JP2013100030A - Tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel technology that obscures irregularities generated on an outer surface of a side part of a tire instead of disposing a number of ridges.SOLUTION: A decorative part 17 formed by printing is provided on at least a portion of an outer surface of at least one side 15 of a tire. The decorative part 17 extends along a tire circumferential direction and has a gradation portion 19 in which at least one from among hue, saturation, and brightness gradually changes in the tire circumferential direction.

Description

  The present invention relates to a novel technique for making inconspicuous unevenness that may occur in the manufacture or structure of a tire on the outer surface of a side portion.

  On the outer surface of the side portion of the tire, a joint portion where the end portions in the tire circumferential direction of the carcass layer are overlapped and a folded end portion in the tire radial direction appear as local unevenness. When the internal pressure of the tire is high or the thickness of the side rubber is thin, the tire is easily noticeable and the appearance of the tire is impaired. Conventionally, for the purpose of making such local unevenness inconspicuous, by arranging a large number of minute protrusions, usually called ridges, on the outer surface of the side portion of the tire, a belt-like decorative portion is formed. According to this, the unevenness can be made inconspicuous due to the reflection of light by the surface of the ridge.

Japanese Patent Application Laid-Open No. 2004-299662

  However, the ridges tend to crack due to stress concentration in the ridges or between the ridges due to repeated deformation of the side parts during running, and the ridges have a height with respect to the surface of the side parts. Therefore, there is a problem that air resistance during running increases.

  SUMMARY OF THE INVENTION Therefore, an object of the present invention is to propose a novel technique capable of making the unevenness generated on the outer surface of the side portion of the tire inconspicuous, instead of disposing a large number of ridges.

  The present invention has been made to solve the above problems, and the tire of the present invention includes a decorative portion formed by printing on at least a part of the outer surface of at least one side portion of the tire, The decorative portion has a gradation portion that extends along the tire circumferential direction and at least one of hue, saturation, and lightness gradually changes in the tire circumferential direction.

  According to the tire having such a configuration, local unevenness (steps) generated in the manufacturing or structure of the tire can be camouflaged on the outer surface of the side portion by the shade of the color of the gradation portion formed on the side portion of the tire. Therefore, the unevenness can be made inconspicuous. Also, the gradation part is a smooth surface formed by printing, and the air resistance due to the decoration part at the time of rolling of the tire can be greatly reduced compared to the case where the decoration part is formed with the ridge as in the prior art. In addition, a crack caused by the ridge as described above does not occur in the side portion. In this specification, “color shading” means that there is a difference (change) in at least one of hue, saturation, and brightness.

  In the tire of the present invention, the gradation portion preferably has a length in the tire circumferential direction of 5 mm to 300 mm, and according to this, the gradation of the gradation portion can be visually recognized reliably. The effect of making the unevenness inconspicuous can be obtained with certainty.

  In the tire according to the present invention, it is preferable that at least one of the hue, saturation, and brightness of the gradation portion gradually changes in the tire radial direction. It can be made even less noticeable.

  Furthermore, in the tire according to the present invention, the gradation portion preferably has a length in the tire radial direction (linear distance) of 5 mm to 100 mm. According to this, the gradation of the gradation portion is visually ensured. Therefore, the effect of making the unevenness inconspicuous can be surely obtained.

  Further, in the tire of the present invention, the surface of at least one side portion of the tire has a plurality of the gradation portions, and each gradation portion has a tire circumferential length of 5 mm to 300 mm and a tire radial direction length. The strip has a length (straight line distance) of 2 mm to 15 mm, and the gradation portion of the strip is continuously arranged in the tire circumferential direction so that the color gradation is repeated in the tire circumferential direction and the tire. It is preferable that two or more steps are arranged adjacent to each other in the radial direction, and the gradation phases of gradation portions adjacent to each other in the tire radial direction are shifted from each other in the tire circumferential direction. A gradation pattern can be formed. In addition, by providing a phase difference in the color gradation of the gradation part adjacent in the tire radial direction, the color gradation appears alternately in the tire radial direction, so that the unevenness (step) on the outer surface of the side part is even less conspicuous. can do. In addition, when a decorative part exceeding the width of the print head is formed by inkjet printing, printing must be performed in a plurality of times in the tire radial direction. By matching the boundary of the gradation part of the shape, the boundary of printing can be made inconspicuous.

