JP2012224134A - Non-pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blowout-less non-pneumatic tire improved in shock absorbing performance and reduced weight.SOLUTION: The non-pneumatic tire 10 includes a tire body 11, and a tire base 12 all or part of which is encircled by the tire body 11, the tire base 12 being a foam. The tire base 12 exists ranging from a rim bottom through a rim flange to the further tire radial outside than the rim flange. In the cross section of the tire on the further tire radial outside than the rim flange, the area of the tire base 12 is 0.1-0.5 time the total area of the tire. In the cross section of the tire on the further tire radial inside than the rim flange, the area of the tire base 12 is 0.2-0.8 time the total area of the tire. The tire base 12 being the foam has an expansion ratio of 20-400%. The percentage of a tire assembly width in the state that no binding occurs to the rim width of an assembly rim 15 is 103-134%. The non-pneumatic tire 10 is manufactured using an injection molding method.

Description

The present invention relates to a structure of a non-pneumatic tire, and more particularly to a non-pneumatic tire for a light vehicle such as a bicycle, a wheelchair, and a golf cart.

Pneumatic tires are mainly used for light vehicle tires such as bicycles, wheelchairs, golf carts, etc. However, in recent years, non-pneumatic tires have been proposed due to advantages such as punctures, and some of them have been put into practical use. Has been.

This non-pneumatic tire is usually a so-called solid tire, and FIG. 8 is a diagram showing an example of a cross-sectional structure of a conventional annular (tube-shaped) non-pneumatic tire. A non-pneumatic tire 201 shown in FIG. 8 includes a tire body 202 and a rim 205 on which the tire body 202 is assembled. In FIG. 8 (a), the tire body 202 is formed of a solid annular body made of a rubber material or the like. Grooves 203 are formed on both sides of the tire body 202 over the entire circumference of the tire. The groove 203 of the tire body 202 is fitted to the flange protrusion 206 of the rim 205, and the tire body 202 and the rim 205 are fixed. Further, a tread groove 204 is provided on the ground contact surface of the tire as necessary. The material used here is an ordinary rubber such as natural rubber, styrene-butadiene rubber (SBR), butadiene rubber (BR), or isoprene rubber (IR). Although not shown, the rim 205 is integrated with a wheel that is a wheel fitted with a tire, and the wheel includes a rim 205, a spoke, a hub, and the like.

Further, as a tire that is not punctured (a punctureless tire), a part 207 of the solid tire main body 202 as shown in FIG. 8B has a hollow structure so that the overall weight reduction and shock absorption effect can be obtained. Non-pneumatic tires for wheelchairs and automobiles have also been proposed. (Patent Document 1)

JP2010-184686A

FIG. 8 is a view showing a single-layer solid tire using a conventional non-foamed normal rubber. The solid tire shown in FIG. 8A is made of a normal rubber such as natural rubber, styrene-butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), etc. Or it is inferior in buffering property and is not comfortable to ride, and there is also a problem in terms of weight reduction. Further, since the tire width when the tire main body 202 is free and the rim width of the rim 205 are approximately the same, the rim is likely to be detached when the tire main body 202 is assembled to the rim 205. That is, it is inferior in rim detachment resistance.

In order to solve the shock-absorbing property and weight reduction, it has been proposed to provide a hollow portion (cavity) 207 inside the tire body 202 as shown in FIG. In the case of a solid tire with a cavity in which the tire width is approximately the same as the rim width (tire width≈rim width), and the cavity 207 is present above the position of the rim flange portion (indicated by the alternate long and short dash line 208) (see FIG. 8B) When shown), the cushioning and weight reduction are improved, but the rim removal resistance is not improved. That is, as shown in FIG. 8 (c), there is a possibility that the rim may be disengaged during stationary or turning.

Even in a solid tire with a cavity in which the tire width is larger than the rim width (tire width> rim width), the cavity 207 exists on the outer side in the tire radial direction from the position of the rim flange portion (indicated by the alternate long and short dash line 208) and does not exist on the inner side in the tire radial direction. In this case, although the shock-absorbing property and the weight reduction are improved, the reaction force for pressing the rim from the solid tire after the solid tire is assembled to the rim is small, so the rim removal resistance is not improved. Moreover, in this case, if the part to be assembled to the rim 205 is too wider than the rim width (that is, there are many invariable regions), the rim cannot be assembled, and if it is too narrow, the reaction force effect is reduced and the rim resistance is not improved.

