JP3144992U - Recycled solid tire and manufacturing method thereof - Google Patents

Abstract

The present invention provides a reclaimed solid tire that has excellent wear resistance and shock absorption / relaxation characteristics, and is less prone to chipping and cracking at the corners of the tread portion.
A room temperature curing type polyurethane elastomer layer is integrally formed at a predetermined thickness on an outer peripheral surface of a rubber layer having a predetermined thickness, which is a residual wear of a worn solid rubber tire, and a tread surface is formed. The corner portions on both sides in the width direction of 20 are configured to be curved portions 22a and 22b having radii of curvature: Ra and Rb, respectively.
[Selection] Figure 2

Description

  The present invention relates to a reclaimed solid tire, and more particularly to a reclaimed solid tire that effectively suppresses the problem of chipping and cracking at the corners of a tread portion.

  Conventionally, an air having a structure in which air is enclosed in a hollow portion as a tire that bears a load on a vehicle such as an automobile or an industrial vehicle and has a function of transmitting a smooth force between the vehicle and a road surface. A solid tire made of a solid rubber ring is well known in addition to a tire. The solid tire uses load capacity, shock absorbing capacity, and rubber elasticity as tire functions, and is mainly used for low speed, heavy load vehicles such as forklift trucks, industrial tractors, battery storage vehicles, trailers, etc. In many cases, a single tread rubber is baked directly on the wheel, a rubber material is vulcanized and bonded to the base band, and the ring is pressed into the wheel. Such a tread rubber is fitted into the outer periphery of the wheel.

  By the way, such a solid tire is generally used as a solid rubber tire in which a tread rubber is composed of a rubber material such as NR or SBR. However, such a tire is in contact with a road surface and has a frictional force. Since the vehicle is allowed to move by the long-term use, the wear of the contact surface with the road surface will progress and the service life will be discarded. Has become a major social problem. In particular, solid rubber tires are heavier than pneumatic tires used in passenger cars, etc., making them difficult to handle, difficult to incinerate, and difficult to use for other purposes. There is a great difficulty in its disposal.

  For this reason, Japanese Patent Laid-Open No. 5-318225 (Patent Document 1) proposes a pneumatic solid tire having a structure in which the surface of a worn tire is buffed and a tread rubber is adhered to the tread portion. As a result, it has been clarified that it is possible to effectively use a worn tire that has been difficult to process in the past, and to save tire material and shorten the time for manufacturing the tire.

  However, even if the reclaimed tread rubber is again adhered to the tread portion of such a worn tire, the wear of the tread rubber portion easily occurs again by using the regenerated tire thus obtained. Therefore, in addition to insufficient improvement of the durability of the tread rubber part, the rubber material constituting the tread rubber part is generally blackened with carbon black as a reinforcing agent. Therefore, there is a problem that a black tire mark is formed on the road surface due to friction between the tread rubber portion and the road surface. The black tire marks on the road surface are detrimental to the aesthetics, and at the work sites such as forklift trucks and industrial tractors, together with the black rubber wear powder, the work environment is deteriorated.

  In JP 2002-144442 (Patent Document 2), as a method for regenerating a wheel using a urethane rubber tire, a used tire is used, and after removing the rubber tire from its baseband, the rubber tire is removed. Further, a technique for forming a recycled roller by forming an ether-based urethane rubber layer on the outer peripheral surface of the baseband has been clarified.

  However, in such a regenerative wheel, since the urethane rubber is in contact with the road surface, it is excellent in wear resistance as compared with a tread rubber made of a rubber material such as a normal NR or SBR. Although it has the feature that it has the advantage that the durability or life of the regenerated rolling wheel can be improved effectively, it has cushioning properties (buffering properties) compared to the rolling wheel using such a normal tread rubber. ), An unpleasant impact is transmitted to the driver when driving a vehicle such as a forklift truck or an industrial tractor equipped with such regenerative wheels. However, in order to improve the cushioning properties of such regenerative wheels, it is conceivable to take measures such as making the urethane rubber tire part into a foam structure, or significantly reducing its hardness and increasing its flexibility. In this case, however, the inherent wear resistance of the urethane elastomer is impaired and a problem arises in its durability.

