Multi-layer tire, preparation method and mold for preparing multi-layer tire

Abstract

According to the embodiment of the invention, a multi-layer tire, a preparation method and a mold for preparing the multi-layer tire are provided. The multi-layer tire includes: an inner layer arranged to surround an outer circumferential surface of a hub in a radial direction; the outer layer at least partially wraps the outer peripheral surface of the inner layer in the radial direction, and comprises a main body part; the wear-resistant parts are at least partially coupled to the side, away from the inner layer, of the main body part so as to serve as the surface of the multi-layer tire to make contact with the road surface. Therefore, the tire has the advantages of strong road holding force, wet skid resistance and low rolling resistance, and meanwhile, the elasticity of the tire is also improved, so that the driving comfort is improved.

Description

Technical Field

[0001] Example embodiments of the present disclosure relate generally to the field of bicycle tires, and more particularly to multi-layer tires, methods of making the same, and molds for making the multi-layer tires. Background Art

[0002] Since it is difficult to invest a lot of manpower in the maintenance of shared bicycles, the tires of shared bicycles are generally solid tires without inflation. The solid tires of shared bicycles generally include solid rubber tires and solid polyurethane foam tires. However, pure rubber tires are heavy, which affects the experience, and pure polyurethane (PU) tires have poor anti-skid effect, large rolling resistance, and are not wear-resistant, which affects the user experience. Summary of the invention

[0003] In a first aspect of the present disclosure, a multi-layer tire is provided. The multi-layer tire comprises: an inner layer arranged to surround the outer peripheral surface of a wheel hub in the radial direction of the tire; and an outer layer at least partially wrapping the outer peripheral surface of the inner layer in the radial direction, and comprising: a main body portion in contact with the inner layer; and a wear-resistant portion coupled to the main body portion to serve as a surface of the multi-layer tire in contact with a road surface.

[0004] In some embodiments, the wear-resistant portion includes a plurality of wear-resistant particles, and the plurality of wear-resistant particles are arranged in the main body portion.

[0005] In some embodiments, the wear-resistant portion includes at least one wear-resistant strip, and the at least one wear-resistant strip at least partially surrounds the outer circumferential surface of the main body portion along the circumference of the main body portion.

[0006] In some embodiments, the inner layer further includes a protrusion, which is circumferentially arranged on one side of the inner layer close to the center of the hub, and the protrusion protrudes toward the center of the hub along the middle section of the axial direction of the tire.

[0007] In some embodiments, the inner layer further comprises a pair of undercuts, which are respectively formed at two ends of the inner layer along the axial direction of the tire and are suitable for being coupled with a pair of matching portions of the hub, respectively.

[0008] In some embodiments, the multi-layer tire further includes at least one reinforcing cord arranged to be passed through the inner layer and to extend along the circumference of the inner layer.

[0009] In some embodiments, the inner layer further includes a plurality of fixing grooves respectively arranged at both ends of the inner layer in the axial direction of the tire, and each fixing groove is formed between a fixing rope in the inner layer and a side wall of the inner layer.

[0010] In some embodiments, an annular hole extending in the circumferential direction is further provided in the inner layer.

[0011] In some embodiments, the multi-layer tire further includes an air ring disposed within the annular hole, and is hollow inside and filled with gas to support the air ring.

[0012] In some embodiments, the multi-layer tire further includes at least a plurality of weight-reducing holes arranged at a predetermined interval circumferentially on the inner circumferential surface of the inner layer.

[0013] By using two polyurethane materials with different densities as the inner circumferential surface and the outer layer of the tire respectively, and mixing wear-resistant materials such as rubber into the high-density polyurethane material located in the outer layer, the tire thus has the advantages of strong grip, anti-hydroplaning, and low rolling resistance. At the same time, the inner layer structure uses low-density polyurethane, which not only reduces the weight but also brings better elasticity, thereby improving the driving comfort.

[0014] In a second aspect of the present disclosure, a method for manufacturing a multi-layer tire is provided. The manufacturing method includes: installing a mold, fixing the air ring between the upper mold and the lower mold, and then locking the upper mold and the lower mold; outer layer forming, injecting a mixed slurry containing a wear-resistant part and a main body part into the mold, the mold maintaining a predetermined temperature and pressure inside and rotating around the rotation axis so that the mixed slurry is formed on the inner circumferential surface of the mold away from the rotation axis; inner layer forming, injecting the inner layer slurry into the mold, the inside of the mold maintaining a predetermined temperature and pressure and rotating around the rotation axis so that the inner circumferential surface slurry is formed.

