JP5887751B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire, and more particularly, to a pneumatic tire that can ensure the effect of suppressing water splashing of fins even after the wear of the tire progresses.

  In recent years, a heavy load pneumatic tire employs a structure in which fins are provided in a buttress portion of a tire as a countermeasure against water splashes generated when traveling on a wet road surface. And by this fin, the kinetic energy of water splash is absorbed and the scattering height of water splash is reduced. As conventional pneumatic tires employing such a configuration, techniques described in Patent Documents 1 and 2 are known.

JP 2000-318410 A Japanese Patent Laid-Open No. 11-334322

  An object of the present invention is to provide a pneumatic tire capable of ensuring the effect of suppressing water splashing of fins even after the wear of the tire proceeds.

In order to achieve the above object, a pneumatic tire according to the present invention is a pneumatic tire provided with a fin for water splash suppression in a buttress portion, and the fin extends over the entire circumference of the buttress portion. A plurality of stages of the fitting portions are arranged at different positions in the tire radial direction, and the fin divides the plurality of parts. capable have a cyclic structure formed by connecting, and, characterized in that it comprises a display unit indicating the detachment time of said fins.

  In the pneumatic tire according to the present invention, the arc length X of the predetermined part among the plurality of parts and the arrangement interval Y of the fitting portion have a relationship of X = 2πY + δ, where δ is a tolerance. Is preferred.

  In the pneumatic tire according to the present invention, it is preferable that the adjacent parts are engaged with each other and connected.

  In the pneumatic tire according to the present invention, the fitting portion is a concave portion formed on a wall surface of the buttress portion, and the fin has a convex portion whose root is narrowed in the tire radial direction and the convex portion. It is preferable to insert a portion into the recess and fit into the fitting portion.

  Moreover, in the pneumatic tire according to the present invention, it is preferable that the center position of the convex portion is arranged offset from the center position of the fin in the tire radial direction outer side.

  In the pneumatic tire according to the present invention, it is preferable that the convex portion has a shape curved outward in the tire radial direction from the base toward the tip side.

  In the pneumatic tire according to the present invention, when the distance between the road surface and the foremost fin decreases due to the progress of wear of the tire and the fin does not function, the foremost fin is removed and the fin is inserted into the rear fitting portion. Can be installed. Thereby, since the distance between the road surface and the fin is optimized, there is an advantage that it is possible to appropriately ensure the water splash suppressing action of the fin even after the tire wear proceeds. Further, since the fin can be divided into a plurality of parts, the circumferential length of the fin can be changed by dividing the fin and excluding or replacing some parts. Thereby, there exists an advantage which can move and install a fin to another fitting part.

FIG. 1 is a sectional view in the tire meridian direction showing a pneumatic tire according to an embodiment of the present invention. FIG. 2 is an enlarged view showing fins of the pneumatic tire depicted in FIG. 1. FIG. 3 is an enlarged view showing the fin described in FIG. 2. FIG. 4 is an explanatory diagram showing the configuration of the fin shown in FIG. FIG. 5 is an explanatory diagram showing the configuration of the fin described in FIG. FIG. 6 is an explanatory view showing an installation state of the fins shown in FIG. FIG. 7 is an explanatory view showing an installation state of the fins shown in FIG. FIG. 8 is an explanatory view showing an installation state of the fins shown in FIG. FIG. 9 is an explanatory view showing the action of the fin shown in FIG. FIG. 10 is an explanatory view showing the action of the fin shown in FIG. FIG. 11 is an explanatory view showing a modified example of the pneumatic tire shown in FIG. 1. FIG. 12 is an explanatory diagram illustrating a modification of the pneumatic tire depicted in FIG. 1. FIG. 13 is an explanatory view illustrating a modified example of the pneumatic tire depicted in FIG. 1. FIG. 14 is an explanatory view showing a modified example of the pneumatic tire depicted in FIG. 1. FIG. 15 is an explanatory view showing a modified example of the pneumatic tire shown in FIG. 1. FIG. 16 is an explanatory diagram illustrating a modification of the pneumatic tire depicted in FIG. 1. FIG. 17 is an explanatory diagram illustrating a modification of the pneumatic tire depicted in FIG. 1. FIG. 18 is an explanatory diagram showing a modification of the pneumatic tire depicted in FIG. FIG. 19 is an explanatory diagram showing a modification of the pneumatic tire depicted in FIG. FIG. 20 is an explanatory diagram illustrating a modification of the pneumatic tire depicted in FIG. 1. FIG. 21 is an explanatory view showing a modified example of the pneumatic tire depicted in FIG. 1. FIG. 22 is an explanatory view showing a modified example of the pneumatic tire depicted in FIG. 1. FIG. 23 is an explanatory diagram illustrating a modification of the pneumatic tire depicted in FIG. 1. FIG. 24 is an explanatory view showing the results of the performance test of the pneumatic tire according to the embodiment of the present invention. FIG. 25 is a table showing the results of the performance test of the pneumatic tire according to the embodiment of the present invention. FIG. 26 is a table showing the results of the performance test of the pneumatic tire according to the embodiment of the present invention.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. Further, the constituent elements of this embodiment include those that can be replaced while maintaining the identity of the invention and that are obvious for replacement. In addition, a plurality of modifications described in this embodiment can be arbitrarily combined within a range obvious to those skilled in the art.

[Pneumatic tire]
FIG. 1 is a sectional view in the tire meridian direction showing a pneumatic tire according to an embodiment of the present invention. This figure shows a heavy duty radial tire applied to a truck, a bus or the like. Reference sign CL is a tire equator plane.

