Preparation method of wheel

Abstract

The invention relates to a preparation method of a wheel. The preparation method of the wheel comprises the following steps: curing a first material body to form an outer tire, wherein the outer tire is provided with a containing groove; a second material body is centrifugally poured into the containing groove of the outer tire, and the inner tire is cured and formed; and integrally taking out the outer tire and the inner tire. Wherein negative pressure exhaust is carried out at least in the process of curing and forming the inner tube.

Description

Technical Field

[0001] The present application relates to the technical field of children's carriers, and in particular to a method for preparing wheels. Background Art

[0002] Child carriers are convenient for parents to take their children out. The wheels are used to move the child carrier on the road, freeing their hands. Among them, infant strollers are a common child carrier. At present, the outer and inner tubes of the wheels of child carriers are easy to loosen after being used for a period of time, resulting in reduced stability of the wheel operation. In addition, the rubber material used in the wheels is prone to frost spitting problems, and it is also prone to staining problems, that is, leaving black marks on the ground where the wheels pass, which gives users a bad user experience. Summary of the invention

[0003] According to various embodiments of the present application, a method for preparing a wheel is provided. In addition, the present application also provides a wheel and a child carrier having the wheel.

[0004] According to a first aspect of the present application, a method for preparing a wheel is provided. The method comprises: curing and forming an outer tire using a first material body, wherein the outer tire has a receiving groove; curing and forming an inner tire by centrifugally pouring a second material body into the receiving groove of the outer tire; and taking out the outer tire and the inner tire as a whole; wherein, at least during the curing and forming process of the inner tire, negative pressure exhaust is performed.

[0005] In one embodiment, curing and molding a tire using a first material body includes: providing a first mold, wherein the first mold is provided with a first pouring cavity and a first pouring hole connected to the first pouring cavity; centrifugally pouring the first material body into the first mold through the first pouring hole so that the first material body is evenly covered on the inner wall of the first mold; and obtaining the tire body after the first material body is cooled and solidified, wherein the tire body is retained in the first mold.

[0006] In one embodiment, curing and molding the inner tube includes: centrifugally pouring the second material into the first mold through the first pouring hole so that the receiving groove of the outer tube is filled with the second material; and obtaining the inner tube after the second material is foamed and cured, wherein the inner tube and the outer tube are connected as a whole.

[0007] In one embodiment, in providing a first mold, the first mold has a first main channel, and the first perfusion hole penetrates from the side wall of the first main channel to the inner wall of the first perfusion cavity, wherein the number of the first perfusion holes is multiple, and the multiple first perfusion holes are evenly distributed along the circumferential direction of the first mold; or, the number of the first perfusion hole is one, and the first perfusion hole extends along the circumferential direction of the first mold.

[0008] In one embodiment, in providing a first mold, a portion of the cavity wall of the first perfusion cavity covered by the first material body is used as the first cavity wall, and another portion of the cavity wall of the first perfusion cavity not covered by the first material body is used as the second cavity wall, the first perfusion hole penetrates the second cavity wall to communicate with the first perfusion cavity, and the first mold is provided with a first exhaust hole for negative pressure exhaust, and the first exhaust hole penetrates the second cavity wall to communicate with the first perfusion cavity.

[0009] In one embodiment, negative pressure exhaust is performed during the process of centrifugally pouring the first material body into the first mold and cooling and solidifying the first material body.

[0010] In one embodiment, the density of the tire casing is 0.6 g / cm 3 -0.8g / cm 3 The density of the inner tube is 0.2g / cm 3 -0.6g / cm 3 .

[0011] In one embodiment, the first material body includes polyurethane, the second material body includes polyurethane, and the density of the outer tube formed by curing the first material body is greater than the density of the inner tube formed by curing the second material body.

[0012] In one embodiment, curing and molding a tire using a first material body includes: providing a tire mold; injecting the first material body into the tire mold by an injection machine; obtaining a tire after the first material body is cooled and cured; and removing the tire from the tire mold.

[0013] In one embodiment, the curing and molding inner tube includes: providing a second mold, wherein the second mold is provided with a second pouring cavity and a second pouring hole connected to the second pouring cavity; placing an outer tube in the second pouring cavity of the second mold, wherein the outer tube is in contact with the cavity wall of the second pouring cavity; centrifugally pouring a second material body into the second pouring cavity through the second pouring hole so that the receiving groove of the outer tube is filled with the second material body; and obtaining an inner tube after the second material body is foamed and cured, wherein the inner tube and the outer tube are connected as a whole.

[0014] In one embodiment, in providing the second mold, the second mold has a second main channel, and the second injection hole penetrates from the side wall of the second main channel to the inner wall of the second injection cavity.

[0015] There are multiple second pouring holes, which are evenly distributed along the circumferential direction of the second mold; or there is one second pouring hole, which extends along the circumferential direction of the second mold.

[0016] In one embodiment, in providing the second mold, a portion of the cavity wall of the second infusion cavity that is in contact with the outer tire is used as the first cavity wall, another portion of the cavity wall of the second infusion cavity that is not in contact with the outer tire is used as the second cavity wall, and the second infusion hole penetrates the second cavity wall to communicate with the second infusion cavity.

[0017] The second mold is provided with a second exhaust hole for negative pressure exhaust, and the second exhaust hole penetrates the second cavity wall to communicate with the second perfusion cavity.

[0018] In one embodiment, the first body comprises thermoplastic polyurethane and the second body comprises polyurethane.

[0019] In one embodiment, the preparation method further comprises: integrally sleeve the outer tube and the inner tube onto the wheel frame.

[0020] According to a second aspect of the present application, a method for preparing a wheel is provided, the method comprising: using a second material body to solidify and shape an inner tube; providing a first mold, wherein the first mold is provided with a first pouring cavity, a first pouring hole connected to the first pouring cavity, and a plurality of positioning pins that can be partially inserted into the first pouring cavity; fixing the inner tube in the first pouring cavity by means of the plurality of positioning pins, so that an outer tube pouring cavity is formed between the inner wall of the first pouring cavity and the inner tube; pouring the first material body into the outer tube pouring cavity through the first pouring hole and solidifying the first material body; when the first material body is not completely solidified and formed, completely withdrawing the plurality of positioning pins from the first pouring cavity, so as to allow the first material body to enter the space where the plurality of positioning pins withdraw; and obtaining an outer tube after the first material body is completely solidified and formed, wherein the outer tube is coated on the outside of the inner tube.

[0021] In one embodiment, fixing the inner tube in the first infusion cavity by using a plurality of positioning pins specifically includes: the inner tube is provided with a plurality of positioning holes, and the inner tube is fixed in the first infusion cavity by inserting the plurality of positioning pins into the corresponding positioning holes respectively.

[0022] In one embodiment, completely withdrawing the plurality of positioning pins from the first perfusion cavity comprises: withdrawing the ends of the plurality of positioning pins until they are flush with the inner wall of the first perfusion cavity.

[0023] In one embodiment, in curing and molding an inner tube by using the second material body, the inner tube has an outer annular surface, and the outer annular surface is provided with a pattern.

[0024] In one embodiment, the second material body includes ethylene-vinyl acetate copolymer, and the first material body includes polyurethane.

[0025] According to a third aspect of the present application, a wheel is provided. The wheel comprises: an outer tire and an inner tire. The outer tire is made of a first material, and has a receiving groove, and the inner wall of the receiving groove is arc-shaped; the inner tire is made of a second material, and comprises a main body received in the receiving groove and a protruding part protruding from the receiving groove, the main body having an outer annular surface, the outer annular surface is arc-shaped, the outer annular surface is in contact with the inner wall of the receiving groove, and the protruding part is used to connect with the wheel frame.

[0026] In one embodiment, the wheel further comprises: a wheel frame provided with an annular mounting groove; the inner tube and the outer tube are connected as one and are sleeved on the wheel frame, and the protrusion of the inner tube is engaged in the mounting groove.

[0027] In one embodiment, one side of the main body connected to the protruding portion forms a first step surface, and an end of a groove wall of the mounting groove abuts against the first step surface.

[0028] In one embodiment, the density of the tire casing is 0.6 g / cm 3 -0.8g / cm 3 The density of the inner tube is 0.2g / cm 3 -0.6g / cm 3 .

[0029] In one embodiment, the first body comprises polyurethane, the second body comprises polyurethane, and the density of the outer tube is greater than the density of the inner tube.

