JP2015000598A - Tire and method for production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire having a printing layer with reduced unprinted portions, and a method for production thereof.SOLUTION: A tire has spews, on a side wall part, protruding from a tire surface toward the outside in the tire radial direction, and the spew has a hollow shape comprising an outline portion and an inside portion of the outline portion. The height of the tire surface in the inside portion is lower than that of the outline portion. A thickness of the outline portion of the spew is 0.8 mm or less, and a height of the spew is 0.3 mm or more and 1.8 mm or less. The sidewall part has a printing layer whose height is lower than that of the spew. The spews are positioned within a range of 5% or less of a tire sectional height SH on the inside and outside of the tire radial direction from at least a tire maximum width part in the tire radial direction when the tire is incorporated into an application rim, filled with a specified inner pressure, and placed under an unloaded condition.

Description

  The present invention relates to a tire and a manufacturing method thereof.

  Conventionally, when a raw tire is vulcanized, a small hole called a vent hole is provided in the mold, and air in the mold is discharged from the small hole to suppress generation of residual air. At this time, a whisker-like rubber called a spew is formed.

  By the way, in general, in a tire, a predetermined character, symbol, pattern, or the like is displayed on a sidewall portion. For example, as disclosed in Patent Document 1, there is a technique of forming a display portion by printing.

JP 2012-030768 A

  However, the spew usually extends with a slight inclination with respect to the normal direction of the tire surface. Therefore, a tire surface portion that is a shadow of the spew is formed, and therefore, when the display portion is printed. There is a problem that a portion where ink cannot be applied is generated, and an unprinted portion is generated in the printed layer.

  Accordingly, an object of the present invention is to provide a tire having a printed layer with reduced unprinted portions and a method for manufacturing the tire.

  The present inventors have intensively studied to solve the above problems. As a result, the present invention has obtained a new finding that it is effective to reduce the unprinted portion by making the planar shape of the spew hollow and regulating its height and thickness within a predetermined range. It came to be completed. The gist configuration of the present invention is as follows.

  The tire of the present invention has a spew that protrudes from the tire surface toward the outer side in the tire radial direction at a sidewall portion of the tire, and the spew is a hollow shape including a contour portion and an inner portion of the contour portion. The inner surface of the tire has a height lower than that of the contour portion, the thickness of the contour portion of the spew is 0.8 mm or less, and the height of the spew is 0. 3 mm or more and 1.8 mm or less, and having a printing layer on the sidewall portion, and the height of the printing layer is lower than the height of the spew, the spew incorporates the tire into the application rim, and a prescribed internal pressure is set. When filled and unloaded, in the tire radial direction, at least from the tire maximum width portion to the inside and outside of the tire radial direction, the tire is located within a range of 5% or less of the cross-sectional height SH. It is characterized in. According to this structure, the unprinted part of a printing layer can be reduced.

  Here, “applicable rim” is an industrial standard effective in the area where tires are produced and used. In Japan, JATMA (Japan Automobile Tire Association) YEAR BOOK is used, and in Europe, ETRTO (European Tire and Rim Technical Organization). STANDARD MANUAL, refers to the rim defined in TRA (THE TIRE and RIM ASSOCIATION INC.) YEAR BOOK, etc. in the United States. The specified internal pressure refers to an internal pressure corresponding to the maximum load capacity of a tire of the above-mentioned standard in a tire of an applicable size. In addition, “the thickness of the spew” refers to the maximum thickness of the spew in a plan view. Furthermore, “the height of the spew” refers to the maximum height of the spew in a side view.

  In the present invention, the height of the spew is preferably 1.2 mm or less. By setting it as said range, the quality of printing can be improved, further reducing the unprinted part of an unprinted layer.

Furthermore, in the present invention, it is preferable that the area of the contour portion of the spew in a plan view is 25 mm ² or less. By setting it as said range, the discomfort produced by the rubbing of a side wall part can be reduced, protecting a printing layer.

