Patent Publication Number: US-2021178825-A1

Title: Pneumatic tire

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority of Japanese application no. 2019-224318, filed on Dec. 12, 2019, which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present disclosure relates to a pneumatic tire. 
     Description of the Related Art 
     Conventionally a pneumatic tire might, for example, comprise a sidewall region extending in the tire radial direction, and the sidewall region might comprise a plurality of side blocks arrayed in the tire circumferential direction (e.g., JP2013-119277A). In addition, under bad road conditions such as when the terrain is sandy, rocky, and/or muddy, because traction (nonslipping grabbing force) is produced due to the plurality of side blocks, it is possible to improve driveability under bad road conditions. 
     It so happens that the traction that is produced will be greater to the extent that the side blocks protrude by large amounts in the tire width direction. As a result, depending on the pattern of surface irregularities formed by the side blocks that are adjacent in the tire circumferential direction, it may be the case that a bias will arise with respect to the amount of traction that is produced by the side blocks. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present disclosure to provide a pneumatic tire that will make it possible to suppress occurrence of bias in the respective amounts of traction produced by side blocks that are mutually adjacent in the tire circumferential direction. 
     There is provided a pneumatic tire comprises a sidewall region that extends in a tire radial direction; 
     the sidewall region comprises a plurality of side blocks which are arrayed in a tire circumferential direction, and an annular projection which extends in the tire circumferential direction and which protrudes in a tire width direction; 
     the plurality of side blocks include a first side block and a second side block that are adjacent in the tire circumferential direction; 
     the first side block comprises a first outer portion which is arranged toward the exterior in the tire radial direction from the annular projection, and a first inner portion which is arranged toward the interior in the tire radial direction from the annular projection; 
     the second side block comprises a second outer portion which is arranged toward the exterior in the tire radial direction from the annular projection, and a second inner portion which is arranged toward the interior in the tire radial direction from the annular projection; 
     a location at which distance in the tire circumferential direction between the first inner portion and the second inner portion is a minimum is toward the interior in the tire radial direction from centers in the tire radial direction of first inner portion and second inner portion; 
     as viewed in the tire circumferential direction, a maximum value of an amount by which the first inner portion protrudes toward the exterior in the tire width direction beyond the second inner portion is greater than a maximum value of an amount by which the second inner portion protrudes toward the exterior in the tire width direction beyond the first inner portion; and 
     as viewed in the tire circumferential direction, a maximum value of an amount by which the second outer portion protrudes toward the exterior in the tire width direction beyond the first outer portion is greater than a maximum value of an amount by which the first outer portion protrudes toward the exterior in the tire width direction beyond the second outer portion. 
     Further, there is provided a pneumatic tire comprises a sidewall region that extends in a tire radial direction; 
     the sidewall region comprises a plurality of side blocks which are arrayed in a tire circumferential direction, and an annular projection which extends in the tire circumferential direction and which protrudes in a tire width direction; 
     the plurality of side blocks include a first side block and a second side block that are adjacent in the tire circumferential direction; 
     the first side block comprises a first outer portion which is arranged toward the exterior in the tire radial direction from the annular projection, and a first inner portion which is arranged toward the interior in the tire radial direction from the annular projection; 
     the second side block comprises a second outer portion which is arranged toward the exterior in the tire radial direction from the annular projection, and a second inner portion which is arranged toward the interior in the tire radial direction from the annular projection; 
     a location at which distance in the tire circumferential direction between the first inner portion and the second inner portion is a minimum is toward the interior in the tire radial direction from centers in the tire radial direction of first inner portion and second inner portion; 
     a maximum value of an amount by which the first inner portion protrudes relative to a profile surface is greater than a maximum value of an amount by which the second inner portion protrudes relative to the profile surface; and 
     a maximum value of an amount by which the second outer portion protrudes relative to the profile surface is greater than a maximum value of an amount by which the first outer portion protrudes relative to the profile surface. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a view of a section, taken along a tire meridional plane, of the principal components in a pneumatic tire associated with an embodiment; 
         FIG. 2  is a perspective view of the principal components in a pneumatic tire associated with same embodiment; 
         FIG. 3  is a side view (drawing as viewed in the tire width direction) of the principal components of a pneumatic tire associated with same embodiment; 
         FIG. 4  is an enlarged view of the principal components in a section taken along IV-IV in  FIG. 3 ; 
         FIG. 5  is an enlarged view of the principal components in a section taken along V-V in  FIG. 3 ; 
         FIG. 6  is a drawing in which  FIG. 4  and  FIG. 5  are placed one atop the other; 
         FIG. 7  is a side view (drawing as viewed in the tire width direction) of the principal components of a pneumatic tire associated with another embodiment; and 
         FIG. 8  is a side view (drawing as viewed in the tire width direction) of the principal components of a pneumatic tire associated with yet another embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Below, an embodiment of a pneumatic tire is described with reference to  FIG. 1  through  FIG. 6 . At the respective drawings (and the same is true for  FIG. 7  and  FIG. 8 ), note that dimensional ratios at the drawings and actual dimensional ratios are not necessarily consistent, and note further that dimensional ratios are not necessarily consistent from drawing to drawing. 
     As shown in  FIG. 1 , pneumatic tire (hereinafter sometimes referred to as simply “tire”)  1  is provided with a pair of bead regions  11  having beads  11   a;  sidewall regions that extend toward the exterior in the tire radial direction D 2  from respective bead regions  11 ; and tread region  13  having, at the exterior in the tire radial direction D 2 , tread surface  13   a  which comes in contact with the ground and which is coupled to the respective exterior edges in the tire radial direction D 2  of the pair of sidewall regions  12 . Note that tire  1  may be mounted on a rim (not shown). 