In the case of a solid tire with a cavity in which the tire width is larger than the rim width (tire width> rim width) and the cavity 207 is present on the inner side in the tire radial direction from the position of the rim flange portion (indicated by the alternate long and short dash line 208), the tire assembled to the rim Since the main body is compressed and assembled to the rim, the reaction force increases and the rim detachment resistance is improved. However, since there is no cavity on the ground contact side to the ground and the elasticity is small, the buffering property is deteriorated. The hollow tire 207 has a tire width wider than the rim width (tire width> rim width), and the cavity 207 has two locations on the inner side in the tire radial direction and on the outer side in the tire radial direction from the position of the rim flange portion (shown by the alternate long and short dash line 208). In this case, the cushioning property, weight reduction, and rim detachment resistance are improved. This is disadvantageous.

In order to solve the above problems, the present invention provides a base portion made of a foam layer from the inside to the bottom of the tire body. Specifically, the non-pneumatic tire of the present invention has the following features (1) to (5).
(1) The present invention provides a non-pneumatic tire having a tire body portion and a tire base portion partially or entirely surrounded by the tire body portion, wherein the tread surface side of the tire is the tire body portion, and the tire base portion is A non-pneumatic tire characterized by being a foam.
(2) The present invention is a non-pneumatic tire characterized in that the tire base part exists from the rim bottom part to the rim flange part and further to the outer side in the tire radial direction than the rim flange part. In the cross-sectional area of the tire on the outer side in the tire radial direction from the rim flange portion, the area of the tire base portion is 0.1 to 0.5 times the area of the entire tire. Furthermore, in the cross-sectional area of the tire inside the tire diameter from the rim flange portion, the area of the tire base portion is 0.2 to 0.8 times the area of the entire tire. The expansion ratio of the foam in the tire base portion is 20 to 400%.

(3) In the present invention, at least a part of the tire main body and / or the tire base is a side chain containing at least a carbonyl-containing group and a nitrogen-containing heterocycle, or a hydrogen-bonded cross-linked site thereof. It is a non-pneumatic tire characterized by being a thermoreversible cross-linked elastomer composition having a side chain having both a crosslinkable site and a covalent bond. Here, the thermoreversible crosslinked elastomer composition contains a maleic acid-modified olefin elastomer, a nitrogen-containing heterocyclic compound, an olefin resin, a styrene elastomer, and paraffin oil, and the nitrogen-containing heterocyclic compound contains a nitrogen-containing heterocyclic compound. It is a functional alcohol, and / or the olefin resin is polypropylene, and / or the styrene elastomer is a hydrogenated styrene / isoprene / butadiene block copolymer.

(4) The non-pneumatic tire of the present invention is used for a light vehicle tire, and has a tire assembly width of 103 to 134% in a state where no restraining force is generated with respect to the rim width of the assembly rim.
(5) The non-pneumatic tire of the present invention having a tire main body portion and a tire base portion is manufactured using an injection molding method.

Since the tire base part partially or wholly surrounded by the tire body part is a foam, weight reduction of the tire can be realized and cushioning or cushioning properties can be improved. Ride comfort of light vehicles such as wheelchairs is improved. When the tire body is assembled to the rim, the tire base portion is compressed when the tire body is tightened from the outside, so that the tire can be easily assembled to the rim. After assembling the tire to the rim, the rim is pressed from the inside to the outside by the reaction force that the tire base portion tries to return. As a result, the bonding force between the rim and the tire becomes strong, and the rim removal resistance is improved. Moreover, since the foam which comprises a tire base part foams uniformly, there is no inflection point. Thereby, since deterioration of bending fatigue resistance is not caused, the tire life can be prevented from being reduced. Furthermore, since the present invention uses a thermoreversible crosslinked elastomer composition, it is possible to remove the crosslinking by heating. As a result, this elastomer can be used repeatedly without deteriorating its physical properties. Therefore, if the elastomer part is recovered, material recycling becomes possible.