  Furthermore, in the tire according to the present invention, the difference in light and shade phase between the gradation portions adjacent in the tire radial direction when viewed in the tire circumferential direction is 25% to 75 when 0% is the same phase. % Is preferable, and according to this, gradation portions adjacent in the tire radial direction can be reliably identified. That is, when the gradation phase difference between gradation portions adjacent to each other in the tire radial direction is less than 25% or exceeds 75%, the gradation portions adjacent to each other in the tire radial direction are visually integrated, and the outside of the side portion There is a possibility that the effect of making the unevenness (step) in the tire radial direction that appears on the surface inconspicuous decreases.

  Furthermore, in the tire according to the present invention, the strip-shaped gradation portion is arranged in three or more steps in the tire radial direction, and between the gradation portions adjacent to each other with one gradation portion interposed in the tire radial direction. It is preferable to arrange so that the phases of light and shade when viewed in the circumferential direction are the same, and according to this, it is possible to express a sense of unity and unity of colors.

  Furthermore, in the tire according to the present invention, the strip-shaped gradation portion is arranged in three or more steps in the tire radial direction, and between the gradation portions adjacent to each other with one gradation portion interposed in the tire radial direction. It is preferable that the phase difference between the shades when viewed in the circumferential direction is 0% to 30%, where 0% is the same phase. Can express a sense of speed and a sense of speed, and can create design unity.

  Furthermore, in the tire according to the present invention, it is preferable that the brightness difference (difference between the minimum value and the maximum value) of the gradation portion is 30% or more. According to this, the gradation of the gradation portion is visually Therefore, the effect of making the unevenness inconspicuous can be obtained with certainty.

  Furthermore, in the tire of the present invention, the hue difference in the gradation portion (difference between the minimum value and the maximum value of the hue) is preferably 30 degrees or more. According to this, the gradation in the gradation portion is visually Therefore, the effect of making the unevenness inconspicuous can be obtained with certainty.

  Furthermore, in the tire according to the present invention, the saturation difference in the gradation portion (difference between the minimum value and the maximum saturation value) is preferably 30% or more. Since it can be visually recognized reliably, the effect of making the unevenness inconspicuous can be obtained with certainty.

  Furthermore, in the tire according to the present invention, at least one of the hue, saturation, and brightness of the gradation portion is set to a color around the decoration portion (for example, from one end to the other end of the gradation portion in the tire circumferential direction). In this case, the gradation portion can be brought close to the ground color of the side portion of the tire to be visually adapted to the tire.

  Moreover, in the tire according to the present invention, it is preferable that the decorative portion is disposed 15 mm or more away from the rim line on the outer side in the tire radial direction, and according to this, adjacent to the outer side in the tire radial direction of the rim line. Therefore, it is possible to ensure the visibility of various displays required by laws and regulations provided.