[0030] According to a fourth aspect of the present application, a wheel is provided. The wheel comprises: a wheel frame, an inner tube and an outer tube. The wheel frame is an annular structure, and the wheel frame has a mounting groove extending in a circumferential direction. The inner tube is sleeved on the wheel frame and at least partially accommodated in the mounting groove. The outer tube is covered on the outer tube and the inner surface of the outer tube is tightly connected to the inner tube. Among them, one of the outer surface of the outer tube and the wheel frame is provided with a first recess, and the outer surface of the outer tube and the other of the wheel frame are provided with a first convex portion, and the first convex portion is engaged with the first recess; one of the inner surface of the outer tube and the inner tube is provided with a second convex portion, and the inner surface of the outer tube and the other of the inner tube are provided with a second recess, and the second convex portion is engaged with the second recess, and the engaging position of the two is located in the mounting groove.

[0031] In one embodiment, the outer tire includes a first ring portion and two second ring portions arranged at both ends of the first ring portion, the first ring portion is located outside the mounting groove, the outer surfaces of the two second ring portions are respectively pressed against the side walls of the mounting groove, the inner surfaces of the two second ring portions are provided with second convex portions, and the inner tire is provided with a second concave portion.

[0032] In one embodiment, at least a portion of the inner tube extends out of the outer tube and forms an inner annular surface, and the inner annular surface is pressed against the bottom wall of the mounting groove.

[0033] According to a fifth aspect of the present application, a wheel is provided, comprising: an inner tube made of a first material; and an outer tube made of a second material; wherein the first material comprises a thermoplastic polyurethane material, and the second material comprises an ethylene-vinyl acetate copolymer material.

[0034] In one embodiment, the wheel further comprises: a wheel frame in an annular structure, wherein the wheel frame has a mounting groove extending in a circumferential direction. The inner tube is sleeved on the wheel frame and at least partially accommodated in the mounting groove. The outer tube is coated on the outer tube and the inner surface of the outer tube is pressed against the inner tube. Wherein, one of the outer surface of the outer tube and the wheel frame is provided with a first recess, and the outer surface of the outer tube and the other of the wheel frame are provided with a first protrusion, and the first protrusion is engaged with the first recess. One of the inner surface of the outer tube and the inner tube is provided with a second protrusion, and the inner surface of the outer tube and the other of the inner tube are provided with a second concave, and the second protrusion is engaged with the second concave and the engagement position of the two is located in the mounting groove.

[0035] In one embodiment, the first protrusion is disposed at a notch of the mounting groove of the wheel frame, and the first recess is disposed on the outer surface of the tire.

[0036] In one embodiment, the outer tire includes a first ring portion and two second ring portions arranged at both ends of the first ring portion, the first ring portion is located outside the mounting groove, the outer surfaces of the two second ring portions are respectively pressed against the side walls of the mounting groove, the inner surfaces of the two second ring portions are provided with the second protrusions, and the inner tire is provided with the second recesses.

[0037] In one embodiment, a thorn is arranged in the installation groove of the wheel frame. The inner tube has an inner annular surface, the inner annular surface is pressed with the bottom wall of the installation groove, and the thorn passes through the inner annular surface and is embedded in the inner tube.

[0038] In one embodiment, the inner surface of the outer tire is provided with a cross pattern, and / or the outer surface of the inner tire is provided with the cross pattern.

[0039] In one embodiment, at least a portion of the inner tube extends out of the outer tube to form an inner annular surface, and the inner annular surface is pressed against a bottom wall of the mounting groove.

[0040] In one embodiment, the outer tube has a density greater than that of the inner tube.

[0041] According to the sixth aspect of the present application, a method for manufacturing a wheel according to the fifth aspect comprises: obtaining the outer tire by injection molding and curing the first material body in a third mold; obtaining the inner tire by foaming and curing the second material body in a fourth mold; and sleeve the outer tire ring on the outside of the inner tire, and utilize the elasticity of the outer tire to press the inner surface of the outer tire with the inner tire so that the two are assembled into a whole.

[0042] According to a seventh aspect of the present application, a child carrier is provided, comprising the wheel provided according to any one of the embodiments of the third aspect and the fourth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A perspective view of a wheel according to a first embodiment of the present application is shown.

[0044] Figure 2 A schematic exploded view of a wheel according to a first embodiment of the present application is shown.

[0045] Figure 3 Show Figure 1 A partial view of the cross-section of the wheel at U1-U1.

[0046] Figure 4 A schematic diagram of the process of preparing a wheel according to the first embodiment of the present application is shown, which is in the stage of centrifugal infusion of the first material body.

[0047] Figure 5 A schematic diagram of the process of preparing a wheel according to the first embodiment of the present application is shown, which is in the stage of centrifugal infusion of the second material body.

[0048] Figure 6 A schematic diagram of the process of preparing a wheel according to the first embodiment of the present application is shown, which is in the stage of foaming and curing the second material body.

[0049] Figure 7 A perspective view of a first mold according to some embodiments of the present application is shown, where the first mold is used to prepare a wheel according to a first embodiment of the present application.

[0050] Figure 8 A perspective view of a first mold according to some other embodiments of the present application is shown. The first mold is used to prepare a wheel according to the first embodiment of the present application.

[0051] Fig. 9 A perspective view showing a wheel according to a second embodiment of the present application.

[0052] Fig.10 A schematic exploded view of a wheel according to a second embodiment of the present application is shown.

[0053] Fig.11 Show Fig. 9 A partial view of the cross-section of the wheel at U2-U2.

[0054] Fig.12 A schematic diagram showing a process for preparing a wheel according to a second embodiment of the present application is shown.

[0055] Fig.13 A perspective view of a second mold according to some embodiments of the present application is shown, where the second mold is used to prepare a wheel according to a second embodiment of the present application.

[0056] Fig.14 A flow chart showing a method for preparing a wheel according to some embodiments of the present application.

[0057] Fig.15 A top view of a third mold used for curing a tire to form a wheel is shown.

[0058] Fig.16 A flow chart showing a method for manufacturing a wheel according to some embodiments of the present application.

[0059] Fig.17 A perspective view showing a wheel according to a third embodiment of the present application.

[0060] Fig.18 A schematic exploded view of a wheel according to a third embodiment of the present application is shown.

[0061] Fig.19 Show Fig.17 A partial view of the cross-section of the wheel at U3-U3.

[0062] Fig. 20 A schematic diagram showing a process for preparing a wheel according to a third embodiment of the present application is shown.

[0063] Fig.21 A flow chart showing a method for preparing a wheel according to a third embodiment of the present application.

[0064] Fig. 22 The flowchart shows step S1 of the method for preparing a wheel according to the first embodiment of the present application.

[0065] Fig.23 The flowchart shows step S2 of the method for preparing a wheel according to the first embodiment of the present application.

[0066] Fig.24 A flow chart showing step S1 of a method for preparing a wheel according to a second embodiment of the present application.

[0067] Fig.25 A flow chart showing step S2 of the method for preparing a wheel according to the second embodiment of the present application.

[0068] Reference numerals:

[0069] 100. Wheel,

[0070] 1. outer tire, 101. inner surface of the outer tire, 102. outer surface of the outer tire, 103. receiving groove,

[0071] 11. The first concave part, 12. The second convex part, 13. The first ring part, 14. The second ring part, 15. The positioning convex part,

[0072] 2. Inner tube, 201, inner ring surface, 202, outer ring surface,

[0073] 21. second concave portion, 22. pattern, 23. protruding portion, 231. second step surface, 24. main body, 241. first step surface, 25. positioning hole,

[0074] 3. wheel frame, 31. first convex portion, 32. mounting groove, 321. third step surface, 33. thorn,

[0075] 8. first mold, 801. first upper mold, 802. first lower mold, 81. first pouring hole, 82. first pouring cavity, 821. first cavity wall of the first pouring cavity, 822. second cavity wall of the first pouring cavity, 83. first exhaust hole, 86. first main channel, 87. positioning pin, 88. outer tire pouring cavity,

[0076] 9. second mold, 901. second upper mold, 902. second lower mold, 91. second pouring hole, 92. second pouring cavity, 921. first cavity wall of the second pouring cavity, 922. second cavity wall of the second pouring cavity, 93. second exhaust hole, 96. second main channel,

[0077] 10. The third mold, 110. The feed hole,

[0078] R, axis of rotation. DETAILED DESCRIPTION

[0079] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0080] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0081] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0082] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0083] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0084] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0085] The present application provides a wheel 100 and a child carrier having the wheel 100 .

[0086] Figure 1 A perspective view of a wheel 100 according to a first embodiment of the present application is shown. Figure 2 FIG. 1 is an exploded schematic diagram of a wheel 100 according to a first embodiment of the present application.