[0015] In some embodiments, during the outer layer forming and the inner layer forming, the heat preservation temperature of the mold is in the range of 30-50°C.

[0016] In some embodiments, the density of the outer layer is in the range of 0.4-0.7 g / cm 3 .

[0017] In some embodiments, the density of the outer layer is in the range of 0.9-1.1 g / cm 3 .

[0018] In some embodiments, the forming time of the outer layer is in the range of 10-30 s.

[0019] In some embodiments, the rotation speed of the mold is in the range of 60-80 r / min.

[0020] In a third aspect of the present disclosure, a mold for manufacturing a multi-layer tire is provided. The mold includes: a lower mold including a lower cavity; and an upper mold coupled to the lower mold and including an upper cavity; when the upper mold is coupled to the lower mold, the lower cavity and the upper cavity are aligned to form an injection cavity for accommodating the multi-layer tire.

[0021] In some embodiments, the lower mold further includes a plurality of lower ejector pins, which are arranged in the lower cavity at a predetermined interval in the circumferential direction and are adapted to fix the fixing ropes of the multi-layer tire at a predetermined position after the upper cavity is coupled to the lower cavity.

[0022] In some embodiments, the mold further includes a plurality of core rods, which are arranged on the inner circumferential surface of the mold at a predetermined interval in the circumferential direction of the lower mold, and each core rod among the plurality of core rods is arranged between the upper mold and the lower mold in the radial direction of the lower mold.

[0023] In some embodiments, the mold further includes a core-pulling mechanism, which is coupled to the plurality of core rods and is adapted to at least control the plurality of core rods to slide in the radial direction.

[0024] It should be understood that the content described in this part is not intended to define the key features or important features of the embodiments of the present disclosure, nor is it used to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] With reference to the accompanying drawings and the following detailed description, the above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent. In the drawings, the same or similar reference numerals denote the same or similar elements, wherein:

[0026] Figure 1 Shows a schematic diagram of the overall structure of a multi-layer tire in some embodiments according to the present disclosure, wherein the wear-resistant part is a wear-resistant strip;

[0027] Figure 2 Shows Figure 1 a cross-sectional view of the multi-layer tire in the radial direction;

[0028] Figure 3 Shows Figure 2 an enlarged view of detail A in;

[0029] Figure 4 Shows a schematic diagram of the overall structure of a multi-layer tire in some embodiments according to the present disclosure, wherein the wear-resistant part is wear-resistant particles;

[0030] Figure 5 Shows Figure 4 a cross-sectional view of the multi-layer tire in the radial direction in;

[0031] Figure 6 Shows Figure 5 an enlarged view of detail B in;

[0032] Figure 7 Shows a schematic diagram of the overall structure of a mold for manufacturing a multi-layer tire in some embodiments according to the present disclosure; and

[0033] Figure 8 Shows Figure 7 Detail C in the figure should be enlarged. DETAILED DESCRIPTION

[0034] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not intended to limit the scope of protection of the present disclosure.

[0035] It should be noted that the titles of any sections / subsections provided herein are not restrictive. Various embodiments are described throughout this article, and any type of embodiment may be included under any section / subsection. In addition, the embodiments described in any section / subsection may be combined in any manner with any other embodiments described in the same section / subsection and / or different sections / subsections.

[0036] In the description of the embodiments of the present disclosure, the term "including" and similar terms should be understood as open inclusion, that is, "including but not limited to". The term "based on" should be understood as "based at least in part on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The term "some embodiments" should be understood as "at least some embodiments". Other explicit and implicit definitions may be included below. The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may be included below.

[0037] In the description of the embodiments of the present disclosure, the term "inner circumference" refers to the side facing the axis of rotation or the center of rotation. Correspondingly, the term "outer circumference" refers to the side opposite to the "inner circumference", that is, the side away from the axis of rotation or the center of rotation. The term "axial direction R" refers to the straight line direction of the tire rotation axis when the tire rotates, and the term "radial direction" refers to the direction perpendicular to the axial direction.