  The pneumatic tire 1 includes a pair of bead cores 11, 11, a pair of bead fillers 12, 12, a carcass layer 13, a belt layer 14, a tread rubber 15, and a pair of sidewall rubbers 16, 16. (See FIG. 1). The pair of bead cores 11 and 11 has an annular structure and constitutes the core of the left and right bead portions. The pair of bead fillers 12 and 12 includes an upper filler 121 and a lower filler 122, which are disposed on the outer periphery in the tire radial direction of the pair of bead cores 11 and 11, respectively, to reinforce the bead portion. The carcass layer 13 has a single-layer structure and is bridged in a toroidal shape between the left and right bead cores 11 and 11 to constitute a tire skeleton. Further, both end portions of the carcass layer 13 are wound and locked outward in the tire width direction so as to wrap the bead core 11 and the bead filler 12. The belt layer 14 includes a pair of stacked belt plies 141 to 143 and is disposed on the outer periphery in the tire radial direction of the carcass layer 13. These belt plies 141 to 143 are configured by arranging and rolling a plurality of belt cords made of steel or organic fiber material, and by crossing the belt cords in different directions in the tire circumferential direction. Configure the structure. The tread rubber 15 is disposed on the outer circumference in the tire radial direction of the carcass layer 13 and the belt layer 14 to constitute a tread portion of the tire. The pair of side wall rubbers 16 and 16 are respectively arranged on the outer side in the tire width direction of the carcass layer 13 to constitute left and right side wall portions.

  The pneumatic tire 1 includes a plurality of circumferential main grooves 21 and 22 extending in the tire circumferential direction and a plurality of land portions 31 to 33 that are partitioned by the circumferential main grooves 21 and 22. Prepare for the department. In this embodiment, the circumferential main groove 22 at the outermost side in the tire width direction has the deepest groove depth, and the second land portion 32 and the shoulder land portion 33 are partitioned by the circumferential main groove 22. ing. The circumferential main groove means a circumferential groove having a groove depth of 8 mm or more.

  The pneumatic tire 1 has a narrow groove 4 and a thin rib 5. The narrow groove 4 is disposed in the vicinity of the tire ground contact edge and extends in the tire circumferential direction along the edge of the shoulder land portion 33. The fine ribs 5 are ribs defined by the fine grooves 4. In such a configuration, the uneven wear of the shoulder land portion 33 is suppressed when the thin rib 5 is grounded and actively worn during tire rolling.

[Fin for water splash control]
FIG. 2 is an enlarged view showing fins of the pneumatic tire depicted in FIG. 1. FIG. 3 is a perspective view showing the fin described in FIG. 2. These drawings show a state when the fin is installed in the first-stage fitting portion. The cross section of the fin is hatched.

  The pneumatic tire 1 includes fins 6 for suppressing water splash (see FIGS. 2 and 3). The fins 6 are disposed in at least the buttress portions on the left and right sides of the tire at the buttress portion located on the outer side in the vehicle width direction when the vehicle is mounted. The fin 6 has a shape protruding in the tire width direction from the profile of the buttress portion, and has a wall surface on the outer side in the tire radial direction (tire contact end side) and a wall surface on the inner side in the tire radial direction (side wall portion side). . Further, the fin 6 has an annular and rib-like structure that continuously extends over the entire circumference of the tire.

  The buttress portion refers to a side wall portion between the tire ground contact end and the tire maximum width position. Moreover, the fin 6 is arrange | positioned so that attachment or detachment is possible with respect to a buttress part after tire vulcanization molding so that it may mention later.

  Further, the shape and position of the fin 6 are set as follows.

  First, A is a tire ground contact end in a sectional view in the tire meridian direction. Further, a tangent line 1 is drawn from the tire ground contact end A to the fin 6, and a contact point between the tangent line 1 and the fin 6 is defined as B. Further, the inclination angle of the tangent line 1 with respect to the tire axial direction is defined as θ. Further, a curve m parallel to the profile of the tread surface is drawn from the groove bottom of the deepest circumferential main groove (here, the circumferential main groove 22 on the outermost side in the tire width direction). Let P be the intersection with.

  At this time, the top of the fin 6 has an arc-shaped outline, and the contact point B is positioned on the arc of the top. In addition, the wall surface on the outer side in the tire radial direction of the fin 6 is recessed inward of the tire with respect to the tangent l. Thus, a side wall surface that is curved or bent in the tire axial direction from the tire ground contact end A toward the contact point B is formed. In this embodiment, the wall surface on the outer side in the tire radial direction of the fin 6 and the profile of the buttress portion are smoothly connected via an arc-shaped contour line recessed in the tire.

  Further, the inclination angle θ of the tangent l is in the range of θ <45 [deg], and more preferably in the range of 32 [deg] ≦ θ ≦ 37 [deg]. In addition, the intersection (the end portion on the outer side in the tire radial direction at the base of the fin 6) between the fin 6 and the profile of the padless portion is disposed on the wall surface on the inner side in the tire radial direction from the intersection P. Further, the arrangement position and the height H of the fins 6 are adjusted so that the fins 6 do not exceed the maximum tire width. As a result, the shape and position of the fin 6 are optimized. The height H of the fin 6 is measured with reference to the profile of the buttress portion.

  The tire ground contact edge means a tire when a tire is attached to a specified rim and applied with a specified internal pressure and is placed perpendicular to a flat plate in a stationary state and a load corresponding to a specified load is applied. An end in the tire axial direction on the contact surface with the flat plate.

  The tread end of the tire refers to both end portions of the tread pattern portion of the tire when the tire is mounted on the specified rim and applied with the specified internal pressure and is in an unloaded state.

  The specified rim is an “applied rim” defined in JATMA, a “Design Rim” defined in TRA, or a “Measuring Rim” defined in ETRTO. The specified internal pressure means “maximum air pressure” specified by JATMA, the maximum value of “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” specified by TRA, or “INFLATION PRESSURES” specified by ETRTO. The specified load means “maximum load capacity” defined in JATMA, the maximum value of “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” defined in TRA, or “LOAD CAPACITY” defined in ETRTO. However, in JATMA, in the case of tires for passenger cars, the specified internal pressure is air pressure 180 [kPa], and the specified load is 88 [%] of the maximum load capacity.

[Fin attach / detach structure]
4 and 5 are explanatory views showing the configuration of the fin described in FIG. In these drawings, FIG. 4 shows a schematic view of the fin viewed from the tire axial direction, and FIG. 5 shows the relationship between the arrangement intervals Y1 and Y2 of the fitting portion and the arc lengths X1 and X2 of the circumferential length correction portion. Show. Moreover, these figures have shown the mode when a fin is installed in the fitting part of the 1st step | paragraph.

  In a pneumatic tire having fins for suppressing water splash, if the distance between the fin and the road surface decreases due to the progress of wear of the tire, there is a possibility that the water splash suppression effect of the fin may decrease due to, for example, submersion of the fin. is there.