  Therefore, in order to solve such a problem, the inventor of Japanese Patent Application Laid-Open No. 2004-359219 (Patent Document 3) has a predetermined thickness on the peripheral surface of a worn solid tire in which a required rubber layer is left. The construction of recycled solid tires with a room temperature curing type polyurethane elastomer layer was clarified. According to the reclaimed solid tire having such a configuration, the impact received from the ground contact surface of the tread portion is effectively absorbed and mitigated by the inner rubber layer, and the contact surface of such a tread portion is used. Durability can be remarkably improved by the outer room temperature curing type polyurethane elastomer layer to be provided.

  However, in the reclaimed solid tire disclosed in Patent Document 3, when the reclaimed solid tire is actually used, the tread portion that is in contact with the road surface, i.e., the It has been revealed that a problem that a crack is generated or a part of the outer peripheral surface formed of a hard polyurethane elastomer layer in the width direction is newly caused. In particular, in such regenerated solid tires, problems such as chipping at corners located on the outside of the vehicle are likely to be caused by an uneven load due to the rotation of the vehicle.

Japanese Patent Laid-Open No. 5-318225 JP 2002-144442 A JP 2004-359219 A

  Here, the present invention has been made in the background as described above, and the problem to be solved is excellent wear resistance and shock absorption / relaxation characteristics, and corners of the tread portion. An object of the present invention is to provide a reclaimed solid tire that is less prone to chipping and cracking.

  In the present invention, in order to solve such a problem, a room temperature curing type polyurethane elastomer layer is coated at a predetermined thickness on the peripheral surface of the worn solid tire with the required rubber layer remaining. Recycled solid tire is configured so that the corners on both sides of the outer circumferential surface are formed as curved parts, and the radius of curvature of one corner is larger than the radius of curvature of the other corner The gist of the present invention is a reclaimed solid tire characterized in that it is attached to the vehicle so that the one corner is on the outside of the vehicle.

  According to one of desirable aspects of the regenerated solid tire according to the present invention, the curved portion is formed with respect to corners on both sides in the width direction on the outer peripheral surface of the room temperature curing type polyurethane elastomer layer. Therefore, according to another preferred embodiment, an outermost layer made of a polyurethane elastomer having higher wear resistance than that of the room temperature curing type polyurethane elastomer layer is laminated at a predetermined thickness. Will be.

  Moreover, in one of the preferable aspects of this invention, the said curved part is formed with respect to the corner | angular part of the width direction both sides in the outer peripheral surface of the said outermost layer.

  Further, in another preferred embodiment of such a regenerated solid tire according to the present invention, the one corner is formed as a curved portion having a radius of curvature of 40 to 60 mm, and the other The corner portion is formed as a curved portion having a radius of curvature of 20 to 40 mm, and according to another preferred aspect, the curvature radius of the one corner portion is the curvature radius of the other corner portion. It is comprised so that it may become 10-30 mm larger than.

  Furthermore, according to another desirable aspect of the regenerated solid tire according to the present invention, a plurality of grooves parallel to each other are provided on the tire outer peripheral surface so as to extend in the circumferential direction.

  In addition, according to one of the other preferred embodiments of the reclaimed solid tire according to the present invention, a phosphorescent portion is provided in at least one place on the side surface of the tire. According to one of the other preferred embodiments, The phosphorescent part is provided on the side surface of the polyurethane elastomer layer.

  As described above, in the reclaimed solid tire having a structure according to the present invention, the corners on both sides in the width direction of the tread portion that are in contact with the road surface are formed as curved portions, respectively. It is possible to effectively avoid stress concentration at such corners when twisting, and the polyurethane elastomer layer is cracked at both corners over time. It is possible to advantageously suppress the occurrence of a phenomenon that occurs or chipped.