     Furthermore, tire  1  is provided with carcass layer  14  suspended between pair of beads  11   a,    11   a;  and inner-liner layer  15  that is arranged toward the interior from carcass layer  14  and that faces the interior space of tire  1  which is or will be filled with air. Carcass layer  14  and inner-liner layer  15  are arranged in parallel fashion with respect to the inner circumferential surface of the tire over a portion thereof that encompasses bead regions  11 , sidewall regions  12 , and tread region  13 . 
     At the respective drawings, first direction D 1  is the tire width direction D 1  which is parallel to the rotational axis of the tire, second direction D 2  is the tire radial direction D 2  which is the direction of the diameter of tire  1 , and third direction D 3  is the tire circumferential direction D 3  which is the direction that is circumferential about the rotational axis of the tire. Furthermore, tire equatorial plane S 1  is a plane that is located centrally in the tire width direction D 1  and that is perpendicular to the rotational axis of the tire; tire meridional planes are planes that are perpendicular to tire equatorial plane S 1  and that contain the rotational axis of the tire. 
     In the tire width direction D 1 , the side toward the interior is the side which is nearer to tire equatorial plane S 1 , and the side toward the exterior is the side which is farther from tire equatorial plane S 1 . Furthermore, in the tire radial direction D 2 , the side toward the interior is the side which is nearer to the tire rotational axis, and the side toward the exterior is the side which is farther from the tire rotational axis. 
     Bead  11   a  is provided with bead core  11   b  which is formed so as to be annular in shape, and bead filler  11   c  which is arranged toward the exterior in the tire radial direction D 2  from bead core  11   b.  For example, bead core  11   b  might be formed by laminating rubber-covered bead wire(s) (e.g., metal wire(s)), and bead filler  11   c  might be formed from hard rubber that has been made to taper as one proceeds toward the exterior in the tire radial direction D 2 . 
     Bead region  11  is provided with rim strip rubber  11   d  which is arranged toward the exterior in the tire width direction D 1  from carcass layer  14  and which is intended to constitute the outer surface that will come in contact with the rim. Sidewall region  12  is provided with sidewall rubber  12   a  which is arranged toward the exterior in the tire width direction D 1  from carcass layer  14  and which is intended to constitute the outer surface. 
     Tread region  13  is provided with tread rubber  13   b  at which the outer surface constitutes tread surface  13   a,  and belt region  13   c  which is arranged between tread rubber  13   b  and carcass layer  14 . Belt region  13   c  is provided with a plurality (four at  FIG. 1 ) belt plies  13   d.  For example, belt plies  13   d  might be provided with a plurality of belt cords (e.g., organic fiber and/or metal) which are arrayed in parallel fashion, and topping rubber with which the belt cords are covered. 
     Carcass layer  14  is made up of at least one (two at  FIG. 1 ) carcass ply  14   a.  Carcass ply  14   a  folds back upon itself and wraps about bead  11   a  so as to envelop bead  11   a.  Furthermore, carcass ply  14   a  is provided with a plurality of ply cords (e.g., organic fiber and/or metal) which are arrayed in direction(s) more or less perpendicular to the tire circumferential direction D 3 , and topping rubber with which the ply cords are covered. 
     Inner-liner layer  15  has superior functionality in terms of its ability to impede passage of gas therethrough so as to permit air pressure to be maintained. At sidewall region  12 , note that inner-liner layer  15  is in intimate contact with the inside circumferential surface of carcass layer  14 , there being no other member that intervenes between inner-liner layer  15  and carcass layer  14 . 
     For example, distance between the inner circumferential surface of the tire (inner circumferential surface of inner-liner layer  15 ) and the carcass ply  14   a  which is arranged nearest to the inner circumferential surface might be 90% to 180% at sidewall region  12  of what it is at tread region  13 . More preferably, this distance might be 120% to 160% at sidewall region  12  of what it is at tread region  13 . 
     Sidewall regions  12  are such that provided at the outer surface thereof are locations  12   b  which are at the same locations in the tire radial direction D 2  as the locations at which tire width is a maximum (more specifically, the locations at which distance W 1  between respective exterior points in the tire width direction D 1  of carcass layer  14  is a maximum). Below, these locations  12   b  are referred to as tire maximum width locations  12   b.    
     Furthermore, sidewall regions  12  are such that provided at the outer surface thereof are locations  12   c  which are at the same locations in the tire radial direction D 2  as exterior edges  11   e  of bead filler  11   c  in the tire radial direction D 2 . Below, these locations  12   c  are referred to as bead edge locations  12   c.    
     Furthermore, sidewall regions  12  are such that provided at the outer surface thereof are locations  12   d  which are at the same locations in the tire radial direction D 2  as the outer ends  13   e  of belt region  13   c  in the tire width direction D 1 . Below, these locations  12   d  are referred to as belt end locations  12   d.    
     As shown in  FIG. 2  and  FIG. 3 , tread region  13  comprises a plurality of grooves  13   f  extending to the outer end in the tire width direction D 1 , and a plurality of tread blocks  13   g  partitioned by the plurality of grooves  13   f  so as to be arrayed in the tire circumferential direction D 3 . Furthermore, sidewall region  12  comprises a plurality of side blocks  2 ,  3  which are arrayed in the tire circumferential direction D 3 , and annular projection(s)  4  which extend in the tire circumferential direction D 3  and which protrude in the tire width direction D 1 . 
