative examples and Examples 1 to 3 will be described. In addition, this invention is not limited at all by these examples.

  Data on each lug traveling body was measured under the following conditions.

・ Vehicle type: Agricultural machinery vehicle ・ Tire size: 540 / 65R30
・ Wheel size: 16L × 30 (ETRTO)
・ Internal pressure condition: 35 psi
・ Load condition: 7385 lbs
The structure of the lug in the traveling body with a lug which concerns on a comparative example and Examples 1-3 is demonstrated using Table 1. FIG.

  In the lug 101 of the traveling body with a lug according to the comparative example, the tread center end portion 101a is in contact with the tire rotating direction earlier than the tread shoulder end portion 101b (see FIG. 10B). Further, in the lug 101 of the traveling body with a lug according to the comparative example, the stepping-side angle and the kicking-side angle are constant. Furthermore, in the lug 101 of the traveling body with a lug according to the comparative example, the stepping-side average angle and the kicking-side average angle are constant.

  In the lug 5 of the traveling body with a lug according to the first embodiment, the shoulder end portion 5a is in contact with the tire rotating direction earlier than the center end portion 5b (see FIG. 1). Further, in the lug 5 of the traveling body with a lug according to the first embodiment, the stepping-side angle (α1) and the kicking-side angle (α2) are constant. Furthermore, in the lug 101 of the traveling body with a lug according to the comparative example, the stepping-side average angle and the kicking-side average angle are constant.

  In the lug 5 of the traveling body with a lug according to the second embodiment, the shoulder end portion 5a is in contact with the tire rotating direction earlier than the center end portion 5b (see FIG. 1). Further, in the lug 5 of the traveling body with a lug according to the second embodiment, the stepping-side angle (α1) and the kicking-side angle (α2) are gradually increased from the bottom 5C to the top 5B of the lug 5 (FIG. 2 and FIG. 2). (See FIG. 4). Furthermore, in the lug 5 of the traveling body with a lug according to the second embodiment, the stepping-side average angle and the kicking-side average angle are constant.

  In the lug 5 of the traveling body with a lug according to the third embodiment, the shoulder end portion 5a is in contact with the tire rotating direction earlier than the center end portion 5b (see FIG. 1). Further, in the lug 5 of the traveling body with a lug according to the third embodiment, the stepping-side angle (α1) and the kicking-side angle (α2) are gradually increased from the bottom 5C to the top 5B of the lug 5 (FIG. 2 and FIG. 2). (See FIG. 4). Further, in the lug 5 of the traveling body with a lug according to the third embodiment, the stepping-side average angle gradually increases from the tread center portion C toward the tread shoulder portion S (see FIG. 3). Furthermore, in the lug 5 of the traveling body with a lug according to the third embodiment, the kick-side average angle gradually decreases from the tread center portion C toward the tread shoulder portion S (see FIG. 5).

The cultivated land traction force, the grassland traction force, and the cultivated land mud attachment in the traveling body with lugs according to the comparative example and Examples 1 to 3 will be described with reference to Table 2.

<Agricultural traction force>
The traction force on the cultivated land of the traveling body with lag according to the comparative example (hereinafter referred to as cultivating land traction force) was set to “100”, and the cultivating land traction force of the traveling body with lag according to Examples 1 to 3 was displayed as an index. In addition, it is excellent in arable land tractive power, so that a numerical value is large.

  As a result, it was found that the running bodies with lugs according to Examples 1 to 3 are superior in tractable traction force compared to the running bodies with lugs according to the comparative examples, and thus are excellent in traction performance.

<Grassland pulling power>
Similarly to the cultivated land pulling force described above, the pulling force (hereinafter referred to as the grass pulling force) of the traveling body with lag according to the comparative example is set to “100”, and the grassland pulling force of the traveling body with lag according to Examples 1 to 3 is displayed as an index. did. In addition, it is excellent in grassland tractive force, so that a numerical value is large.

  As a result, it was found that the running bodies with lugs according to Examples 1 to 3 are superior in traction performance because they are superior in grassland traction force as compared to the running bodies with lugs according to the comparative examples.

<With arable mud>
It was observed whether mud was attached to the cultivated land between the lugs of the running bodies with lugs according to the comparative example and Examples 1 to 3. “Yes” indicates that mud is attached, and “none” indicates that no mud is attached.

  As a result, the running bodies with lugs according to Examples 1 to 3 were found to be excellent in mud removal performance in arable land because mud was not attached.

It is an expanded view which shows the tread pattern of the traveling body with a lug which concerns on 1st Embodiment. It is a tire peripheral direction cross section which shows the depression side wall of the lug provided in the traveling body with a lug which concerns on 1st Embodiment. It is the upper surface enlarged view (stepping side wall) of the lug provided in the traveling body with a lug which concerns on 1st Embodiment. It is a tire peripheral direction cross section which shows the kicking side wall of the lug provided in the traveling body with a lug which concerns on 1st Embodiment. It is an upper surface enlarged view (extraction side wall) of the lug provided in the traveling body with a lug concerning a 1st embodiment. It is an expanded view which shows the tread pattern of the traveling body with a lug which concerns on 2nd Embodiment. It is an expanded view which shows the tread pattern of the traveling body with a lug which concerns on other embodiment. It is a figure for demonstrating an effect | action and effect to the traveling body with a lug which concerns on this invention (the 1). It is a figure for demonstrating an effect | action and effect to the traveling body with a lug which concerns on this invention (the 2). It is a figure for demonstrating an effect | action and effect to the traveling body with a lug which concerns on this invention (the 3).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Traveling body with a lug, 3 ... Tread part, 5 ... Lug, 5A ... Stepping side wall, 5B ... Top part, 5C ... Bottom part, 5D ... Kicking side wall, 5a ... Shoulder end part, 5b ... Center end part, 100 ... Lug Traveling body with 101, lug, 101a ... tread center end, 101b ... tread shoulder end, C ... tread center, S ... tread shoulder, G ... road surface

Claims (6)

A traveling body with a lug having a plurality of lugs extending obliquely with respect to the tire circumferential direction from the tread center portion to the tread shoulder portion in the tread portion,
A shoulder end portion, which is an end portion of the lug located on the tread shoulder portion side, contacts the tire rotation direction earlier than a center end portion, which is an end portion of the lug located on the tread center portion side. A traveling body with a lug characterized by that.   The traveling body with a lug according to claim 1, wherein the lug is curved at a tread surface of the tread portion.   In the tire circumferential cross section, at least one of the stepping side wall that is the side wall on the lug stepping side or the kicking side wall that is the side wall on the kicking side of the lug is inclined from the top to the bottom of the lug. The traveling body with a lug according to claim 1 or 2, characterized by.   In the tire circumferential cross section, at least one of a depression side angle (α1) that is an angle with respect to the tire radial direction on the depression side wall or a kicking side angle (α2) that is an angle with respect to the tire radial direction on the kicking sidewall is: The traveling body with a lug according to claim 3, wherein the running body gradually increases from the bottom to the top of the lug.   The stepped-side average angle, which is an average angle of the stepped-side angle (α1) in a part of the tire circumferential cross section, gradually increases from the tread center portion toward the tread shoulder portion. A traveling body with a lug as described.   The kick side average angle, which is an average angle of the kick side angle (α2) in a portion of a tire circumferential cross section, gradually decreases from the tread center portion toward the tread shoulder portion. The traveling body with a lug according to claim 4 or claim 5.

Images