[0087] like Figure 1 to Figure 2 As shown, the wheel 100 includes a wheel frame 3, an outer tire 1 and an inner tire 2. The wheel frame 3 is provided with an annular mounting groove 32, and the outer tire 1 and the inner tire 2 are sleeved on the wheel frame 3 and at least partially engaged in the mounting groove 32. The outer tire 1 is made of the first material, and the density of the outer tire 1 is, for example, 0.6 g / cm 3 -0.8g / cm 3 The inner tube 2 is made of the second material, and the density of the inner tube 2 is, for example, 0.2 g / cm 3 -0.6g / cm 3 . The first material body includes polyurethane (PU), for example, and the second material body includes polyurethane (PU), and the density of the outer tire 1 made of the first material is greater than the density of the inner tube 2 made of the second material. In this embodiment, the density of the outer tire 1 is relatively high, so that the outer tire 1 has good wear resistance; the density of the inner tube 2 is lower than that of the outer tire 1. Compared with the case where the densities of the inner tube 2 and the outer tire 1 are both high, the inner tube 2 with a lower density can make the overall cost of the wheel 100 lower, the weight smaller, and improve the elasticity of the wheel 100.

[0088] Combined with reference Figure 3The outer tire 1 has a receiving groove 103, and the inner wall of the receiving groove 103 is arc-shaped. The inner tube 2 includes a main body 24 received in the receiving groove 103 and a protrusion 23 protruding from the receiving groove 103. The main body 24 has an outer ring surface 202, and the outer ring surface 202 is arc-shaped, and the outer ring surface 202 is in contact with the inner wall of the receiving groove 103. In this embodiment, since the first material body used to prepare the outer tire 1 and the second material body used to prepare the inner tube 2 both include polyurethane materials, the two can be well integrated. In this way, the outer tire 1 and the inner tube 2 can be closely connected. Specifically, the outer ring surface 202 of the inner tube 2 can be connected as a whole with the inner wall of the receiving groove 103 of the outer tire 1, thereby enhancing the connection strength between the outer tire 1 and the inner tube 2, and preventing the inner tube 2 from loosening from the outer tire 1 during the use of the wheel 100. The protrusion 23 is used to connect with the wheel frame 3, and specifically, the protrusion 23 is engaged in the mounting groove 32. More specifically, the protrusion 23 of the inner tube 2 forms an inner annular surface 201 of the inner tube 2. The inner annular surface 201 is in contact with the bottom wall of the mounting groove 32. The side of the main body 24 connected to the protrusion 23 forms a first step surface 241, and the end of the groove wall of the mounting groove 32 abuts against the first step surface 241. In other words, in this embodiment, only the protrusion 23 of the inner tube 2 is engaged with the mounting groove 32, and the outer tire 1 and the main body 24 of the inner tube 2 are both located outside the mounting groove 32.

[0089] Continue to refer to Figure 3 The protrusion 23 has a second step surface 231, and the installation groove 32 is provided with a third step surface 321, and the shape of the third step surface 321 matches the shape of the second step surface 231. When the protrusion 23 is engaged in the installation groove 32, the second step surface 231 abuts against the third step surface 321. In this way, the protrusion 23, i.e., the inner tube 2, and the installation groove 32 can be more firmly and stably engaged. Figure 3 As shown, the first step surface 241, the second step surface 231 and the inner ring surface 201 are staggered in a direction parallel to the rotation axis R of the wheel 100, and are also staggered in a radial direction of the wheel 100. In other words, the first step surface 241, the second step surface 231 and the inner ring surface 201 are arranged in a stepped manner. In this way, the pressure bearing range between the inner tube 2 and the wheel frame 3 can be increased, so that when the wheel 100 is elastically deformed during use, the force distribution between the inner tube 2 and the wheel frame 3 is wider and more uniform, and the integral body composed of the outer tube 1 and the inner tube 2 is prevented from being skewed or even separated relative to the wheel frame 3 after the wheel 100 is stressed. In some embodiments, in order to make the inner tube 2 and the wheel frame 3 more firmly and stably connected together, the surface of the protrusion 23 can be at least partially coated with an adhesive, or the inner wall of the mounting groove 32 can be at least partially coated with an adhesive, or the surface of the protrusion 23 and the inner wall of the mounting groove 32 can be at least partially coated with an adhesive.

[0090] According to the wheel 100 provided in the first embodiment of the present application, the outer annular surface 202 of the inner tube 2 is tightly attached to the inner wall of the receiving groove 103 of the outer tube 1 and connected as a whole, which can enhance the connection strength between the inner tube 2 and the outer tube 1 and prevent the inner tube 2 and the outer tube 1 from loosening.

[0091] The present application also provides a method for preparing the wheel 100 in the first embodiment.

[0092] Fig.14 FIG. 1 is a flow chart of a method for preparing a wheel 100 according to some embodiments of the present application. Fig.14 As shown, the method for preparing the wheel 100 according to the first embodiment of the present application includes the following steps S1 to S3.

[0093] S1, using the first material body to solidify and mold the outer tire 1.

[0094] Among them, combined with reference Figure 2 and Figure 3 The tire 1 has a receiving groove 103. The step S1, using the first material body to solidify and mold the tire 1, specifically includes the following steps S11 to S13 (see Fig. 22 ).

[0095] S11, providing a first mold 8.

[0096] Among them, combined with reference Figures 4 to 6 , the first mold 8 is provided with a first infusion cavity 82 and a first infusion hole 81 connected to the first infusion cavity 82. The first mold 8 is also provided with a first main channel 86, which is connected to the first infusion hole 81. The first main channel 86 extends approximately parallel to the central axis of the first mold 8. In other words, the first main channel 86 extends approximately in the longitudinal direction, or extends in parallel to the direction of the rotation axis R of the wheel 100. The first main channel 86 is used to connect the infusion equipment or pipeline. Specifically, the first mold 8 includes a first upper mold 801 and a first lower mold 802, the first upper mold 801 and the first lower mold 802 are detachably connected, and the two together form the first infusion cavity 82. The first infusion hole 81 extends from the side wall of the first main channel 86 to the inner wall of the first infusion cavity 82. Specifically, the first infusion hole 81 extends approximately in the radial direction of the wheel and is connected to the first main channel 86 and the first infusion cavity 82 respectively. The first injection hole 81 may be disposed in the first upper mold 801, or in the first lower mold 802, or at the connection between the first upper mold 801 and the first lower mold 802, which is not limited in the present application. Figure 7 As shown, the number of the first pouring holes 81 is multiple, for example, four, five, six, etc., and the multiple first pouring holes 81 are evenly distributed along the circumferential direction of the first mold 8. In other embodiments, such as Figure 8As shown, the number of the first pouring hole 81 is one, and the first pouring hole 81 extends along the circumferential direction of the first mold 8. That is, the projection of the first pouring hole 81 on a plane parallel to the circumferential direction of the first mold 8 is annular, and the first pouring hole 81 is connected to the first pouring cavity 82.

[0097] S12, centrifugally pouring the first material into the first mold 8 through the first pouring hole 81, so that the first material is evenly covered on the inner wall of the first mold 8. The first material includes PU, for example.

[0098] like Figures 4 to 6 As shown, in the first mold 8, a portion of the cavity wall of the first perfusion cavity 82 covered by the first material body is used as the first cavity wall 821, and another portion of the cavity wall of the first perfusion cavity 82 not covered by the first material body is used as the second cavity wall 822. The first perfusion hole 81 penetrates the second cavity wall 822 to communicate with the first perfusion cavity 82. The first mold 8 is provided with a first exhaust hole 83 for negative pressure exhaust. The first exhaust hole 83 penetrates the second cavity wall 822 to communicate with the first perfusion cavity 82. There are a plurality of first exhaust holes 83, and negative pressure exhaust can be performed in the first perfusion cavity 82 through these first exhaust holes 83. A plurality of first exhaust holes 83 are arranged on the first mold 8 at positions corresponding to the protrusions 23 of the inner tube 2 (i.e., an open end of the first exhaust hole 83 is located on the second cavity wall 822). In this way, the cross-section of the inner tube 2 of the wheel 100 formed after cutting off the excess parts formed in the plurality of first exhaust holes 83 can be hidden in the mounting groove 32 of the wheel frame 3, making the wheel 100 more beautiful.