  Moreover, in the present invention, when such a recycled solid tire is used in a vehicle, a large stress is caused by the operation of twisting the tire caused by operating the steering wheel or turning a curve. From the place where the radius of curvature of the corner on the vehicle outer side to be added is larger than the radius of curvature of the inner corner, the occurrence of cracks and cracks at such corners, It becomes possible to suppress more effectively.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

  First, FIG. 1 and FIG. 2 show an embodiment of a recycled solid tire having a structure according to the present invention. In these drawings, FIG. 1 (a) shows such a recycled solid tire in the form of a side view, and FIG. 1 (b) shows an AA cross section in FIG. 1 (a). In the form of a radial cross-sectional view, FIG. 2 further shows an enlarged portion B of FIG.

  In those figures, the reclaimed solid tire 10 has a donut shape as a whole, and a wheel 12 is attached to the inner periphery of the donut shape, while being located on the inner periphery side of the donut shape. A rubber layer 14 having a predetermined thickness is provided. On the outer peripheral surface 16 of the rubber layer 14, a room temperature curing type polyurethane elastomer layer 18 is integrally formed at a predetermined thickness to form a new tread surface 20. That is, the recycled solid tire 10 has a two-layer structure including a rubber layer 14 and a polyurethane elastomer layer 18 each having a predetermined thickness. Furthermore, the corners on both sides in the width direction of the outer peripheral surface (tread surface 20) of the polyurethane elastomer layer 18 are curved portions 22a and 22b having predetermined radii of curvature (Ra and Rb), respectively, as shown in FIG. It is said that.

  More specifically, the polyurethane elastomer layer 18 is formed by cast molding on the outer peripheral surface of the rubber layer 14 by using a conventionally well-known room temperature curing type polyurethane raw material. It is formed in a thickness that gives a diameter. Specifically, the room temperature curing type polyurethane raw material employed here generally uses MDI-based isocyanates such as modified diphenylmethane-4,4′-diisocyanate as the polyisocyanate component, and polyether as the polyol component. Using a polyol or the like, and using an aromatic amine such as an aromatic primary amine as a catalyst for rapidly reacting and curing the polyisocyanate component and the polyol component at low temperatures, For example, a product commercially available under the name “Baytec” from Bayer AG, Germany, is used for reaction curing at a temperature of 10 to 50 ° C. It is done. In addition, after about 1 minute has passed after the mixing of the respective components, the reaction has achieved a certain degree of solidification, and after about 3 days at room temperature, the substantial reaction has been completed and the final physical properties have been reached. Will be realized.

  Then, the corners on both sides in the width direction of the tread surface 20 of the recycled solid tire 10 formed by the polyurethane elastomer layer 18 as described above are shown in FIG. 2, and one corner has a radius of curvature: Ra. The curved portion 22a and the other corner are formed as a curved portion 22b having a radius of curvature Rb. Here, when the recycled solid tire 10 is attached to the vehicle, the curvature radius Ra of the curved portion 22a formed at the corner on the vehicle outer side is formed at the corner on the other side. The radius of curvature of the curved portion 20b is set to be larger than the radius of curvature Rb (Ra> Rb). This effectively relieves stress concentration at the corners of the polyurethane elastomer layer 18 located on the outside of the vehicle where stress is easily applied when the vehicle is running, thereby advantageously avoiding problems such as chipping. Or it can be suppressed.

  Furthermore, the curvature radii Ra and Rb are preferably set such that the curvature radius Ra on the vehicle outer side is 40 to 60 mm, while the curvature radius Rb on the vehicle inner side is 20 to 40 mm. More preferably, the radius of curvature Ra is 10 to 30 mm larger than the radius of curvature Rb. And the objective of this invention can be achieved still more advantageously by employ | adopting such a curvature radius.

  On the other hand, the rubber layer 14 is formed by blending one or more rubber materials such as NR, IR, SBR, BR, EPM, EPDM, IIR, etc., as in the case of a conventional solid rubber tire. Specifically, it is vulcanized and molded using a blend rubber mainly composed of NR and IR. In other words, the rubber layer 14 of the regenerated solid tire 10 is generally in the state of being sold as a solid tire, and the tread surface is worn away by wear and remains in the required thickness over the entire circumference of the wheel 12. is there.