  Therefore, this pneumatic tire 1 employs the following configuration in order to maintain the effect of suppressing the splash of water on the fins even after the tire wear progresses.

  That is, in this pneumatic tire 1, the fins 6 extend over the entire circumference of the buttress portion and are fitted and installed in the fitting portion 7 formed in the buttress portion (FIGS. 2 to 4). reference). Therefore, the fin 6 is a component independent of the tire body, and is manufactured separately and attached to the buttress portion.

  For example, in this embodiment, the fin 6 has an annular shape, and has a convex portion 61 on one end face (the buttress portion side). Moreover, the convex part 61 has the rib-like structure extended over the perimeter of the fin 6, and has a uniform shape, height, and width. Further, the convex portion 61 has a jigsaw puzzle-like contour whose base is narrowed in the radial direction (tire radial direction) of the fin 6. Moreover, the fitting part 7 consists of the recessed part 71 formed in the wall surface of a buttress part. Specifically, the concave portion 71 is an annular groove extending over the entire circumference of the buttress portion, and has a uniform groove shape, groove depth, and groove width that match the convex portion 61 of the fin 6. And the fin 6 is fixed to the wall surface of a buttress part by inserting the convex part 61 in the recessed part 71, and fitting to the fitting part 7. FIG. Further, by inserting the entire convex portion 61 into the concave portion 71, the wall surface on the outer side in the tire radial direction of the fin 6 and the profile of the buttress portion are connected.

  Further, the plurality of stages of fitting portions 7 are arranged at different positions in the tire radial direction. Out of these fitting portions 7, the outermost fitting portion 7 in the tire radial direction is referred to as a first-stage fitting portion. It is called the fitting part of the stage,..., The fitting part of the Nth stage (final stage).

  For example, in this embodiment, three recesses 71 are formed in the buttress portion as the fitting portion 7. Moreover, these recessed parts 71 consist of annular grooves which have mutually different diameters, and are arrange | positioned concentrically with respect to a tire rotating shaft. For this reason, these recesses 71 are arranged at predetermined intervals in the tire radial direction along the wall surface of the buttress portion in a sectional view in the tire meridian direction.

  Further, the fin 6 has an annular structure formed by connecting a plurality of parts 62 and 63 so as to be split (see FIGS. 4 and 5). Specifically, the fin 6 has a main body part 62 that constitutes the main body of the fin 6 and a peripheral length correction part 63 that corrects the peripheral length of the fin 6. Further, the circumference correction part 63 is shorter than the main body part 62. Further, the fin 6 is configured by connecting the main body part 62 and the circumferential length correcting part 63 in a ring and in series. Further, the arc length X of the circumferential length correction part 63 and the arrangement interval Y of the fitting portion 7 have a relationship of X = 2πY + δ, where δ is a tolerance.

  For example, in this embodiment, the fin 6 has a single main body part 62 and two circumference correction parts 63A and 63B. Moreover, these parts 62, 63A, and 63B each have the convex part 61, and are fitted and installed with respect to the recessed part 71 of a buttress part. Moreover, these parts 62, 63A, 63B have an end portion structure that can be connected to each other. This connection structure will be described later.

  Further, in a state where the three parts 62, 63A, 63B are connected, the circumferential length of the fin 6 is the length corresponding to the circumferential length of the first-stage fitting portion 7, and is the longest. Further, in the state where the main body part 62 and the other circumference correction part 63B are connected except for one circumference correction part 63A, the circumference of the fin 6 corresponds to the circumference of the fitting portion 7 at the second stage. It becomes the length. Further, in the state where the main body part 62 is formed in an annular structure by excluding the other circumference correction part 63B, the circumference of the fin 6 corresponds to the circumference of the fitting portion 7 at the third stage (final stage). It becomes the length and becomes the minimum.

  Specifically, the arc lengths X1 and X2 [mm] of the circumferential length correction parts 63A and 63B and the arrangement intervals Y1 and Y2 [mm] of the fitting portion 7 have a relationship of X1 = 2πY1 + δ and X2 = 2πY2 + δ. . Thereby, whenever one circumference correction part 63A, 63B is excluded, the circumference of the fin 6 becomes short and becomes the length corresponding to the circumference of the fitting part 7 of the back | latter stage side. Note that δ is preferably δ = ± 5 [mm], and more preferably δ = 1 ± 2 [mm].

  6-8 is explanatory drawing which shows the installation state of the fin described in FIG. In these drawings, FIGS. 6 and 7 show the state when the fin is installed in the second-stage fitting portion, and FIG. 8 shows the state when the fin is installed in the third-stage fitting portion. It shows a state.

  When the tire is new, the fin 6 is installed in the first-stage fitting portion 7 (see FIGS. 3 and 5). In this state, as described above, the fin 6 is configured by connecting the single main body part 62 and the two peripheral length correction parts 63A and 63B in an annular shape (see FIG. 4). Further, the convex portion 61 of the fin 6 is fitted into the concave portion 71 which is the fitting portion 7, and the fin 6 is fixed to the buttress portion.

  Next, in the middle stage of wear, the fin 6 is removed from the first-stage fitting portion 7 and installed in the second-stage fitting portion 7 (see FIGS. 6 and 7). At this time, one circumference correction part 63A is excluded, and the main body part 62 and the other circumference correction part 63B are connected to form the fin 6 that is one step shorter.

  Further, at the end of wear, the fin 6 is removed from the second-stage fitting portion 7 and installed in the third-stage fitting portion 7 (see FIG. 8). At this time, the other peripheral length correction part 63B is excluded, and both end portions 621 and 622 of the main body part 62 are connected to form the fin 6 including only the main body part 62.

  9 and 10 are explanatory diagrams showing the action of the fin described in FIG. These figures show the water splash suppression effect of the fins when traveling on wet roads. FIG. 9 shows a state when the tire is new (when the fin is installed in the first-stage fitting portion), and FIG. 10 shows a middle stage of wear (when the fin is installed in the second-stage fitting portion). The state of is shown.

  In the pneumatic tire 1, when traveling on a wet road, the splash of water splashed by the fins 6 is guided in the tire width direction to suppress the splash height of the splash of water (see FIGS. 9 and 10). As a result, the influence of water splash on other vehicles traveling in the adjacent lane and the oncoming lane (water splash on the windshield of the passenger car and obstructing the driver's view) is suppressed.