     Side blocks  2 ,  3  have surface irregularities. This permits formation of surface and edge components. In addition, at locations where contact with the ground takes place at mud, sand, or rock, formation of irregular shapes permits increase in the area over which contact with the ground occurs at mud, sand, or rock; furthermore, surfaces and edges resulting from such irregular shapes facilitate contact with the ground at mud, sand, or rock at a variety of locations. In this way, formation of irregular shapes at locations where contact with the ground takes place at mud, sand, or rock improves traction capability. 
     In addition, side blocks  2 ,  3  are arranged at least at the exterior in the tire radial direction D 2  of sidewall regions  12 . While there is no particular limitation with respect thereto, side blocks  2 ,  3  might, for example, arranged toward the exterior in the tire radial direction D 2  from bead end locations  12   c  (see  FIG. 1 ) of sidewall regions  12 . Furthermore, side blocks  2 ,  3  might, for example, arranged toward the exterior in the tire radial direction D 2  from tire maximum width locations  12   b  (see  FIG. 1 ) of sidewall regions  12 . 
     As a result, under muddy and/or sandy conditions, when the weight of the vehicle causes tire  1  to sink such that it is buried under mud and/or sand, side blocks  2 ,  3  are able to come in contact with the ground; and under rocky conditions, side blocks  2 ,  3  are able to come in contact with irregular surfaces of rocks. That is, side blocks  2 ,  3  come in contact with the ground under bad road conditions such as when the terrain is muddy, sandy, and/or rocky. Note that side blocks  2 ,  3  do not come in contact with the ground during normal travel on a flat road. 
     As shown in  FIG. 3 , as viewed in the tire width direction D 1 , the plurality of side blocks  2 ,  3  appear to at least partially overlap tread blocks  13   g  in the tire radial direction D 2 . While there is no particular limitation with respect thereto, in accordance with the present embodiment, the number of side blocks  2 ,  3  is the same as the number of tread blocks  13   g.    
     It so happens that the plurality of side blocks  2 ,  3  include first side blocks  2  and second side blocks  3  which are adjacent in the tire circumferential direction D 3 . While there is no particular limitation with respect thereto, in accordance with the present embodiment, first side blocks  2  and second side blocks  3  are arranged in alternating fashion in the tire circumferential direction D 3 . 
     First side block  2  comprises first outer portion  2   a  which is arranged toward the exterior in the tire radial direction D 2  from annular projection  4 , and first inner portion  2   b  which is arranged toward the interior in the tire radial direction D 2  from annular projection  4 . Second side block  3  comprises second outer portion  3   a  which is arranged toward the exterior in the tire radial direction D 2  from annular projection  4 , and second inner portion  3   b  which is arranged toward the interior in the tire radial direction D 2  from annular projection  4 . 
     Furthermore, the location at which the distance W 2  in the tire circumferential direction D 3  between first inner portion  2   b  and second inner portion  3   b  is a minimum is toward the interior in the tire radial direction D 2  from the centers  2   c,    3   c  in the tire radial direction D 2  of first inner portion  2   b  and second inner portion  3   b.  As a result, there will be a tendency for production of traction at side blocks  2 ,  3  to cause occurrence of damage at, for example, the side blocks  2 ,  3  themselves (especially inner portions  2   b,    3   b ) and at regions peripheral thereto. 
     While there is no particular limitation with respect thereto, in accordance with the present embodiment, distance W 2  between inner portions  2   b,    3   b  is a minimum at the inner ends in the tire radial direction D 2  of respective inner portions  2   b,    3   b.  More specifically, the inner ends in the tire radial direction D 2  of respective inner portions  2   b,    3   b  are mutually contiguous. That is, in accordance with the present embodiment, the minimum value of the distance W 2  between inner portions  2   b,    3   b  is zero. Furthermore, in accordance with the present embodiment, step  5  (also see  FIG. 2 ) is provided at the boundary between first inner portion  2   b  and second inner portion  3   b.    
     Here, the pattern of surface irregularities formed by first side blocks  2  and second side blocks  3  relative to the profile surface (reference surface) of tire  1  will be described with reference to  FIG. 4  and  FIG. 5 . At  FIG. 4  and  FIG. 5 , note that the double-dash chain line indicates profile surface S 2 , and the dashed line indicates annular projection  4 . 
     As shown in  FIG. 4 , first outer portion  2   a  comprises first outermost portion  2   d  which is arranged toward the exterior in the tire radial direction D 2 , and first intermediate portion  2   e  which is arranged toward the interior in the tire radial direction D 2 . This being the case, first intermediate portion  2   e  is arranged between first outermost portion  2   d  and first inner portion  2   b.  Note that first outermost portion  2   d  and first intermediate portion  2   e  are those regions into which first outer portion  2   a  is divided when bisected in the tire radial direction D 2 . 
     In addition, the location at which the amount by which first outer portion  2   a  protrudes relative to profile surface S 2  in a direction normal to profile surface S 2  is a maximum (also referred to as the “first outer maximum protruding location”) is a prescribed location at first intermediate portion  2   e.  While there is no particular limitation with respect thereto, in accordance with the present embodiment, the first outer maximum protruding location is the inner end in the tire radial direction D 2  of first outer portion  2   a.  Note that the maximum value W 3  of the amount by which first outer portion  2   a  protrudes relative to profile surface S 2  is referred to as the first outer maximum protruding amount W 3 . 
     Furthermore, the location at which the amount by which first outer portion  2   a  is recessed relative to profile surface S 2  in a direction normal to profile surface S 2  is a maximum (also referred to as the “first outer maximum recessed location”) is a prescribed location at first outermost portion  2   d.  Note that the maximum value W 4  of the amount by which first outer portion  2   a  is recessed relative to profile surface S 2  is referred to as the first outer maximum recessed amount W 4 . In addition, the first outer maximum recessed location is toward the exterior in the tire radial direction D 2  from the first outer maximum protruding location. While there is no particular limitation with respect thereto, in accordance with the present embodiment, note that the first outer maximum recessed amount W 4  is zero. 