  In addition, the attachment with respect to the wheel 12 of such a reproduction | regeneration solid tire 10 is the outer peripheral surface of the wheel 12 attached to the axle of a vehicle with respect to the inner peripheral part of the donut shape, ie, the inner peripheral part of the rubber layer 14, As is well known, it can be attached by a printing type, a press-fitting type, a fitting type, or the like.

  As described above, in the recycled solid tire 10 configured according to the present invention, the corners on both sides in the width direction of the tread surface 20 are the curved portions 22a and 22b, so that the tread surface 20 is applied. It is possible to effectively avoid stress concentration at the corners on both sides in the width direction. That is, even if the tread surface 20 of the regenerated solid tire 10 is twisted with respect to the road surface by a steering operation or the like, the stress applied to the tread surface 20 is applied from the corners on both sides in the width direction of the tread surface 20. By being dispersed, it is possible to advantageously solve the problem that the polyurethane elastomer layer 18 constituting the tread surface 20 is cracked or chipped at both corners (curved portions 22a and 22b). It can be done.

  In addition, of the curvature radii (Ra, Rb) of the curved portions 22a, 22b, the curvature radius: Ra of the curved portion 22a that is the vehicle outer side when the recycled solid tire 10 is attached to the vehicle is the other curve. Since the radius of curvature of the portion 22b is larger than Rb, the occurrence of cracks and chipping in the corner portion (curved portion 22a) on the vehicle outer side where a larger stress than that on the inside is generated when turning a curve is more effectively achieved. It becomes possible to suppress.

  Further, in the recycled solid tire 10, the impact received from the ground contact surface from the rubber layer 14 having a predetermined thickness and the room temperature curing type polyurethane elastomer layer 18 integrally formed thereon. However, it can be effectively absorbed and relaxed by the inner rubber layer 14 and can advantageously exhibit cushioning or shock-absorbing properties against impact, and the outer polyurethane elastomer layer 18 serving as a ground plane has a polyurethane elastomer material. Due to the good wear resistance characteristics, the durability is remarkably enhanced, so that the useful life of the recycled solid tire 10 can be advantageously improved.

  In addition, unlike the rubber layer 14, the polyurethane elastomer layer 18 does not contain any carbon black as a reinforcing agent, so that the recycled solid tire 10 is rolled on the road surface. However, there is no black tire mark, so that it contributes to beautification of the environment and does not cause any fear of deteriorating the working environment. Further, since the recycled solid tire 10 reuses the rubber layer remaining after the worn solid rubber tire as an inner layer, it is far more than the case where the entire tread portion is formed of a polyurethane elastomer layer. In addition, it is possible to reduce the amount of polyurethane elastomer material used, and it is possible to greatly save the material and thus reduce the production cost of the recycled solid tire 10.

  The regenerated solid tire 10 having the configuration according to the present invention as described above can be manufactured by using various known methods. For example, in the above-mentioned Patent Document 3 (Japanese Patent Laid-Open No. 2004-359219). It can be produced using a casting method as has been clarified. When the recycled solid tire 10 is manufactured by such a casting method, the curved portions 22a and 22b at both corners in the width direction of the tread surface 20 form the polyurethane elastomer layer 18 having a predetermined thickness. Then, by performing cutting or the like, a method of forming the curved portions 22a and 22b having desired radii of curvature (Ra, Rb), or the curved portions 22a and 22b in the molding die for molding the polyurethane elastomer layer 18 is performed. By adopting various known methods such as a method of forming the curved portions 22a and 22b at the same time as the formation of the polyurethane elastomer layer 18, the shape of the portion to give the desired curvature radius is adopted in advance. Will be done.