  Further, when the tire is new, the fin 6 is installed in the first-stage fitting portion 7 (see FIG. 9). And this fin 6 functions and the splash height of water splash is suppressed. Next, when wear progresses and the wear is in the middle stage, the distance from the road surface to the fins 6 is shortened. Therefore, the fin 6 is removed from the first-stage fitting portion 7, the circumferential length of the fin 6 is adjusted, and the fin 6 is installed in the second-stage fitting portion 7 (see FIGS. 6 and 10). . And this fin 6 functions and the splash height of water splash is suppressed. Further, when the end of wear is reached and the distance from the road surface to the fin 6 is further shortened, the second-stage fin 6 is removed, the circumferential length of the fin 6 is adjusted, and the fin corresponding to the third-stage fitting portion 7 is removed. 6 is newly installed (see FIG. 8). And this fin 6 functions and the splash height of water splash is suppressed. In this way, the fins 6 are sequentially installed with respect to the three-stage fitting portions 7, thereby optimizing the distance from the road surface to the fins 6. Thereby, the water splash suppression function by the fin 6 can be ensured throughout the entire period of use of the tire from when the tire is new to the end of wear.

[Modification]
FIGS. 11-18 is explanatory drawing which shows the modification of the pneumatic tire described in FIG. In these drawings, FIGS. 11 to 13 show a state in which the connecting portions of the parts are viewed from the axial direction of the fin (the tire axial direction), and FIGS. 14 and 15 show the connecting portions of the parts in the radial direction of the fins ( It shows a state seen from the tire radial direction.

  In this pneumatic tire 1, it is preferable that adjacent parts 62 and 63 (63A, 63B) are engaged with each other and connected (see FIGS. 11 to 18). Thereby, the drop-off of the fin when the fin (particularly, the circumference correction part 63) contacts the curb stone X or the like is effectively suppressed.

  For example, in the modification example of FIGS. 11 to 13, the end portions (connecting portions) of the parts 62 and 63 are engaged with each other with unevenness in the circumferential direction when the fin 6 is viewed in the axial direction. Specifically, the ends of the parts 62 and 63 have a concave and convex portion at the center (see FIG. 11), a shape that curves and meshes in an S shape (see FIG. 12), an arc shape or Examples include a shape that curves and engages in a parabolic shape (see FIG. 13). Further, one end of each part 62, 63 is convex, and the other end is concave, so that each part 62, 63 has an end shape that meshes with each other. Thereby, each part 62 and 63 can be meshed | engaged by arbitrary combinations and can be connected. Further, when the fin 6 is installed in the final stage (see FIG. 8), one end 621 and the other end 622 of the main body part 62 can be engaged with each other and connected.

  14 and 15, the end portions of the parts 62 and 63 have a shape inclined with respect to the circumferential direction when the fin 6 is viewed in the radial direction. Specifically, the end portions of the parts 62 and 63 are curved and meshed in an arc shape or a parabolic shape (see FIG. 14), curved and meshed in an S shape (see FIG. 15), and circumferentially. Examples thereof include a linear shape (not shown) inclined with respect to the surface. Note that it is sufficient that the end portions of the parts 62 and 63 have a portion that is inclined with respect to the circumferential direction, and the end portions of the parts 62 and 63 do not have to have a shape that meshes with each other. In addition, in the configuration in which the end portions of the parts 62 and 63 are linearly inclined with respect to the circumferential direction when viewed in the radial direction of the fin 6, the inclination angle φ is 20 [deg] ≦ φ ≦ 70 [deg]. It is preferable to be within the range.

  Further, in the pneumatic tire 1 of FIG. 1, the fin 6 is configured by connecting a single main body part 62 and a plurality of peripheral length correction parts 63A and 63B (see FIG. 4). And the circumference of fin 6 is adjusted by attaching and detaching circumference correction parts 63A and 63B.

  However, the present invention is not limited to this, and the fin 6 may be composed of a single main body part 62 and a single circumference correction part 63 (not shown). Then, a plurality of circumference correction parts 63 having different arc lengths may be prepared, and the circumference of the fins 6 may be adjusted by replacing these circumference correction parts 63. For example, when the fin 6 is installed in the first-stage fitting portion 7, the first-stage long and single peripheral length correcting part 63 is used, and the second-stage fitting portion 7 has a fin. 6 is used, a single circumference correction part 63 that is shorter than the first stage circumference correction part is used. In the third stage, the peripheral length correction part 63 is omitted, and the fin 6 is configured only by the main body part 62.

  16-18 is explanatory drawing which shows the modification of the pneumatic tire described in FIG. In these drawings, FIG. 16 and FIG. 17 show modified examples of the fin and the fitting portion, and FIG. 18 shows a modified example when the installation position of the fin is changed.

  In the pneumatic tire 1 of FIG. 1, the fin 6 has one convex part 61, and this convex part 61 is engage | inserted and arrange | positioned at the recessed part 71 (refer FIG. 2 and FIG. 7). However, the present invention is not limited thereto, and the fin 6 may have a pair of convex portions 61 and 61, and these convex portions 61 and 61 may be fitted into different concave portions 71 and 71, respectively (see FIG. 16). In such a configuration, since one fin 6 is supported via the two convex portions 61 and 61, the falling off of the fin 6 is effectively suppressed.

  Further, in the pneumatic tire 1 of FIG. 1, the convex portion 61 has a rib-like shape extending over the entire length of each of the parts 62 and 63 constituting the fin 6, and is one in the circumferential direction of the fin 6. It has such a cross-sectional shape (not shown). However, the present invention is not limited to this, and the convex portion 61 may be composed of a plurality of protrusions arranged at predetermined intervals in the circumferential direction of the fin 6 (not shown). In this case, the concave portion 71 is composed of a plurality of depressions arranged corresponding to the respective convex portions 61.

  Moreover, in the pneumatic tire 1 of FIG. 1, the convex part 61 has a circular top part (refer FIG. 7). Such a configuration is preferable in that the fins 6 can be easily attached and detached because the convex portions 61 can be easily fitted into the concave portions 71. However, the present invention is not limited to this, and the convex portion 61 may have a semicircular top (see FIG. 17) or may have a polygonal (triangle, quadrangle, rhombus, etc.) top (not shown). ).