[0038] As briefly mentioned above, in existing shared bicycles or electric motorcycles, in order to reduce the cost of manpower maintenance, solid airless tires are often used. Such tires generally include solid rubber tires and solid polyurethane foam tires.

[0039] For solid rubber tires, because the density of rubber is relatively high, it increases the weight of the entire vehicle body. Rubber has poor heat dissipation, so when riding in summer, the inner layer of the tire is easy to burn. At the same time, the price of rubber itself is relatively high, so the cost of solid tires is also relatively high.

[0040] For polyurethane solid tires, the existing polyurethane solid tires have the disadvantages of weak wet skid resistance and poor grip. At the same time, polyurethane solid tires are prone to wear and have poor abrasion resistance.

[0041] According to a multi-layer tire, a preparation method and a mold for preparing a multi-layer tire provided by the present disclosure, to solve or at least partially solve the above problems and other potential problems existing in the traditional solutions. According to an embodiment of the present disclosure, by using two polyurethane materials with different densities as the inner circumferential surface and the outer layer of the tire respectively, and mixing wear-resistant materials such as rubber into the high-density polyurethane material located in the outer layer, the tire thus has the advantages of strong grip, good wet skid resistance and low rolling resistance. At the same time, the inner layer structure uses low-density polyurethane, which brings better elasticity while reducing weight, thereby improving driving comfort.

[0042] Figure 1 Shows a schematic diagram of the overall structure of a multi-layer tire in some embodiments according to the present disclosure, as Figure 1 Shown. The multi-layer tire provided by the present disclosure generally includes an inner layer 1 and an outer layer 2 coupled to the inner layer 1. The inner layer 1 is adapted to surround and be coupled to the outer circumferential surface of the wheel hub, and the outer layer 2 at least partially wraps around the outer circumferential surface of the inner circumferential surface (that is, the side facing away from the wheel hub). The axes of the outer layer 2, the inner layer 1 and the wheel hub are aligned with each other so that the outer layer 2, the inner layer 1 and the wheel hub remain in a coaxial state. The outer layer 2 serves as the surface of the multi-layer tire, and the outer layer 2 contacts the ground when the multi-layer tire rolls on the ground.

[0043] Figure 2 Shows Figure 1 A cross-sectional view of the multi-layer tire in the radial direction, Figure 3 Shows Figure 2 An enlarged view of detail A in Figure 2 And Figure 3 Shown, the outer layer 2 includes a main body portion 21 and a plurality of wear-resistant portions coupled to the main body portion 21. The main body portion 21 is used to fix at least the wear-resistant portions on the surface of the multi-layer tire so that when the multi-layer tire rolls on the bottom surface, the wear-resistant portions can contact the ground, thereby improving the wear resistance of the multi-layer tire. In some embodiments, the wear-resistant portions can be mixed in the slurry for forming the main body portion 21 and molded in the mold together with the slurry. In other embodiments, the wear-resistant portions and the main body portion 21 can also be fixed together by bonding or other means.

[0044] As Figure 2 And Figure 3As shown, in some embodiments, the wear-resistant part may include at least one wear-resistant strip 22. At least one wear-resistant strip wraps at least partially around the outer peripheral surface of the main body part 21 in the circumferential direction of the main body part 21. In some embodiments, the wear-resistant strip 22 may be annular or strip-shaped. The wear-resistant strip 22 may be adhesively fixed to the outer peripheral surface of the main body part 21 by an adhesive or the like after the main body part 21 is formed. The wear-resistant strip 22 may also be pre-attached to the inner peripheral surface of the mold, and then after injecting slurry into the mold, the main body part 21 is formed on the wear-resistant strip 22.

[0045] In some other embodiments, at least one wear-resistant strip 22 may include two or more wear-resistant strips 22. Taking two wear-resistant strips 22 as an example, the two wear-resistant strips 22 are respectively arranged along the axial direction of the main body part 21 and the two wear-resistant strips 22 respectively surround the outer peripheral surface of the main body part 21.