[0099] In some embodiments, Figures 4 to 6 As shown, the first exhaust hole 83 can be arranged along a substantially longitudinal direction (i.e., a direction parallel to the rotation axis R of the wheel 100). Exemplarily, the first exhaust hole 83, for example, penetrates from the upper surface of the first mold 8 to the inner wall of the first infusion cavity 82. In other embodiments, the first exhaust hole 83 can also be arranged along a substantially transverse direction, i.e., a direction parallel to the radial direction of the wheel 100. Exemplarily, the first exhaust hole 83 penetrates from the inner wall of the first main channel 86 to the second cavity wall 822. Specifically, referring to Figure 8 , the plurality of first exhaust holes 83 may be distributed vertically with the first injection hole 81 in the longitudinal direction. Figure 7 The plurality of first exhaust holes 83 may also be located on the same transverse plane as the plurality of first injection holes 81, and the plurality of first exhaust holes 83 and the plurality of first injection holes 81 are spaced apart from each other in the circumferential direction. This application does not impose any limitation on this.

[0100] It should be noted that centrifugal pouring refers to centrifugally rotating the mold when pouring the material into the mold. Figures 4 to 7As shown, the first material (for example, PU) is poured into the first pouring cavity 82 through multiple first pouring holes 81, and in the process, the first mold 8 is centrifugally rotated so that the first material is thrown toward and evenly covers the first cavity wall 821 of the first pouring cavity 82 under the action of centrifugal force, so that the first material can form an arc-shaped inner surface 101 (that is, the bottom wall of the accommodating groove 103) after cooling and solidification.

[0101] S13, after the first material body is cooled and solidified, a tire 1 is obtained, wherein the tire 1 is retained in the first mold 8. The density of the tire 1 is, for example, 0.6 g / cm 3 -0.8g / cm 3 The wall thickness of the outer tire 1 is, for example, above 2.2 mm. Of course, in other embodiments, the wall thickness of the outer tire 1 may be set to other appropriate wall thicknesses according to the purpose of the wheel 100 and the weight it needs to bear. In this embodiment, the amount of the required material body needs to be determined according to the size of the outer tire 1 including the wall thickness, diameter, height, etc., thereby controlling the amount of the first material body poured into the first pouring cavity 82.

[0102] In this embodiment, the outer tire 1 after curing and forming has a receiving groove 103. Since the first material body is thrown onto the first cavity wall 821 of the first pouring cavity 82 by centrifugal rotation, the inner wall of the receiving groove 103 of the outer tire 1 is generally an arc surface. And the outer tire 1 after curing and forming is continued to be retained in the first pouring cavity 82 of the first mold 8, so as to pour the second material body to form the inner tire 2.

[0103] In the above steps S12 and S13, negative pressure exhaust is required to be performed through the first exhaust hole 83 to keep the pressure in the first filling chamber 82 less than 0, for example, maintained at about -0.05Mpa. Compared with natural exhaust using the exhaust hole (i.e., exhaust using the naturally generated air pressure difference, the same below), negative pressure exhaust can help exhaust air, making the filling process of the first material body smoother and accelerating the forming speed of the outer tire 1.

[0104] By combining negative pressure exhaust and centrifugal infusion, the material body (such as the first material body) can be cured and formed better and more evenly, and the density of the product can be improved, so that the parameters of the product (such as the outer tire 1) are closer to the theoretical values. For example, the actual weight of the outer tire 1 is compared with the theoretical weight, and the error range of the actual weight is within ±5% to ±10%.

[0105] S2, by centrifugally pouring the second material into the receiving groove 103 of the outer tire 1, curing and forming the inner tire 2. Among them, step S2, curing and forming the inner tire 2 specifically includes the following steps S21 to S22 (see Fig.23 ).

[0106] S21, centrifugally pour the second material into the first mold 8 through the first pouring hole 81, so that the receiving groove 103 of the outer tire 1 is filled with the second material. Wherein, due to the centrifugal pouring, the second material is evenly thrown to and covered on the inner wall of the receiving groove 103 of the outer tire 1 (i.e., the inner surface 101 of the outer tire 1) and the second cavity wall 822 of the first pouring cavity 82, so as to fill the space of the first pouring cavity 82 that is not filled with the first material. In this embodiment, the second material includes PU, for example. The amount of the second material to be poured can be determined according to the size of the inner tube 2 to be obtained. Since the first material and the second material both include polyurethane materials, when the second material covers the inner wall of the receiving groove 103 of the outer tire 1 (i.e., the inner surface 101 of the outer tire 1), the two can be well integrated together, so that the outer tire 1 and the inner tube 2 can be tightly connected, so that the inner tube 2 and the outer tire 1 can be prevented from loosening during the use of the wheel 100.

[0107] S22, after the second material body is foamed and solidified, an inner tube 2 is obtained. The density of the inner tube 2 is about 0.2 g / cm 3 -0.6g / cm 3 The density of the inner tube 2 is lower than that of the outer tube 1. Specifically, the foaming time of the second material body is about 3 minutes to 4 minutes. Of course, for inner tubes 2 of different sizes, the foaming and curing time will also change accordingly. The inner tube 2 after curing and forming is connected to the outer tube 1 as a whole. Specifically, the outer ring surface 202 of the inner tube 2 is connected to the inner side surface of the outer tube 1 as a whole to prevent the outer tube 1 and the inner tube 2 from loosening during the use of the wheel 100.

[0108] In the above steps S21 and S22, negative pressure exhaust is performed through multiple first exhaust holes 83, which can speed up the forming speed of the inner tube 2. It can be understood that during the infusion process, the air in the first infusion cavity 82 will become less and less. When the infusion process is close to completion, there is a small amount of air in the small space left inside the first infusion cavity 82. Compared with the natural exhaust using the exhaust holes, the remaining small space may not be filled by the second material body, and the second material body may not be able to enter the first infusion cavity 82 to squeeze out the last small amount of air. However, this embodiment can form a negative pressure environment in the first infusion cavity 82 through negative pressure exhaust, which can be more conducive to air discharge, and the second material body is filled into the first infusion cavity 82, so that the first mold 8 is more full, so that the tire body (including the outer tire 1 and the inner tube 2) is fuller, and the bubbles or depressions in the tire body are reduced. In addition, after the second material is poured into the first pouring chamber 82 , the inner tube 2 is formed through a foaming process. The negative pressure environment in the first pouring chamber 82 is also conducive to the foaming and expansion of the second material, which can accelerate the forming speed of the inner tube 2 .

[0109] By combining negative pressure exhaust and centrifugal infusion, the material body (such as the second material body) can be cured and formed better and more evenly, and the density of the product (such as inner tube 2) can be improved, so that the parameters of the product (such as inner tube 2) are closer to the theoretical values. For example, the actual weight of the product (such as inner tube 2) is compared with the theoretical weight, and the error range of the actual weight is within ±5% to ±10%.

[0110] S3, taking out the outer tire 1 and the inner tube 2 as a whole. Specifically, after taking out the outer tire 1 and the inner tube 2 as a whole from the first mold 8, the excess parts of the first material body and / or the second material body corresponding to the first exhaust hole 83, the first injection hole 81 and the like during the molding process are removed, and the outer tire 1 and the inner tube 2 connected as one body as required can be obtained, wherein the main body 24 of the inner tube 2 is accommodated in the accommodation groove 103 of the outer tire 1.

[0111] In some embodiments, the method for preparing the wheel 100 in the first embodiment further includes the following step S4.

[0112] S4, the outer tire 1 and the inner tire 2 are integrally mounted on the wheel frame 3.

[0113] The outer tube 1 and the inner tube 2 are connected as a whole, the protrusion 23 of the inner tube 2 is engaged in the mounting groove 32 of the wheel frame 3, and the outer tube 1 is located outside the mounting groove 32. In order to improve the connection strength between the inner tube 2 and the wheel frame 3, at least one of the protrusion 23 of the inner tube 2 and the inner wall of the mounting groove 32 may be at least partially coated with glue, and then the outer tube 1 and the inner tube 2 are integrally mounted on the wheel frame 3.

[0114] In the method for preparing a wheel according to the first embodiment of the present application, the outer tire 1 and the inner tube 2 are formed by centrifugal infusion and curing in the same mold (first mold 8), wherein both the outer tire 1 and the inner tube 2 include polyurethane material, so that the outer tire 1 and the inner tube 2 can be tightly connected together, reducing the risk of loosening between the outer tire 1 and the inner tube 2. In this preparation method, negative pressure exhaust is performed through the first exhaust hole 83 during the centrifugal infusion and curing of the outer tire 1 and the inner tube 2, which not only speeds up the curing speed of the outer tire 1 and the inner tube 2, saves the preparation time of the wheel 100, but also makes the outer tire 1 and the inner tube 2 more uniform and dense in structure.