  Furthermore, in the present invention, the thickness of the contour portion of the spew is preferably 0.1 mm or more and 0.5 mm or less. This is because, by setting the above range, it is possible to reduce the uncomfortable feeling caused by the rubbing of the sidewall portion while ensuring the rigidity of the spew.

  Here, the tire manufacturing method of the present invention includes a vulcanization step in which a raw tire is vulcanized using a mold to form a tire, and a printed layer on a sidewall portion of the tire formed by the vulcanization step. And in the vulcanization step, the sidewall portion protrudes from the tire surface toward the outer side in the tire radial direction at a position corresponding to a position of an air outlet provided in the mold. The spew has a hollow shape composed of a contour portion and an inner portion of the contour portion, and the height of the tire surface of the inner portion is lower than the height of the contour portion, The thickness of the contour part of the spew is 0.8 mm or less, the height of the spew is 0.3 mm or more and 1.8 mm or less, the height of the printed layer is lower than the height of the spew, Spew is before When the tire is incorporated into the applied rim, filled with the specified internal pressure, and brought into an unloaded state, in the tire radial direction, at least 5% of the cross-sectional height SH of the tire from the tire maximum width portion to the inside and outside of the tire radial direction It is located within the following range. According to this method, a tire in which the unprinted portion of the printed layer is reduced can be manufactured without man-hours.

  ADVANTAGE OF THE INVENTION According to this invention, the tire which has a printing layer which reduced the unprinted part, and its manufacturing method can be provided.

1 is a cross-sectional view in the width direction of a tire according to an embodiment of the present invention. It is a figure which expands and shows the point P vicinity of FIG. (A) (b) It is a top view which shows the spew 7. FIG. It is a side view which shows the spew 7. (A) It is a figure which shows typically the mode at the time of the printing in the manufacture process of the conventional tire. (B) It is a figure which shows typically the additional process in the conventional tire manufacturing process. It is a figure which shows typically the mode at the time of the printing in the manufacturing process of the tire concerning one Embodiment of this invention. It is sectional drawing which shows the vent hole on-off valve in an open state. It is sectional drawing which shows the vent hole on-off valve in a closed state.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

<Tire>
FIG. 1 is a cross-sectional view in the width direction of a tire according to an embodiment of the present invention. FIG. 1 shows a cross section in the tire width direction in a reference state in which a tire is incorporated in an applied rim, filled with a specified internal pressure, and in a no-load state. In FIG. 1, only one half of the tire width direction with the tire equatorial plane CL as a boundary is shown, but the other half is also the same, and is not shown. As shown in FIG. 1, this tire includes a pair of bead cores 1 a (only one side in the drawing), a carcass 2 straddling the bead core 1 a in a toroidal shape, and a tire radial direction of a crown portion of the carcass 2. It has a belt 3 and a tread 4 arranged on the outside.

  2 is an enlarged view of the vicinity of a point P (indicated by a dotted circle in FIG. 1) of the sidewall portion 5 of the tire in FIG. 1, particularly corresponding to the tire maximum width portion. As shown in FIG. 2, this tire has a spew 7 that protrudes from the tire surface 6 toward the tire outer surface side in the sidewall portion 5. The spew 7 is formed by rubber discharged together with air from an air discharge port provided in the mold when the tire is molded by vulcanizing a raw tire using a mold. Accordingly, the spew 7 is formed at a position corresponding to the position of the air discharge port of the mold. More specifically, as shown in FIG. 2, in the reference state, in the tire radial direction, at least a range Z of 5% or less of the tire cross-sectional height SH from the tire maximum width portion to the inside and outside of the tire radial direction. The spew 7 is located inside.