FIG. 1 is a view showing the structure of a non-pneumatic tire of the present invention. FIG. 2 is a diagram showing a positional relationship between a tire main body portion and a tire base portion in the non-pneumatic tire of the present invention. FIG. 3 is a diagram schematically illustrating a method of assembling the tire 10 to the rim 15. FIG. 4 is a view showing a method for producing a tire having a tire base portion made of a foamed layer of the present invention and a tire main body portion surrounding part or all of the base portion by an injection molding method. FIG. 5 is a view showing a method for producing a tire having a tire base portion made of a foamed layer of the present invention and a tire main body portion surrounding part or all of the base portion by an injection molding method. FIG. 6 is a view showing another shape of the tire 10 having the tire base portion 12 and the tire main body portion 11 made of the foamed layer of the present invention. FIG. 7 is a diagram showing an example of producing an extrudate using a pickerback type two-color extruder. FIG. 8 is a view showing a single-layer solid tire using a conventional non-foamed normal rubber.

The present invention relates to the structure of a non-pneumatic tire as a puncture tire. The tire of the present invention has a tire base portion formed of a foam layer on the inner side in the tire radial direction of the tire body portion on the outer side in the tire radial direction. FIG. 1 is a view showing a structure of a tire according to the present invention. FIG. 1 is a view showing a cross section of an annular tire 10 before being assembled to a rim. The tire 10 has a tire base portion 12 made of a foam layer on the inner side in the tire radial direction of the tire main body portion 11. Although the tire base portion 12 shown in FIG. 1 is exposed on the rim side bottom portion B side, the tire base portion may be completely covered with the tire main body portion 11 without being exposed. (Described in FIG. 6) A tread pattern (groove) 14 is formed on the ground contact surface A side of the tire body 11 to the ground or the like. Further, the tire body 11 is formed with a rim fitting groove 13 that fits into the rim flange. As described above, the non-pneumatic tire 10 of the present invention is a non-pneumatic tire having a tire body portion and a tire base portion that is partially or entirely surrounded by the tire body portion, and the tread surface side of the tire is a tire body portion. Yes, the tire base portion is a foam.

FIG. 2 is a view showing the positional relationship between the tire body 11 and the tire base 12 in the non-pneumatic tire 10 of the present invention. 2A is a view showing a cross section of the annular tire before being assembled to the rim 15, and FIG. 2B is a view showing the rim 15 to which the tire 10 is assembled. The tire base portion 12 is exposed to the rim side bottom portion B side, and the tire base portion 12 is the upper end (indicated by a straight line R) of the rim fitting groove 13 of the tire main body portion 11 that is fitted to the rim flange 16 of the rim 15. ) Also on the outer side in the tire radial direction. That is, the distance from the upper end R of the rim fitting groove 13 of the tire body 11 fitted to the rim flange 16 of the rim 15 to the lower end of the rim side bottom B is h1, and the upper end of the tire base 12 and the rim fitting groove 13 are set. H3> h1, h2> 0, and h3 = h1 + h2, where h2 is the distance from the upper end R of h2 and h3 is the distance between the upper end of the tire base portion 12 and the rim side bottom B (the lowermost end thereof). The height h4 of the tire is the distance between the uppermost end on the ground contact surface A side and the rim side bottom B (the lowermost end thereof), but naturally h4> h3. In addition, the distance between the uppermost end on the ground contact surface A side and the upper end of the tire base portion 12 is h5. Of course, h5 = h4−h3.

The tire body portion 11 and the tire base portion 12 are formed substantially symmetrically with respect to the lateral direction. That is, the tire (its structure) is substantially bilaterally symmetric. If the left and right widths of the tire body 11 below the upper end R of the rim fitting groove 13 with respect to the tire center line O are W1 and W2, then W1 = W2. Further, if the left and right widths of the tire base portion 12 below the upper end R of the rim fitting groove 13 with respect to the tire center line O are W4 and W5, W4 = W5. If the width of the tire body 11 below the upper end R of the rim fitting groove 13 of the tire body 11 is W3 and the width of the tire base 12 is W6, then naturally W3 = W1 + W2 and W6 = W4 + W5.

