JP5922492B2 - Non-pneumatic tire manufacturing method and non-pneumatic tire - Google Patents

Description

  The present invention relates to a method for manufacturing a non-pneumatic tire including a substantially annular support structure and a transparent or translucent tread layer positioned on the outer peripheral side of the support structure, and the non-pneumatic tire.

  In a general pneumatic tire, a display mark made up of characters, numbers, symbols, figures, or the like indicating a tire size, a manufacturing lot number, a manufacturer name, a brand name, or the like is displayed on a sidewall portion.

  In the following Patent Document 1, an identification mark composed of letters, numbers, symbols, etc. is provided on the tread surface of an unvulcanized tire so that the type, size, etc. of the manufactured tire can be accurately identified in the tire manufacturing process. Printing. However, unvulcanized tires are exposed to high temperature and high pressure in the vulcanization process, and deformation and flow of the unvulcanized rubber occur, so that the finished tire has poor appearance such as distortion of identification marks. Moreover, the identification mark printed on the tread surface is mainly intended for identification in the manufacturing process, and there is a high possibility that identification will be impossible early due to the use of a tire.

  Patent Document 2 below describes a pneumatic tire that is mainly composed of a rubber layer and a fiber layer, and that covers the rubber layer with a transparent tread composed of an ultrafine silicon compound. A colored rubber layer can be provided between the transparent tread and the rubber layer to decorate the tire. However, the ultrafine silicon compound constituting the transparent tread is inorganic and cannot follow the deformation of the flexible rubber layer, which may cause problems such as separation and crushing. Further, also in this pneumatic tire, appearance defects such as distortion of the color rubber layer occur due to pressure in the vulcanization process.

  Patent Document 3 below discloses a pneumatic tire using a highly transparent rubber composition for a tire in at least one of a tread portion and a sidewall portion for the purpose of observing the internal structure of the tire from the outside. Yes. Even in this pneumatic tire, if a display mark is provided, distortion due to pressure in the vulcanization process is unavoidable.

JP 2011-46001 A Utility Model Registration No. 3071490 JP 2011-252090 A

  Accordingly, an object of the present invention is to provide a non-pneumatic tire manufacturing method and a non-pneumatic tire in which the durability of the display mark is improved while preventing the appearance defect of the display mark provided in the tread portion.

The above object can be achieved by the present invention as described below.
That is, the non-pneumatic tire manufacturing method of the present invention includes a step of forming a substantially annular support structure and a step of forming a tread layer positioned on the outer peripheral side of the support structure. A method,
A support structure molding step of molding the support structure by supplying a raw material of the first polymer material to the first cavity and curing it;
Before or after the support structure molding step, the transparent or translucent tread is obtained by supplying the second polymer material to the second cavity located on the outer periphery of the first cavity and curing it. A tread layer molding process for molding the layer;
Between the support structure molding step and the tread layer molding step, the display mark is applied to the surface molded first of the outer peripheral surface of the support structure or the inner peripheral surface of the tread layer. And a process.

  In the method for producing a non-pneumatic tire according to the present invention, after either one of the support structure and the tread layer is molded, the display mark is formed on the surface formed first on the outer peripheral surface of the support structure or the inner peripheral surface of the tread layer. Then, either the support structure or the tread layer is molded. Thereby, the non-pneumatic tire which provided the display mark in the tread part can be manufactured. This non-pneumatic tire has a tread layer that is transparent or translucent, so that the display mark provided on the tread portion can be visually recognized from the outside, and the display mark is covered with the tread layer, so that the durability is good. It becomes. In addition, according to the manufacturing method of the present invention, since a pressurizing step (molding by a compression method) is unnecessary, appearance defects such as display mark distortion can be prevented. Furthermore, the surface molded first of the outer peripheral surface of the support structure or the inner peripheral surface of the tread layer has already been cured, and the support structure or The display mark is less likely to be distorted when the tread layer is molded.

  In the method for producing a non-pneumatic tire according to the present invention, the polymer material is preferably a resin or an elastomer and can be molded by a casting method or an injection method. Thus, by molding the support structure and the tread layer, a pressurizing step (molding by a compression method) is unnecessary, and thus it is possible to appropriately prevent the appearance defect of the display mark.