  FIGS. 3A and 3B are views of the tire spew 7 of the present embodiment as viewed from the tire outer surface side. As shown in FIGS. 3A and 3B, the spew 7 has a hollow shape including a contour portion 7a and an inner portion 7b. The height of the tire surface 6 of the inner portion 7b of the contour portion 7a of the spew 7 is lower than the height of the contour portion 7a. In the example shown in FIG. 3A, the spew 7 has an annular contour portion 7a having a thickness t in plan view, and thus the spew 7 has a hollow cylindrical shape. In addition, in the example shown in FIG. 3B, the spew 7 has a contour portion 7a having a shape having a thickness t on four sides of a square in a plan view. Therefore, the spew 7 has a hollow corner. It is cylindrical. Here, the thickness t of the contour portion 7a of the spew 7 is 0.8 mm or less. In FIGS. 3A and 3B, the thickness t of the contour portion 7a of the spew 7 is constant, but the thickness may be changed. Further, in the example shown in FIGS. 3A and 3B, the contour portion 7a of the spew 7 has a continuous shape, but the contour portion 7a may be interrupted in the middle. In this case, the inner portion 7b refers to the inner side when the contour portion 7a is virtually smoothly connected.

  FIG. 4 is a side view of the spew 7 of the tire according to the present embodiment. As shown in FIG. 4, in this example, the tire surface 6 inside the contour portion 7 a of the spew 7 has the same height as the tire surface 6 outside the contour portion of the spew 7. As in this example, in the present invention, the height of the tire surface 6 of the inner portion 7b of the contour portion 7a of the spew 7 is lower than the height of the contour portion 7a. Furthermore, the height of the spew 7 is not less than 0.3 mm and not more than 1.8 mm. And this tire has the printing layer 8 in the side wall part 5, and the height of this printing layer 8 is lower than the height of the spew 7. As shown in FIG. Hereinafter, the function and effect of the tire of this embodiment will be described.

  Fig.5 (a) is a figure which shows typically the mode at the time of the printing in the conventional tire manufacturing process. As shown in FIG. 5A, the conventional tire spew 7 has a solid cylindrical shape. As shown in FIG. 5A, conventionally, when the spew 7 is broken during printing, a shadowed portion of the spew 7 remains on the sidewall portion 5 of the tire as a large unprinted portion. On the other hand, FIG. 6 is a diagram schematically showing a state during printing in the tire manufacturing process of the present embodiment. As shown in FIG. 6, in this embodiment, the spew 7 has a hollow shape, and the height h of the spew 7 and the thickness t of the spew 7 are within the predetermined ranges. While having the spew 7 in the part 5, it is possible to reduce an unprinted part (area) when printing the display part or the like. That is, if the height h of the spew 7 is greater than 1.8 mm, the spew 7 tends to be inclined with respect to the tire radial direction, and a portion that becomes a shadow of the spew 7 is likely to occur on the tire surface. Further, if the height h of the spew 7 is more than 1.8 mm, the head becomes difficult to approach the tire surface 6 during printing, and print quality may be deteriorated. On the other hand, if the height h of the spew 7 is less than 0.3 mm, there is a concern that the spew portion is hitting the tire, and it is considered that a crack or the like starting from that portion may occur. It will not be sufficient as durability. Further, when the thickness t of the spew 7 is greater than 0.8 mm, for example, when the spew 7 has a solid columnar shape or a prismatic shape, if the sidewall portion 5 is rubbed during running, the spew 7 portion However, in the tire according to the present embodiment, the spew 7 is hollow, and the thickness t of the spew 7 is 0.8 mm or less. While playing the role of protecting the printing layer 8 when rubbed, the discomfort caused by the peeling of the printing layer 8 in the spew 7 portion can be minimized. Here, in the tire according to the present embodiment, the spew 7 is within the range of 5% or less of the cross-sectional height SH of the tire at least inside and outside the tire radial direction from the tire maximum width portion in the tire radial direction in the reference state. Therefore, in the vicinity of the tire maximum width portion that is most likely to be rubbed during traveling, the above-described effects can be obtained.