FIG. 2B is a view showing the rim 15 to which the tire 10 is assembled. The upper part of the rim is a flange 16 and is fitted to the rim fitting groove 13 of the tire body 11. When the inner width of the portion of the rim 15 to which the portion having the width W3 of the tire body 11 is fitted is W7, it is necessary to satisfy W7 ≦ W3. This is because when W7> W3, when the tire 10 is assembled to the rim 15, a gap is formed, and the risk that the tire 10 is detached from the rim 15 increases. The present invention is characterized in that the tire assembly width W3 in a state where no restraining force is generated is 103 to 134% with respect to the rim width W7 of the assembly rim. That is, 1.03W7 ≦ W3 ≦ 1.34W7.

Note that 1.03W7 ≦ W3 ≦ 1.34W7 is established at an arbitrary position below the upper end R of the rim fitting groove 13 of the tire body 11 with respect to the distance h from the rim side bottom B (the lowermost end thereof). When W3 <1.03W7, the reaction force of the tire 10 pressing the rim 15 when the tire 10 is assembled to the rim 15 is weak, and the tire 10 is easily detached from the rim 15. In order to increase the bonding force between the rim 15 and the tire 10, a bonding tape or an adhesive layer may be sandwiched between the rim 15 and the tire 10. When the bonding tape or the adhesive layer is present, the tire assembly width W3 includes the thickness of the bonding tape and the thickness of the adhesive layer. That is, 1.03W7≤W3 + 2t≤1.34W7 where t is the thickness of the bonding tape and the adhesive layer. In order to further increase the fitting force between the rim 15 and the tire 10, W3 or W3 + 2t is preferably set to 110% or more.

Since the tire width W3 is larger than the rim width W7, the tire 10 cannot be assembled to the rim 15 as it is. However, in the present invention, since the tire base portion 12 is formed of a foam layer, the tire base portion is excellent in elasticity and compressibility. FIG. 3 is a diagram schematically illustrating a method of assembling the tire 10 to the rim 15. Since the tire 10 of the present invention has the tire base portion 12 as an inner layer and the tire main body portion 11 on the outer side thereof, as shown in FIG. 3, the lower side of the rim fitting groove 13 of the tire main body portion 11 is below the upper end R. In the portion, when the force P1 is applied from the left and right of the tire main body 11, the base 12 made of the foamed layer is compressed, and the tire width W3 can be made smaller than the rim width W7. Actually, it is made smaller than the rim flange width and inserted into the rim 15 (in the V direction shown in FIG. 3A).

When the rim fitting groove 13 of the tire body 11 is aligned with the rim flange 16 of the rim 15 and the force P1 is removed, the tire 10 tries to return to the original state, and the rim 15 is pressed by the reaction force of the tire 10 to press the tire 10. Is fixed to the rim 15. In particular, since the deformation of the foam layer due to the force P1 is large, the restoring force (reaction force) P2 from the base portion 12 made of the foam layer pushes the tire body 11 outward, and the tire body 11 further reacts with the reaction force P3 to the rim 15. The tire 10 is fixed to the rim 15 by pressing. Furthermore, since the bonding force between the rim 15 and the tire 10 is increased by interposing an adhesive tape or an adhesive layer at the contact portion between the rim 15 and the tire 10, the rim 15 and the tire 10 are more firmly fixed. .

The tire body 11 is made of ordinary rubber such as natural rubber, styrene-butadiene rubber (SBR), butadiene rubber (BR), and isoprene rubber (IR) used for ordinary solid tires. No deformation. Therefore, when the tire 10 is composed only of the tire main body portion, when 1.03W7 ≦ W3, sufficient compression deformation cannot be performed, so that insertion is difficult. Even if it can be inserted, in that case, since the deformation rate is small and the reaction force is weak, the tire 10 is easily detached from the rim 15.

In FIG. 2, when the region of the tire base portion 12 is too large in the portion above the upper end R of the rim fitting groove 13 of the tire main body portion 11, the strength of the tire main body portion 11 is reduced and used as a light vehicle tire. The degree of deformation of the tire 10 increases due to the weight applied to the tire 10. Therefore, it is preferable that h2 is in the range of 0.1 ≦ h2 / (h2 + h5) ≦ 0.7. h5 is a distance from the upper end of the ground contact surface A of the tire 10 to the upper end of the tire base portion 12, and h5 = h4−h3. If it is less than 0.1, the shock-absorbing property is weak and the ride comfort is deteriorated, and the weight reduction cannot be achieved. If it exceeds 0.7, the tire 10 is excessively deformed as described above, the ground contact surface increases, and the rolling resistance is deteriorated.