[0046] In some embodiments, when the strip-shaped wear-resistant strip 22 at least partially surrounds the outer peripheral surface of the main body part 21, the ends of adjacent wear-resistant strips 22 will form seams on the circumferential surface of the main body part 21. The seams of two groups of wear-resistant strips 22 arranged along the axial direction can be staggered by a predetermined distance, thereby reducing the tension borne by the seams during the rolling of the tire.

[0047] Figure 4 Shows a schematic diagram of the overall structure of a multi-layer tire according to some embodiments of the present disclosure. Figure 5 Shows Figure 4 A cross-sectional view of the multi-layer tire in Figure 6 Shows Figure 5 An enlarged view of detail B in Figures 4 to 6 As shown, in some embodiments, the wear-resistant part may be wear-resistant particles 23, such as rubber particles, etc. The particle size of the wear-resistant particles can be in the range of 2 mm to 20 mm. The wear-resistant particles 23 can be integrally formed after being mixed with the slurry used to form the main body part 21, so that the wear-resistant part can be stably coupled with the main body part 21.

[0048] In some embodiments, the main body parts 21 of the inner layer 1 and the outer layer 2 are made of two different density polyurethane materials, and the density of the polyurethane material of the main body part 21 is greater than the density of the polyurethane material of the inner layer 1. On the one hand, this improves the wear resistance of the outer layer 2, and on the other hand, it also improves the elasticity of the inner layer 1. In some embodiments, the wear-resistant part may be made of rubber material. Thus, while ensuring that the outer layer 2 of the multi-layer tire has high friction resistance, using rubber material can also reduce the elastic loss of the multi-layer tire.

[0049] In some embodiments, the density of the polyurethane material of the main body part 21 may be in the range of 0.9 g / cm³ to 1.1 g / cm³. For example, the density of the main body part 21 may be 0.9 g / cm 3, 1.0g / cm 3 or 1.1 g / cm 3 In some embodiments, the density of the polyurethane material of the inner layer 1 may be in the range of 0.4 g / cm3 to 0.7 g / cm3. For example, the density of the inner layer 1 may be 0.4 g / cm3. 3 , 0.5g / cm 3 , 0.6g / cm 3 or 0.7g / cm 3 .

[0050] In some embodiments, the inner layer 1 also includes a raised portion 3, which is arranged on the inner circumferential surface of the inner layer 1, and the raised portion 3 protrudes toward the center of the hub in the middle section along the axial direction R, so that the raised portion 3 can be pressed against the outer circumferential surface of the hub, making the multi-layer tire and the hub more tightly assembled, thereby reducing the displacement noise of the tire.

[0051] return Figure 3 In some embodiments, the inner layer 1 further comprises a pair of undercuts 11, which are arranged at both ends of the inner layer 1 along the axial direction R, and when the multi-layer tire is coupled to the wheel hub, the pair of undercuts 11 are respectively engaged with a pair of matching portions at both ends of the wheel hub along the axial direction R, so that the multi-layer tire can be coupled to the wheel hub. In some embodiments, the pair of undercuts 11 can be a pair of grooves formed at both ends of the inner layer 1 along the axial direction R, and each groove extends along the circumference of the inner layer 1. Correspondingly, the pair of matching portions on the wheel hub can be a pair of convex edges, and the pair of grooves are respectively engaged on the pair of convex edges, so that the multi-layer tire can be coupled to the wheel hub.

[0052] In other embodiments, the pair of undercuts 11 may also be a pair of snap rings, which are coaxially coupled at both ends of the inner layer 1 along the axial direction R, and the mating portion on the wheel hub may be an annular groove that cooperates with the snap ring. Through the cooperation between the snap ring and the annular groove, the multi-layer tire can also be coupled to the wheel hub.

[0053] like Figure 3 As shown, in some embodiments, the multi-layer tire also includes at least one reinforcement cord 4, which is annular as a whole and is inserted into the inner layer 1. The axis of the reinforcement cord 4 is aligned with the axis of the inner layer 1. The reinforcement cord 4 can reinforce the tire as a whole, thereby reducing the possibility of deformation of the multi-layer tire due to pulling during installation. At the same time, it can also reduce the deformation of the multi-layer tire after long-term use. In some alternative embodiments, the multi-layer tire can also include multiple reinforcement cords 4. For example, two pairs of reinforcement cords 4 can be inserted into the multi-layer tire, and the two pairs of reinforcement cords 4 are arranged along the axial direction R.