  Moreover, in the pneumatic tire 1 of FIG. 1, the convex part 61 has the shape which narrowed the root, and the recessed part 71 has the shape which narrowed the opening part corresponding to this convex part 61 ( (See FIG. 7). Thereby, the convex portion 61 has a structure that is difficult to come off from the concave portion 71. Further, since the convex portion 61 has a shape in which the root is narrowed in the tire radial direction, the falling off of the fin at the time of contact between the fin and the curb is effectively suppressed.

  At this time, it is preferable that the maximum width W1 of the convex portion 61 and the minimum width W2 of the narrowed root portion have a relationship of 0.5 ≦ W2 / W1 ≦ 0.8 (see FIG. 7). Thereby, falling off of the fin 6 can be effectively suppressed while securing the detachability of the fin 6.

  In addition, it is not restricted to the above, The convex part 61 and the recessed part 71 may be fitted by having a bayonet shape (gagged shape) or a screw shape (not shown). Even with this configuration, it is possible to effectively prevent the fins 6 from falling off while ensuring the detachability of the fins 6.

  Moreover, in the pneumatic tire 1 of FIG. 1, the fin 6 is detachably installed with respect to the fitting part 7 by fitting the convex part 61 of the fin 6 and the concave part 71 of the fitting part 7 ( (See FIG. 7). And when changing the installation position of the fin 6, after the fin 6 of the front | former stage (the side closest to a road surface) is removed from the fitting part 7, and the circumference of the fin 6 is adjusted, the fitting part of a back | latter stage 7 is provided with fins 6. At this time, after removing the fin 6 in the previous stage from the fitting portion 7, the fitting portion 7 may be closed with a predetermined patch 9 (see FIG. 18). In such a configuration, since the patch 9 fills the concave portion 71, the water splash suppressing action of the fin 6 at the subsequent stage is improved. Further, the patch 9 closes the recess 71, whereby the rigidity of the buttress portion is reinforced and the falling off of the fin 6 is suppressed.

  Moreover, in the pneumatic tire 1 of FIG. 1, it is preferable that the fin 6 consists of elastic members, such as rubber | gum and vinyl, for example. Thereby, since the fin 6 can be elastically deformed at the time of the contact between the fin 6 and the curb X, the drop-off resistance of the fin 6 is improved. Or since the fin 6 can be elastically deformed when fitting the fin 6 in the fitting part 7, the mounting | wearing ease of the fin 6 improves.

  Moreover, in the pneumatic tire 1 of FIG. 1, the fitting part 7 of 3 steps | paragraphs is formed, and the installation position of the fin 6 is made into 3 steps | paragraphs by attaching / detaching the fin 6 corresponding to these fitting parts 7 one by one. It is changed (see FIGS. 3, 6 and 8). However, the present invention is not limited to this, and two-stage fitting portions 7 may be formed (not shown), or four or more stages of fitting portions 7 may be formed (not shown). Therefore, it is only necessary to form a plurality of stages of fitting portions 7 and change the installation position of the fin 6 in a plurality of stages.

[Fin installation position of each stage]
In the pneumatic tire 1, as described above, the position of the first-stage fin 6 is defined by the relationship between the inclination angle θ of the tangent l and the intersection P (curve m from the groove bottom) (see FIG. 2). At this time, the distance D1 in the tire radial direction from the tire ground contact edge A to the contact point B in the first-stage fin 6 is preferably in the range of 10 [mm] ≦ D1 ≦ 30 [mm], and 15 [mm ] ≦ D1 ≦ 25 [mm] is more preferable. For example, when D1 <10 [mm], since the distance from the road surface to the fin is short, there is a possibility that the water splash suppressing function cannot be sufficiently obtained due to the submergence of the fin. Further, when 30 [mm] <D1, the distance from the road surface to the fins is long, and thus there is a possibility that the water splash suppression function by the fins cannot be obtained sufficiently. The distance D is measured as a no-load state while applying a specified internal pressure by mounting the tire on a specified rim.

  The position of the fin 6 at the last stage (the innermost side in the tire radial direction) is defined by the relationship between the distance D1 of the fin 6 at the first stage and the groove depth G of the deepest circumferential main groove 22 (see FIG. 2). Specifically, the distance D1 between the first-stage fin 6 and the distance D3 in the tire radial direction from the tire ground contact edge A to the contact point B in the last-stage fin 6 is −5 [mm] ≦ G− (D3 -D1) It is preferable to have a relationship of ≦ 5 [mm]. For example, when G- (D3-D1) <5 [mm], when the final stage fin is used at the end of wear of the tire, the distance from the road surface to the fin becomes short, and the water is submerged due to the submergence of the fin. There is a possibility that the splash suppression function cannot be sufficiently obtained. In addition, when -5 [mm] <G- (D3-D1), when the final fin is used, the distance from the road surface to the fin is reduced, and the water splash suppression function by the fin is sufficient. May not be obtained. The fin 6 is configured not to protrude outward in the tire width direction from the tire maximum width position. Further, the groove depth G is measured by attaching a new tire to a specified rim to apply a specified internal pressure and at the same time no load.

  Further, the arrangement interval ΔD (= D2−D1 = D3−D2) of the fins 6 has a relationship of 0.1 ≦ ΔD / D1 ≦ 1.5 with respect to the distance D1 of the first-stage fin 6. preferable. In such a configuration, when the foremost fin 6 whose water splash suppression effect has been reduced due to the progress of wear is removed, and the fin 6 is installed in the rear fitting portion 7 to form the foremost fin 6, this fin 6 and the road surface And the distance between them is optimized. Thereby, the water splash suppression effect of the fin 6 is ensured appropriately. For example, when 1.5 <ΔD / D1, it is not preferable because the arrangement interval ΔD of the fins 6 is too wide and the subsequent fins 6 may not function sufficiently. Further, if ΔD / D1 <0.1, the number of fins installed is unnecessarily large, and the tire weight increases, which is not preferable.

[Projection offset structure]
19-21 is explanatory drawing which shows the modification of the pneumatic tire described in FIG. In these drawings, FIG. 19 shows the offset structure of the convex part, FIG. 20 shows the operation of the convex part described in FIG. 19, and FIG. 21 shows a modification of the offset structure of the convex part shown in FIG. Is shown.

