JP6196555B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire that improves the appearance of a tire by preventing the depth of a lug groove extending beyond the ground contact end in the tire axial direction from appearing shallow.

  As shown in FIGS. 8 (A) and 8 (B), a lug groove a that extends outward in the tire axial direction beyond the ground contact end Te is generally formed in the tread portion of the pneumatic tire in order to enhance drainage performance. ing. However, even when the groove depth of the lug groove a is the same, the camber amount Ca that is the distance in the tire radial direction from the equator position Co on the tread surface to the outer end a1 of the lug groove a is small (FIG. 8B )), When the camber amount Ca is large (FIG. 8 (A)), the groove depth looks shallow, which reduces the appearance of the tire and gives the illusion that the wet performance is low. Invite fear.

  However, the position of the outer end a1, which is the camber amount Ca, depends on the split position between the tread mold and the side mold in the vulcanization mold. Therefore, it is difficult to extend the position of the outer end a1 to the inner side in the tire radial direction than the split position. Therefore, for a tire having a small camber amount Ca in the lug groove a, a new device is desired so that the lug groove a can be seen deeply.

JP2013-216119A

  Accordingly, an object of the present invention is to provide a pneumatic tire that can improve the appearance of the tire by preventing the depth of the lug groove from appearing shallow even when the camber amount of the lug groove is small.

The present invention is a pneumatic tire having a lug groove extending outward in the tire axial direction beyond the ground contact end in the tread portion,
On the outer surface of at least one of the sidewall portions, a ring-shaped first pattern region that is concentric with the tire shaft core and adjacent to the outer end of the lug groove in the tire radial direction,
The first pattern region has a plurality of first pattern portions spaced apart in the tire circumferential direction, and each of the first pattern portions extends on the outer surface of the sidewall portion in the tire circumferential direction. Alternatively, the present invention is characterized in that a plurality of striated bodies made of ridges are formed from a striated body row arranged in parallel in the tire radial direction.

  In the pneumatic tire according to the present invention, it is preferable that a circumferential width of the first pattern portion is smaller than a groove width at a ground contact end of the lug groove.

  In the pneumatic tire according to the present invention, the pitch number of the first pattern portion is preferably 1 to 3 times the pitch number of the lug grooves.

  In the pneumatic tire according to the present invention, it is preferable that the number of linear bodies forming the first pattern portion is 3 to 5.

  In the pneumatic tire according to the present invention, in the first pattern portion, it is preferable that the circumferential lengths of the respective linear bodies are equal to each other, or the linear bodies on the inner side in the tire radial direction are shorter.

  In the pneumatic tire according to the present invention, in the first pattern portion, it is preferable that each linear body is sequentially displaced to one side in the tire circumferential direction.

  In the pneumatic tire according to the present invention, the ratio Ca / H between the camber amount Ca and the tire cross-section height H, which is the distance in the tire radial direction from the equator position on the tread surface to the outer end of the lug groove, is 23%. This is particularly effective when:

  In the pneumatic tire according to the present invention, a second pattern region having a serration pattern in which ridges extending in the tire radial direction are juxtaposed in the tire circumferential direction may be arranged on the inner side in the tire radial direction of the first pattern region. preferable.

  The contact end means the position of the outermost end in the tire axial direction of the contact surface that comes into contact when a normal load is applied to a tire that is assembled with a normal rim and filled with a normal internal pressure.

  The “regular rim” is a rim determined for each tire in the standard system including the standard on which the tire is based, for example, a standard rim for JATMA, “Design Rim” for TRA, or ETRTO means "Measuring Rim". The “regular internal pressure” is the air pressure defined by the standard for each tire. The maximum air pressure for JATMA, the maximum value described in the table “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” for ETRA, Means "INFLATION PRESSURE", but in the case of passenger car tires, it is 180 kPa. The “regular load” is a load determined by the standard for each tire, and if it is JATMA, the maximum load capacity, and if it is TRA, the maximum value described in the table “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” If it is ETRTO, it is "LOAD CAPACITY".

  In the present specification, unless otherwise specified, the dimensions and the like of each part of the tire are values specified in the normal internal pressure state.

  As described above, according to the present invention, an annular first pattern region adjacent to the inner side in the tire radial direction is provided at the outer end of the lug groove, and a plurality of first patterns spaced apart in the tire circumferential direction are provided in the first pattern region. The pattern part is arranged.