[0115] It can be understood that in the first embodiment, since the outer tire 1 and the inner tube 2 are centrifugally poured and cured in the same mold to form a whole, the inner surface of the outer tire 1 (i.e., the inner wall of the accommodating groove 103) and the outer annular surface 202 of the inner tube 2 fit together, and a specially designed buckling structure between the outer tire 1 and the inner tube 2 will not be formed.

[0116] However, it should be noted that in actual products, due to factors such as mold shape design or processing errors, the inner surface of the tire 1 may not be as smooth as the inner surface of the tire 1 after it is formed. Figure 3 For example, if some bubbles in the first material body are not removed, the inner surface of the outer tire 1 formed after the first material body is solidified may have convex parts. The arc surface mentioned in this application only needs to be roughly arc-shaped, and the outer ring surface 202 of the inner tire 2 is in contact with the inner surface of the outer tire 1 because the second material body covers the inner surface of the outer tire 1. In actual products, the inner surface of the outer tire 1 may not maintain an ideal arc within the entire circumference.

[0117] Fig. 9 A perspective view showing a wheel 100 according to a second embodiment of the present application is shown. Fig.10 FIG. 1 is an exploded schematic diagram of a wheel 100 according to a second embodiment of the present application.

[0118] The wheel 100 according to the second embodiment of the present application is mainly different from the wheel 100 in the first embodiment described above in the following aspects.

[0119] like Figures 9 and 10 As shown, in some embodiments, the wheel 100 includes a wheel frame 3, an inner tube 2 and an outer tube 1. The wheel frame 3 is annular in structure, and the wheel frame 3 has a mounting groove 32 extending in the circumferential direction. The outer tube 1 and the inner tube 2 are connected as a whole and are annularly sleeved on the wheel frame 3, and the inner tube 2 is at least partially accommodated in the mounting groove 32. Specifically, the outer tube 1 has a receiving groove 103, at least a part of the inner tube 2 is accommodated in the receiving groove 103 and has an outer annular surface 202, and the bottom wall of the receiving groove 103 is formed as the inner surface 101 of the outer tube 1. It should be noted that "the outer tube 1 and the inner tube 2 are connected as a whole" means that the outer tube 1 and the inner tube 2 are annularly sleeved on the wheel frame 3 as a whole. The outer annular surface 202 of the inner tube 2 can be tightly connected to the inner surface 101 of the outer tube 1 by at least partially merging with each other, or the inner surface 101 of the outer tube 1 can be pressed with the outer annular surface 202 of the inner tube 2 to make the two tightly connected.

[0120] Continue to refer to Figures 9 and 10 In this embodiment, the outer tire 1 is made of a first material. The first material includes thermoplastic polyurethane (TPU) material. The outer tire 1 has a relatively high density and has advantages such as good wear resistance, puncture resistance, and support, so that the wheel 100 has a relatively long life and good quiet performance. At the same time, the outer tire 1 made of TPU material can also avoid the problems of white frost and black marks. The inner tube 2 is made of a second material. Among them, the second material includes polyurethane (PU) material, and the density of the inner tube 2 is lower than that of the outer tire 1. Compared with the situation where the densities of the inner tube 2 and the outer tire 1 are both high, making an inner tube with a lower density can make the overall cost of the wheel 100 lower and the weight lighter.

[0121] In some embodiments, Figures 9 to 11As shown, the wheel frame 3, the inner tube 2 and the outer tube 1 have the same rotation axis R. The outer surface 102 of the outer tube 1 and one of the wheel frame 3 are provided with a first recess 11, and the outer surface 102 of the outer tube 1 and the other of the wheel frame 3 are provided with a first convex portion 31, and the first convex portion 31 is engaged with the first recess 11. The inner surface 101 of the outer tube 1 and one of the inner tube 2 are provided with a second convex portion 12, and the inner surface 101 of the outer tube 1 and the other of the inner tube 2 are provided with a second concave portion 21, and the second convex portion 12 is engaged with the second concave portion 21, and the engaging position of the two is located in the mounting groove 32. In this embodiment, the outer surface 102 of the outer tube 1 is provided with a first concave portion 11, and the first concave portion 11 is arranged in an annular shape; accordingly, the wheel frame 3 is provided with a first convex portion 31, and the first convex portion 31 is arranged in an annular shape. The inner surface 101 of the outer tire 1 is provided with a second convex portion 12, which is arranged in an annular shape; correspondingly, the inner tire 2 is provided with a second concave portion 21, which is arranged in an annular shape. The first convex portion 31 is engaged with the first concave portion 11, the second convex portion 12 is engaged with the second concave portion 21, and the engaging position of the second convex portion 12 and the second concave portion 21 is located in the mounting groove 32, so that the connection strength between the outer tire 1 and the wheel frame 3 and between the outer tire 1 and the inner tire 2 can be increased, and the inner tire 2 and the outer tire 1 and the outer tire 1 and the wheel frame 3 can be prevented from being loosened during the use of the wheel 100, so that the inner tire 2 and the outer tire 1 can be more firmly encircled on the wheel frame 3. In addition, since the engaging position of the second protrusion 12 and the second recess 21 is located in the installation groove 32, the outer tire 1 and the inner tube 2 may loosen from each other only when the outer tire 1 is separated outward relative to the wheel frame 3. Therefore, the engagement between the first protrusion 31 and the first recess 11 indirectly helps the engagement stability between the second protrusion 12 and the second recess 21, making it difficult for the outer tire 1 and the inner tube 2 to loosen from each other.

[0122] like Fig.10 and Fig.11As shown, the outer tire 1 includes a first ring portion 13 and two second ring portions 14 arranged at both ends of the first ring portion 13, the first ring portion 13 and the second ring portion 14 are both annular, the second ring portion 14 is embedded between the wheel frame 3 and the inner tube 2, and the first ring portion 13 is located outside the mounting groove 32. Among them, the outer surface 102 of the outer tire 1 is provided with a first recess 11, and the notch of the mounting groove 32 of the wheel frame 3 is provided with a first convex portion 31. Specifically, a first recess 11 is formed on the outer surface 102 of the second ring portion 14, and the first recess 11 is recessed inwardly from the outer surface 102 along a direction substantially parallel to the rotation axis R. The outer surfaces 102 of the two second ring portions 14 are respectively pressed against the side walls of the mounting groove 32, and the inner surfaces 101 of the two second ring portions 14 are respectively provided with second convex portions 12, and the outer ring surface 202 of the inner tube 2 is correspondingly provided with a second recess 21, and the second recess 21 is recessed inwardly from the outer ring surface 202 along a direction substantially parallel to the rotation axis R. In this embodiment, the second protrusion 12 is closer to the bottom wall of the mounting groove 32 than the first recess 11. That is, the distance between the second protrusion 12 and the rotation axis R is smaller than the distance between the first recess 11 and the rotation axis R.

[0123] The inner tube 2 has an inner ring surface 201 and an outer ring surface 202 opposite to the inner ring surface 201. The outer tube 1 is coated on the outer tube 2, and the inner surface 101 of the outer tube 1 is pressed against the outer ring surface 202 of the inner tube 2. A portion of the inner tube 2 extends out of the outer tube 1 and forms an inner ring surface 201, which is pressed against the bottom wall of the mounting groove 32 of the wheel frame 3. The mounting groove 32 of the wheel frame 3 is provided with thorns 33, which pass through the inner ring surface 201 and are embedded in the inner tube 2. By providing the thorns 33 embedded in the inner tube 2, the connection strength between the inner tube 2 and the wheel frame 3 is increased, and the inner tube 2 and the outer tube 1 are further prevented from loosening from the wheel frame 3, thereby improving the service life of the wheel 100.

[0124] In some embodiments, Fig.10 As shown, the inner surface 101 of the outer tire 1 is provided with a pattern (not shown), and the pattern (not shown) is arranged along the inner circumference of the outer tire 1. The pattern (not shown) is, for example, a prismatic pattern. The pattern (not shown) is mutually interlocked with the outer annular surface 202 of the inner tube 2, that is, the outer annular surface 202 of the inner tube 2 forms another pattern 22 interlocked with the pattern. The pattern 22 can be a cross pattern. In this way, the friction between the inner tube 2 and the outer tire 1 can be increased, thereby preventing the outer tire 1 and the inner tube 2 from rotating relative to each other.

[0125] The present application also provides a method for preparing a wheel 100 in a second embodiment. The method for preparing the wheel 100 in the second embodiment differs from the method for preparing the wheel in the first embodiment in the following ways.