[0054] In some embodiments, the fixing rope may be made of organic materials such as nylon and plastic, or inorganic materials such as glass fiber and steel wire.

[0055] In some embodiments, in order to accommodate the fixing rope in the inner layer 1 when processing a multi-layer tire, the inner layer 1 further includes a plurality of fixing grooves 11, which are respectively distributed at both ends of the inner layer 1 along the axial direction R, and the fixing grooves 11 on each side extend from the side of the inner layer 1 to the fixing rope. The setting of the fixing grooves 11 enables the fixing rope to be supported through the fixing grooves 11 when processing a multi-layer tire, so that the fixing rope can be kept at a predetermined position.

[0056] In some embodiments, the inner layer 1 further includes an annular hole 12, which is formed inside the inner layer 1 and is coaxial with the inner layer 1. The provision of the annular hole 12 improves the elasticity of the inner layer 1 and also reduces the weight of the multi-layer tire.

[0057] Furthermore, a balloon 5 may be provided in the annular hole 12, and the balloon 5 may be filled with gas, so as to support the annular hole 12, thereby further improving the elasticity of the multi-layer tire. In some embodiments, the air pressure in the balloon 5 may be in the range of 1.5 to 3 atmospheres, for example, the air pressure in the balloon 5 may be 2 atmospheres.

[0058] In some embodiments, the inner layer 1 further includes a plurality of weight-reducing holes 13, which are formed on the inner circumferential surface of the inner layer 1 at predetermined intervals along the circumference of the inner layer 1, and the axis of each weight-reducing hole 13 is arranged along the radial direction of the inner layer 1. On the one hand, the opening of the weight-reducing holes 13 reduces the material used in the inner layer 1 and reduces the dead weight of the multi-layer tire, and on the other hand, the weight-reducing holes 13 can also be used as cavities to improve the elasticity of the inner layer 1.

[0059] Figure 7 A schematic diagram of the overall structure of a mold for preparing a multi-layer tire according to some embodiments of the present disclosure is shown. Figure 8 Shows Figure 7 The detail C in the figure should be enlarged. Figure 7 and Figure 8 As shown, the mold generally includes a lower mold 6 and an upper mold 7 that can be coupled to the lower mold 6. The lower mold 6 has a lower cavity on one side facing the upper mold 7, and the upper mold 7 has an upper cavity on one side facing the lower mold 6. The upper mold 7 has an injection hole on one side facing away from the lower mold 6 that is connected to the upper cavity. When the lower mold 6 and the upper mold 7 are locked together, the upper cavity and the lower cavity are aligned with each other, thereby forming an injection cavity for accommodating a multi-layer tire. The operator can inject the slurry into the injection cavity through the injection hole. Thus, the slurry is formed into the desired multi-layer tire in the injection cavity according to the shape of the cavity.

[0060] It should be understood that the "upper" mold and "lower" mold mentioned in this application are only used to distinguish the two main parts 21 of the mold, rather than being limited in a specific direction or orientation. For example, in some embodiments, the upper mold 7 and the lower mold 6 may be arranged along the direction of gravity. In some other embodiments, the arrangement of the upper mold 7 and the lower mold 6 may also deviate from the direction of gravity by a predetermined angle.

[0061] In some embodiments, a necessary locking device should also be included between the upper mold 7 and the lower mold 6 to make the upper mold 7 and the lower mold 6 fit tightly. In some other embodiments, a pressing device may also be provided on the side of the upper mold 7 facing away from the lower mold 6 to press the upper mold 7 against the lower mold 6.

[0062] In some embodiments, the mold can be installed on a centrifuge device. After the slurry is injected into the mold, the mold rotates around the axis driven by the centrifuge device, and the slurry is formed inside the injection cavity under the action of centrifugation.