  Thus, by arranging the plurality of first pattern portions in the tire circumferential direction at positions adjacent to the outer ends of the lug grooves, the tire circumferential direction of the lug grooves and the tire circumferential direction of the first pattern portions are arranged. Are recognized as a series of patterns. For this reason, the camber amount of the lug groove can be shown to be large by associating the first pattern portion with a part of the lug groove. As a result, the lug groove can be seen deeply, and the appearance of the tire can be improved.

  Moreover, each 1st pattern part is formed of the linear body row | line | column with which the several linear body body extended in a tire peripheral direction parallels in a tire radial direction. Therefore, the processing for the mold for forming the first pattern portion can be performed in the same manner as the processing for the conventional serration pattern, and the decrease in workability can be minimized. Moreover, since it can be made to harmonize with a serration pattern, the design property as the whole tire can be ensured highly.

It is sectional drawing which shows the right half of one Example of the pneumatic tire of this invention. It is an expanded view which shows the right half of the tread pattern. It is a fragmentary sectional view which expands and shows a part of outer surface of a side wall part. It is a partial side view which expands and shows a part of outer surface of a side wall part. It is a side view which expands and shows a 1st pattern part. (A), (B) is a side view which shows the other Example of a 1st pattern part. (A) is a partial side view of a 2nd pattern area | region, (B) is a partial enlarged view. (A), (B) is a fragmentary perspective view explaining the problem of the conventional tire.

Hereinafter, embodiments of the present invention will be described in detail.
As shown in FIG. 1, the pneumatic tire 1 of the present embodiment includes a tread portion 2, a pair of sidewall portions 3 extending inward in the tire radial direction from both ends in the tire axial direction, and each sidewall portion 3. And a bead portion 4 provided inward in the tire radial direction. In this example, the case where the pneumatic tire 1 is a passenger tire is shown.

  The internal structure of the pneumatic tire 1 is not particularly restricted, and a conventional well-known structure is suitably employed. In the case of this example, the pneumatic tire 1 includes a toroidal carcass 6 extending from the tread portion 2 through the sidewall portion 3 to the bead portion 4, and the carcass 6 on the outer side in the tire radial direction and inside the tread portion 2. Belt layer 7 to be applied.

  Further, the tread portion 2 is formed with a tread groove including a lug groove 9 extending beyond the ground contact end Te and extending outward in the tire axial direction. As shown in FIG. 2, the lug groove 9 of the present example extends outward in the tire axial direction from the outer circumferential groove 10 o disposed closest to the ground contact Te to the ground contact Te. In this example, the outer ends 9E in the tire axial direction of the lug grooves 9 are connected to each other by shallow design narrow grooves 11 extending in the tire circumferential direction in order to improve the design. As shown in FIG. 3, the design narrow groove 11 has, for example, a depth 11H of about 1.0 mm and a width 11W of about 5.0 mm, and is formed with substantially the same depth as the outer end 9E of the lug groove 9. ing. In the case of this example, the tire radial direction inner edge 11Ei of the design narrow groove 11 is the split position P between the tread mold and the side mold in the vulcanization mold.

  Next, as shown in FIGS. 3 and 4, the outer surface 3S of at least one of the sidewall portions 3 (hereinafter sometimes referred to as “sidewall surface 3S”) is concentric with the tire shaft and the lug groove. 9 is provided with an annular first pattern region 12 adjacent to the outer end 9E of the tire 9 on the inner side in the tire radial direction. In this example, an annular second pattern region 13 having a serration pattern is disposed on the inner side in the tire radial direction of the first pattern region 12.

  The first pattern region 12 includes a plurality of first pattern portions 14 spaced in the tire circumferential direction. In the present example, the first pattern region 12 has a small design protrusion 15 extending in the tire circumferential direction along the split position P between the first pattern portion 14 and the outer end 9E of the lug groove 9. The case where it is arranged further is shown. This design protrusion 15 is for blinding the parting line mark generated at the split position P, and the protrusion height 15H from the side wall surface 3S is as small as about 0.4 ± 0.2 mm, for example. Is set. The design protrusion 15 can be deleted upon request.