  In the non-pneumatic tire manufacturing method according to the present invention, it is preferable to perform the tread layer molding step after the support structure molding step. By forming the support structure first, the visibility of the display mark is deteriorated even when an adhesive member or the like is provided on the back side of the display mark in order to give the display mark to the outer peripheral surface of the support structure. There is no.

  In the non-pneumatic tire manufacturing method according to the present invention, in the display mark applying step, the display mark is preferably applied to the outer peripheral surface of the support structure or the inner peripheral surface of the tread layer by printing or sticking. According to this configuration, display marks having various shapes and sizes can be easily provided on the tread portion.

  On the other hand, the non-pneumatic tire of the present invention comprises a substantially annular support structure made of a first polymer material and a transparent or translucent second polymer material located on the outer peripheral side of the support structure. A tread layer and a display mark provided on the outer peripheral surface of the support structure or the inner peripheral surface of the tread layer are provided.

  In this non-pneumatic tire, a display mark is provided in the tread portion, and the display mark is provided at the interface between the support structure and the tread layer. This non-pneumatic tire has a tread layer that is transparent or translucent, so that the display mark provided on the tread portion can be visually recognized from the outside, and the display mark is covered with the tread layer, so that the durability is good. It becomes. In addition, the support structure and the tread layer are molded from the respective polymer materials, and a display mark is provided on the first outer peripheral surface of the support structure or the inner peripheral surface of the tread layer, thereby providing a non-pneumatic pressure. When a tire is manufactured, a pressurizing step (molding by a compression method) becomes unnecessary, and appearance defects such as distortion of display marks can be prevented.

  In the non-pneumatic tire according to the present invention, the support structure connects the inner annular portion, the outer annular portion provided concentrically outside the inner annular portion, and the inner annular portion and the outer annular portion. It is preferable that it is comprised from the connection part which performs. Even when the support structure of the non-pneumatic tire has a configuration that does not have a sidewall portion like a normal pneumatic tire, according to the present invention, the display mark can be easily given to the tread portion. Visibility can be improved.

The front view and side view which show an example of the non-pneumatic tire of this invention AA sectional view of the non-pneumatic tire of FIG. Sectional drawing which shows the manufacturing process of a non-pneumatic tire typically Sectional drawing which shows typically the manufacturing process of the non-pneumatic tire which concerns on other embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, the configuration of the non-pneumatic tire of the present invention will be described. FIG. 1 shows an example of a non-pneumatic tire, which is a front view and a side view. Here, O indicates an axis. 2 is a cross-sectional view of the non-pneumatic tire of FIG. 1 taken along the line AA.

  The non-pneumatic tire T includes a substantially annular support structure SS made of a first polymer material, and a tread layer 6 made of a transparent or translucent second polymer material located on the outer peripheral side of the support structure SS. And. The support structure SS has a function of supporting a load from the vehicle. The outer peripheral surface of the tread layer 6 is in contact with the road surface.

  The non-pneumatic tire T of the present invention includes display marks 7 provided on the outer peripheral surface of the support structure SS or the inner peripheral surface of the tread layer 6. Here, the display mark 7 is given to the outer peripheral surface 3a of the support structure SS. The display mark in the present invention is a character, number, symbol, figure, or the like that displays a tire size, a production lot number, a manufacturer name, a brand name, and the like. Is provided. In this embodiment, an example in which a manufacturer name is used as the display mark 7 is shown. However, in the present invention, other characters, numbers, symbols, figures, or the like can be used.

  In the present embodiment, the display mark 7 is provided at the center in the tire axial direction, but the position where the display mark 7 is provided is not limited to this. The display mark 7 may be provided, for example, at the end in the tire axial direction. Note that the ratio of the area occupied by the display mark 7 to the tread portion may actually be smaller or larger. That is, for example, the display mark 7 may be provided over the entire width or the entire circumference of the tread portion.

  The display mark 7 can be directly printed on or adhered to the outer peripheral surface of the support structure SS or the inner peripheral surface of the tread layer 6. When the display mark 7 is pasted, it is preferable to use the display mark 7 obtained by laminating printing paper on which characters or the like are printed. Thereby, when manufacturing the non-pneumatic tire T, it can suppress that the display mark 7 is distorted. The display mark 7 does not have to be a thin sheet such as paper, and may have a certain thickness. In the case of the display mark 7 having a thickness, in the conventional tire manufacturing process, problems such as air accumulation are likely to occur around the display mark 7, but according to the present invention, such a problem is unlikely to occur.