  According to the present invention, the unevenness on the outer surface of the side portion can be camouflaged by the gradation portion of the decorative portion, so that the unevenness can be made inconspicuous.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a tire width direction cross-sectional view (half view) showing a pneumatic tire of a first embodiment according to the present invention in a rim assembled state. It is a partial side view which shows the side part of the tire of FIG. It is a figure which expands and shows one of the gradation parts in FIG. It is a partial side view shown in the state where the pneumatic tire of a 2nd embodiment according to this invention was assembled with a rim. (A) is a side view showing the pneumatic tire of Example 1 according to the first embodiment in a rim assembled state, and (b) is the pneumatic tire of Example 2 according to the first embodiment. It is a side view shown in the state which assembled rim. (A) is a side view showing the pneumatic tire of Example 3 according to the first embodiment in a rim assembled state, and (b) is the pneumatic tire of Example 4 according to the first embodiment. It is a side view shown in the state which assembled rim. (A) is a side view showing the pneumatic tire of Example 5 according to the first embodiment in a rim assembled state, and (b) is the pneumatic tire of Example 6 according to the first embodiment. It is a side view shown in the state which assembled rim. (A) is a side view showing the pneumatic tire of Example 7 according to the first embodiment in a rim assembled state, and (b) is the pneumatic tire of Example 8 according to the first embodiment. It is a side view shown in the state which assembled rim. (A) is a side view showing the pneumatic tire of Example 9 according to the first embodiment in a rim assembled state, and (b) is the pneumatic tire of Example 10 according to the first embodiment. It is a side view shown in the state which assembled rim. (A) is a side view showing the pneumatic tire of Example 11 according to the first embodiment in a state where the rim is assembled, and (b) shows the pneumatic tire of Comparative Example 1 in a state where the rim is assembled. It is a side view. (A) is a side view showing the pneumatic tire of Example 12 according to the second embodiment in a rim assembled state, and (b) is the pneumatic tire of Example 13 according to the second embodiment. It is a side view shown in the state which assembled rim. (A) is a side view showing the pneumatic tire of Example 14 according to the second embodiment in a rim assembled state, and (b) is the pneumatic tire of Example 15 according to the second embodiment. It is a side view shown in the state which assembled rim. (A) is a side view showing the pneumatic tire of Example 16 according to the second embodiment in a rim assembled state, and (b) is the pneumatic tire of Example 17 according to the second embodiment. It is a side view shown in the state which assembled rim. (A) is a side view showing the pneumatic tire of Example 18 according to the second embodiment in a rim assembled state, and (b) is the pneumatic tire of Example 19 according to the second embodiment. It is a side view shown in the state which assembled rim. (A) is a side view showing the pneumatic tire of Example 20 according to the second embodiment in a rim assembled state, and (b) is the pneumatic tire of Example 21 according to the second embodiment. It is a side view shown in the state which assembled rim. It is a partial side view shown in the state where the rim of the pneumatic tire of conventional example 1 according to the prior art was assembled.

  Embodiments according to the present invention will be described below in detail with reference to the drawings.

  As shown in FIG. 1, the present invention includes a pair of bead portions 3, a pair of sidewall portions 5 extending in the tire radial direction of the bead portion 3, and a tread portion 7 straddling between the sidewall portions 5. In addition, the carcass extends in a toroidal shape across the bead portion 3, the sidewall portion 5, and the tread portion 7, and the end portions thereof are folded around the bead core 9 embedded in each bead portion 3. Although it can be applied to a pneumatic tire that can include the layer 11 and the belt layer 13 disposed on the outer side in the tire radial direction of the carcass layer 11, of course, for a solid tire (not shown) having a solid structure Is also applicable. Further, the unevenness on the outer surface of the side part targeted by the present invention is not limited to that formed by the joint part of the carcass layer or the folded end part in the tire radial direction, and may occur in tire manufacturing or structure, for example, vulcanization Unevenness caused by uneven rubber flow at the time can also be targeted. Hereinafter, an example in which the present invention is applied to a pneumatic tire will be described.

  As shown in FIG. 1, the side portion 15 includes the sidewall portion 5 and the bead portion 3. More specifically, the side portion 15 extends from the outer edge in the tire width direction of the tread surface to the rim fitting portion of the bead portion 3. It shall mean a range. Here, “tread surface” means that when the tire is a pneumatic tire, the tread portion when the pneumatic tire is assembled to a regular rim, filled with regular internal pressure, and pressed against a flat surface with a regular load applied. Refers to the surface in contact with the flat surface. The regular rim means “standard rim” defined in JATMA, “Design Rim” defined in TRA, or “Measuring Rim” defined in ETRTO. The normal internal pressure means “maximum air pressure” defined by JATMA, the maximum value of “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” defined by TRA, or “INFLATION PRESSURES” defined by ETRTO. The normal 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. In the figure, symbol R is a rim. Further, in this specification, when “the length in the tire circumferential direction” and “the length in the tire radial direction” of the gradation portion are measured, the pneumatic tire is assembled to a normal rim, filled with a normal internal pressure, and measured in an unloaded state. It shall refer to the length.