     Furthermore, the location at which the amount by which first inner portion  2   b  protrudes relative to profile surface S 2  in a direction normal to profile surface S 2  is a maximum (also referred to as the “first inner maximum protruding location”) is a prescribed location toward the interior in the tire radial direction D 2  within first inner portion  2   b.  Note that the maximum value W 5  of the amount by which first inner portion  2   b  protrudes relative to profile surface S 2  is referred to as the first inner maximum protruding amount W 5 . 
     As shown in  FIG. 5 , second outer portion  3   a  comprises second outermost portion  3   d  which is arranged toward the exterior in the tire radial direction D 2 , and second intermediate portion  3   e  which is arranged toward the interior in the tire radial direction D 2 . This being the case, second intermediate portion  3   e  is arranged between second outermost portion  3   d  and second inner portion  3   b.  Note that second outermost portion  3   d  and second intermediate portion  3   e  are those regions into which second outer portion  3   a  is divided when bisected in the tire radial direction D 2 . 
     In addition, the location at which the amount by which second outer portion  3   a  protrudes relative to profile surface S 2  in a direction normal to profile surface S 2  is a maximum (also referred to as the “second outer maximum protruding location”) is a prescribed location at second intermediate portion  3   e.  Note that the maximum value W 6  of the amount by which second outer portion  3   a  protrudes relative to profile surface S 2  is referred to as the second outer maximum protruding amount W 6 . 
     Furthermore, the location at which the amount by which second outer portion  3   a  is recessed relative to profile surface S 2  in a direction normal to profile surface S 2  is a maximum (also referred to as the “second outer maximum recessed location”) is a prescribed location at second outermost portion  3   d.  Note that the maximum value W 7  of the amount by which second outer portion  3   a  is recessed relative to profile surface S 2  is referred to as the second outer maximum recessed amount W 7 . In addition, the second outer maximum recessed location is toward the exterior in the tire radial direction D 2  from the second outer maximum protruding location. 
     Furthermore, the location at which the amount by which second inner portion  3   b  protrudes relative to profile surface S 2  in a direction normal to profile surface S 2  is a maximum (also referred to as the “second inner maximum protruding location”) is the outer end in the tire radial direction D 2  of second inner portion  3   b.  Note that the maximum value W 8  of the amount by which second inner portion  3   b  protrudes relative to profile surface S 2  is referred to as the second inner maximum protruding amount W 8 . 
     In addition, as shown in  FIG. 4  and  FIG. 5 , second outer maximum protruding amount W 6  is greater than first outer maximum protruding amount W 3 . Furthermore, second outer maximum recessed amount W 7  is greater than first outer maximum recessed amount W 4 . In addition, first inner maximum protruding amount W 5  is greater than second inner maximum protruding amount W 8 . 
     While there is no particular limitation with respect thereto, in accordance with the present embodiment, note that second outer maximum protruding amount W 6  is greater than second outer maximum recessed amount W 7 . Furthermore, while there is no particular limitation with respect thereto, in accordance with the present embodiment, second outer maximum protruding amount W 6  and second outer maximum recessed amount W 7  are each greater than first inner maximum protruding amount W 5 . 
     As shown in  FIG. 5 , it so happens that second side block  3  comprises outward facing surface  3   f  (also see  FIG. 2  and  FIG. 3 ) which faces the exterior in the tire radial direction D 2 . In addition, outward facing surface  3   f  is arranged toward the exterior in the tire radial direction D 2  from belt end location  12   d.  While there is no particular limitation with respect thereto, as viewed in a tire meridional section, note that intersection angle θ 1  that outward facing surface  3   f  makes with tire width direction D 1  might, for example, be not greater than 45°; or might, for example, be not greater than 30°; or might, for example, be not greater than 15°. 
     Furthermore, the location of the outer end in the tire width direction D 1  of outward facing surface  3   f  is the second outer maximum protruding location. This being the case, because outward facing surface  3   f  of second side block  3  protrudes toward the exterior in the tire width direction D 1  by a large amount, it will be possible to ensure that the amount by which outward facing surface  3   f  of second side block  3  protrudes in the tire width direction D 1  is adequate. Accordingly, it will, for example, be possible to increase the traction produced by outward facing surface  3   f.    
     Next, the difference in the pattern of surface irregularities at first side block  2  and second side block  3  will be described with reference to  FIG. 6 . Note that  FIG. 6  is a drawing in which  FIG. 4  and  FIG. 5  are placed one atop the other; that is, the drawing depicts the situation as it appears when viewed in the tire circumferential direction D 3 , the solid line indicates the outer edge of first side block  2 , the dashed line indicates the outer edge of second side block  3 , and the double-dash chain line indicates profile surface S 2  and annular projection  4 . 
     As shown in  FIG. 6 , as viewed in the tire circumferential direction D 3 , the location at which the amount by which first outer portion  2   a  protrudes toward the exterior in the tire width direction D 1  beyond second outer portion  3   a  is a maximum (also referred to as the “first outer maximum protruding difference location”) is a prescribed location at first outermost portion  2   d.  Note that the maximum value W 9  of the amount by which first outer portion  2   a  protrudes toward the exterior in the tire width direction D 1  beyond second outer portion  3   a  is referred to as the first outer maximum protruding difference W 9 . 