[0063] In some embodiments, the lower mold 6 further includes ejector pins. The ejector pins are arranged in the lower cavity and are coupled to the bottom wall of the lower cavity at one point, and the other end is arranged towards the opening of the lower cavity. The ejector pins are suitable for supporting and fixing the fixing rope so that the fixing rope can be suspended at a predetermined position inside the injection cavity before pouring in the mold. There are multiple ejector pins, and the multiple ejector pins are evenly distributed along the circumference of the lower mold 6. Thus, after the multi-layer tire is poured, the fixing rope can maintain a more regular circle in the inner layer 1, so that the fixing rope can provide a more stable tensile resistance for the multi-layer tire.

[0064] After the multi-layer tire is formed in the mold, due to the existence of the ejector pins, multiple fixing grooves 11 are also formed at both ends of the inner layer 1 along the axial direction R. The existence of the fixing grooves 11 can also provide additional elasticity for the inner layer 1 of the multi-layer tire, and is beneficial to the heat dissipation inside the multi-layer tire, reducing the situation that the temperature of the inner layer 1 is too high after the long-term use of the multi-layer tire, which affects the tire performance.

[0065] In some embodiments, the lower mold 6 further includes a plurality of lower support rods, and the plurality of lower support rods are evenly distributed along the circumference in the lower cavity. One end of each lower support rod is coupled to the bottom wall of the lower cavity facing the opening, and the other end faces the opening of the lower cavity. The lower support rods are suitable for fixing the air ring 5 in the injection cavity, so that the air ring 5 can be kept at a predetermined position when injecting the slurry into the cavity.

[0066] In some other embodiments, the upper mold 7 includes a plurality of upper support rods, and the plurality of lower support rods are evenly distributed along the circumference in the upper cavity. One end of the upper support rod is coupled to the bottom wall of the upper cavity facing the opening. After the upper mold 7 is buckled to the lower mold 6, the upper support rod touches the side of the air ring 5 facing away from the lower support rod, so that the upper support rod and the lower support rod jointly fix the air ring 5 at a predetermined position in the injection cavity.

[0067] In some embodiments, the mold further includes a plurality of core rods 8, which are uniformly distributed along the circumferential direction of the lower mold 6. Each core rod 8 is arranged between the upper mold 7 and the lower mold 6, and the length direction of the core rod 8 is arranged along the radial direction of the lower mold 6. Both the upper mold 7 and the lower mold 6 are provided with mutually matching grooves, and the grooves communicate the upper cavity (or the lower cavity) with the inner circumferential surface of the upper mold (or the lower mold). After the upper mold 7 and the lower mold 6 are coupled, the grooves of the upper mold 7 and the grooves of the lower mold 6 are spliced to form a channel for the core rod 8 to pass through. The core rod 8 passes through the channel and at least partially enters the injection cavity. In this way, weight-reducing holes 13 are formed on the multi-layer tire after injection.

[0068] In other embodiments, the core rod 8 further includes a core-pulling mechanism 81 for controlling the core rod 8 to slide in and out of the channel along the radial direction of the lower mold 6. The axis is simultaneously coupled to the plurality of core rods 8, and the core-pulling mechanism 81 is adapted to drive the core rod 8 to slide at least along the radial direction of the lower mold 6, thereby controlling the core rod 8 to enter the channel. In some embodiments, the core rod 8 mechanism may include a cam device, and the rotation of the cam device is used to control the sliding of the connecting rod along the radial direction of the lower mold 6. In other embodiments, the core rod 8 mechanism may further include a connecting rod device, and the swing of the connecting rod device can also be used to control the sliding of the core rod 8 along the radial direction of the lower mold 6.

[0069] It should be understood that the above description of the core-pulling mechanism 81 is only illustrative and is not intended to limit the protection scope of the core-pulling mechanism 81. In fact, any transmission or drive structure that can be used to control the sliding of the core rod 8 along the radial direction of the lower mold 6 can be used for the core-pulling mechanism 81 of the present application.

[0070] In some embodiments, the air ring 5 can be fixed in the injection cavity by the core rod 8. For example, the core-pulling mechanism 81 can control the core rod 8 to penetrate into the cavity, and the end of the core rod 8 abuts against the inner surface of the air ring 5. Thus, the air ring 5 can be fixed at a predetermined position in the injection cavity by the tension provided by the plurality of core rods 8. This facilitates the subsequent molding of the inner layer 1.

[0071] According to an embodiment of the present disclosure, a method for manufacturing a multi-layer tire is further provided, including the following steps.