It can also be defined from the areas of the tire body 11 and the tire base 12 in the tire 10. The area of the tire body (in the cross section of the tire shown in FIG. 2) above the upper end R of the rim fitting groove 13 of the tire body 11 is S1, the area of the tire base is S3, and the area of the tire 10 is S5 ( If S5 = S1 + S3), the area S3 of the tire base portion is preferably 0.1 ≦ S3 / S5 ≦ 0.5.

Also, in the portion below the upper end R of the rim fitting groove 13 of the tire main body 11, if the area of the tire base 12 is too large, the strength of the tire main body 11 is reduced. The tire base portion w4 preferably satisfies 0.2 ≦ w4 / w1 ≦ 0.8. Similarly, the tire base portion w5 desirably satisfies 0.2 ≦ w5 / w2 ≦ 0.8. Since the tire base portion 12 and the tire 10 are substantially symmetrical with respect to the tire center line O, the tire base portion w6 preferably satisfies 0.2 ≦ w6 / w3 ≦ 0.8. When these values are less than 0.2, the deformation of the lower portion of the tire is small and it is difficult to assemble the tire to the rim, and the weight of the tire cannot be reduced. If these values exceed 0.8, the strength of the lower part of the tire becomes small, which is not preferable. It can also be defined from the areas of the tire body 11 and the tire base 12 in the tire 10. The area of the tire body (in the cross section of the tire shown in FIG. 2) in the portion below the upper end R of the rim fitting groove 13 of the tire body 11 is S2, the area of the tire base is S4, and the area of the tire 10 is S6. If (S6 = S2 + S4), the area S4 of the tire base portion is preferably 0.1 ≦ S4 / S6 ≦ 0.5.

The non-pneumatic tire having a tire base portion made of the foamed material of the present invention and a tire main body portion surrounding at least a part thereof has a cushioning property, a weight reduction, a rim removal resistance, a bending fatigue resistance, etc. Since it has excellent characteristics, it can be used as puncture tires for various light vehicles such as bicycles, wheelchairs, golf carts, rear cars, etc., which normally run at low speeds under light loads. In the non-pneumatic tire of the present invention, the size of the tire base portion is appropriately selected as described above in accordance with the use purpose and the use environment described above, and cushioning, weight reduction, rim removal resistance, bending fatigue resistance, etc. These characteristics can be set as appropriate. As a result, it is possible to provide a non-pneumatic tire having optimum safety and driving performance for the user.

4 and 5 are views showing a method for producing a tire having a tire base portion made of a foamed layer of the present invention and a tire body portion surrounding part or all of the base portion by injection molding. Fig.4 (a) is a figure which shows the metal mold | die used when producing a tire by the injection molding method, and has shown the cross section of the cyclic | annular metal mold | die. Fig.4 (a) shows the metal mold | die which produces a tire main-body part. A cavity having substantially the same shape as the outer shape of the tire (the shape of the tire body) is formed by the mold 32, and a cavity 33 having substantially the same shape as the tire body is produced by inserting a mold 33 having the same shape as the tire base. . A rubber material is injected into the cavity 34. At that time, an appropriate pressurizing / heating treatment or the like is performed, and the tire body 35 can be produced as shown in FIG.

Next, when a mold 33 having substantially the same shape as the tire base portion is pulled out, a space 36 is formed inside the tire main body portion 35 as shown in FIG. Next, as shown in FIG. 5B, a mold 37 is placed in this space 36 in accordance with the mold 32 to form a cavity 38 having the shape of a tire base. Next, as shown in FIG. 5 (c), a foam material is injected into the hollow portion 38 and subjected to appropriate pressurization and heat treatment to produce a tire base portion 39 made of a foam layer. By removing the mold 32 and the mold 37, the tire 10 having a two-layer structure of the tire base portion 39 and the tire main body portion 35 surrounding the tire base portion 39 can be manufactured. By forming the tire body 35 before the tire base 39, the shape of the tire body 35 can be secured. In addition, after producing the tire main-body part 35, the outer metal mold | die 32 other than the metal mold | die 33 may also be removed, and type | mold adjustment may be carried out by another metal mold | die again.