  Here, in the present invention, the height h of the spew 7 is preferably 1.2 mm or less. The inclination of the spew 7 can be further suppressed, the spout 7 can be prevented from obstructing printing, and the head during printing can easily approach the tire surface 6 to improve the printing quality. Because you can.

Moreover, in this invention, it is preferable that the area in planar view of the outline part 7a of the spew 7 is 25 mm < ² > or less. It is because it can prevent feeling of strangeness in the printing layer 8 further by setting it as the said range.

  Furthermore, in the tire of the present invention, the thickness t of the spew 7 is preferably 0.1 mm or more and 0.5 mm or less. By setting the thickness t to 0.1 mm or more, it is possible to ensure the rigidity of the spew 7 when the sidewall portion 5 is rubbed. On the other hand, by setting the thickness t to 0.5 mm or less, more This is because when the sidewall portion 5 is rubbed further, it is possible to prevent a sense of incongruity.

<Tire manufacturing method>
Next, the manufacturing method of the tire concerning one embodiment of the present invention is explained. This manufacturing method includes a vulcanization step of forming a tire by vulcanizing a raw tire using a mold, a step of forming a printed layer 8 on the sidewall portion 5 of the tire formed by the vulcanization step, including. Here, in the vulcanization process, the spew 7 protruding from the tire surface 6 toward the outer side in the tire radial direction is formed in the sidewall portion 5 at a position corresponding to the position of the air outlet provided in the mold. . More specifically, the spew 7 is within the range of 5% or less of the cross-sectional height SH of the tire in the tire radial direction at least inside and outside the tire radial width in the tire radial direction in the reference state. It is formed to be located. In the step of forming the printing layer 8, the height of the printing layer 8 to be formed is lower than the height h of the spew.

  The spew 7 as described above can be formed by using a vent hole opening / closing valve as shown in FIGS. 7 and 8 as an example. FIG. 7 is a cross-sectional view showing the vent hole on-off valve in the open state, and FIG. 8 is a cross-sectional view showing the vent hole on-off valve in the closed state. The spring body 9 urges the valve body 10 to close the valve hole 11, and the valve hole 11 is normally closed. First, as shown in FIG. 7, when the tire is molded, the tire raw cover 12 is pressed against the inner surface 13 of the mold by the molding pressure, and immediately before the tire raw cover 12 and the inner surface 13 of the mold are in close contact with each other, Residual air between the mold inner surface 13 raises the air pressure, pushes up the valve body 10 against the urging force of the spring body 9, opens the valve hole 11, and exhausts the residual air to the outside. On the other hand, as shown in FIG. 8, when the tire raw cover 13 is in close contact with the mold inner surface 12, the air pressure of the residual air between the mold inner surface 12 and the tire raw cover 13 is reduced, and the attachment by the spring body 9 is performed. Since the force exceeds the air pressure, the valve body 10 is pushed down and the valve hole 11 is closed. The spew 7 is formed by discharging the residual air by opening and closing the valve hole 11 as described above.

  As described above, the thickness t of the spew 7 formed by this manufacturing method is 0.8 mm or less, and the height h of the spew 7 is 0.3 mm or more and 1.8 mm or less. The thickness t and height h of the spew 7 and the hollow shape are, for example, in the above range and shape depending on the width and height H of the rubber reservoir 14 shown in FIGS. 7 and 8 and the shape. be able to.

  According to this tire manufacturing method, as described above, the printing layer has a printing layer with high printing quality and reduced unprinted portions, the printing layer can be protected from rubbing, and the spew portion is rubbed. It is possible to manufacture a tire that reduces the uncomfortable feeling at the time of wear. Furthermore, as shown in FIG. 6B, it is possible to reduce the man-hours as compared with the case where the spew 7 is cut off before printing and the sidewall portion 5 is smoothed.

  In order to confirm the effect of the present invention, tires according to Invention Examples 1 to 7 and Comparative Examples 1 to 5 were manufactured as trial products. The specifications of each tire are shown in Table 1 below. In Table 1, “range Z” means “range Z of 5% or less of tire cross-section height SH from the tire maximum width portion to the inside and outside in the tire radial direction”.

