JP6848332B2 - Non-pneumatic tires - Google Patents

Description

The present invention relates to a non-pneumatic tire, and more particularly to a non-pneumatic tire capable of preventing rim detachment due to tire deformation when turning under a load.

In recent years, as tires used for light vehicles such as bicycles and wheelchairs, it has been proposed to use non-pneumatic tires that are puncture-less and do not require time and effort for maintenance (see, for example, Patent Document 1).

When such a non-pneumatic tire is used for a light vehicle, a groove or the like is provided on the side surface of the non-pneumatic tire so that the rim and the groove are fitted to be assembled into a rim. However, in such a configuration, since the non-pneumatic tire is simply fitted to the concave portion of the rim, the rim will come off if a lateral force is further applied by turning or the like while a vertical load is applied. There is a problem that it is easy to occur.

On the other hand, it has been proposed to devise a profile of a non-pneumatic tire and to suppress rim detachment by embedding a reinforcing member extending in the tire circumferential direction inside the tire (for example, Patent Document). 2). However, even if such a structure is adopted, there is a concern that the rim may still easily come off because the structure is such that the reinforcing member can easily rotate around the reinforcing member due to the reaction force from the ground contact surface during turning.

Japanese Unexamined Patent Publication No. 2009-286183 JP-A-2015-44436

An object of the present invention is to provide a non-pneumatic tire capable of preventing rim detachment due to tire deformation when turning under a load.

The non-pneumatic tire of the present invention for achieving the above object is a non-pneumatic tire provided with an annular tire body and a reinforcing member attached to the tire body, and the tire body is in the width direction thereof. It has a plurality of through holes that penetrate, and these through holes are intermittently arranged along the tire circumferential direction, and the reinforcing member is inserted into the through holes and crosses the tire body in the width direction. the Rukoto disposed so as to extend along the circumferential direction of the tire body, the extension portion in the tire circumferential direction through the outside of the extension portion and the through hole in the tire width direction through the inside of the reinforcing member is the through-hole The reinforcing member is made of an organic fiber cord .

In the present invention, the reinforcing member is arranged so as to extend along the circumferential direction of the tire body while crossing the tire body in the width direction, thereby suppressing rotation around the tire central axis and resistance to rim disengagement. Can be improved.

In the present invention, it is preferable that the reinforcing member is arranged in a range in which the distance from the radial outer top of the tire body is 0.5 SH or more and 0.95 SH or less with respect to the cross-sectional height SH of the tire body. This makes it possible to effectively improve the rim detachment resistance. More preferably, it is in the range of 0.65SH or more and 0.95SH or less.

In the present invention, the tire body has a plurality of through holes penetrating in the width direction thereof, these through holes are arranged intermittently along the tire circumferential direction, and the reinforcing member is inserted into the through holes in the tire body. Is preferably crossed in the width direction. As a result, the reinforcing member can be inserted after the tire is molded, so that the productivity can be improved.

In the present invention, it is preferable that the through holes are arranged periodically along the tire circumferential direction and are arranged at regular intervals. As a result, the tightening in the tire circumferential direction can be stabilized, so that the rim detachment resistance can be effectively improved.

In the present invention, the through hole preferably has a chamfered portion at its entrance. This makes it possible to prevent cracks due to the cord at the entrance of the through hole.

In the present invention, it is preferable that the cords constituting the reinforcing member are arranged so as to form a loop straddling a plurality of through holes. This makes it possible to effectively improve the rim detachment resistance.

In the present invention, the reinforcing member is preferably made of a steel cord or an organic fiber cord. This makes it possible to effectively improve the rim detachment resistance.

In the present invention, the tire body is preferably composed of a thermoplastic elastomer composition, a thermoreversible crosslinked elastomer, or a mixture thereof. As a result, the material can be recycled because it can be used repeatedly without deteriorating the physical properties.

In the present invention, the thermoreversible crosslinked elastomer preferably contains a maleic acid-modified olefin-based elastomer, a nitrogen-containing heterocyclic compound, an olefin-based resin, a styrene-based elastomer, and paraffin oil. As a result, it has good physical properties, high fluidity, and good moldability.