Since the cavities 34 and 38 have an annularly continuous structure, the tire 10 formed by the injection molding method also has an annularly continuous joint, that is, a tire without a fused portion. A homogeneous tire can be formed by forming an injection port for injection and an extraction port for discharging excess generated gas and excess injection in optimal portions. In this way, the injection molding method does not require a fusing process, and since there is no connection portion, there is no concentration of stress on the connection portion, so a highly reliable long-life tire can be produced. In addition, since defects such as cavities can be suppressed between the base portion made of the foam layer and the tire body portion made of the rubber layer, and the adhesion between these layers is also very good, these two layers are separated. It is difficult to achieve a long-life tire. In addition, since the dimensional accuracy is high, it is possible to mass-produce products with stable quality.

A tire body part and a tire base part are separately produced using an injection molding method, and the tire base part is pushed into a space part of the tire body part to produce a non-pneumatic tire. In particular, in the case of the tire as shown in FIGS. 1 to 5 in which a part of the tire base portion is exposed to the outside, the production is also simple. At this time, since the tire base portion is foamed and the volume is increased, the tire base portion is compressed and pushed. Further, if an adhesive layer is formed between the tire base portion and the tire main body portion using an adhesive or an adhesive tape, the connection between the tire base portion and the tire main body portion becomes strong.

The tire 10 of the present invention can also be produced using an extrusion method. For example, the two-color extrusion of two different rubber layers such as the tire body 11 and the tire base 12 can be performed using the picker-back type two-color extruder shown in FIG. The extruder shown in FIG. 7 is a pickerback type two-color extruder having two extruders 3-1 and 3-2. In FIG. 7, 27 indicates a preform die and 28 indicates a base. Moreover, the accuracy of the discharge amount is improved by installing a gear pump in front of the die 28 of the extruder 3 (3-1, 3-2) or in front of the preform die 27 when there is a preform die. Is preferable.

A rubber material (for example, THC rubber, which will be described later) used for a solid tire in a tire main body portion is charged in one extruder (3-1), and a tire base portion is loaded in the other extruder (3-2). For rubbers containing foaming agents (eg, thermally expandable hollow elastic microspheres, inorganic foaming agents (sodium bicarbonate, ammonium carbonate, etc.), nitroso foaming agents, azo foaming agents, sulfonyl hydrazide foaming agents, etc.) A material (for example, THC rubber described later) or the like is introduced, and a tire base portion having various shapes and a tire body portion constituting the outside thereof are integrated (extruded product 1) through a preform die 27 and a base 28. Extrude. Since this extrusion-molded product 1 is an elongated cylindrical product, it is cut into a predetermined length, rounded into a ring shape, and both ends are fusion-bonded to obtain a tire 10. Since the extrusion method does not require a mold and the manufacturing method is simple, the equipment cost can be kept low. Further, since a precise mold is not required, there is an advantage that the design can be easily changed and the tire base portion and the tire body portion having various shapes can be easily manufactured.

FIG. 6 is a view showing another shape of the tire 10 having the tire base portion 12 and the tire main body portion 11 made of the foamed layer of the present invention. FIG. 6A is a view showing the tire base 12 that is completely surrounded by the tire body 11. In FIG. 6A, the tire base portion 12 has a substantially elliptical shape and exists in both the upper and lower regions from the upper end R of the rim fitting groove 13 of the tire main body portion 11, but the rim side bottom portion. The tire main body 11 exists on the rim side bottom B side without being exposed on the B side. Even in this case, h2 is preferably in the range of 0.1 ≦ {h2 / (h4−h3)} ≦ 0.7. Alternatively, S3 is preferably 0.1 ≦ S3 / S5 ≦ 0.5. Further, the area S4 of the tire base portion is preferably 0.1 ≦ S4 / S6 ≦ 0.5.