[0072] Installation of the mold, fixing the air ring between the upper mold and the lower mold, and then locking the upper mold and the lower mold;

[0073] In some embodiments, the balloon can be fixed in the injection cavity by a core-pulling mechanism. Specifically, the operator first places the balloon at a predetermined position, and then controls the core rod to extend through the core-pulling mechanism. The end of the core rod abuts against the inner side of the balloon, so that the balloon is fixed to the end face of the core rod by the tension generated by the extension of the core rod. In some embodiments, the operator can also clamp a fixing rope on the ejector pin of the lower mold.

[0074] Outer layer forming: Inject the mixed slurry containing the wear-resistant part and the main body part into the mold. The mold maintains a predetermined temperature and pressure inside and rotates around the rotation axis so that the mixed slurry is formed on the inner circumferential wall of the mold away from the rotation axis.

[0075] In some embodiments, the slurry used to form the outer main body part and the inner layer can include polyurethane. After the polyurethane is injected into the mold, it is set according to the shape of the cavity in the mold after being kept warm for a period of time.

[0076] In some embodiments, the mold is placed on a centrifugal device and can rotate with the centrifugal device. The mixed slurry is formed on the side wall of the injection cavity away from the rotation axis under the drive of centrifugal force. And because the mass of the wear-resistant part (such as wear-resistant particles) is relatively large, the wear-resistant part is formed on the side of the injection cavity farther from the rotation axis, that is, on the outer surface of the formed tire. When the tire is in use, the wear-resistant part can contact the ground, thereby reducing the loss of the main body part.

[0077] In some other embodiments, when the wear-resistant part is a wear-resistant strip, the wear-resistant strip can be pre-attached to the surface of the injection cavity away from the rotation axis before injecting the mixed slurry. After injecting the mixed slurry, the mixed slurry combines with the wear-resistant strip under the action of centrifugal force to form the outer layer of the multi-layer tire.

[0078] In some embodiments, the temperature of the mold during outer layer forming can be in the range of 30-50°C. Preferably, the temperature of the mold can be 40°C.

[0079] In some embodiments, the rotation speed of the mold is in the range of 60-80 r / min.

[0080] In some embodiments, the time for outer layer forming can be in the range of 10-40 minutes.

[0081] After forming, the average density of the outer layer is in the range of 0.9-1.1 g / cm 3 of.

[0082] Inner layer forming: Inject the inner layer slurry into the mold. The mold maintains a predetermined temperature and pressure inside and rotates around the rotation axis so that the inner circumferential surface slurry is formed.

[0083] In some embodiments, the temperature of the mold during inner layer forming can be in the range of 30 to 50 °C. Preferably, the temperature of the mold can be 40 °C.

[0084] In some embodiments, the rotation speed of the mold is in the range of 60 - 80 r / min.

[0085] In some embodiments, the time for inner layer forming can be in the range of 10 - 40 minutes.

[0086] After forming, the average density of the outer layer is in the range of 0.4 - 0.7 g / cm 3 of.

[0087] When the inner layer is completely formed, the core pulling mechanism can control the core rod to retract. At this time, the mold is opened, and the obtained multi-layer tire can be taken out of the mold.

[0088] The various implementations of the present disclosure have been described above. The above description is exemplary and not exhaustive, and is also not limited to the disclosed implementations. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described implementations. The choice of terms used herein is intended to best explain the principles of the implementations, practical applications, or improvements to technologies in the market, or to enable other ordinary skilled artisans in the art to understand the various implementation manners disclosed herein.

Claims

1. A multi-layer tire, comprising: An inner layer (1), arranged to surround the outer peripheral surface of the wheel hub along the radial direction of the tire; And An outer layer (2), at least partially wrapping the outer peripheral surface of the inner layer (1) along the radial direction, and comprising: A main body portion (21), in contact with the inner layer (1); And A wear-resistant portion, coupled to the main body portion (21) to provide a surface of the multi-layer tire in contact with the road surface.

2. The multi-layer tire according to claim 1, wherein the wear-resistant portion comprises a plurality of wear-resistant particles (23), and the plurality of wear-resistant particles (23) are arranged within the main body portion (21).