[0126] Combined with reference Fig.14According to the second embodiment of the present application, the method for preparing the wheel 100 includes the following steps S1 to S3.

[0127] S1, using the first material body to solidify and mold the outer tire 1, wherein the outer tire 1 has a receiving groove 103. The step S1, using the first material body to solidify and mold the outer tire 1 specifically includes the following steps S11' to S14' (see Fig.24 ).

[0128] S11′, providing a tire mold (such as Fig.15 It should be noted that the tire mold in this embodiment is different from the first mold 8 used to prepare the wheel 100 in the first embodiment.

[0129] In this embodiment, the tire mold is provided with a tire pouring cavity, and the tire pouring cavity is used for curing and molding the tire.

[0130] S12', injecting the first material into the tire mold through an injection molding machine.

[0131] In this embodiment, the first material fills the outer tire injection cavity of the outer tire mold. The first material includes, for example, thermoplastic polyurethane (TPU). The first material can be injected into the outer tire mold by an injection molding machine, so that the wall thickness of the outer tire 1 is more uniform by injection molding, which is convenient for realizing the thinness of the outer tire 1 and shortening the curing molding cycle of the outer tire.

[0132] S13', after the first material body is cooled and solidified, a tire casing 1 is obtained.

[0133] Among them, the outer tire 1 after curing and molding has a receiving groove 103, which is annular and is used for curing and molding and accommodating the inner tire 2. The side wall of the receiving groove 103 (i.e., the inner surface 101 of the outer tire 1) forms a second convex portion 12. The wall thickness of the outer tire 1 is 2.0mm-4.0mm. In one example, the wall thickness of the outer tire 1 is about 2.4mm. In this embodiment, the first material body is cooled and cured, and there is no need to add a foaming agent to the first material body for foaming and curing molding. In this way, the outer tire 1 obtained after curing and molding can be relatively dense and have better wear resistance.

[0134] It should be noted that in the above steps S12 and S13, there is no need to perform negative pressure exhaust, which makes the curing molding process of the outer tire 1 simpler. It can be understood that the first material body fills the outer tire injection cavity to form the outer tire 1, and the shape and wall thickness of the outer tire 1 are controlled by setting the shape of the outer tire injection cavity. This embodiment makes the wall thickness of the outer tire 1 more controllable, reduces the influence of uncontrollable factors on the wall thickness of the outer tire 1 during the molding process, and is conducive to molding an outer tire 1 with uniform wall thickness.

[0135] S14', taking the outer tire 1 out of the outer tire mold. After removing the redundant part, the outer tire 1 can be used in the curing molding step of the inner tire 2.

[0136] S2, by centrifugally pouring the second material into the receiving groove 103 of the outer tire 1, curing and forming the inner tire 2. The step S2 specifically includes the following steps S21' to S24' (see Fig.25 ).

[0137] S21′, providing a second mold 9, such as Fig.12 As shown, the second mold 9 is provided with a second pouring cavity 92 and a second pouring hole 91 communicating with the second pouring cavity 92 .

[0138] Specifically, the second mold 9 is annular. It should be noted that the annular shape here includes a circular ring shape, a rectangular ring shape, etc. Fig.12 and Fig.13 The second mold 9 includes a second upper mold 901 and a second lower mold 902, and the second upper mold 901 and the second lower mold 902 are detachably connected, and the two together form a second infusion cavity 92. The second mold 9 has a second main channel 96. The second main channel 96 extends approximately along the longitudinal direction (i.e., the rotation axis R of the wheel 100). The second infusion hole 91 extends from the side wall of the second main channel 96 to the inner wall of the second infusion cavity 92. That is, the second infusion hole 91 is connected to the second main channel 96 and the second infusion cavity 92, respectively. Among them, the second infusion hole 91 can be arranged in the second upper mold 901, or in the second lower mold 902, or in the connection between the second upper mold 901 and the second lower mold 902, and the present application does not limit this. In some embodiments, such as Fig.13 As shown, the number of the second pouring holes 91 is multiple, for example, four, five, six, etc., and the multiple second pouring holes 91 are evenly distributed on the second mold 9 along the circumferential direction.

[0139] S22 ′, placing the tire 1 in the second pouring cavity 92 of the second mold 9 , wherein the tire 1 is in contact with the cavity wall of the second pouring cavity 92 .

[0140] like Figure 12 to Figure 13As shown, in the second mold 9, the part of the cavity wall of the second pouring cavity 92 that is in contact with the outer surface 102 of the outer tire 1 is used as the first cavity wall 921, and the other part of the cavity wall of the second pouring cavity 92 that is not in contact with the outer tire 1 is used as the second cavity wall 922. The second pouring hole 91 penetrates the second cavity wall 922 to communicate with the second pouring cavity 92. The second mold 9 is provided with a second exhaust hole 93 for negative pressure exhaust. The second exhaust hole 93 penetrates the second cavity wall 922 to communicate with the second pouring cavity 92. There are a plurality of second exhaust holes 93, and negative pressure exhaust can be performed in the second pouring cavity 92 through these second exhaust holes 93. A plurality of second exhaust holes 93 are arranged on the second mold 9 at positions corresponding to the portions of the inner tube 2 protruding from the accommodating groove 103 of the outer tube 1 (i.e., the protruding ends of the plurality of second exhaust holes 93 are all located on the second cavity wall 922). In this way, the cross-section formed by cutting off the excess portions of the inner tube 2 formed in the plurality of second exhaust holes 93 of the wheel 100 can be hidden in the mounting groove 32 of the wheel frame 3, thereby making the appearance of the wheel 100 more beautiful.

[0141] Specifically, refer to Fig.12 , the second exhaust hole 93 can be arranged along a substantially longitudinal direction, i.e., a direction parallel to the rotation axis R of the wheel 100. Exemplarily, the second exhaust hole 93, for example, extends from the upper surface of the second mold 9 to the inner wall of the second pouring cavity 92. The second exhaust hole 93 can also be arranged along a substantially transverse direction, i.e., a direction parallel to the radial direction of the wheel 100. Specifically, in some embodiments, the second exhaust hole 93 can be distributed up and down with the second pouring hole 91 in the longitudinal direction. Fig.13 The plurality of second exhaust holes 93 may also be located on the same transverse plane as the plurality of second injection holes 91, and the plurality of second exhaust holes 93 and the plurality of second injection holes 91 are spaced apart from each other in the circumferential direction. This application does not impose any limitation on this.

[0142] S23', centrifugally pour the second material into the second pouring cavity 92 through the second pouring hole 91, so that the receiving groove 103 of the outer tire 1 is filled with the second material.

[0143] The second material includes polyurethane (PU), for example. The density of the inner tube is lower than that of the outer tube, and the density of the inner tube is 0.2 g / cm 3 -0.6g / cm 3. A foaming agent needs to be added to the second material body to facilitate foaming and curing. In this embodiment, the first material body used for curing and molding the outer tire 1 and the second material body used for molding the inner tire 2 are both selected from the polyurethane series. For example, the first material body includes thermoplastic polyurethane material (TPU), and the second material body includes polyurethane material (PU). After the second material body is poured and covered on the inner surface 101 of the outer tire 1, the two can be better fused, so that the outer tire 1 and the inner tube 2 after curing and molding can be more tightly connected, avoiding the formation of a gap between the inner tube 2 and the outer tire 1, and reducing the risk of loosening between the outer tire 1 and the inner tube 2.

[0144] S24', after the second material body is foamed and solidified, an inner tube 2 is obtained, wherein the inner tube 2 is connected to the outer tube 1 as a whole. The foaming and solidification time of the second material body is about 3 minutes to 4 minutes.

[0145] In both step S23 and step S24, it is necessary to perform negative pressure exhaust through the second exhaust hole 93 to keep the pressure in the second infusion chamber 92 less than 0, for example, the pressure is maintained at about -0.05Mpa. Compared with natural exhaust through the exhaust hole, negative pressure exhaust can speed up the curing and molding speed of the inner tube 2. And by combining negative pressure exhaust and centrifugal infusion, the material body (such as the second material body) can be better cured and molded, and the compactness of the product can be improved, so that the parameters of the product (such as the inner tube 2) are closer to the theoretical value. For example, the actual weight of the product such as the inner tube 2 is compared with the theoretical weight, and the error range of the actual weight is ±5% to ±10%.

[0146] S3, taking out the outer tire 1 and the inner tire 2 as a whole. Specifically, after taking out the outer tire 1 and the inner tire 2 as a whole from the second mold 9, the excess parts of the second material body corresponding to the second exhaust hole 93, the second injection hole 91 and the like are removed, so that the outer tire 1 and the inner tire 2 connected as one body as required can be obtained.