In FIG. 6B, the tire base portion 12 continues to both the upper and lower regions from the upper end R of the rim fitting groove 13 of the tire main body portion 11 in the same manner as that shown in FIGS. 1 to 5. It exists and is exposed to the rim side bottom B side. However, the width of the upper portion of the tire base portion 12 is wider than the width of the lower portion and has a substantially circular shape. In the case of FIG. 6B, the same relational expression as that shown in FIG. 2 is satisfied. That is, h2 is preferably in the range of 0.1 ≦ {h2 / (h4−h3)} ≦ 0.7. Alternatively, S3 is preferably 0.1 ≦ S3 / S5 ≦ 0.5. The tire base portion w4 preferably satisfies 0.2 ≦ w4 / w1 ≦ 0.8. Similarly, the tire base portion w5 desirably satisfies 0.2 ≦ w5 / w2 ≦ 0.8. Since the tire base portion 12 and the tire 10 are substantially symmetrical with respect to the tire center line O, the tire base portion w6 preferably satisfies 0.2 ≦ w6 / w3 ≦ 0.8. The area S3 of the tire base portion is preferably 0.1 ≦ S3 / S5 ≦ 0.5. The area S4 of the tire base portion is preferably 0.1 ≦ S4 / S6 ≦ 0.5.

The expansion ratio of the foam material of the tire base portion is 20 to 400%, preferably 50 to 200%. Here, the expansion ratio Q is represented by Q = {(D0 / D1) -1} * 100 (%), where D0 is the specific gravity of the foamed material before foaming and D1 is the specific gravity of the foamed material after foaming. When it is less than 20%, the buffering effect is poor, and when it is more than 400%, physical properties such as fracture strength and wear resistance are lowered, the contact surface with the rim is worn away, and the fitting force between the rim and the tire is lowered.

The tire body of the non-pneumatic tire of the present invention is an elastomer composition, and as this elastomer composition, at least a part of the non-pneumatic tire is a THC rubber (a thermoreversible cross-linked elastomer composition using hydrogen bonding). It is preferable to use Thermoreversible Hydrogen-bond Crosslinking Rubber). Thereby, the recyclability of the tire can be improved. Moreover, THC rubber can also be used for the tire base portion of the non-pneumatic tire of the present invention. That is, a foaming agent (for example, a heat-expandable microcapsule encapsulating a low-boiling hydrocarbon expander (for example, Matsumoto oil-based Matsumoto Microsphere F series)) is added to the THC rubber production material to foam the THC rubber. Let

Since the resin or elastomer composition containing the thermoreversible crosslinked elastomer composition is softened by heating and can be easily extended, the work for attaching and detaching the tire to the rim is simplified. And the ratio for which a thermoreversible bridge | crosslinking elastomer composition occupies for the whole resin and an elastomer composition can be determined as needed. In addition, the thermoreversible cross-linked elastomer composition can be melted and can be used repeatedly without deteriorating physical properties, and therefore material recycling is possible.

The thermoreversible cross-linked elastomer composition contains various functional groups such as carbonyl group, hydroxy group, oxy group, epoxy group, phenyl group or cross-linked sites containing these functional groups or nitrogen-containing heterocycles, or these as side chains. Thermally reversible having at least a side chain containing a hydrogen-bonding cross-linking site having a carbonyl-containing group and a nitrogen-containing heterocycle, or a side chain having both a hydrogen-bonding cross-linking site and a covalent cross-linking site A cross-linked elastomer composition is preferable in order to achieve good thermoreversible cross-linking properties.

In the hydrogen bondable crosslinking site having a carbonyl-containing group and a nitrogen-containing heterocycle, the carbonyl group of the carbonyl-containing group and the amino group of the nitrogen-containing heterocycle form a hydrogen bond. You may mix | blend a nitrogen-containing heterocyclic ring by adding a nitrogen-containing heterocyclic containing compound as a crosslinking agent. Examples of the carbonyl compound constituting the hydrogen bonding crosslinking site include a carbonyl group, a carboxyl group, an amide group, an ester group, and an imide group.

The thermoreversible crosslinked elastomer composition preferably contains a maleic acid-modified olefin elastomer, a nitrogen-containing heterocyclic compound, an olefin resin, a styrene elastomer, and paraffin oil. Thus, by comprising a thermoreversible crosslinked elastomer composition, it has favorable physical properties, high fluidity, and good moldability.