  As shown in FIG. 5, each first pattern portion 14 is formed as a linear body row 16 </ b> R in which a plurality of linear bodies 16 extending on the sidewall surface 3 </ b> S in the tire circumferential direction are arranged in parallel in the tire radial direction. The As the linear body 16, the groove | channel which is recessedly provided in the sidewall surface 3S, or the protruding protrusion can be employ | adopted. As shown in FIG. 3, in this example, the case where the linear body 16 consists of a protrusion is shown. As the cross-sectional shape of the linear member 16, a triangular shape having an apex angle θ of about 90 ± 20 °, for example, and a trapezoidal shape from which the top portion is deleted can be suitably employed. Note that a rectangular shape or a semicircular shape can also be adopted as required. Further, the height 16H from the side wall surface 3S of the linear body 16 (in the case of a groove, the depth from the side wall surface 3S) is not particularly limited, but is preferably about 0.4 ± 0.2 mm, for example. In this example, it is formed at substantially the same height as the design protrusion 15. Further, the arrangement pitch 16P between the filaments 16 is not particularly limited, but is preferably about 1.0 to 3.0 mm, for example. In FIGS. 4 to 6, the outline shape of the root portion is illustrated as the filament 16 for convenience. The linear body 16 may be a straight line extending in the tire circumferential direction or a curve concentric with the tire axis.

  The circumferential width 14W of the first pattern portion 14 is preferably smaller than the groove width 9W (shown in FIG. 2) at the ground contact Te of the lug groove 9. In this example, the case where the circumferential width 14W is constant, that is, the circumferential lengths of the linear bodies 16 are equal to each other in one first pattern portion 14 is shown. However, in the case where the circumferential width 14W is not constant (for example, as shown in FIG. 6B), in each of the first pattern portions 14, the circumferential length of each linear body 16 is a linear body on the inner side in the tire radial direction. In the case where the width is shortened by 16 or the like), the maximum value 14Wmax of the circumferential width 14W is made smaller than the groove width 9W. When the tread groove has plural kinds of lug grooves 9 having different groove widths 9W, the groove width 9W of the widest lug groove 9 is adopted.

  Thus, in the pneumatic tire 1, a plurality of first pattern portions 14 that are spaced apart in the tire circumferential direction are arranged at positions adjacent to the outer end 9 </ b> E of the lug groove 9. At this time, the arrangement in the tire circumferential direction at the outer end 9E of the lug groove 9 and the arrangement in the tire circumferential direction of the first pattern portion 14 are recognized as a series of patterns. Therefore, the 1st pattern part 15 is associated like a part of lug groove 9, and the camber amount Ca (shown in FIG. 1) of the lug groove 9 can be shown large. As a result, the lug groove 9 becomes deeper and the appearance of the tire is improved. The radial distance L (shown in FIG. 3) along the sidewall surface between the outer end 9E of the lug groove 9 and the outermost linear member 16 in the radial direction is 5 mm or less. This is preferable for recognition as a pattern. The first pattern portion 14 is formed on the outer side in the tire radial direction from the tire maximum width position Pm.

  Further, since the first pattern portion 14 is formed by the striate body row 16R, a mold for forming the first pattern portion 14 is processed by a mold for a serration pattern in the second pattern region 13, for example. This can be performed in the same manner as the processing, and the deterioration of workability can be minimized. In addition, it is possible to harmonize with other serration patterns, and it is possible to ensure high design properties as a whole tire. In addition, it is more advantageous in the point of workability to form the linear body 16 with a protrusion with a small amount of processing to a metal mold | die compared with the case where it forms with a groove.

  When the circumferential width 14W of the 1st pattern part 14 is more than the groove width 9W of the lug groove 9, it becomes difficult to recognize as a series of patterns, and the effect which makes the lug groove 9 look deep is reduced. The circumferential width 14W is preferably about 3 to 10 mm. Further, if the pitch number n1 of the first pattern portion 14 is too small or too large, it is difficult to recognize as a series of patterns. Therefore, it is preferable that the pitch number n1 of the first pattern portion 14 is 1 to 3 times the pitch number n2 of the lug grooves 9. In particular, by increasing the ratio n1 / n2 to a multiple of 0.5, or even a multiple of 1, and synchronizing the arrangement of the lug grooves 9 and the arrangement of the first pattern portions 14 will increase recognition as a series of patterns. Is preferable.

  As for the number of the linear bodies 16 which comprise one 1st pattern part 14, 3-5 are preferable. In order to improve the design, as shown in this example, within each first pattern portion 14, each linear body 16 is sequentially displaced to one side in the tire circumferential direction so that the first pattern portions 14 are parallel. It can be configured in a quadrilateral shape. In this case, it is preferable that the angle β of the side of the parallelogram with respect to the tire circumferential direction is 45 degrees or more. However, as shown in FIG. 6A, the first pattern portion 14 can be formed in a rectangular shape (β = 90 degrees) without being displaced. Further, as shown in FIG. 6B, the first pattern portion 14 can be formed in a trapezoidal shape as short as the linear member 16 on the inner side in the tire radial direction. In this case, the lug grooves 9 gradually converge. You can have an image as if it were.