In the present invention, it is preferable that the nitrogen-containing heterocyclic compound is a nitrogen-containing heterocyclic polyfunctional alcohol, the olefin resin is polypropylene, and the styrene elastomer is a hydrogenated styrene / isoprene / butadiene block copolymer.

The non-pneumatic tire of the present invention can be suitably used for a tire for a light vehicle, and the rim detachment resistance can be effectively improved.

It is a meridian cross-sectional view which shows an example of the Embodiment which assembled the non-pneumatic tire of this invention to a rim. It is a meridian cross-sectional view which shows the position of the reinforcing member arranged in the non-pneumatic tire of FIG. It is a perspective view which shows the state which the reinforcing member is inserted into the through hole in the non-pneumatic tire of this invention. It is a top view which cuts out the through hole in the state which the reinforcing member is inserted in the non-pneumatic tire of this invention. The through holes formed in the non-pneumatic tire of the present invention are cut out and shown, and FIGS. (A) to (E) are plan views showing each modification. In the non-pneumatic tire of the present invention, the positions of the through holes are shown, and (a) to (c) are side views showing other modified examples. It is a top view which shows the other modification which shows the state which the reinforcing member is inserted into the through hole in the non-pneumatic tire of this invention. It is a top view which shows the other modification which shows the state which the reinforcing member is inserted into the through hole in the non-pneumatic tire of this invention. It is a top view which shows the other modification of the non-pneumatic tire of this invention in the state which the reinforcing member is inserted into a through hole. It is a perspective view which shows the other modified example in the state which the reinforcing member is inserted into the through hole in the non-pneumatic tire of this invention.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings. FIGS. 1 to 4 show a non-pneumatic tire T according to an embodiment of the present invention. In FIGS. 1 and 2, E is the tire equator, in FIG. 4, Tc is the tire circumferential direction and Tw is the tire width direction.

As shown in FIG. 1, the non-pneumatic tire T is composed of an annular tire body 3. The tire body 3 includes a tread portion 1 that comes into contact with the road surface during traveling, and a base portion 2 that is located inside the tread portion 1 in the tire radial direction and enters the inside of the rim R. The cross-sectional shape of the non-pneumatic tire T is symmetrical with respect to the tire equator E.

The tread portion 1 is a portion that actually functions as a tire by being exposed from the rim R and touching the ground during traveling. As shown in FIG. 1, the contour line of the tread portion 1 in the meridian cross section has a smooth substantially semicircular shape. In the aspect of FIG. 1, a groove 4 extending in the circumferential direction is provided on the surface of the tread portion 1 (particularly, a region that comes into contact with the road surface during use) for the purpose of obtaining drainage. The width, depth, extending direction and number of such grooves 4 may be determined according to the purpose of use of the tire, or the grooves 4 may not be provided.

As described above, the base portion 2 is arranged inside the tread portion 1 in the tire radial direction (rim R side). The shape of the base portion 2 is determined according to the rim R, and the base portion 2 in the embodiment of FIG. 1 has a tapered portion 2c formed between the side surface 2a and the bottom surface 2b so as to be inside the illustrated rim R. It has a polygonal shape. When the non-pneumatic tire T is fitted to the rim R, as shown in FIG. 1, the convex portion Rb (the portion protruding inward in the tire width direction) existing at the end of the rim flange Ra of the rim R becomes the base portion 2. The side surface 2a is pressure-welded near the outer end in the radial direction so that the non-pneumatic tire T does not easily come off from the rim R when the tire is used. A recessed portion may be formed on the outer end portion of the side surface 2a of the base portion 2 by pressure contacting the convex portion Rb of the rim R. This recessed portion may or may not be molded in advance as the shape of the side surface 2a of the base portion 2.

In the non-pneumatic tire T, as shown in FIGS. 3 and 4, a plurality of through holes 6 penetrating in the width direction of the tire body 3 are formed, and a reinforcing member 5 is arranged in these through holes 6. There is. More specifically, the reinforcing members 5 are sequentially arranged in the adjacent through holes 6, and extend along the circumferential direction on the outside of the base portion 2 while crossing the tire body 3 in the width direction through the through holes 6. are doing. By arranging the reinforcing members 5 so as to alternately have the extension portion in the tire circumferential direction and the extension portion in the tire width direction in this way, the rotation around the tire center axis is suppressed and the rim disengagement resistance is improved. can do.