     Furthermore, as viewed in the tire circumferential direction D 3 , the location at which the amount by which second outer portion  3   a  protrudes toward the exterior in the tire width direction D 1  beyond first outer portion  2   a  is a maximum (also referred to as the “second outer maximum protruding difference location”) is a prescribed location at second intermediate portion  3   e.  Note that the maximum value W 10  of the amount by which second outer portion  3   a  protrudes toward the exterior in the tire width direction D 1  beyond first outer portion  2   a  is referred to as the second outer maximum protruding difference W 10 . 
     In addition, second outer maximum protruding difference W 10  is greater than first outer maximum protruding difference W 9 . Furthermore, the second outer maximum protruding difference location is toward the interior in the tire radial direction D 2  from the first outer maximum protruding difference location. Note that the second outer maximum protruding difference location is located at the outer end in the tire width direction D 1  of outward facing surface  3   f.    
     Furthermore, as viewed in the tire circumferential direction D 3 , the location at which the amount by which first inner portion  2   b  protrudes toward the exterior in the tire width direction D 1  beyond second inner portion  3   b  is a maximum (also referred to as the “first inner maximum protruding difference location”) is a prescribed location toward the interior in the tire radial direction D 2  within first inner portion  2   b.  Note that the maximum value W 11  of the amount by which first inner portion  2   b  protrudes toward the exterior in the tire width direction D 1  beyond second inner portion  3   b  is referred to as the first inner maximum protruding difference W 11 . 
     Furthermore, as viewed in the tire circumferential direction D 3 , the locations at which the amount by which second inner portion  3   b  protrudes toward the exterior in the tire width direction D 1  beyond first inner portion  2   b  is a maximum (also referred to as the “second inner maximum protruding difference locations”) are the inner end and the outer end in the tire radial direction D 2  of second inner portion  3   b.  Note that the maximum value W 12  of the amount by which second inner portion  3   b  protrudes toward the exterior in the tire width direction D 1  beyond first inner portion  2   b  is referred to as the second inner maximum protruding difference W 12 . 
     In addition, first inner maximum protruding difference W 11  is greater than second inner maximum protruding difference W 12 . While there is no particular limitation with respect thereto, in accordance with the present embodiment, note that the second inner maximum protruding difference W 12  is zero. Furthermore, while there is no particular limitation with respect thereto, in accordance with the present embodiment, second outer maximum protruding difference W 10  and first outer maximum protruding difference W 9  are each greater than first inner maximum protruding difference W 11 . 
     Note that the foregoing respective dimensions and the relative magnitudes thereamong should be understood to be as measured under normal conditions when a tire mounted on a normal rim and inflated to normal internal pressure is under no load. A normal rim is that particular rim which is specified for use with a particular tire  1  in the context of the body of standards that contains the standard that applies to the tire  1  in question, this being referred to, for example, as a standard rim in the case of JATMA, or a measuring rim in the cases of TRA and ETRTO. 
     Furthermore, normal internal pressure is that air pressure which is specified for use with a particular tire  1  in the context of the body of standards that contains the standard that applies to the tire  1  in question, this being “maximum air pressure” in the case of JATMA, the maximum value listed at the table entitled “Tire Load Limits at Various Cold Inflation Pressures” in the case of TRA, or “inflation pressure” in the case of ETRTO. 
     Constitution of tire  1  associated with the present embodiment is as described above; action of tire  1  associated with the present embodiment is described below. 
     As shown in  FIG. 4  through  FIG. 6 , whereas first outermost portion  2   d  is located toward the exterior in the tire width direction D 1  from second outermost portion  3   d,  second intermediate portion  3   e  is located toward the exterior in the tire width direction D 1  from first intermediate portion  2   e.  Moreover, whereas second intermediate portion  3   e  is located toward the exterior in the tire width direction D 1  from first intermediate portion  2   e,  first inner portion  2   b  is located toward the exterior in the tire width direction D 1  from second inner portion  3   b.    
     This being the case, at first side block  2 , there is a tendency for a large amount of traction to be produced at first outermost portion  2   d  and first inner portion  2   b,  and there is a tendency for a small amount of traction to be produced at first intermediate portion  2   e.  On the other hand, at second side block  3 , there is a tendency for a large amount of traction to be produced at second intermediate portion  3   e,  and there is a tendency for a small amount of traction to be produced at second outermost portion  3   d  and second inner portion  3   b.    
     Thus, the portions at which large amounts of traction are produced are distributed among first side blocks  2  and second side blocks  3 . Accordingly, it will be possible to suppress occurrence of bias in the respective amounts of traction produced by first side blocks  2  and second side blocks  3  that are mutually adjacent in the tire circumferential direction D 3 . As a result, it will be possible to suppress occurrence of damage at, for example, the side blocks  2 ,  3  themselves and at regions peripheral thereto. 