  Note that in a tire with a small camber amount Ca in the lug groove 9, particularly in a tire with a small ratio Ca / H of the camber amount Ca to the tire cross-section height H of 23% or less, the lug groove 9 tends to appear shallow. Therefore, the present invention can exert a greater effect especially in a tire having the ratio Ca / H of 23% or less.

  Next, on the inner side in the tire radial direction of the first pattern region 12, a second pattern region 13 having a serration pattern for making the bulge and dent of the sidewall surface 3S inconspicuous is arranged next to each other.

  As shown in FIG. 4, the second pattern region 13 of this example includes at least one (one in this example) small design protrusion 18 i extending in the tire circumferential direction along the radially inner edge thereof, and At least one (three in this example) small design protrusion 18o extending in the tire circumferential direction along the radial outer edge is provided, and a serration portion 19 is formed between the design protrusions 18i and 18o. The

  The serration portion 19 is formed by the ridges 20 extending in the tire radial direction being arranged in parallel in the tire circumferential direction. As shown in FIG. 7B, the ridge 20 is formed as the remaining portion of the groove 21 recessed in the sidewall surface 3S in this example. That is, the ridge 20 of the present example is formed as a narrow ridge protruding from the groove bottom 21S at a small height, and the upper end surface thereof is the same height as the sidewall surface 3S. As the cross-sectional shape of the ridge 20, the same triangular shape, trapezoidal shape, rectangular shape, and semicircular shape as the linear body 16 are preferable, and the same shape as the linear body 16 is particularly preferable. The height 20H of the ridge 20 is also preferably in the range of 0.4 ± 0.2 mm, particularly the same height as that of the filament 16. 4 and 7A, only the ridgeline of the virtual top portion 20P of the ridge 20 is drawn for convenience.

  As shown in FIG. 7A, the serration portion 19 of the present example includes a plurality of pitch gradually increasing portions 22 formed of a group of ridges 20 in which the arrangement pitch of the ridges 20 gradually increases toward one side in the tire circumferential direction. In this example, the case where the pitch gradually increasing portions 22 are arranged adjacent to each other in the tire circumferential direction is shown, but a constant pitch portion (a group of ridges 20 having a constant arrangement pitch between the pitch gradually increasing portions 22 and 22 ( (Not shown) may be interposed. In the pitch gradually increasing portion 22, in the region where the arrangement pitch is small, the amount of reflected light decreases and this region appears dark. Conversely, in the region where the arrangement pitch is large, the amount of reflected light increases and this region appears bright. For this reason, the pitch gradually increasing part 22 forms a gradation of light. Further, by providing a plurality of pitch gradually increasing portions 22, the gradation of light is repeated and the contrast is enhanced, and the concealment effect of bulges and dents can be enhanced.

  When the arrangement pitch is expressed by the size of the central angle centered on the tire axis, the minimum arrangement pitch α1 of the pitch gradually increasing portion 22 is preferably 0.2 to 0.3 °, and the maximum arrangement pitch α2 is 0. It is preferably larger than 3 ° and not larger than 0.6 °. The difference between adjacent arrangement pitches is preferably 0.07 to 0.14 °.

  In the serration unit 19, a mark made up of characters, figures and the like can be formed. In addition to this, various conventional serration patterns can be employed as the serration pattern of the serration unit 19.

  As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.

  A pneumatic tire (size: 195 / 65R15) having the basic structure of FIG. 1 and having the pattern pattern shown in FIG. 4 on the sidewall surface was prototyped based on the specifications in Table 1 and evaluated for appearance. Each tire has substantially the same specifications except for the pattern in the first pattern region. For comparison, a comparative example 1 was formed in which the first pattern region was not provided and the second pattern region having the serration pattern was arranged adjacent to the outer end of the lug groove. The second pattern region has the same specifications for each tire.

The common specifications in the first pattern portion are as follows.
-Number of striatum: 4-Alignment pitch of striatum 16P: 1.3mm
・ Cross section of wire body ・ ・ Shape: Trapezoid ・ ・ Height (or depth) 16H: 0.4 mm
・ ・ Vertex angle θ: 90 degrees ・ ・ Width: 4.5mm

<Appearance>
The sample tire was assembled with a rim under the following conditions, and visually inspected for the appearance of the sidewall portion (how the groove depth of the lug groove looks). Evaluation is shown by the index | exponent which sets the comparative example 1 to 100, and the one where a value is large is excellent.