A preferable composition of the thermoreversible cross-linking elastomer composition is 0.1 to 3 parts by weight of a nitrogen-containing heterocyclic compound, 50 to 150 parts by weight of an olefin resin, and styrene elastomer with respect to 100 parts by weight of maleic acid-modified olefin elastomer. 20 to 80 parts by weight and 50 to 150 parts by weight of paraffin oil are preferably blended. 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 preferred.

When a thermoreversible cross-linked elastomer composition is used for a tire, it is easy to form an annular shape, and since crosslinking is removed by applying heat, material recycling is easy in addition to the moldability of the tire. That is, since the thermoreversible cross-linked elastomer composition can be de-crosslinked by heating, if this elastomer portion is recovered, it can be used again as a material having no deterioration in physical properties.

The present invention is a non-pneumatic tire having a two-layer structure of a tire main body portion made of a rubber material and a tire base portion made of a foam material, which are usually used for solid tires. In addition to these, other different layers are included. But it ’s okay. For example, a reinforcing rubber layer including a reinforcing cord or the like can be added in order to further strengthen the tread portion in contact with the ground or the like.

The non-pneumatic tire of the present invention can be used as a non-pneumatic tire for various light vehicles such as bicycles, wheelchairs, golf carts, rear cars, etc., which normally run at low speeds under light loads. it can.

1 ... Extruded product,
3 (3-1, 3-2) ... Extruder 10 ... (Non-pneumatic) Tire 11 ... Tire body,
12 ... tire base,
13: Rim fitting groove,
14 ... tread pattern 15 ... rim 16 ... rim flange 27 ... preform die,
28 ... The base,
32 ... mold,
33 ... Mold,
34 ... hollow part,
35 ... tire body,
36 ... space,
37 ... mold,
39 ... Tire base portion 204 ... Tread groove,

Claims (11)

In a non-pneumatic tire having a tire body part and a tire base part partially or entirely surrounded by the tire body part, the tread side of the tire is the tire body part, and the tire base part is a foam Non-pneumatic tire characterized by. The non-pneumatic tire according to claim 1, wherein the tire base portion exists from a rim bottom portion to a tire radial direction outer side than the rim flange portion. The area of the tire base part is 0.1 to 0.5 times the area of the entire tire in the cross-sectional area of the tire on the outer side in the tire radial direction from the rim flange part. Non-pneumatic tire. The area of the tire base portion is 0.2 to 0.8 times the area of the entire tire in the cross-sectional area of the tire inside in the tire radial direction from the rim flange portion. The non-pneumatic tire according to any one of items 3. The non-pneumatic tire according to any one of claims 1 to 4, wherein an expansion ratio of the foam of the tire base portion is 20 to 400%. At least a part of the tire body and / or tire base is a side chain containing at least a carbonyl-containing group and a hydrogen-bonded cross-linked site having a nitrogen-containing heterocycle, or a hydrogen-bonded cross-linked site and a covalent-bonded cross-linked site. The non-pneumatic tire according to any one of claims 1 to 5, wherein the non-pneumatic tire is a thermoreversible crosslinked elastomer composition having a side chain. The said thermoreversible crosslinking elastomer composition contains a maleic acid modified olefin elastomer, a nitrogen-containing heterocyclic compound, an olefin resin, a styrene elastomer, and paraffin oil, The Claim 6 characterized by the above-mentioned. Non-pneumatic tire. The nitrogen-containing heterocyclic compound is a nitrogen-containing heterocyclic polyfunctional alcohol, and / or the olefin resin is polypropylene, and / or the styrene elastomer is a hydrogenated styrene / isoprene / butadiene block copolymer. The non-pneumatic tire according to claim 6 or 7, wherein the non-pneumatic tire is provided. Any one of claims 1 to 8, characterized in that a tire assembling width in a state where no restraining force is generated is 103 to 134% with respect to a rim width of the assembling rim. The non-pneumatic tire described. The non-pneumatic tire according to any one of claims 1 to 9, wherein the tire main body portion and the tire base portion are manufactured using an injection molding method. The non-pneumatic tire according to any one of claims 1 to 10, wherein the tire is a light vehicle tire.