  In the pneumatic tire 1 of FIG. 1, the center position of the convex part 61 is arrange | positioned in the same position as the center position of the fin 6 (refer FIG. 7).

  On the other hand, in the modification of FIG. 19, the center position of the convex portion 61 is arranged offset from the center position of the fin 6 in the tire radial direction. Here, the midpoint of the line segment when the fin 6 is projected onto the profile of the buttress portion in a sectional view in the tire meridian direction is defined as the center position of the fin 6. Further, the midpoint of the line segment when the convex portion 61 is projected onto the profile of the buttress portion is set as the center position of the convex portion 61. In the configuration in which the fin 6 has a plurality of convex portions 61 (see FIG. 7), the midpoint of the center position of each convex portion 61 is arranged offset from the center position of the fin 6 in the tire radial direction. .

  In such a configuration, the holding force of the fin 6 against the moment around the end point I inside the tire radial direction of the fin 6 increases (see FIG. 20). Thereby, the drop-off of the fin 6 when the fin 6 contacts the curb X or the like is suppressed. Moreover, in this structure, the attachment / detachment workability of the fin 6 is ensured.

  Further, in the above configuration, the offset amount S of the center position of the convex portion 61 is 10 [%] or more and 40 [%] with respect to the width of the bottom surface of the fin 6 (the distance between the end points O and I of the fin 6 in the profile of the buttress portion). %] Is preferably within the following range (see FIG. 19). Thereby, the drop-off of the fin 6 is effectively suppressed.

  Moreover, in said structure, it is preferable that the convex part 61 has the shape curved to the tire radial direction outer side toward the front end side from the base (refer FIG. 21). For example, in the modification of FIG. 21, the center line of the convex portion 61 has an arc shape having a center on the outer side in the tire radial direction of the fin 6 in a sectional view in the tire meridian direction. Moreover, when the intersection of the center line of the convex part 61 and the outline of the convex part 61 is set to T, the straight line which passes along this intersection T and the end point I inside the tire radial direction of the fin 6 and the tire diameter of the fin 6 The angle α formed with the profile of the buttress portion at the end point O on the outer side in the direction is in the range of 0 [deg] <α ≦ 70 [deg]. In such a configuration, the holding force of the fin 6 against the moment around the end point I increases. Thereby, the drop-off of the fin 6 when the fin 6 contacts the curb X or the like is effectively suppressed. Further, the workability of attaching and detaching the fin 6 is ensured.

[Display section showing fin installation / removal time]
22 and 23 are explanatory views showing a modification of the pneumatic tire shown in FIG. In these drawings, FIG. 22 shows a state when the tire is new, and FIG. 23 shows a fin attachment / detachment time in the middle period of wear.

  In the modification of FIG. 22, a display unit 8 that indicates the attachment / detachment time of the fin 6 is provided. The display unit 8 is used as a guideline for attaching and detaching the fins 6 when the front-stage fins 6 are removed and the rear-stage fins 6 are installed as the tire wear progresses. Moreover, the display part 8 which displays the attachment or detachment time of the fin 6 of the at least 1st step | stage (the outermost side of a tire radial direction) is provided. In addition, the display unit 8 may be, for example, embossing or unevenness attached to the buttress unit, or may be a wear indicator formed in the circumferential main groove.

  For example, in this modification, the display unit 8 is formed by a line-shaped stamp formed on the side wall surface of the buttress unit. The display portion 8 is formed at a predetermined position with respect to the tire ground contact end A. Specifically, the distance Dm in the tire radial direction from the tire ground contact edge A to the display portion 8 and the arrangement interval ΔD of the fins 6 and 6 when the fins 6 are installed in the adjacent fitting portions 7 and 7 respectively. Are substantially matched (so as to have a relationship of 0.7 ≦ Dm / ΔD ≦ 1.3), the display unit 8 is formed. In addition, the display unit 8 indicating the attachment / detachment time of the first-stage fin 6 (the time of removing the first-stage fin 6 and attaching the second-stage fin 6) and the attachment / detachment time of the second-stage fin 6 (two-stage) The display portion 8 is formed at predetermined intervals to indicate when the fin 6 of the eye is removed and the third-stage fin 6 is attached.

  In this modification, when the tire is new, there is a distance Dm between the display unit 8 and the tire ground contact end A (see FIG. 22). Next, due to the progress of wear of the tire, when the tire ground contact surface is lowered and the tire ground contact end A 'coincides with the display portion 8, it is time to attach and detach the first-stage fin 6 (see FIG. 23). Then, using this as a guide, the first-stage fin 6 is removed and installed in the second-stage fitting portion 7. The same applies to the attachment / detachment time of the second-stage fin 6.

  The display unit 8 indicating the attachment / detachment timing of the first-stage fin 6 is configured such that when the tire ground contact end A ′ and the display unit 8 coincide with the progress of wear of the tire, the tire ground contact end A ′ and the first-stage fin 6 are displayed. The distance D1 ′ from 6 is preferably 10 [mm] ≦ D1 ′ <D1 (preferably 15 [mm] ≦ D1 ′ ≦ D1) (see FIG. 14). In other words, the difference D1-Dm (= D1 ′) between the distance Dm of the display unit 8 and the distance D1 of the first-stage fin 6 when the tire is new is 10 [mm] ≦ D1−Dm <D1 (preferably The distance Dm of the display unit 8 is set so that 15 [mm] ≦ D1−Dm ≦ D1). Thereby, the water splash suppressing action of the first-stage fin 6 is ensured until the first-stage fin 6 is attached and detached.

  At the same time, the display unit 8 indicating the attachment / detachment timing of the first-stage fin 6 has a distance D2 ′ between the tire ground contact end A ′ and the second-stage fin 6 of 10 [mm] ≦ D2 ′ ≦ 30 [mm] (preferably Is preferably arranged at a position within a range of 15 [mm] ≦ D2 ′ ≦ 25 [mm]) (see FIG. 14). In other words, the difference D2-Dm (= D2 ′) between the distance Dm of the display unit 8 and the distance D2 of the second-stage fin 6 when the tire is new is 10 [mm] ≦ D2−Dm ≦ 30 [mm] ( Preferably, the distance Dm of the display unit 8 is set so that 15 [mm] ≦ D2−Dm ≦ 25 [mm]. Thereby, the water splash suppression effect of the fin 6 of the 2nd step is ensured appropriately.