  By the way, in the present invention, on the outer peripheral surface of the room temperature curing type polyurethane elastomer layer 18 formed on the rubber layer 14, the outermost layer made of the polyurethane elastomer having excellent wear resistance is further formed. Constructing the solid tire 30 can also be advantageously employed, an example of which is shown in FIG. In this case, the outermost layer 24 formed on the polyurethane elastomer layer 18 is a polyurethane elastomer having a higher abrasion resistance than the polyurethane elastomer constituting the polyurethane elastomer layer 18 and is formed in a predetermined thickness. It is configured as a recycled solid tire 30 that constitutes a tread portion of a three-layer structure.

  Then, both corners (28a, 28b) in the width direction of the tread surface 26 of the outermost layer 24 are outside the vehicle when the recycled solid tire 30 is attached to the vehicle, like the above-described recycled solid tire 10. The corner portion on the side is a curved portion 28a having a radius of curvature: Ra, and the other corner portion is a curved portion 28b having a radius of curvature: Rb (<Ra). Further, the radius of curvature on the vehicle outer side: Ra is preferably 40 to 60 mm, and the radius of curvature on the vehicle inner side: Rb is preferably 20 to 40 mm, and more preferably, the radius of curvature: Ra is the radius of curvature: Rb. 10 to 30 mm larger than that.

  Here, the polyurethane elastomer constituting the outermost layer 24 is formed by using a known polyurethane raw material that gives a polyurethane elastomer having excellent abrasion resistance. Generally, a thermosetting NDI elastomer is used. Specifically, naphthalene-1,5-diisocyanate (NDI) is used as the polyisocyanate component, polyester polyol or the like is used as the polyol component, these components are reacted in advance, and NDI / After forming the ester prepolymer, a glycol cross-linking agent and water are blended into it to form the target solid NDI elastomer or microcellular NDI elastomer, so that the target outermost layer 18 is formed by a casting method. Will be formed. In addition, as a polyurethane raw material which gives such a polyurethane elastomer excellent in abrasion resistance, as long as the desired abrasion resistance is obtained, it is not limited to a thermosetting material, but is a room temperature curing type material. However, any of them can be obtained on the market, and for example, a polyurethane raw material provided under the name “Bulkolan” from Bayer AG, Germany can be used advantageously.

  Even in the recycled solid tire 30 in which the outermost layer 24 having excellent wear resistance is formed, it is possible to advantageously suppress cracking and chipping at both corners (28a, 28b) in the width direction of the tread surface 26. In addition, the service life of the outermost layer 24 can be further improved, and the outermost layer 24 has a higher hardness than the inner polyurethane elastomer layer 18. Excellent wear resistance characteristics can be realized. Further, the presence of the outermost layer 24 makes it possible to increase the foam structure of the polyurethane elastomer layer 18 located on the inner side thereof and to reduce the hardness thereof. The elastomer layer 18 can also contribute to absorption or suppression of impact.

  Although preferred embodiments of the present invention have been described in detail above, it is literally an example, and it is understood that the present invention is not construed as being limited in any way by the description of such embodiments. It should be.

  For example, in the illustrated embodiment, the outer peripheral surfaces (tread surfaces 20, 26) of the recycled solid tires 10, 30 are flat surfaces, but a plurality of parallel grooves extending continuously in the circumferential direction, For example, as shown in FIG. 4, two circumferential grooves 32 and 32 may be formed. By forming such a circumferential groove 32, it is possible to suppress the rigidity of the polyurethane elastomer layer 18 (24) and improve the shock absorption as compared with the case without the groove.

  Further, in the recycled solid tire 10 (30) having the structure according to the present invention, the phosphorescent portion 34 made of a phosphorescent material is provided on the side surface (sidewall portion) of the polyurethane elastomer layer 18 (24). It is desirable that it is formed at a place or a plurality of places (see FIG. 5). In the case of the embodiment shown in FIG. 3, the phosphorescent portion 34 can be provided on the side surface of the polyurethane elastomer layer 18 on the inner layer side in addition to the side surface of the polyurethane elastomer layer 24 on the outermost layer. It is also possible to provide them in both layers. In this way, by providing the phosphorescent part 34 on the side surface of the regenerated solid tire 10 (30), when the vehicle equipped with the regenerated solid tire 10 (30) travels in a dark place, the phosphorescent part 34 emits. By the presence of light, it is possible to notify the people around the vehicle that the vehicle is running, and thus it is possible to prevent an accident between the person and the vehicle.