As the reinforcing member 5, a steel cord, an organic fiber cord, or a cord coated with rubber or resin can be used. In particular, it is preferable to use an organic fiber cord from the viewpoint of arranging the cord on the tire body 3. Examples of the organic fiber cord include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), nylon, and aramid. Further, the code may be a single-line code or a double-line code. In the case of a double-track cord, it may be a twisted cord, a cord that is stacked, bundled, or arranged side by side, or the cord may be coated with rubber, resin, or the like. The cord coated with rubber may be vulcanized in advance. In order to arrange such a cord on the tire body 3 and form an annular shape in the circumferential direction, the end portion of the cord may be joined by fusion, fixed by a caulking tool, an adhesive may be used, or tied. Can be combined.

As shown in FIG. 2, the reinforcing member 5 is preferably located in the tire radial direction in a range in which the distance from the top P on the outer side in the tire radial direction is 0.5 SH or more and 0.95 SH or less with respect to the tire cross-sectional height SH. Is arranged in the range of 0.65SH or more and 0.95SH or less. By appropriately setting the position of the reinforcing member 5 in the tire radial direction with respect to the tire cross-sectional height SH, it is possible to effectively improve the rim detachment resistance. Here, if the position of the reinforcing member 5 in the tire radial direction is less than 0.5 SH, the rim detachment resistance cannot be sufficiently improved, and if it exceeds 0.95 SH, a through hole is formed from the lowermost surface of the base portion 2. Since it is not possible to secure a sufficient thickness in the vertical direction to the lowermost surface, it may not be possible to completely suppress the cord biting into the tire body 3 when assembling the rim, and as a result, the tire body 3 may be pierced. The rim assembly property deteriorates.

On the other hand, the through holes 6 for arranging the reinforcing members are formed intermittently along the tire circumferential direction. As described above, the reinforcing member 5 crosses the tire body 3 in the width direction in a state of being inserted into the through hole 6. By forming the through hole 6 for arranging the reinforcing member in this way, the reinforcing member 5 can be inserted after the tire is molded, so that the productivity can be improved. That is, since the reinforcing member 5 can be arranged without being integrally molded with the tire body 3, the production process can be simplified. The number of through holes 6 is preferably in the range of 10 to 180 and more preferably in the range of 15 to 60 on the tire circumference. Here, if the number of through holes 6 is less than 10 on the tire circumference, the reinforcing effect cannot be sufficiently obtained, and if it exceeds 180 on the tire circumference, the productivity deteriorates. The cross-sectional shape of the through hole 6 is not particularly limited, but for example, a circular shape, a quadrangular shape, a polygonal shape, a rhombus shape, or the like can be adopted. The hole diameter of the through hole 6 is preferably 0.3 mm to 12 mm, more preferably 1 mm to 7 mm.

As long as the through hole 6 is formed intermittently along the tire circumferential direction, the arrangement of the through hole 6 in the tire width direction is not particularly limited. 5 (a) to 5 (e) are shown by cutting out through holes formed in the non-pneumatic tire of the present invention. FIG. 5A is an example in which the through holes 6 are inclined with respect to the tire width direction and the adjacent through holes 6 are arranged in parallel. FIG. 5B is an example in which the through holes 6 are inclined with respect to the tire width direction, but the adjacent through holes 6 are not parallel to each other. FIG. 5C is an example in which a part of the through hole 6 is bent. FIG. 5D is an example in which the through hole 6 has a plurality of inflection points and is formed in a wavy shape. FIG. 5E is an example in which the through hole 6 has one inflection point.

The through holes 6 are arranged periodically along the tire circumferential direction and are arranged at regular intervals. Through holes 6 are arranged at equal intervals along the tire circumferential direction as shown in FIG. 6 (a) or close to each other as shown in FIG. 6 (b). When the tires 6a and 6b are arranged at regular intervals, the heights of the base portion 2 in the tire radial direction from the bottom surface 2b of the base portion 2 are different in the adjacent through holes 6a and 6b as shown in FIG. 6C. An example can be given of the case where the tires are arranged in such a manner. As shown in FIG. 6C, the heights of the through holes 6 in the tire radial direction can be different, but it is preferable to arrange the through holes 6 so that the heights in the tire radial direction are the same. .. By periodically arranging the through holes 6 along the tire circumferential direction and arranging them at regular intervals in this way, it is possible to stabilize the tightening in the tire circumferential direction, so that the rim disengagement resistance can be improved. It is possible to improve effectively.