[effect]
As described above, the pneumatic tire 1 includes the fins 6 for suppressing water splash in the buttress portion (see FIGS. 1 to 3). In addition, the fin 6 extends over the entire circumference of the buttress portion and is fitted and installed in the fitting portion 7 formed in the buttress portion. Further, the plurality of stages of fitting portions 7 are arranged at different positions in the tire radial direction. Further, the fin 6 has an annular structure formed by connecting a plurality of parts 62 and 63 so as to be split (see FIGS. 4 and 5).

  In such a configuration, when the distance between the road surface and the foremost fin 6 decreases due to the progress of wear of the tire and the fin 6 does not function, the foremost fin 6 is removed and the fin 6 is attached to the rear fitting portion 7. Can be installed (see FIGS. 9 and 10). Thereby, since the distance between the road surface and the fin 6 is optimized, there is an advantage that the splashing action of the fin 6 can be appropriately ensured even after the tire progresses. Further, since the fin 6 can be divided into a plurality of parts 62 and 63, the peripheral length of the fin 6 can be changed by dividing the fin 6 and removing or replacing some parts 63 (FIGS. 3, 6 and 6). (See FIG. 8). Thereby, there exists an advantage which can move and install the fin 6 to the other fitting part 7. FIG.

  Further, in this pneumatic tire 1, the arc length X of a predetermined part (circumferential length correction part 63) of the plurality of parts 62 and 63 and the arrangement interval Y of the fitting portion 7 are X = 2πY + δ (see FIG. 5). In such a configuration, when the fin 6 is moved from the front-stage fitting portion 7 to the next-stage fitting portion 7, the fin 6 is configured by excluding the part having the arc length X. Can be appropriately adjusted (see FIGS. 3, 6 and 8). Thereby, there exists an advantage which adjustment of the perimeter of the fin 6 becomes easy.

  Moreover, in this pneumatic tire 1, the adjacent parts 62 and 63 are mutually meshed | engaged and connected (refer FIGS. 11-13). Thereby, there exists an advantage by which the drop-off | omission of the fin 6 when the fin 6 contacts the curb X etc. is suppressed effectively.

  Moreover, in this pneumatic tire 1, the fitting part 7 is the recessed part 71 formed in the wall surface of a buttress part, and the fin 6 has the convex part 61 which narrowed the root to the tire radial direction, and this convex part 61 is inserted into the recess 71 and fitted into the fitting portion 7 (see FIG. 7). Thereby, there exists an advantage which can comprise easily the fitting structure of the fin 6 and the fitting part 7. FIG.

  Moreover, in this pneumatic tire 1, the center position of the convex part 61 is offset and arrange | positioned rather than the center position of the fin 6 in the tire radial direction (refer FIG. 19). Thereby, there exists an advantage by which the drop-off of the fin 6 when the fin 6 contacts the curb X etc. is suppressed.

  Further, in the pneumatic tire 1, the convex portion 61 has a shape curved outward in the tire radial direction from the root toward the tip side (see FIG. 21). Thereby, the drop-off of the fin 6 when the fin 6 contacts the curb X or the like is effectively suppressed.

  Moreover, this pneumatic tire 1 has the display part 8 which shows the attachment or detachment time of the fin 6 (refer FIG. 22). Thereby, since the attachment / detachment time of the fin 6 can be optimized, there is an advantage that the water splash suppression performance by the fin 6 can be appropriately secured.

  24 to 26 are an explanatory diagram (FIG. 24) and tables (FIGS. 25 and 26) showing the results of the performance test of the pneumatic tire according to the embodiment of the present invention.

  In this example, for a plurality of mutually different pneumatic tires, (1) water splash suppression performance, (2) dropout resistance, and (3) attachment / detachment workability were evaluated (FIGS. 24 to 26). reference). In these performance tests, a pneumatic tire with a tire size of 275 / 80R22.5 was assembled to a rim with a rim size of 22.5 × 7.50, and the pneumatic tire had a pneumatic pressure of 900 [kPa] and a maximum load capacity specified by JATMA. Is granted. A pneumatic tire is mounted on a test vehicle which is a truck having a total weight of 25 tons.

  (1) In the evaluation regarding the water splash suppression performance, the test vehicle travels straight on a wet road having a water depth of 10 [mm], and the splash height of the water splash is photographed with a video camera and measured. Then, based on the measurement result, index evaluation is performed with reference to (100) when the tire is new in the conventional example. This evaluation is preferable as the numerical value increases. In addition, if the index at each stage at a wear rate of 0% (when a tire is new), a wear rate of 50% (middle wear), and a wear rate of 80% (end of wear) is 110 or more, the water splash suppression performance of the fin is appropriate. It can be said that it is demonstrated to.

  (2) In the evaluation regarding the anti-drop-off performance, the number of fins drop-off is observed after the test vehicle repeats the run-up test of the curbstone having a height of 250 [mm] 20 times. Then, based on this observation result, index evaluation is performed with the comparative example as a reference (100). This evaluation is preferable as the numerical value increases. In addition, if this evaluation is 50 or more, it can be said that it is in an allowable range.

  (3) In the evaluation relating to the attachment / detachment workability, the time required for the attachment / detachment work of the fins is measured, and based on this measurement result, index evaluation is performed with the comparative example as the reference (100). This evaluation is preferable as the numerical value increases.

  In the pneumatic tires 1 of Examples 1 to 11, the buttress portion has the three-stage fitting portions 7, and the fins 6 are detachably installed on these fitting portions 7 (see FIG. 2). Further, the inclination angle θ of the tangent l is θ = 35 [deg], and the groove depth G of the deepest circumferential main groove 22 is G = 18 [mm]. Further, the height H of the fin 6 is 15 [mm]. Further, the distance D1 of the contact point B of the fin 6 when the fin 6 is installed in the first-stage fitting portion 7 is D1 = 20 [mm], and the fin 6 is installed in the adjacent fitting portions 7 and 7. In this case, the arrangement interval ΔD of the fins 6 is ΔD = D2-D1 = D3-D2 = 9 [mm]. Accordingly, the arrangement interval ΔD is set on the assumption that the wear rate 100 [%] is shared by the three-stage fins 6, and the installation position of the fins 6 is moved to the rear stage side every time the wear rate advances 33 [%]. Moved.