  The display mark 7 is provided at the interface between the support structure SS and the tread layer 6. However, since the tread layer 6 is transparent or translucent, the display mark 7 provided in the tread portion can be visually recognized from the outside. . Further, since the display mark 7 is covered with the tread layer 6, durability is improved.

  As shown in the front view of FIG. 1, the non-pneumatic tire T according to the present embodiment includes an inner annular portion 1, an intermediate annular portion 2 provided concentrically on the outer side thereof, and an outer side thereof. An outer annular portion 3 concentrically provided, an inner coupling portion 4 that couples the inner annular portion 1 and the intermediate annular portion 2, and an outer coupling portion 5 that couples the outer annular portion 3 and the intermediate annular portion 2. I have. In this embodiment, the support structure SS includes the intermediate annular portion 2, but the intermediate annular portion 2 is not always necessary, and the intermediate annular portion 2 is not provided, and the inner connecting portion 4 and the outer connecting portion 5 are continuous. Thus, one connecting portion may be configured. Moreover, in this embodiment, although the some inner side connection part 4 and the outer side connection part 5 become a structure independent in the tire circumferential direction, the inner side connection part 4 and the outer side connection part 5 may be a single structure. Good.

  The polymer material constituting the support structure SS and the tread layer 6 is preferably a resin or an elastomer and can be molded by a casting method or an injection method. Examples of such resin or elastomer include polyolefin, polyvinyl chloride, polystyrene, methacrylic resin, polycarbonate, polyamide, polyimide, polyacetal, fluorine resin, urea resin, phenol resin, polyester, polyurethane, epoxy resin, melamine resin, silicon resin, etc. Is mentioned.

  Of the above polymer materials, polyurethane is preferably used from the viewpoints of molding / workability and freedom of material design. As the polymer material, a foam material may be used, and a material obtained by foaming the above polymer material may also be used.

  In the support structure SS integrally molded with the polymer material, all or part of the inner annular portion 1, the intermediate annular portion 2, the outer annular portion 3, the inner connecting portion 4, and the outer connecting portion 5 are reinforced with reinforcing fibers. It is preferable that

  Examples of the reinforcing fibers include reinforcing fibers such as long fibers, short fibers, woven fabrics, and non-woven fabrics. As a form using long fibers, fibers arranged in the tire axial direction and fibers arranged in the tire circumferential direction It is preferable to use a net-like fiber assembly composed of:

  Examples of the types of reinforcing fibers include rayon cords, polyamide cords such as nylon-6,6, polyester cords such as polyethylene terephthalate, aramid cords, glass fiber cords, carbon fibers, and steel cords.

  The tread layer 6 is provided on the outer peripheral side of the support structure SS. As shown in FIG. 2, the tread layer 6 of the present embodiment has a curvature in the tire axial direction. However, the tread layer 6 is not limited to this. May be. In a vehicle that corners with a camber, the tread layer 6 has a curvature, so that the variation of the contact area between straight traveling and cornering is reduced, and the turning performance can be improved.

  When the tread layer 6 has a curvature, the display mark 7 is preferably provided at the end in the tire axial direction. When the tread layer 6 has a curvature, the center portion in the tire axial direction is more likely to contact the ground than the end portion, and the center portion of the tread layer 6 is rubbed and the transparency is likely to be lowered. Therefore, the visibility of the display mark 7 is easily maintained for a long period of time by providing the display mark 7 at the end in the tire axial direction.

  The tread layer 6 is molded from a polymer material. Examples of the polymer material of the present invention include the above-described resins or elastomers that can be molded by a casting method and an injection method. Of the above polymer materials, polyurethane is preferably used from the viewpoint of molding / workability and freedom of material design. In particular, the polymer material used for the tread layer 6 is highly transparent after curing.

  On the outer surface of the tread layer 6, a pattern similar to that of a conventional pneumatic tire can be provided as a tread pattern.