The following tests were conducted on the above tires.
<Discomfort>
The tires described above were mounted on a vehicle, and the uncomfortable feeling when observing the printed layer of the sidewall portion after traveling 10,000 km was evaluated. The sensory evaluation by 20 people was performed, and the case where there were 15 or more evaluators with a sense of incongruity was designated as C, the case where there were 5 or more people as B, and the case where there were less than 5 people as A.
<Rubbing evaluation>
Each of the above tires was mounted on a vehicle, and the degree of printing peeling of the printed layer on the sidewall portion after traveling 10,000 km was evaluated. Evaluation is evaluated by an index when the peeling area of the printed layer in the tire according to Comparative Example 1 is defined as 100. In Table 1, the smaller the numerical value, the smaller the peeling area.
<Unprinted part>
The presence or absence of a portion to which the printing paint did not adhere was evaluated by the evaluator's visual observation.
The evaluation results are shown in Table 1 below together with tire specifications.

  As shown in Table 1, none of the tires according to Invention Examples 1 to 7 have an unprinted portion when viewed by an evaluator, and the tires according to Comparative Example 1 have a better feeling of discomfort and rubbing. It can be seen that it is.

  ADVANTAGE OF THE INVENTION According to this invention, the tire which has a printing layer which reduced the unprinted part, and its manufacturing method can be provided.

1: Bead part, 1a: Bead core, 2: Carcass, 3: Belt, 4: Tread,
5: sidewall portion, 6: tire surface, 7: spew, 8: printed layer, 9: spring body,
10: valve body, 11: valve hole, 12: tire raw cover, 13: inner surface of mold, 14: rubber reservoir

Claims (5)

Tire,
In the sidewall portion of the tire, there is a spew protruding from the tire surface toward the outside in the tire radial direction,
The spew has a hollow shape composed of a contour portion and an inner portion of the contour portion,
The height of the tire surface of the inner part is lower than the height of the contour part,
The thickness of the contour portion of the spew is 0.8 mm or less,
The height of the spew is 0.3 mm or more and 1.8 mm or less,
The sidewall portion has a printing layer, and the height of the printing layer is lower than the height of the spew,
In the tire radial direction, when the tire is incorporated into the applicable rim, filled with a specified internal pressure, and is in a no-load state, the spew has at least a tire cross-sectional height from the tire maximum width portion to the inside and outside of the tire radial direction. The tire is located within a range of 5% or less of the length SH.   The tire according to claim 1, wherein a height of the spew is 1.2 mm or less. The tire according to claim 1 or 2, wherein an area of the contour portion of the spew in a plan view is 25 mm ² or less.   The tire according to any one of claims 1 to 3, wherein a thickness of the contour portion of the spew is 0.1 mm or more and 0.5 mm or less. A vulcanization process in which a raw tire is vulcanized using a mold to form the tire;
A step of forming a printed layer on the sidewall portion of the tire formed by the vulcanization step,
In the vulcanization step, a spew protruding from the tire surface toward the outer side in the tire radial direction is formed on the sidewall portion at a position corresponding to the position of the air outlet provided in the mold,
The spew has a hollow shape composed of a contour portion and an inner portion of the contour portion,
The height of the tire surface of the inner part is lower than the height of the contour part,
The thickness of the contour portion of the spew is 0.8 mm or less,
The height of the spew is 0.3 mm or more and 1.8 mm or less,
The height of the printed layer is lower than the height of the spew,
In the tire radial direction, when the tire is incorporated into the applicable rim, filled with a specified internal pressure, and is in a no-load state, the spew has at least a tire cross-sectional height from the tire maximum width portion to the inside and outside of the tire radial direction. A method for manufacturing a tire, wherein the tire is located within a range of 5% or less of the length SH.

Images