The through hole 6 may be configured to have a chamfered portion at its entrance. Alternatively, instead of forming the chamfered portion, a reinforcing patch may be attached to the entrance of the through hole 6. In either case, it is possible to prevent cracks at the entrance of the through hole 6 due to rubbing between the through hole 6 and the cord.

FIGS. 7 to 10 show another modification showing a state in which the reinforcing member is inserted into the through hole in the non-pneumatic tire of the present invention. FIG. 7 shows an example in which one cord is arranged so as to form a loop straddling a pair of through holes 6 adjacent to each other, and such loops are arranged so as to be continuous in the tire circumferential direction. FIG. 8 shows an example in which one cord is arranged so as to form a loop straddling the through holes 6 adjacent to each other, and such a loop is intermittently arranged in the tire circumferential direction. In this way, in the non-pneumatic tire T, when the cords constituting the reinforcing member 5 are arranged in the through holes 6, the cords are arranged so as to form a loop straddling the plurality of through holes 6, so that the rim resistance resistance It is possible to effectively improve the detachability.

Further, when inserting the cord into the through hole 6, the cord can be inserted multiple times for one tire, or the cord can be inserted from both sides of the through hole 6. In FIG. 9, two reinforcing members 5a and 5b are inserted from both sides of the through hole 6, and the reinforcing members 5a and 5b are crossed with each other at the central portion of the through hole 6, and then the respective through holes inserted first. This is an example of arranging so as to come out from the entrance of 6. In this way, the composite of the two reinforcing members 5a and 5b may extend along the circumferential direction of the tire body 3 while crossing the tire body 3 in the width direction. In FIG. 10, one cord is inserted into the through hole 6, and the cord pulled out from one side in the tire width direction is guided through the lower side of the tire body 3 to the opposite side in the tire width direction, and is adjacent to the cord. This is an example of insertion into the through hole 6. Such a spiral arrangement is also possible.

In the non-pneumatic tire T, a thermoplastic resin, a thermoplastic elastomer composition, a thermoreversible crosslinked elastomer composition, or a mixture thereof is used as a material constituting the tire body 3 composed of the tread portion 1 and the base portion 2. Can be done. It is preferably composed of a thermoplastic elastomer composition, a thermoreversible crosslinked elastomer composition and a mixture thereof, or a tire material selected from the group consisting of foams thereof. By using these materials, moldability and material recyclability at the time of tire manufacturing can be improved.

Examples of the thermoplastic resin include olefin resins, polystyrene resins, polyester resins, polyamide resins, polyvinyl alcohol resins, polyacrylonitrile resins, polyacrylic acid resins, polyether resins, polycarbonate resins, and polyurethane resins. Examples include resins. These thermoplastic resins may be homopolymers, block copolymers, or random copolymers.

Examples of the thermoplastic elastomer include olefin-based elastomers, styrene-based elastomers, polyvinyl chloride-based elastomers, polyurethane-based elastomers, polyester-based elastomers, and polyamide-based elastomers. Examples of the olefin-based elastomer include ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), and ethylene-butene rubber (EBM). Examples of styrene-based elastomers include styrene-butadiene-styrene copolymer (SBS), styrene-isoprene-styrene copolymer (SIS), styrene / ethylene / propylene / styrene block copolymer (SEPS), and styrene / ethylene / butylene. -Styrene block copolymer (SEBS, hydrogenated additive of SBS), styrene / ethylene / ethylene / propylene / styrene block copolymer (SEEPS, hydrogenated styrene / isoprene / butadiene block copolymer) and the like can be mentioned. ..

Since the thermoreversible crosslinked elastomer composition can be repeatedly used while being melt-molded without deteriorating its physical properties, material recycling is possible. Further, the thermoreversible crosslinked elastomer composition has high flexibility and good low temperature characteristics, can be reinforced with a filler, is an elastomer having properties similar to vulcanized rubber, and is injected (like a thermoplastic resin). Injection) molding is possible, and no vulcanization step is required. The thermoreversible crosslinked elastomer composition contains a main chain selected from natural polymers and synthetic polymers, and is a side chain containing a hydrogen-binding cross-linking site or a side having both a hydrogen-binding cross-linking site and a covalent cross-linking site. Includes chain-containing thermoreversible crosslinked polymers.