  As shown in FIG. 2, the tire includes an annular decorative portion 17 formed by printing in at least a part of the outer surface of the side portion 15 of at least one (one in this example). In addition, the decoration part 17 does not necessarily need to cover the circumference of the side part 15, and may be provided intermittently or partially in the tire circumferential direction. The decorative portion 17 is spaced at least 15 mm from the rim line m outward in the tire radial direction in order to ensure the visibility of various indications (not shown) required adjacent to the outer side in the tire radial direction of the rim line m. It is preferable to provide them. The decorative portion 17 includes a plurality of gradation portions 19 formed by printing shown in an enlarged manner in FIG. 3, and each gradation portion 19 extends along the tire circumferential direction and has hue, saturation, and brightness (hereinafter, At least one of the "hue etc.") gradually changes in the tire circumferential direction from one end 19a in the tire circumferential direction toward the other end 19b. In addition, you may form the decoration part 17 in both the side parts 15 of a tire. Moreover, in forming the decoration part 17, known printing techniques, such as inkjet printing, letterpress printing, intaglio printing, and planographic printing, can be used.

  Hereinafter, the details of the decorative portion 17 will be described based on a specific example. The decorative portion 17 has a plurality of gradation portions 19, and each gradation portion 19 has a strip shape elongated in the tire circumferential direction. As shown in FIG. 2, the gradation portion 19 is continuously arranged in the tire circumferential direction so that color shades are repeated in the tire circumferential direction. Further, the gradation portion is arranged in two or more steps (here 12 steps) adjacent to each other in the tire radial direction. Further, the gradation phases of the gradation portions 19 adjacent to each other in the tire radial direction are shifted from each other in the tire circumferential direction.

  Further, the strip-shaped gradation portion 19 is arranged so that the shade phase between adjacent gradation portions 19 with one gradation portion 19 sandwiched in the tire radial direction is shifted to one side in the tire circumferential direction with a relatively small phase difference. Has been.

  In each gradation portion 19, in expressing gradation, any one of hue, saturation, and brightness is made constant, and the remaining two are gradually moved from one end 19a to the other end 19b in the tire circumferential direction. It may be changed, or any two of hue, saturation and lightness may be constant, and the remaining one may be gradually changed from one end 19a to the other end 19b in the tire circumferential direction. . Alternatively, the gradation of the gradation portion 19 may be expressed by gradually changing the hue, saturation, and brightness from the one end 19a to the other end 19b in the tire circumferential direction. In this example, each gradation portion 19 has a hue of 240 degrees and a saturation of 80%, and the brightness is changed from 80% to 30% (lightness difference 50%) from one end 19a to the other end 19b in the tire circumferential direction. It is composed of gradation that changes gradually (smoothly). In this embodiment, at least one of the hue, saturation, and brightness of the gradation portion 19 (in this case, brightness) is blackened from one end 19a to the other end 19b of the gradation portion 19 in the tire circumferential direction. (Lightness 0%), that is, it is changed so as to approach the ground color of the side portion 15 of the tire. Note that brightness, saturation, and hue are defined in an HSV model (also referred to as an HSV color space). In addition, lightness, saturation and hue can be measured by the following methods. That is, using a spectrocolorimeter (for example, manufactured by Konica Minolta), the brightness, saturation, and hue of the gradation portion 19 are measured in another system (for example, Lab color space) and then necessary software (for example, photoshop). (Registered trademark)) to convert to the HSV system. In addition, brightness, saturation, and hue may be measured by preparing or creating and identifying a color sample.In other words, a number of similar color samples are created by outputting paper from a personal computer to a printer. Simple identification may be performed by comparing the sample with the gradation portion 19.