  The non-pneumatic tire T of the present invention is useful as a tire used for a vehicle that travels at a low speed without applying a large load, such as a senior car, a personal mobility robot, a bicycle, and a wheelchair.

  Next, a method for manufacturing the non-pneumatic tire T of the present invention will be described. FIG. 3 is a cross-sectional view showing an example of a manufacturing process of the non-pneumatic tire T.

  The manufacturing method of the non-pneumatic tire T according to the present invention includes a support structure molding step of molding a support structure SS by supplying a raw material of the first polymer material to the first cavity and curing it, and a support structure Before or after the molding step, a tread that forms a transparent or translucent tread layer 6 by supplying the second polymer material to the second cavity located on the outer periphery of the first cavity and curing it. Between the layer molding process, the support structure molding process, and the tread layer molding process, the display mark 7 is applied to the surface molded first of the outer peripheral surface of the support structure SS or the inner peripheral surface of the tread layer 6. And a display mark applying step. In the manufacturing method according to the present invention, it is preferable to perform a tread layer molding step after the support structure molding step, and here, an example of manufacturing in this order is shown.

  First, as shown in FIG. 3A, an inner mold 13 for molding the inner peripheral surface of the inner annular portion 1 between the upper mold 11 and the lower mold 12 for molding both ends of the non-pneumatic tire T in the axial direction. A plurality of inserts 14 for molding the outer circumferential surface of the inner annular portion 1, the inner and outer circumferential surfaces of the intermediate annular portion 2, the inner circumferential surface of the outer annular portion 3, and the connecting portions 4, 5, and the outer annular portion 3. The outer mold 15 for molding the outer peripheral surface 3a is disposed and closed to form a first cavity C1 for molding the support structure SS. The first cavity C1 molds the cavity 21 for molding the inner annular portion 1, the cavity 22 for molding the intermediate annular portion 2, the cavity 23 for molding the outer annular portion 3, and the connecting portions 4 and 5. It comprises a cavity (not shown).

  The upper mold 11 is provided with a first injection hole 11a that allows the first cavity C1 to communicate with the outside. By supplying the raw material of the first polymer material constituting the support structure SS to the first cavity C1 through the first injection hole 11a, the raw material is supplied to the first cavity C1 as shown in FIG. 3B. And the support structure SS is molded by curing the raw material. In this figure, the first injection hole 11a is provided at a position facing the cavity 22 for molding the intermediate annular portion 2, but the position at which the first injection hole 11a is provided is not limited to this.

  Next, as shown in FIG. 3C, the outer mold 15 is removed from between the upper mold 11 and the lower mold 12 to expose the outer peripheral surface 3 a of the support structure SS. The direction in which the outer mold 15 is removed may be upward or sideward. The outer mold 15 may be appropriately divided in order to facilitate removal.

  A display mark 7 is applied to the outer peripheral surface 3a of the exposed support structure SS. The display mark 7 is provided by printing or pasting directly on the outer peripheral surface 3a. An adhesive member such as a double-sided tape or an adhesive can be used for attaching the display mark 7.

  Next, as shown in FIG. 3 (d), a tread mold 16 for molding the outer peripheral surface of the tread layer 6 is disposed between the upper mold 11 and the lower mold 12, and the mold is closed, and the tread layer 6 is molded. A second cavity C2 is formed. The second cavity C2 is a space located on the outer periphery of the first cavity C1 and surrounded by the tread mold 16 and the outer peripheral surface 3a of the already formed support structure SS.

  The upper mold 11 is provided with a second injection hole 11b that allows the second cavity C2 to communicate with the outside. By supplying the raw material of the second polymer material constituting the tread layer 6 to the second cavity C2 through the second injection hole 11b, the raw material is supplied to the second cavity C2 as shown in FIG. The tread layer 6 that is filled and integrated with the support structure SS is formed by curing the raw material. Finally, the non-pneumatic tire T constituted by the support structure SS and the tread layer 6 is removed from the mold.

  Examples of the molding method of the support structure SS and the tread layer 6 include an injection method or a casting method.

[Other Embodiments]
In the above-described embodiment, the method of performing the tread layer molding process after the support structure molding process has been described. However, the support structure molding process may be performed after the tread layer molding process. FIG. 4 is a cross-sectional view showing manufacturing steps for manufacturing in this order.