  As shown in Table 1, in the tires of the examples, the depth of the lug grooves can be seen deeply, and it can be confirmed that the appearance of the tire is improved. In addition, as compared with Examples 1 and 2, with respect to the appearance, it is better to form the striated body with the groove than the one formed with the ridge, but there is a disadvantage with respect to the workability of the mold. is there.

DESCRIPTION OF SYMBOLS 1 Pneumatic tire 2 Tread part 3 Side wall part 3S Outer surface 9 Lug groove 9E Outer end 12 1st pattern area 13 2nd pattern area 14 1st pattern part 16 Line body 16R Line body row 20 Ridge Te Grounding end

Claims (8)

A pneumatic tire having a lug groove extending outside the tire axial direction beyond the ground contact end in the tread portion,
On the outer surface of at least one of the sidewall portions, a ring-shaped first pattern region that is concentric with the tire shaft core and adjacent to the outer end of the lug groove in the tire radial direction,
The first pattern region has a plurality of first pattern portions spaced apart in the tire circumferential direction, and each of the first pattern portions extends on the outer surface of the sidewall portion in the tire circumferential direction. Or, a plurality of striated bodies made of ridges are formed from a striated body row arranged in parallel in the tire radial direction ,
Wherein the first pattern portion, the striatum pneumatic tire according to claim Rukoto to be shifted sequentially on one side in the tire circumferential direction. A pneumatic tire having a lug groove extending outside the tire axial direction beyond the ground contact end in the tread portion,
On the outer surface of at least one of the sidewall portions, a ring-shaped first pattern region that is concentric with the tire shaft core and adjacent to the outer end of the lug groove in the tire radial direction,
The first pattern region has a plurality of first pattern portions spaced apart in the tire circumferential direction, and each of the first pattern portions extends on the outer surface of the sidewall portion in the tire circumferential direction. Or, a plurality of striated bodies made of ridges are formed from a striated body row arranged in parallel in the tire radial direction,
The circumferential width of the first pattern portion is air-filled tire you, characterized in that is smaller than the groove width at the grounding end of the lug groove. A pneumatic tire having a lug groove extending outside the tire axial direction beyond the ground contact end in the tread portion,
On the outer surface of at least one of the sidewall portions, a ring-shaped first pattern region that is concentric with the tire shaft core and adjacent to the outer end of the lug groove in the tire radial direction,
The first pattern region has a plurality of first pattern portions spaced apart in the tire circumferential direction, and each of the first pattern portions extends on the outer surface of the sidewall portion in the tire circumferential direction. Or, a plurality of striated bodies made of ridges are formed from a striated body row arranged in parallel in the tire radial direction,
The number of pitches of the first pattern portion is air-filled tire you being a 1-3 times the number of pitches of the lug groove. A pneumatic tire having a lug groove extending outside the tire axial direction beyond the ground contact end in the tread portion,
On the outer surface of at least one of the sidewall portions, a ring-shaped first pattern region that is concentric with the tire shaft core and adjacent to the outer end of the lug groove in the tire radial direction,
The first pattern region has a plurality of first pattern portions spaced apart in the tire circumferential direction, and each of the first pattern portions extends on the outer surface of the sidewall portion in the tire circumferential direction. Or, a plurality of striated bodies made of ridges are formed from a striated body row arranged in parallel in the tire radial direction,
Wherein the first pattern portion, air pneumatic tire you, wherein the circumferential length is equal for each striatum. Wherein the first pattern portion, the circumferential length of each striatum, pneumatic tire according to any one of claims 1 to 3, wherein the shorter striatum radially inner tire. The pneumatic tire according to any one of claims 1 to 5 , wherein the number of the striate bodies forming the first pattern portion is 3 to 5 . The ratio Ca / H of the camber amount Ca, which is the distance in the tire radial direction from the equator position on the tread surface to the outer end of the lug groove, and the tire cross-section height H is 23% or less. The pneumatic tire according to any one of 1 to 6 . The radially inner side of the first pattern area, any claim 1-7, characterized in that the second pattern region having a serration pattern was parallel ridges extending in the tire radial direction in the tire circumferential direction is disposed The pneumatic tire according to Crab.

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