  In this embodiment, each gradation portion 19 has at least one of hue, saturation, and brightness changed from one end (inner end) to the other end (outer end) in the tire radial direction in addition to the tire circumferential direction. doing. In this example, in the HSV model, each gradation portion 19 has two hues, saturations, and brightness values that are constant at 240% (degrees) and 80%, and the remaining brightness values from the inner end in the tire radial direction. The gradation is gradually (smoothly) changed from 80% (degrees) to 30 (degrees)% toward the outer end.

  In FIG. 2, reference numeral 21 denotes a mark composed of characters, symbols, etc. printed in a color (white in this case) different from that of the gradation portion 19 with the gradation portion 19 as a background portion. By providing the mark 21 so as to overlap with the mark 19, the visibility of the mark 21 can be improved.

  According to the tire having such a configuration, the joint portion in which the end portions in the tire circumferential direction of the carcass layer 11 generated on the side portion 15 are overlapped due to the color shade of the gradation portion 19 formed on the side portion 15 of the tire. Since it is possible to camouflage local irregularities (steps) due to folded ends in the tire radial direction, the irregularities can be made inconspicuous (hereinafter referred to as “camouflage effect”). Further, the gradation portion 19 is a smooth surface formed by printing, and greatly reduces the air resistance due to the decorative portion during rolling of the tire as compared with the case where the decorative portion is formed with the ridge as in the prior art. In addition, a crack caused by the ridge as described above does not occur in the side portion 15.

  Further, according to the tire of the above-described embodiment, at least one of the hue, saturation, and brightness of the gradation portion 19 is changed from one end 19a to the other end 19b of the gradation portion 19 in the tire circumferential direction. Since the gradation is changed so as to approach the ground color of the side portion 15, the gradation portion 19 can be visually adapted to the tire.

  Furthermore, according to the embodiment, since at least one of the hue, saturation, and lightness of the gradation portion 19 is gradually changed in the tire radial direction, in particular, the folded end portion of the carcass layer 11 and the like. It is possible to make the tire radial direction unevenness (step) generated visually inconspicuous.

  Furthermore, in the said embodiment, since each gradation part 19 was made into strip shape, a repeating gradation pattern can be formed in a tire peripheral direction. Further, by providing a phase difference (a phase difference in the tire circumferential direction) between the gradations of colors between the gradation portions 19 adjacent in the tire radial direction, the color gradations appear alternately in the tire radial direction. Concavities and convexities (steps) caused by the folded end or the like can be made even more inconspicuous. In addition, when the decorative portion 17 that exceeds the width of the print head is formed by ink jet printing, printing must be performed in a plurality of times in the tire radial direction, and at that time, the boundary of printing is adjacent to the tire radial direction. By matching the border of the strip-like gradation portion 19, the border of printing can be made inconspicuous.

  In the present invention, the gradation phase difference between the gradation portions 19 adjacent to each other in the tire radial direction when viewed in the tire circumferential direction is 25% to 75% when 0% is the same phase. Is preferable (50% in the above embodiment), and according to this, the gradation portion 19 adjacent in the tire radial direction can be reliably identified. That is, when the gradation phase difference between the gradation portions 19 adjacent to each other in the tire radial direction is less than 25% or exceeds 75%, the gradation portions 19 adjacent to each other in the tire radial direction are visually integrated, resulting in the carcass. There is a possibility that the effect of making the unevenness (step) in the tire radial direction caused by the folded end portion of the layer 11 inconspicuous decreases.

  In the present invention, the strip-shaped gradation portion 19 has a gradation phase difference of 0% when viewed in the tire circumferential direction between adjacent gradation portions 19 with one gradation portion 19 sandwiched in the tire radial direction. Are set to be slightly shifted to one side in the tire circumferential direction with a phase difference of 0% to 30% (in the above embodiment, the phase difference is 25%). As a whole, it can express “flow” and “feeling of speed”, and can create design unity. Instead of this, the strip-shaped gradation portion 19 may be arranged so that the gradation phases between the gradation portions 19 adjacent to each other with the gradation portion 19 in the tire radial direction are the same phase (not shown). According to this, it is possible to express a sense of unity and unity of colors.