[0147] In some embodiments, the method for preparing the wheel 100 in the second embodiment further includes the following step S4.

[0148] S4, the outer tire 1 and the inner tire 2 are integrally mounted on the wheel frame 3.

[0149] The inner annular surface 201 of the inner tube 2 is fitted with the groove bottom of the mounting groove 32, the second ring portion 14 of the outer tube 1 is accommodated in the mounting groove 32, and the first protrusion 31 of the wheel frame 3 is engaged with the first recess 11 of the outer tube 1. In some embodiments, in order to improve the connection strength between the inner tube 2 and the wheel frame 3, at least one of the inner annular surface 201 of the inner tube 2 and the bottom wall of the mounting groove 32 may be at least partially coated with glue, and then the outer tube 1 and the inner tube 2 are integrally mounted on the wheel frame 3.

[0150] In the preparation methods of the wheel 100 in the first and second embodiments mentioned above, it is necessary to first mold the outer tube 1 of the wheel 100, and then centrifugally pour the inner tube 2 of the wheel 100 into the receiving groove 103 of the outer tube 1. After the inner tube 2 is cured and formed, it is connected to the outer tube 1 as a whole, thereby making the inner tube 2 and the outer tube 1 tightly connected together to avoid loosening between the outer tube 1 and the inner tube 2.

[0151] It should be noted that Figures 9 to 11 The wheel shown can be obtained by the preparation method including steps S1 to S4 of the second embodiment described above, and can also be obtained by the following process: forming the outer tire 1 by injection molding, forming the inner tire 2 by foaming and curing molding in a mold, and after the outer tire 1 and the inner tire 2 are formed respectively, the outer tire 1 is sleeved on the outer side of the inner tire 2, and then the outer tire 1 and the inner tire 2 are sleeved on the wheel frame 3 as a whole. Among them, the inner tire 2 can be bound by the elastic force of the outer tire 1, so that the outer ring surface 202 of the inner tire 2 and the inner surface 101 of the outer tire 1 are mutually attached. At this time, for example, the first material body of the outer tire 1 can include thermoplastic polyurethane (TPU) material, and the second material body of the inner tire 2 can include ethylene-vinyl acetate copolymer (EVA) material. At least one of the inner wall surface of the outer tire 1 and the outer wall surface of the inner tire 2 can be provided with a pattern, such as a diamond cross pattern, to increase the friction between the outer tire 1 and the inner tire 2 and reduce the mutual rotation between the two. Of course, glue can be applied between the outer tire 1 and the inner tire 2 as needed to increase the connection stability between the two. It can be understood that the shape of the outer tire 1 (for example, including the first recess 11 and the second protrusion 12) can be formed by setting an injection molding mold, and the shape of the inner tire 2 (for example, including the second recess 21) can be formed by setting a mold for foaming and curing the second material.

[0152] Specifically, according to a variation of the second embodiment of the present application, Figures 9 to 11 , Figure 15 to Figure 16 As shown, the wheel 100 includes a wheel frame 3, an inner tube 2 and an outer tube 1. The wheel frame 3 is annular in structure and has a mounting groove 32 extending in the circumferential direction. The inner tube 2 is sleeved on the wheel frame 3 and at least partially accommodated in the mounting groove 32. The outer tube 1 is covered on the outer tube 2 and the inner surface 101 of the outer tube 1 is pressed against the inner tube 2. The wheel frame 3, the inner tube 2 and the outer tube 1 have the same rotation axis R.

[0153] Among them, the outer tire 1 is made of a first material. The first material includes a thermoplastic polyurethane (TPU) material. The outer tire 1 made of TPU material can solve the problem of frost and staining on the outer tire surface (i.e., leaving a black mark on the ground where the wheel 100 passes) that occurs after a certain period of use of a wheel with a rubber outer tire. At the same time, the outer tire 1 also has the advantages of good wear resistance, puncture resistance, and support, so that the wheel has a longer life and better quiet performance. The inner tube 2 is made of a second material. The second material includes an ethylene-vinyl acetate (EVA) copolymer material. Since the EVA material has high elasticity, the inner tube 1 has good shock resistance, so that the wheel 100 can run more smoothly even when driving on a relatively bumpy road.

[0154] One of the outer surface 102 of the outer tire 1 and the wheel frame 3 is provided with a first recess 11, and the other of the outer surface 102 of the outer tire 1 and the wheel frame 3 is provided with a first convex portion 31, and the first convex portion 31 is engaged with the first recess 11. One of the inner surface 101 of the outer tire 1 and the inner tube 2 is provided with a second convex portion 12, and the other of the inner surface 101 of the outer tire 1 and the inner tube 2 is provided with a second concave portion 21, and the second convex portion 12 is engaged with the second concave portion 21, and the engaging position of the two is located in the mounting groove 32. In this variant, the outer surface 102 of the outer tire 1 is provided with a first concave portion 11, and the first concave portion 11 is arranged in an annular manner; accordingly, the wheel frame 3 is provided with a first convex portion 31, and the first convex portion 31 is arranged in an annular manner. The inner surface 101 of the outer tire 1 is provided with a second convex portion 12, and the second convex portion 12 is arranged in an annular manner; accordingly, the inner tube 2 is provided with a second concave portion 21, and the second concave portion 21 is arranged in an annular manner. By engaging the first protrusion 31 with the first recess 11, the second protrusion 12 with the second recess 21, and the engaging position of the second protrusion 12 with the second recess 21 being located in the mounting groove 32, the connection strength between the outer tire 1 and the wheel frame 3, and between the outer tire 1 and the inner tube 2 can be increased, and the inner tube 2 and the outer tire 1, and between the outer tire 1 and the wheel frame 3 can be prevented from being loosened during the use of the wheel 100, so that the inner tube 2 and the outer tire 1 can be more firmly encircled on the wheel frame 3. In addition, since the engaging position of the second protrusion 12 with the second recess 21 is located in the mounting groove 32, the outer tire 1 and the inner tube 2 may be loosened from each other only when the outer tire 1 is separated outwards relative to the wheel frame 3, so the engaging position between the first protrusion 31 and the first recess 11 indirectly helps the engaging stability between the second protrusion 12 and the second recess 21, so that the outer tire 1 and the inner tube 2 are not easy to be loosened from each other.

[0155] like Fig.11As shown, the outer tire 1 includes a first ring portion 13 and two second ring portions 14 arranged at both ends of the first ring portion 13, the first ring portion 13 and the second ring portion 14 are both annular, the second ring portion 14 is embedded between the wheel frame 3 and the inner tube 2, and the first ring portion 13 is located outside the mounting groove 32. Among them, the outer surface 102 of the outer tire 1 is provided with a first recess 11, and the notch of the mounting groove 32 of the wheel frame 3 is provided with a first convex portion 31. Specifically, the outer surface 102 of the second ring portion 14 forms a first recess 11, and the first recess 11 is recessed inwardly from the outer surface 102 along a direction substantially parallel to the rotation axis R. The outer surfaces 102 of the two second ring portions 14 are respectively pressed against the side walls of the mounting groove 32, and the inner surfaces 101 of the two second ring portions 14 are respectively provided with second convex portions 12, and the outer ring surface 202 of the inner tube 2 is correspondingly provided with a second recess 21, and the second recess 21 is recessed inwardly from the outer ring surface 202 along a direction substantially parallel to the rotation axis R. In this modification, the second protrusion 12 is closer to the bottom wall of the mounting groove 32 than the first recess 11. That is, the distance between the second protrusion 12 and the rotation axis R is smaller than the distance between the first recess 11 and the rotation axis R.

[0156] Continue to refer to Figures 9 to 11 The inner tube 2 has an inner ring surface 201 and an outer ring surface 202 opposite to the inner ring surface 201. The outer tube 1 is coated on the outer tube 2, and the inner surface 101 of the outer tube 1 is pressed against the outer ring surface 202 of the inner tube 2. A portion of the inner tube 2 extends out of the outer tube 1 and forms an inner ring surface 201, which is pressed against the bottom wall of the mounting groove 32 of the wheel frame 3. The mounting groove 32 of the wheel frame 3 is provided with thorns 33, which pass through the inner ring surface 201 and are embedded in the inner tube 2. By providing the thorns 33 embedded in the inner tube 2, the connection strength between the inner tube 2 and the wheel frame 3 is increased, and the inner tube 2 and the outer tube 1 are further prevented from loosening from the wheel frame 3, thereby improving the service life of the wheel 100.