     As described above, the pneumatic tire  1  of the embodiment includes a sidewall region  12  that extends in a tire radial direction D 2 ; 
     the sidewall region  12  comprises a plurality of side blocks  2 ,  3  which are arrayed in a tire circumferential direction D 3 , and an annular projection  4  which extends in the tire circumferential direction D 3  and which protrudes in a tire width direction D 1 ; 
     the plurality of side blocks  2 ,  3  include a first side block  2  and a second side block  3  that are adjacent in the tire circumferential direction D 3 ; 
     the first side block  2  comprises a first outer portion  2   a  which is arranged toward the exterior in the tire radial direction D 2  from the annular projection  4 , and a first inner portion  2   b  which is arranged toward the interior in the tire radial direction D 2  from the annular projection  4 ; 
     the second side block  3  comprises a second outer portion  3   a  which is arranged toward the exterior in the tire radial direction D 2  from the annular projection  4 , and a second inner portion  3   b  which is arranged toward the interior in the tire radial direction D 2  from the annular projection  4 ; 
     a location at which distance W 2  in the tire circumferential direction D 3  between the first inner portion  2   b  and the second inner portion  3   b  is a minimum is toward the interior in the tire radial direction D 2  from centers  2   c,    3   c  in the tire radial direction D 2  of first inner portion  2   b  and second inner portion  3   b;    
     as viewed in the tire circumferential direction D 3 , a maximum value W 11  of an amount by which the first inner portion  2   b  protrudes toward the exterior in the tire width direction D 1  beyond the second inner portion  3   b  is greater than a maximum value W 12  of an amount by which the second inner portion  3   b  protrudes toward the exterior in the tire width direction D 1  beyond the first inner portion  2   b;  and 
     as viewed in the tire circumferential direction D 3 , a maximum value W 10  of an amount by which the second outer portion  3   a  protrudes toward the exterior in the tire width direction D 1  beyond the first outer portion  2   a  is greater than a maximum value W 9  of an amount by which the first outer portion  2   a  protrudes toward the exterior in the tire width direction D 1  beyond the second outer portion  3   a.    
     In accordance with such constitution, as viewed in the tire circumferential direction D 3 , because the maximum value W 11  of the amount by which first inner portion  2   b  protrudes toward the exterior in the tire width direction D 1  beyond second inner portion  3   b  is large, there is a tendency for the traction that is produced by first inner portion  2   b  of first side block  2  to be large. Furthermore, as viewed in the tire circumferential direction D 3 , because the maximum value W 10  of the amount by which second outer portion  3   a  protrudes toward the exterior in the tire width direction D 1  beyond first outer portion  2   a  is large, there is a tendency for the traction that is produced by second outer portion  3   a  of second side block  3  to be large. 
     This being the case, the portions at which large amounts of traction tend to be produced are distributed among first side blocks  2  and second side blocks  3 . Accordingly, it will be possible to suppress occurrence of bias in the respective amounts of traction produced by first side blocks  2  and second side blocks  3  that are mutually adjacent in the tire circumferential direction D 3 . 
     Further, in the pneumatic tire  1  of the embodiment, 
     a location at which an amount by which the second outer portion  3   a  protrudes toward the exterior in the tire width direction D 1  beyond the first outer portion  2   a  is a maximum value W 10  is toward the interior in the tire radial direction from a location at which an amount by which the first outer portion  2   a  protrudes toward the exterior in the tire width direction D 1  beyond the second outer portion  3   a  is a maximum value W 9 . 
     In accordance with such constitution, at second outer portion  3   a  of second side block  3 , that portion  3   e  which is toward the interior in the tire radial direction D 2  is where the traction that is produced tends to be large. On the other hand, at first outer portion  2   a  of first side block  2 , that portion  2   d  which is toward the exterior in the tire radial direction D 2  is where the traction that is produced tends to be large; moreover, the traction that is produced at first inner portion  2   b  of first side block  2  tends to be large. This being the case, the portions at which large amounts of traction are produced are effectively distributed among first side blocks  2  and second side blocks  3 . 
     Further, in the pneumatic tire  1  of the embodiment, 
     the second side block  3  further comprises an outward facing surface  3   f  which faces the exterior in the tire radial direction D 2 ; and 
     a location of an outer end in the tire width direction D 1  of the outward facing surface  3   f  is a location at which an amount by which the second outer portion  3   a  protrudes toward the exterior in the tire width direction D 1  beyond the first outer portion  2   a  is a maximum value W 10 . 
     In accordance with such constitution, outward facing surface  3   f  of second side block  3  protrudes toward the exterior in the tire width direction D 1  by a large amount. This being the case, it will be possible to ensure that the amount by which outward facing surface  3   f  of second side block  3  protrudes in the tire width direction D 1  is adequate. 
     Further, the pneumatic tire  1  of the embodiment includes a sidewall region  12  that extends in a tire radial direction D 2 ; 
     the sidewall region  12  comprises a plurality of side blocks  2 ,  3  which are arrayed in a tire circumferential direction D 3 , and an annular projection  4  which extends in the tire circumferential direction D 3  and which protrudes in a tire width direction D 1 ; 
     the plurality of side blocks  2 ,  3  include a first side block  2  and a second side block  3  that are adjacent in the tire circumferential direction D 3 ; 
     the first side block  2  comprises a first outer portion  2   a  which is arranged toward the exterior in the tire radial direction D 2  from the annular projection  4 , and a first inner portion  2   b  which is arranged toward the interior in the tire radial direction D 2  from the annular projection  4 ; 
     the second side block  3  comprises a second outer portion  3   a  which is arranged toward the exterior in the tire radial direction D 2  from the annular projection  4 , and a second inner portion  3   b  which is arranged toward the interior in the tire radial direction D 2  from the annular projection  4 ; 
     a location at which distance W 2  in the tire circumferential direction D 3  between the first inner portion  2   b  and the second inner portion  3   b  is a minimum is toward the interior in the tire radial direction D 2  from centers  2   c,    3   c  in the tire radial direction D 2  of first inner portion  2   b  and second inner portion  3   b;    
     a maximum value W 5  of an amount by which the first inner portion  2   b  protrudes relative to a profile surface S 2  is greater than a maximum value W 8  of an amount by which the second inner portion  3   b  protrudes relative to the profile surface S 2 ; and 
     a maximum value W 6  of an amount by which the second outer portion  3   a  protrudes relative to the profile surface S 2  is greater than a maximum value W 3  of an amount by which the first outer portion  2   a  protrudes relative to the profile surface S 2 . 