  In the present invention, the gradation portion 19 preferably has a tire circumferential length L of 5 mm to 300 mm. Because, if the length L in the tire circumferential direction of the gradation portion 19 is less than 5 mm, the gradation effect of the gradation portion 19 cannot be sufficiently exerted, and the unevenness on the surface of the side portion 15 may not be sufficiently camouflaged. On the other hand, if it exceeds 300 mm, the change in hue and the like per unit length is reduced, and as a result, the gradation effect cannot be fully exhibited, and the unevenness of the surface of the side portion 15 may not be sufficiently camouflaged. Because there is.

  The gradation portion 19 preferably has a length in the tire radial direction of 5 mm to 100 mm. Because, if the length of the gradation portion 19 in the tire radial direction is less than 5 mm, the gradation effect of the gradation portion 19 cannot be sufficiently exhibited, and the unevenness of the surface of the side portion may not be sufficiently camouflaged. On the other hand, if the thickness exceeds 100 mm, the change in hue and the like per unit length becomes small, so that the gradation effect cannot be fully exhibited and the unevenness on the surface of the side portion 15 may not be sufficiently camouflaged. It is. Note that the gradation portion 19 has a maximum length in the tire circumferential direction of 300 mm, whereas the maximum length in the tire radial direction is set to 100 mm. A pneumatic tire has a cross section in the tire radial direction. This is because the change in shape is large, and if the distance in the tire radial direction is too long, the effect is reduced.

  In the present invention, when the brightness and saturation are constant and the hue is changed, the hue difference (difference between the minimum value and the maximum value of the hue) is preferably 30 degrees or more in the HSV model. This is because when the hue difference in the gradation portion 19 is less than 30 degrees, the camouflage effect by gradation may be insufficient.

  Similarly, when the hue and saturation are constant and the brightness is changed, the brightness difference (difference between the minimum value and the maximum value) is preferably 30% or more in the HSV model. This is because when the brightness difference in the gradation portion 19 is less than 30%, the camouflage effect due to gradation may be insufficient.

  Similarly, when the hue and lightness are constant and the saturation is changed, the saturation difference (difference between the minimum value and the maximum value of saturation) is preferably 30% or more in the HSV model. This is because when the saturation difference in the gradation portion 19 is less than 30%, the camouflage effect due to gradation may be insufficient.

  In the present invention, the decorative portion 17 is preferably provided in a range of at least 10 to 15 mm from the end of the tread pattern of the side portion 15 to the outer side of the rim line portion (portion substantially corresponding to the rim flange portion). This is because the unevenness of the side portion is likely to occur near the ply folding end, and the folding end is often disposed between the tread pattern end and the rim line position, and the maximum width is the largest. On the other hand, it is necessary to provide a display (tire size, etc.) defined by each standard (JATMA, ETRTO, etc.) near the rim line, but there are positions specified by each standard and the display is required inside the maximum width. Since there are many cases, a space for display is required outside the rim line about 10 to 15 mm. Therefore, it is preferable that the above decoration is not provided in the range for easy reading.

  FIG. 4 is a partial side view showing a side portion of a tire according to another embodiment of the present invention.

  The tire includes a decorative portion 25 formed by printing on at least a part of the outer surface of the side portion 15, and the decorative portion 25 extends in the tire circumferential direction and includes hue, saturation, and lightness. Although it is the same as the tire of the previous embodiment in that at least one has a gradation portion 27 that gradually changes in the tire circumferential direction, the configuration of each gradation portion 27 is different. That is, in the tire of this embodiment, the decorative portion 25 has a plurality of gradation portions extending in the tire circumferential direction while inclining toward one side of the tire circumferential direction with respect to the tire radial direction from the inner end to the outer end in the tire radial direction. 27 are arranged at predetermined intervals in the tire circumferential direction. In the illustrated example, in the HSV model, each gradation portion 27 has a constant hue of 240 degrees hue and 80% saturation, and lightness is 80% to 30% from the one end 27a to the other end 27b in the tire circumferential direction (lightness difference). 50%), which is composed of gradation that gradually changes (continuously). Of course, also in this embodiment, the gradation in the gradation portion 27 is not limited to the illustrated example, and can be expressed by gradually changing two or all of hue, saturation and brightness. Also in this embodiment, a mark 29 (white) made of characters or the like is provided by printing so as to overlap the gradation portion 27.