  First, as shown in FIG. 4A, a tread mold 16 for molding the outer peripheral surface of the tread layer 6 between the upper mold 11 and the lower mold 12 for molding both ends in the axial direction of the non-pneumatic tire T, and the tread. An inner circumferential side tread mold 17 for molding the inner circumferential surface of the layer 6 is disposed and the mold is closed to form a second cavity C2 for molding the tread layer 6. By supplying the raw material of the second polymer material constituting the tread layer 6 to the second cavity C2 through the second injection hole 11b, the raw material is supplied to the second cavity C2 as shown in FIG. 4B. The tread layer 6 is molded by filling and curing the raw material.

  Next, as shown in FIG. 4C, the inner peripheral side tread mold 17 is removed from between the upper mold 11 and the lower mold 12 to expose the inner peripheral surface 6 a of the tread layer 6. A display mark 7 is provided on the inner peripheral surface 6 a of the exposed tread layer 6.

  Next, as shown in FIG. 4D, the inner mold 13 for molding the inner peripheral surface of the inner annular portion 1 between the upper mold 11 and the lower mold 12, the outer peripheral surface of the inner annular portion 1, and the middle In order to mold the support structure SS by arranging the inner peripheral surface of the annular portion 2, the inner peripheral surface of the outer annular portion 3, and a plurality of inserts 14 for molding the connecting portions 4 and 5, and closing the mold. The first cavity C1 is formed. The first cavity C1 molds the cavity 21 for molding the inner annular portion 1, the cavity 22 for molding the intermediate annular portion 2, the cavity 23 for molding the outer annular portion 3, and the connecting portions 4 and 5. It comprises a cavity (not shown). The cavity 23 is a space surrounded by the insert 14 and the inner peripheral surface 6a of the tread layer 6 that has already been molded.

  By supplying the raw material of the first polymer material constituting the support structure SS to the first cavity C1 through the first injection hole 11a, the raw material is supplied to the first cavity C1 as shown in FIG. The support structure SS integrated with the tread layer 6 is molded by curing this raw material. Finally, the non-pneumatic tire T constituted by the support structure SS and the tread layer 6 is removed from the mold.

DESCRIPTION OF SYMBOLS 1 Inner ring part 2 Middle ring part 3 Outer ring part 3a Outer peripheral surface of support structure 4 Inner connection part 5 Outer connection part 6 Tread layer 7 Display mark C1 First cavity C2 Second cavity SS Support structure T Non-air pressure tire

Claims (6)

A step of molding a substantially annular support structure, located on the outer peripheral side of the support structure, a manufacturing method of a non-pneumatic tire comprising a step of molding a tread layer to have a curvature in the tire axial direction ,
A support structure molding step of molding the support structure by supplying a raw material of the first polymer material to the first cavity and curing it;
Before or after the support structure molding step, the transparent or translucent tread is obtained by supplying the second polymer material to the second cavity located on the outer periphery of the first cavity and curing it. A tread layer molding process for molding the layer;
Between the support structure molding step and the tread layer molding step, the outer surface of the support structure or the inner peripheral surface of the tread layer is the surface molded first and at the end in the tire axial direction. And a display mark applying step of applying a display mark.   The method for producing a non-pneumatic tire according to claim 1, wherein the polymer material is a resin or an elastomer and can be molded by a casting method or an injection method.   The method for manufacturing a non-pneumatic tire according to claim 1, wherein the tread layer molding step is performed after the support structure molding step.   The said display mark provision process WHEREIN: The said display mark is provided to the outer peripheral surface of the said support structure, or the inner peripheral surface of the said tread layer by printing or sticking, The Claim 1 characterized by the above-mentioned. Non-pneumatic tire manufacturing method. A support structure substantially annular made of a first polymeric material, positioned on the outer peripheral side of the support structure, made of a transparent or translucent second polymeric material to have a curvature in the tire axial direction tread A non-pneumatic tire comprising a layer and a display mark provided at an end in the tire axial direction on the outer peripheral surface of the support structure or the inner peripheral surface of the tread layer.   The support structure includes an inner annular portion, an outer annular portion concentrically provided outside the inner annular portion, and a connecting portion that connects the inner annular portion and the outer annular portion. The non-pneumatic tire according to claim 5.

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