     In accordance with such constitution, because the maximum value W 5  of the amount by which first inner portion  2   b  protrudes relative to profile surface S 2  is large, there is a tendency for the traction that is produced by first inner portion  2   b  of first side block  2  to be large. Furthermore, because the maximum value W 6  of the amount by which second outer portion  3   a  protrudes relative to profile surface S 2  is large, there is a tendency for the traction that is produced by second outer portion  3   a  of second side block  3  to be large. 
     This being the case, the portions at which large amounts of traction tend to be produced are distributed among first side blocks  2  and second side blocks  3 . Accordingly, it will be possible to suppress occurrence of bias in the respective amounts of traction produced by first side blocks  2  and second side blocks  3  that are mutually adjacent in the tire circumferential direction D 3 . 
     Further, in the pneumatic tire  1  of the embodiment, 
     a maximum value W 7  of an amount by which the second outer portion  3   a  is recessed relative to a profile surface S 2  is greater than a maximum value W 4  of an amount by which the first outer portion  2   a  is recessed relative to the profile surface S 2 ; and 
     a location at which an amount by which the second outer portion  3   a  protrudes relative to the profile surface S 2  is a maximum value W 6  is toward the interior in the tire radial direction D 2  from a location at which an amount by which the second outer portion  3   a  is recessed relative to the profile surface S 2  is a maximum value W 7 . 
     In accordance with such constitution, at second outer portion  3   a  of second side block  3 , that portion  3   e  which is toward the interior in the tire radial direction D 2  is where the traction that is produced tends to be large. On the other hand, at first outer portion  2   a  of first side block  2 , that portion  2   d  which is toward the exterior in the tire radial direction D 2  is where the traction that is produced tends to be large; moreover, the traction that is produced at first inner portion  2   b  of first side block  2  tends to be large. This being the case, the portions at which large amounts of traction are produced are effectively distributed among first side blocks  2  and second side blocks  3 . 
     Further, in the pneumatic tire  1  of the embodiment, 
     the second side block  3  further comprises an outward facing surface  3   f  which faces the exterior in the tire radial direction D 2 ; and 
     a location of an outer end in the tire width direction D 1  of the outward facing surface  3   f  is a location at which an amount by which the second outer portion  3   a  protrudes relative to the profile surface S 2  is a maximum value W 6 . 
     In accordance with such constitution, outward facing surface  3   f  of second side block  3  protrudes toward the exterior in the tire width direction D 1  by a large amount. This being the case, it will be possible to ensure that the amount by which outward facing surface  3   f  of second side block  3  protrudes in the tire width direction D 1  is adequate. 
     Further, the pneumatic tire  1  of the embodiment further comprises a tread region  13  having a belt region  13   c  at the interior thereof, 
     the outward facing surface  3   f  is arranged toward the exterior in the tire radial direction D 2  from an outer end  13   e  in the tire width direction D 1  of the belt region  13   c.    
     In accordance with such constitution, outward facing surface  3   f  is arranged at that portion of sidewall region  12  which is toward the exterior in the tire radial direction D 2 . As a result, because traction is produced by outward facing surface  3   f  at a location which is near the road surface, it will be possible to cause effective production of traction by outward facing surface  3   f.    
     The pneumatic tire  1  is not limited to the configuration of the embodiment described above, and the effects are not limited to those described above. It goes without saying that the pneumatic tire  1  can be variously modified without departing from the scope of the subject matter of the present invention. For example, the constituents, methods, and the like of various modified examples described below may be arbitrarily selected and employed as the constituents, methods, and the like of the embodiments described above, as a matter of course. 
     (1) The constitution of pneumatic tire  1  associated with the foregoing embodiment is such that first inner portion  2   b  and second inner portion  3   b  are contiguous; that is, the minimum value of the distance W 2  between inner portions  2   b  and  3   b  is zero. However, pneumatic tire  1  is not limited to such constitution. For example, as shown in  FIG. 7 , it is also possible to adopt a constitution in which first inner portion  2   b  and second inner portion  3   b  are separated in the tire circumferential direction D 3 . 
     (2) Furthermore, the constitution of pneumatic tire  1  associated with the foregoing embodiment is such that distance W 2  between inner portions  2   b  and  3   b  is a minimum at the inner ends in the tire radial direction D 2  of respective inner portions  2   b  and  3   b.  However, pneumatic tire  1  is not limited to such constitution. 
     For example, as shown in  FIG. 7 , it is also possible to adopt a constitution in which distance W 2  between inner portions  2   b,    3   b  is a minimum at location(s) toward the interior in the tire radial direction D 2  from the inner end(s) in the tire radial direction D 2  of respective inner portion(s)  2   b,    3   b.  In other words, it is also possible to adopt a constitution in which distance W 2  between inner portions  2   b,    3   b  is a minimum at location(s) toward the interior in the tire radial direction D 2  from center(s)  2   c,    3   c  in the tire radial direction D 2  of respective inner portion(s)  2   b,    3   b.    
     (3) Furthermore, the constitution of pneumatic tire  1  associated with the foregoing embodiment is such that step  5  is provided at the boundary between first inner portion  2   b  and second inner portion  3   b.  However, pneumatic tire  1  is not limited to such constitution. 
     For example, as shown in  FIG. 8 , it is also possible to adopt a constitution in which step  5  is not provided at the boundary between first inner portion  2   b  and second inner portion  3   b.  As shown in  FIG. 8 , in accordance with such constitution, first inner portion  2   b  and second inner portion  3   b  may be demarcated by a tire meridional plane S 3  which passes through the center in the tire circumferential direction D 3  of groove  13   f  at tread region  13 . While there is no particular limitation with respect thereto, note that first inner portion  2   b  of first side block  2  associated with  FIG. 8  comprises projection  2   f  which protrudes in the tire width direction D 1 . 