The hydrogen-bonding cross-linking site is composed of a carbonyl-containing group and a nitrogen-containing heterocycle, and the carbonyl group of the carbonyl-containing group and the amino group of the nitrogen-containing heterocycle form a hydrogen bond. The nitrogen-containing heterocycle may be blended by adding a nitrogen-containing heterocycle-containing compound as a cross-linking agent. Examples of the carbonyl-containing group include a carbonyl group, a carboxyl group, an amide group, an ester group, and an imide group. The nitrogen-containing heterocycle may have a structure that contains or generates a hydrogen-bonding amino group in the heterocycle, and may contain other heteroatoms in the ring. The nitrogen-containing heterocycle is preferably a 5-membered ring or a 6-membered ring.

Examples of the compound containing a nitrogen-containing heterocycle include a nitrogen-containing heterocyclic alcohol, a nitrogen-containing heterocyclic amine, a nitrogen-containing heterocyclic polyfunctional amine, a nitrogen-containing heterocyclic alcohol, a nitrogen-containing heterocyclic thiol, and a nitrogen-containing heterocyclic polyfunctional. Nitrogen is preferred. In particular, by blending a nitrogen-containing heterocyclic polyfunctional alcohol and a nitrogen-containing heterocyclic polyfunctional amine, a hydrogen-bonding cross-linking site and a covalent-bonding cross-linking site are simultaneously formed to obtain high strength and compression-resistant permanent strain resistance.

The side chain containing the covalent bridging site reacts with a compound that produces a covalent bond consisting of a polyamine compound, a polyol compound, a polyisocyanate compound, a polythiol compound, etc., thereby amide, ester, lactone, urethane, ether, thio. It is not particularly limited as long as it is a side chain having a functional group capable of causing at least one bond selected from the group consisting of urethane and thioether. As such a functional group, a cyclic acid anhydride group, a hydroxyl group, an amino group, a carboxy group, an isocyanate group, a thiol group and the like are preferably exemplified. The side chain containing the covalently cross-linked site may be the same as the side chain containing the hydrogen-bonded cross-linked site described above.

The thermoreversible crosslinked elastomer composition is selected from thermoplastic elastomers, thermoplastic resins, and diene rubbers, in addition to the above-mentioned thermoreversible crosslinked polymers and compounds that form covalent bonds with nitrogen-containing heterocyclic compounds or nitrogen-containing heterocyclic compounds. At least one of these can be blended. The thermoreversible crosslinked elastomer composition preferably contains a maleic acid-modified olefin-based elastomer, a nitrogen-containing heterocyclic compound, an olefin-based resin, a styrene-based elastomer, and paraffin oil. By constructing the thermoreversible crosslinked elastomer composition in this way, it has good physical properties, high fluidity, and good moldability.

In the thermoreversible crosslinked elastomer composition, the nitrogen-containing heterocyclic compound is preferably a nitrogen-containing heterocyclic polyfunctional alcohol, the olefin resin is preferably polypropylene, and the styrene elastomer is preferably a hydrogenated styrene / isoprene / butadiene block copolymer. It would be nice to have it.

The thermoreversible elastomer composition includes 0.1 to 3 parts by mass of a nitrogen-containing heterocyclic compound, 50 to 150 parts by mass of an olefin resin, and 20 parts by mass of a styrene elastomer with respect to 100 parts by mass of a maleic acid-modified olefin elastomer. It is preferable to mix up to 80 parts by mass and 50 to 150 parts by mass of the elastomer oil. Further, here, the nitrogen-containing heterocyclic compound is a nitrogen-containing heterocyclic polyfunctional alcohol, the olefin resin is polypropylene, and the styrene elastomer is a hydrogenated styrene / isoprene / butadiene block copolymer. Is preferable.

The non-pneumatic tire of the present invention can be suitably used for a tire for a light vehicle such as a bicycle or a wheelchair, and the rim detachment resistance can be effectively improved.