  According to the tire of this embodiment, as in the tire of the previous embodiment, the end of the carcass layer 11 in the tire circumferential direction of the carcass layer 11 generated on the side portion 15 due to the color shade of the gradation portion 27 formed on the side portion 15 of the tire. Since it is possible to camouflage local irregularities (steps) due to the joint portions where the portions are overlapped or the folded end portions in the tire radial direction, the irregularities can be made inconspicuous. Further, the gradation portion 27 is a smooth surface formed by printing, and greatly reduces the air resistance due to the decorative portion during rolling of the tire as compared with the case where the decorative portion is formed with the ridge as in the prior art. In addition, cracks caused by the ridge as described above do not occur in the side portion. In the decoration shown in FIG. 2, the gradation portion is divided into strips in the tire radial direction, so that the printing range can be easily separated, and is particularly suitable when it is required to widen the printing width in the tire radial direction. On the other hand, in the present embodiment shown in FIG. 4, the gradation portion extends in the tire radial direction as opposed to the decoration in FIG. 2, so that a dynamic impression can be given.

  The above description is only a part of the present invention, and various changes and improvements can be made in the present invention. For example, the color (hue) of the gradation portion may be substantially matched with the color of the vehicle body on which the tire is mounted, and according to this, a design integrated with the vehicle body can be created.

  In the tire according to the embodiment according to the present invention, the brightness difference, the saturation difference, and the hue difference of the gradation portion are changed, and the unevenness generated in the side portion of each tire is visually checked, and the experiment is performed on the conspicuousness of the unevenness. Since it went, it demonstrates below.

  Here, the tires of Examples 1 to 11 have a size of 195 / 65R15, respectively, and are provided with the decorative portions shown in FIG. 5 to FIG. In the tires of Examples 1 to 11, the arrangement range of the decorative portion is an annular region extending from the rim line to the outer side in the tire radial direction and extending to 55 mm from the position of 15 mm in the tire radial direction. The tire circumferential direction length and tire radial direction length of the strip-shaped gradation part, and the lightness difference (%), saturation difference (%) and hue difference (degree) in the tire circumferential direction according to the HSV model of the gradation part are As shown in Table 1.

  The tire of Comparative Example 1 has a size of 195 / 65R15, and has a decorative portion shown in FIG. In the tire of Comparative Example 1, the arrangement range of the decorative portion is an annular region extending from the rim line to the outer side in the tire radial direction and extending to 55 mm as viewed in the tire radial direction from a position of 15 mm. The tire circumferential direction length and tire radial direction length of the strip-shaped gradation part, and the lightness difference (%), saturation difference (%) and hue difference (degree) in the tire circumferential direction according to the HSV model of the gradation part are As shown in Table 1.

  In addition, the tires of Examples 12 to 21 have a size of 195 / 65R15, respectively, and include the decorative portions shown in FIGS. 11 to 15 on the side portions. In the tires of Examples 12 to 21, the arrangement range of the decoration portion is an annular region extending from the rim line to the outer side in the tire radial direction and extending to 55 mm from the position of 15 mm in the tire radial direction. The tire circumferential direction length and the tire radial direction length of the gradation part, and the brightness difference (%), saturation difference (%) and hue difference (degree) of the tire circumferential direction and the tire radial direction according to the HSV model of the gradation part. Is as shown in Table 2.