  In addition, as a method of forming such a phosphorescent portion 34 on the side surface of the recycled solid tire 10 (30), a polyurethane elastomer material blended with a phosphorescent material at the time of cast molding of the polyurethane elastomer layer 18 (24) is used. It is possible to form the phosphorescent portion 34 at the same time as the formation of the polyurethane elastomer layer 18 (24), but it is desirable to form a predetermined shape on the portion that becomes the side surface of the tire in the mold used for casting. With the cut phosphorescent tape attached, a polyurethane elastomer material is injected into the mold so that the phosphorescent tape is embedded and integrated in the side surface of the polyurethane elastomer layer 18 (24) to be formed. Thus, the phosphorescent portion 34 is formed. By adopting such a method, the phosphorescent part 34 can be formed easily and at low cost.

  In addition, although not enumerated one by one, the present invention can be carried out in a mode to which various variations, modifications, improvements, and the like are added based on the knowledge of those skilled in the art. It should be understood that all are within the scope of the present invention without departing from the spirit of the present invention.

It is explanatory drawing which shows an example of the reproduction | regeneration solid tire according to this invention, Comprising: (a) shows side surface explanatory drawing, (b) is AA cross-section explanatory drawing in (a). It is a fragmentary sectional explanatory view which expands and shows the B section of Drawing 1 (b). It is a fragmentary sectional view equivalent to FIG. 2 which shows another example of the reproduction | regeneration solid tire according to this invention. It is front explanatory drawing which shows another example of the reproduction | regeneration solid tire according to this invention. It is side explanatory drawing which shows an example of the preferable aspect of the reproduction | regeneration solid tire according to this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Recycled solid tire 12 Wheel 14 Rubber layer 16 Outer peripheral surface 18 Polyurethane elastomer layer 20 Tread surface 22a, 22b Curved part

Claims (9)

  A recycled solid tire is formed by covering a peripheral surface of a worn solid tire with a predetermined rubber layer remaining thereon with a room temperature curing type polyurethane elastomer layer at a predetermined thickness. Each is formed as a curved portion, and is configured so that the radius of curvature of one corner is larger than the radius of curvature of the other corner, and is attached to the vehicle so that the one corner is outside the vehicle. Recycled solid tire characterized by being made to be able to.   The recycled solid tire according to claim 1, wherein the curved portion is formed with respect to corner portions on both sides in the width direction on the outer peripheral surface of the room temperature curing type polyurethane elastomer layer.   3. The reclaimed solid tire according to claim 1, wherein an outermost layer made of a polyurethane elastomer having higher wear resistance than that of the room temperature curing type polyurethane elastomer layer is overlapped at a predetermined thickness. .   The regenerated solid tire according to claim 3, wherein the curved portion is formed with respect to corner portions on both sides in the width direction on the outer peripheral surface of the outermost layer.   The one corner is formed as a curved portion having a radius of curvature of 40 to 60 mm, and the other corner is formed as a curved portion having a radius of curvature of 20 to 40 mm. 4. The recycled solid tire according to any one of 4 above.   The reclaimed solid tire according to any one of claims 1 to 5, wherein a radius of curvature of the one corner is 10 to 30 mm larger than a radius of curvature of the other corner.   The reclaimed solid tire according to any one of claims 1 to 6, wherein a plurality of parallel grooves are provided on the outer peripheral surface of the tire so as to extend in the circumferential direction.   The regenerated solid tire according to any one of claims 1 to 7, wherein a phosphorescent portion is provided at at least one location on a side surface of the tire. The regenerated solid tire according to claim 8, wherein the phosphorescent portion is provided on a side surface of the polyurethane elastomer layer.

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