  Moreover, the pneumatic tire 1 of Examples 1-11 has the cyclic structure where the fin 6 connects the some parts 62 and 63 so that division | segmentation is possible (refer FIG. 4 and FIG. 5). In the second embodiment, the end shapes of the parts 62 and 63 (the shape of the connecting portion) are flat and have a linear shape when viewed in the axial direction and radial direction of the fin 6 (not shown). On the other hand, in Examples 1 and 3 to 11, the end portions of the parts 62 and 63 have shapes that mesh with each other in at least one of the axial view and the radial view of the fin 6 (see FIG. 11).

  Further, in the pneumatic tires 1 of Examples 9 to 11, the center position of the convex portion 61 is disposed offset from the center position of the fin 6 in the tire radial direction outside (see FIG. 19). In Examples 10 and 11, the convex portion 61 has a shape curved outward in the tire radial direction from the root toward the tip side (see FIG. 21).

  Further, in Examples 12 to 18, the distance D1 between the road surface and the fin 6 and the adjacent fin 6 when the fin 6 is installed in the first-stage fitting portion 7 when the tire is new with respect to the first example. , 6 is different (see FIG. 22). In addition, a display unit 8 is provided to indicate when the first-stage fin 6 is attached and detached, and a distance Dm in the tire radial direction from the tire ground contact edge A to the display unit 8 and an arrangement interval ΔD between the adjacent fins 6 and 6 are provided. , Is set to a predetermined numerical value. Further, when the tire ground contact end A ′ and the display unit 8 coincide with each other due to the progress of wear, the first-stage fin 6 is removed and the second-stage fin 6 is attached. At this time, the distance between the tire ground contact edge A 'and the first-stage fin 6 is D1', and the distance between the tire ground contact edge A 'and the second-stage fin 6 is D2' (see FIG. 23).

  The conventional pneumatic tire has a single fin formed integrally with the buttress portion. This fin is located at the same position as the fin 6 installed in the first-stage fitting portion 7 in the pneumatic tire 1 of the first embodiment. Further, the pneumatic tire of the comparative example is the same as the pneumatic tire 1 of Example 1, but the fins 6 have a single structure, and the fins having a predetermined diameter are respectively attached to and detached from the fitting portions 7. Is done.

  As shown in the test results, it can be seen that in the pneumatic tire of Example 1, the water splash suppression performance of the tire can be maintained over the entire use period of the tire (see FIG. 24).

  Moreover, when Examples 1-8 are compared, the edge part shape of parts 62 and 63 has a meshing shape, Preferably, it has a three-dimensional meshing shape mesh | engaged in both the axial direction view and radial direction view of a fin. Thus, it can be seen that the drop-off resistance of the fin is improved (see FIG. 25). Further, when Examples 6 to 8 are compared, the width ratio W2 / W1 of the convex portion 61 whose base is narrowed is optimized, so that the fin 6 can be attached and detached while ensuring the drop-off resistance. It can be seen that it can be improved. Further, when Examples 6 and 9 are compared with each other, the center position of the convex portion 61 is offset from the center position of the fin 6 toward the outer side in the tire radial direction, so that the drop resistance of the fin 6 is improved. I understand. Further, when Examples 9 to 11 are compared, it can be seen that the protrusions 61 are curved outwardly in the tire radial direction with an inclination angle α within a predetermined range, whereby the drop-off resistance and workability of the fins 6 are improved.

  Further, when Example 1 is compared with Examples 12 to 18, the distance D1 between the road surface and the fin 6 when the tire is new, the tire ground contact end A ′ and the first-stage fin 6 at the attachment / detachment time of the first-stage fin 6. And the distance D2 ′ between the tire ground contact edge A ′ and the second-stage fin 6 when the first-stage fin 6 is cut off are set to 15 mm or more. Thus, it can be seen that the water splash suppressing effect is appropriately secured (see FIG. 26). Moreover, it turns out that the water splash suppression effect is ensured reliably by optimizing the position Dm of the display part 8 which shows the attachment or detachment time of the fin 6. FIG.

  DESCRIPTION OF SYMBOLS 1 Pneumatic tire, 21 and 22 Circumferential main groove, 31-33 Land part, 4 Fine groove, 5 Fine rib, 6 Fin, 7 Fitting part, 8 Display part, 9 Patch, 11 Bead core, 12 Bead filler, 121 Upper filler, 122 Lower filler, 13 Carcass layer, 14 Belt layer, 141-143 Belt ply, 15 Tread rubber, 16 Side wall rubber, 61 Convex part, 62 Body parts, 621, 622 End part, 63A, 63B Perimeter correction Parts, 71 recess, X curb

Claims (6)

It is a pneumatic tire provided with fins for water splash suppression in the buttress part,
The fin extends over the entire circumference of the buttress portion and is fitted and installed in a fitting portion formed in the buttress portion,
The plurality of fitting portions are arranged at different positions in the tire radial direction ,
The fins have a cyclic structure formed by connecting a plurality of parts to be divided, and,
A pneumatic tire comprising a display unit that indicates when the fins are attached and detached .   2. The pneumatic tire according to claim 1, wherein the arc length X of a predetermined part among the plurality of parts and the arrangement interval Y of the fitting portions have a relationship of X = 2πY + δ, where δ is a tolerance.   The pneumatic tire according to claim 1 or 2, wherein the adjacent parts are engaged with each other and connected.   The fitting portion is a concave portion formed on the wall surface of the buttress portion, and the fin has a convex portion whose root is narrowed in the tire radial direction, and the convex portion is inserted into the concave portion and the fitting is performed. The pneumatic tire according to any one of claims 1 to 3, wherein the pneumatic tire is fitted to a portion.   The pneumatic tire according to claim 4, wherein a center position of the convex portion is disposed offset from a center position of the fin in a tire radial direction outer side.   The pneumatic tire according to claim 4 or 5, wherein the convex portion has a shape curved outward in the tire radial direction from the root toward the tip side.

Images