  The tire of the conventional example has a size of 195 / 65R15, and a decorative part is formed by a ridge on the side part as shown in FIG.

  The conspicuousness of the unevenness was judged by visual observation after mounting each test tire on a rim of size 6J × 15 and filling the maximum internal pressure (240 kPa) based on JATMA standard. The evaluation results are shown in Tables 1 and 2. The results shown in Tables 1 and 2 were evaluated by 30 observers in three stages. When less than 10 people obtained an opinion that the unevenness was conspicuous, "2" when the opinion that the unevenness is conspicuous is 10 or more and less than 20 people, and "1" when the opinion that the unevenness is conspicuous is 20 or more It is said.

  As can be seen from the results of Tables 1 and 2, according to the tires of Examples 1 to 21 to which the present invention is applied, the tire is produced on the outer surface of the side part of the tire at almost the same level as the case where the decorative part is formed by the ridge. It can be seen that the unevenness can be made inconspicuous.

  Thus, according to the present invention, it has become possible to propose a novel technique capable of making the unevenness generated on the outer surface of the side portion of the tire inconspicuous, instead of arranging a large number of ridges.

3 Bead part 5 Side wall part 7 Tread part 9 Bead core 11 Carcass layer 13 Belt layer 15 Side part 17 Decoration part 19 Gradation part 25 Decoration part 27 Gradation part m Rimline R Rim

Claims (13)

  At least a part of the outer surface of at least one side portion of the tire includes a decorative portion formed by printing, and the decorative portion extends in the tire circumferential direction and has at least one of hue, saturation, and brightness. One of the tires has a gradation portion that gradually changes in the tire circumferential direction.   The tire according to claim 1, wherein the gradation portion has a length in the tire circumferential direction of 5 mm to 300 mm.   The tire according to claim 1 or 2, wherein at least one of hue, saturation, and brightness of the gradation portion gradually changes in the tire radial direction.   The tire according to claim 3, wherein the gradation portion has a length in the tire radial direction of 5 mm to 100 mm. The surface of at least one side portion of the tire has a plurality of gradation portions, and each gradation portion has a strip shape in which the length in the tire circumferential direction is 5 mm to 300 mm and the length in the tire radial direction is 2 mm to 15 mm. Yes,
The strip-shaped gradation portion is continuously arranged in the tire circumferential direction so that color shades are repeated in the tire circumferential direction and arranged in two or more steps adjacent to each other in the tire radial direction,
The tire according to claim 1, wherein the gradation phases of gradation portions adjacent to each other in the tire radial direction are shifted from each other in the tire circumferential direction.   6. The tire according to claim 5, wherein a difference in gradation phase between the gradation portions adjacent in the tire radial direction when viewed in the tire circumferential direction is 25% to 75% when 0% is the same phase. .   The strip-like gradation portions are arranged in three or more stages in the tire radial direction, and the gradation phases when viewed in the tire circumferential direction between the gradation portions adjacent to each other with one gradation portion sandwiched in the tire radial direction are the same. The tire according to claim 5 or 6 arranged so that it may become a phase.   The strip-shaped gradation portion is arranged in three or more steps in the tire radial direction, and the difference in light and shade phase when viewed in the tire circumferential direction between adjacent gradation portions sandwiching one gradation portion in the tire radial direction. The tire according to claim 5 or 6, wherein the tire is arranged to be 0% to 30% when 0% is in the same phase.   The tire according to any one of claims 1 to 8, wherein a difference in brightness of the gradation portion is 30% or more.   The tire according to any one of claims 1 to 9, wherein a hue difference of the gradation portion is 30 degrees or more.   The tire according to any one of claims 1 to 10, wherein a saturation difference in the gradation portion is 30% or more.   The at least one of hue, saturation, and lightness of the gradation portion is changed so as to approach the decorative portion peripheral color from one end to the other end in the tire circumferential direction of the gradation portion. Tire described in.   The tire according to any one of claims 1 to 12, wherein the decorative portion is disposed 15 mm or more away from the rim line on the outer side in the tire radial direction.