3. The multi-layer tire according to claim 1, wherein the wear-resistant portion comprises at least one wear-resistant strip (22), and the at least one wear-resistant strip (22) at least partially surrounds the outer peripheral surface of the main body portion (21) along the circumferential direction of the main body portion (21).

4. The multi-layer tire according to any one of claims 1 to 3, wherein the inner layer (1) further comprises a raised portion (3), the raised portion (3) is arranged circumferentially on a side of the inner layer (1) close to the center of the wheel hub, and the middle section of the raised portion (3) along the axial direction (R) of the tire bulges towards the center of the wheel hub.

5. The multi-layer tire according to any one of claims 1 to 3, wherein the inner layer (1) further comprises a pair of reverse buckles (11), respectively formed at both ends of the inner layer (1) along the axial direction (R) of the tire and adapted to be respectively coupled to a pair of mating portions of the wheel hub.

6. The multi-layer tire according to any one of claims 1 to 3, further comprising at least one reinforcing rope (4), arranged to be threaded through the inner layer (1) and extending along the circumferential direction of the inner layer (1).

7. The multi-layer tire according to claim 6, wherein the inner layer (1) further comprises a plurality of fixing grooves (11), respectively arranged at both ends of the inner layer (1) along the axial direction (R) of the tire, and each fixing groove (11) is formed between the fixing rope in the inner layer (1) and the side wall of the inner layer (1).

8. The multi-layer tire according to any one of claims 1 to 3, wherein an annular hole (12) extending in the circumferential direction is further provided within the inner layer (1).

9. The multi-layer tire according to claim 8, further comprising an air ring (5), arranged within the annular hole (12), and being hollow inside and filled with gas to support the air ring (5).

10. The multi-layer tire according to any one of claims 1 to 3, further comprising at least a plurality of weight-reducing holes (13), arranged at a predetermined interval along the circumferential direction on the inner peripheral surface of the inner layer (1).

11. A method for manufacturing a multi-layer tire, comprising: Installation of the mold, fixing the air ring between the upper mold and the lower mold, and then locking the upper mold and the lower mold; Outer layer forming, injecting a mixed slurry containing a wear-resistant portion and a main body portion into the mold, the mold maintaining a predetermined temperature and pressure inside and rotating around a rotation axis, so that the mixed slurry is formed on the inner peripheral surface of the mold away from the rotation axis; And Inner layer forming: Inject the inner layer slurry into the mold. The interior of the mold is maintained at a predetermined temperature and pressure and rotates around the axis of rotation to form the slurry on the inner peripheral surface.

12. The preparation method according to claim 11, wherein, During the outer layer forming and the inner layer forming, the heat preservation temperature of the mold is in the range of 30 to 50 °C.

13. The preparation method according to claim 11, wherein the density of the outer layer is in the range of 0.4 to 0.7 g / cm 3 .

14. The preparation method according to claim 11, wherein the density of the outer layer is in the range of 0.9 to 1.1 g / cm 3 .

15. The preparation method according to claim 11, wherein the forming time of the outer layer is in the range of 10 to 30 s.

16. The preparation method according to claim 11, wherein the rotation speed of the mold is in the range of 60 - 80 r / min.

17. A mold for preparing a multi-layer tire, comprising: A lower mold (6), including a lower cavity; And An upper mold (7), coupled to the lower mold (6) and including an upper cavity; When the upper mold (7) is coupled to the lower mold (6), the lower cavity is aligned with the upper cavity to form an injection cavity for accommodating the multi-layer tire.

18. The mold according to claim 17, wherein the lower mold (6) further includes a plurality of lower ejector pins, which are arranged in the lower cavity at a predetermined circumferential interval and are adapted to fix the fixing rope of the multi-layer tire at a predetermined position after the upper cavity is coupled to the lower cavity.

19. The mold according to claim 17, further comprising a plurality of core rods (8), which are arranged on the inner peripheral surface of the mold at a predetermined circumferential interval along the lower mold (6), and each of the plurality of core rods (8) is arranged in the radial direction of the lower mold (6) between the upper mold (7) and the lower mold (6).

20. The mold according to claim 19, further comprising a core pulling mechanism (81), which is coupled to the plurality of core rods (8) and is adapted to at least control the plurality of core rods (8) to slide along the radial direction.

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