In a non-pneumatic tire having a tire size of 24 × 1 3/8 and having an annular tire body and a reinforcing member attached to the tire body, the extending direction of the reinforcing member and the distance from the top of the reinforcing member. The tires of the conventional example and Examples 1 to 5 in which the above values were set as shown in Table 1 were manufactured.

The non-pneumatic tires of the conventional examples and Examples 1 to 5 use polyester cords as reinforcing members, and more specifically, three 1670 dtex yarns are aligned and yarned, and three yarns are twisted together. A polyester cord was used.

These test tires were evaluated for rim disengagement resistance and rim assembly by the following test methods, and the results are also shown in Table 1.

Rim removal resistance:
When each test tire is mounted on a wheelchair equipped with a rim size of 24 x 1 3/8, and a sharp turn is made on the floor of the floor with a slope of 5 degrees from a position with a run-up distance of 10 m, the rim comes off. It was tested whether or not. The evaluation was performed three times by one panelist, and when the rim came off even once, it was evaluated as "NG", and when it did not come off even once, it was evaluated as "OK". Described.

Rim assembly:
When each test tire was rim-assembled on a rim with a rim size of 24 × 1 3/4, the ease of rim assembly was sensuously evaluated based on the following criteria.
◎: Very easy to assemble 〇: Easy to assemble rim △: Slightly difficult to assemble rim ×: Very difficult to assemble rim

As can be seen from Table 1, by arranging the reinforcing members so as to extend along the circumferential direction of the tire body while crossing the tire body in the width direction, the tires of Examples 1 to 5 make a sharp turn on the inclined floor. Even at times, the rim did not come off. It was confirmed that the rim assembly property decreased as the distance from the top of the reinforcing member increased.

1 Tread part 2 Base part 2a Side surface of base part 2b Bottom part of base part 2c Tapered part of base part 3 Tire body 4 Groove 5 Reinforcing member 6 Through hole E Tire equatorial line R Rim Ra Rim flange Rb Rim convex part T Non-pneumatic tire

Claims (9)

In a non-pneumatic tire provided with an annular tire body and a reinforcing member attached to the tire body, the tire body has a plurality of through holes through which the tire body penetrates in the width direction, and these through holes are the tire circumference. are intermittently arranged along the direction, the reinforcing member is Ru are arranged so as to extend along the circumferential direction of the tire body while traversing the tire body in the width direction in a state of being inserted into the through hole As a result, the reinforcing member alternately has an extension portion in the tire width direction passing through the inside of the through hole and an extension portion in the tire circumferential direction passing outside the through hole, and the reinforcing member is made of an organic fiber cord. A non-pneumatic tire that features that. A claim characterized in that the reinforcing member is arranged in a range in which the distance from the radial outer top of the tire body is 0.5 SH or more and 0.95 SH or less with respect to the cross-sectional height SH of the tire body. Item 1. The non-pneumatic tire according to Item 1. The non-pneumatic tire according to claim 1 or 2 , wherein the through holes are periodically arranged along the tire circumferential direction and are arranged at regular intervals. The non-pneumatic tire according to any one of claims 1 to 3 , wherein the through hole has a chamfered portion at its entrance. The non-pneumatic tire according to any one of claims 1 to 4 , wherein the cords constituting the reinforcing member are arranged so as to form a loop straddling a plurality of through holes. The non-pneumatic tire according to any one of claims 1 to 5 , wherein the tire body is made of a thermoplastic elastomer composition, a thermoreversible crosslinked elastomer, or a mixture thereof. The non-pneumatic tire according to claim 6 , wherein the heat-reversible crosslinked elastomer contains a maleic acid-modified olefin-based elastomer, a nitrogen-containing heterocyclic compound, an olefin-based resin, a styrene-based elastomer, and paraffin oil. The above-mentioned nitrogen-containing heterocyclic compound is a nitrogen-containing heterocyclic polyfunctional alcohol, the olefin-based resin is polypropylene, and the styrene-based elastomer is a hydrogenated styrene / isoprene / butadiene block copolymer. Item 7. The non-pneumatic tire according to Item 7. The non-pneumatic tire according to any one of claims 1 to 8 , wherein the tire is for a light vehicle.

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