     (4) Furthermore, the constitution of pneumatic tire  1  associated with the foregoing embodiment is such that first side blocks  2  and second side blocks  3  are arranged in alternating fashion in the tire circumferential direction D 3 . However, pneumatic tire  1  is not limited to such constitution. For example, it is also possible to adopt a constitution in which sidewall region  12  comprises—in addition to first side blocks  2  and second side blocks  3 —side block(s) other than first side blocks  2  and second side blocks  3 . 
     (5) Furthermore, the constitution of pneumatic tire  1  associated with the foregoing embodiment is such that the second outer maximum protruding difference location (the location at which the amount by which second outer portion  3   a  protrudes toward the exterior in the tire width direction D 1  beyond first outer portion  2   a  is a maximum value W 10 ) is toward the interior in the tire radial direction D 2  from the first outer maximum protruding difference location (the location at which the amount by which first outer portion  2   a  protrudes toward the exterior in the tire width direction D 1  beyond second outer portion  3   a  is a maximum value W 9 ). However, pneumatic tire  1  is not limited to such constitution. For example, it is also possible to adopt a constitution in which the second outer maximum protruding difference location is toward the exterior in the tire radial direction D 2  from the first outer maximum protruding difference location. 
     (6) Furthermore, the constitution of pneumatic tire  1  associated with the foregoing embodiment is such that second side block  3  comprises outward facing surface  3   f  which faces the exterior in the tire radial direction D 2 . However, pneumatic tire  1  is not limited to such constitution. For example, it is also possible to adopt a constitution in which second side block  3  does not comprise outward facing surface  3   f  which faces the exterior in the tire radial direction D 2 . 
     (7) Furthermore, the constitution of pneumatic tire  1  associated with the foregoing embodiment is such that the second outer maximum recessed amount (the maximum value of the amount by which second outer portion  3   a  is recessed relative to profile surface S 2 ) W 7  is greater than the first outer maximum recessed amount (the maximum value of the amount by which first outer portion  2   a  is recessed relative to profile surface S 2 ) W 4 . However, pneumatic tire  1  is not limited to such constitution. For example, it is also possible to adopt a constitution in which the second outer maximum recessed amount W 7  is less than the first outer maximum recessed amount W 4 . 
     (8) Furthermore, the constitution of pneumatic tire  1  associated with the foregoing embodiment is such that the second outer maximum protruding location (the location at which the amount by which second outer portion  3   a  protrudes relative to profile surface S 2  is a maximum value W 6 ) is toward the interior in the tire radial direction D 2  from the second outer maximum recessed location (the location at which the amount by which second outer portion  3   a  is recessed relative to profile surface S 2  is a maximum value W 7 ). However, pneumatic tire  1  is not limited to such constitution. For example, it is also possible to adopt a constitution in which the second outer maximum protruding location is toward the exterior in the tire radial direction D 2  from the second outer maximum recessed location. 
     (9) Furthermore, the constitution of pneumatic tire  1  associated with the foregoing embodiment is such that the location of the outer end in the tire width direction D 1  of outward facing surface  3   f  is the second outer maximum protruding difference location (the location at which the amount by which second outer portion  3   a  protrudes toward the exterior in the tire width direction D 1  beyond first outer portion  2   a  is a maximum value W 10 ). However, pneumatic tire  1  is not limited to such constitution. For example, it is also possible to adopt a constitution in which the location of the outer end in the tire width direction D 1  of outward facing surface  3   f  is a location other than the second outer maximum protruding difference location. 
     (10) Furthermore, the constitution of pneumatic tire  1  associated with the foregoing embodiment is such that the location of the outer end in the tire width direction D 1  of outward facing surface  3   f  is the second outer maximum protruding location (the location at which the amount by which second outer portion  3   a  protrudes relative to profile surface S 2  is a maximum value W 6 ). However, pneumatic tire  1  is not limited to such constitution. For example, it is also possible to adopt a constitution in which the location of the outer end in the tire width direction D 1  of outward facing surface  3   f  is a location other than the second outer maximum protruding location. 
     (11) Furthermore, the constitution of pneumatic tire  1  associated with the foregoing embodiment is such that outward facing surface  3   f  is arranged toward the exterior in the tire radial direction D 2  from outer end  13   e  in the tire width direction D 1  of belt region  13   c.  However, pneumatic tire  1  is not limited to such constitution. For example, it is also possible to adopt a constitution in which outward facing surface  3   f  is arranged toward the interior in the tire radial direction D 2  from outer end  13   e  in the tire width direction D 1  of belt region  13   c.    
     (12) Furthermore, the constitution of pneumatic tire  1  associated with the foregoing embodiment is such that outer portions  2   a,    3   a  and inner portions  2   b,    3   b  are contiguous in the tire radial direction D 2 . However, pneumatic tire  1  is not limited to such constitution. For example, it is also possible to adopt a constitution in which outer portions  2   a,    3   a  and inner portions  2   b,    3   b  are separated in the tire radial direction D 2 . 
     (13) Furthermore, at pneumatic tire  1 , the constitution may be such that first and second side blocks  2 ,  3  are provided at only one of the sidewall regions  12 , or the constitution may be such that these are provided at both sidewall regions  12 . While there is no particular limitation with respect thereto, it is also possible, for example, to adopt a constitution in which first and second side blocks  2 ,  3  are at least provided at the sidewall region  12  which of the two sidewall regions  12  is the sidewall region  12  that is arranged so as to be toward the exterior when mounted on a vehicle.