[0157] like Fig.10As shown, the outer ring surface 202 of the inner tube 2 is provided with a cross pattern 22, and the cross pattern 22 is arranged along the outer periphery of the inner tube 2 to increase the friction between the inner tube 2 and the outer tube 1, so as to prevent the outer tube 1 and the inner tube 2 from rotating and rubbing against each other. Wherein, the cross pattern 22 is, for example, a diamond pattern. In some other examples not shown, the inner surface 101 of the outer tube 1 may be provided with a cross pattern 22, and the cross pattern 22 is arranged along the inner periphery of the outer tube 1. In other other examples, the outer ring surface 202 of the inner tube 2 and the inner surface 101 of the outer tube 1 may be provided with cross patterns 22 respectively. Wherein, the cross pattern 22 on the outer ring surface 202 of the inner tube 2 and the cross pattern 22 on the inner surface 101 of the outer tube 1 may be the same or different, and in the process of putting the outer tube 1 on the inner tube 2, it is not necessary to align the cross pattern 22 on the outer ring surface 202 of the inner tube 2 with the cross pattern 22 on the inner surface 101 of the outer tube 1. In some other examples, adhesive may be further applied between the outer annular surface 202 of the inner tube 2 and the inner surface 101 of the outer tube 1 to increase the connection strength between the inner tube 2 and the outer tube 1 .

[0158] See also Fig.15 and Fig.16 According to the modified example of the second embodiment of the present application, the method for preparing the wheel 100 includes the following steps S1 to S4.

[0159] S1, a first material body is injection molded and cured in a third mold 10 to obtain a tire 1. The first material body includes TPU material.

[0160] Specifically, after the TPU solid raw material is heated and melted, it is injected into the third mold 10 by an injection machine, and the outer tire 1 is obtained after the TPU material is solidified. The wall thickness of the outer tire 1 is 2.0 mm-3 mm, and specifically, the wall thickness of the outer tire 1 is about 2.4 mm. The curing time is 40 seconds to 80 seconds, and specifically, the curing time is about 70 seconds. Fig.15 In this modification, the injection molding machine (not shown in the drawings) can use a four-point feeding method (i.e., four feeding holes 110 are set on the third mold 10) to fill the TPU material into the third mold 10. Of course, the position and number of the feeding holes 110 can also be set according to the product size, shape, etc. The outer tire 1 made by injection molding has a uniform wall thickness and does not need to add a foaming agent, which not only makes the outer tire 1 have good wear resistance, but also reduces costs.

[0161] S2, using the second material body to foam and solidify in a fourth mold (not shown in the drawings) to obtain an inner tube 2. The second material body includes EVA material.

[0162] Specifically, the EVA material is foamed in the fourth mold, and after foaming and molding, the inner tube 2 is obtained. The EVA inner tube 2 obtained by foaming and molding has good elasticity and light weight. The inner wall of the fourth mold can be pre-set with a pattern model. The EVA material is foamed and molded in the fourth mold, and the outer ring surface 202 of the molded inner tube 2 can leave a pattern corresponding to the pattern model of the fourth mold.

[0163] Step S1 and step S2 may be performed in any order. Specifically, step S1 and step S2 may be performed simultaneously, step S1 may be performed first and then step S2, or step S2 may be performed first and then step S1. In other words, step S1 and step S2 may be performed in parallel or sequentially.

[0164] S3, the outer tire 1 is put on the outer tire 2, and the inner surface 101 of the outer tire 1 is pressed against the inner tire 2 by utilizing the elasticity of the outer tire 1. The two second protrusions 12 of the outer tire 1 are respectively engaged in the two second recesses 21 of the inner tire 2, so that the two are assembled into a whole.

[0165] In order to make the connection between the outer tire 1 and the inner tube 2 more firmly and avoid separation of the two, before step S3, glue can be applied to the inner side of the outer tire 1 and / or the outer annular surface 202 of the inner tube 2, and then the outer tire 1 is used to wrap the inner tube 2.

[0166] S4, assembling the assembled outer tire 1 and inner tire 2 onto the prepared wheel frame 3, thereby completing the assembly of the wheel 100.

[0167] In the wheel according to the modified example of the second embodiment of the present application, the outer tire is made of a first material body including TPU material, which can avoid the problem of frost and staining on the outer tire surface after the wheel has been used for a certain period of time. At the same time, the outer tire also has the advantages of good wear resistance, puncture resistance, support, etc., so that the life of the wheel is relatively long and the quiet performance is good. The inner tube is made of a second material body including ethylene-vinyl acetate copolymer material (EVA). Since the EVA material has high elasticity, the inner tube has good shock resistance, so that the wheel can run more smoothly even when driving on a relatively bumpy road. In addition, in some embodiments, the density of the inner tube can be further set to be less than the density of the outer tire, which not only ensures the good wear resistance and support of the wheel, but also reduces the overall weight and manufacturing cost of the wheel.

[0168] Fig.17 A perspective view showing a wheel 100 according to a third embodiment of the present application is shown. Fig.18 The exploded schematic diagram of the wheel 100 according to the embodiment of the present application is shown. The wheel 100 in the third embodiment is different from the wheel 100 in the first embodiment and the second embodiment described above mainly in the following ways.

[0169] like Figures 17 to 19 As shown, the wheel 100 includes a wheel frame 3, an inner tube 2 and an outer tube 1. The outer tube 1 is covered on the outer tube 2, that is, the inner tube 2 is contained in the outer tube 1. The outer tube 1 is sleeved on the wheel frame 3 and at least partially engaged in the mounting groove 32 of the wheel frame 3. The inner surface 101 of the outer tube 1 is tightly fitted with the outer annular surface 202 of the inner tube 2. Figure 18 to Figure 19 In some embodiments, the inner tube 2 is provided with a plurality of positioning holes 25, and the outer tube 1 forms a plurality of positioning protrusions 15 that can be accommodated in the corresponding positioning holes 25. In this way, the connection strength between the outer tube 1 and the inner tube 2 can be increased, and the inner tube 2 can be easily fixed during the process of forming the outer tube 1. Of course, in other embodiments not shown, the inner tube 2 may not be provided with positioning holes 25, and accordingly, the outer tube 1 does not have positioning protrusions 15, which is not limited by the present application. The outer tube 1 includes a polyurethane (PU) material, and the inner tube 2 includes an ethylene-vinyl acetate copolymer (EVA) material.

[0170] The present application also provides a method for preparing the wheel 100 in the third embodiment. Fig.21 A flow chart showing a method for preparing a wheel 100 according to a third embodiment of the present application is shown.

[0171] like Fig.21 As shown, the method for preparing the wheel 100 in the third embodiment includes the following steps S1 to S5.

[0172] S1, using the second material body to solidify and form the inner tube 2.

[0173] Among them, the inner tube 2 has a plurality of positioning holes 25. The plurality of positioning holes 25 are distributed along the circumferential direction of the inner tube 2 of the wheel 100. Specifically, the plurality of positioning holes 25 are respectively distributed on the upper surface and the lower surface of the inner tube 2. More specifically, the plurality of positioning holes 25 are evenly distributed on the upper surface and the lower surface of the inner tube 2. The second material body includes, for example, ethylene-vinyl acetate copolymer (EVA). The inner tube 2 also has an outer annular surface 202, and the outer annular surface 202 is provided with a pattern. In other embodiments, the inner tube 2 may not be provided with positioning holes 25, and this application does not limit this.

[0174] S2. Provide a first mold 8.

[0175] Among them, Fig. 20As shown, the first mold 8 is provided with a first infusion cavity 82, a first infusion hole 81 connected to the first infusion cavity 82, and a plurality of positioning pins 87 that can be partially inserted into the first infusion cavity 82. The first mold 8 includes a first upper mold 801 and a first lower mold 802, which are detachably connected and enclosed to form the first infusion cavity 82. The first upper mold 801 is provided with a plurality of positioning pins 87, and the first lower mold 802 is provided with a plurality of positioning pins 87. Specifically, the plurality of positioning pins 87 on the first upper mold 801 and the plurality of positioning pins 87 on the first lower mold 802 can be arranged one-to-one, or they can be arranged staggered with each other. Correspondingly, the plurality of positioning holes 25 located on the upper surface of the inner tube 2 and the plurality of positioning holes 25 located on the lower surface of the inner tube 2 can be arranged one-to-one, or they can be arranged staggered with each other. The position of the first infusion hole 81 of the third embodiment can refer to the position setting of the first infusion hole 81 of the first mold 8 involved in the wheel 100 preparation method of the first embodiment, and will not be described in detail here.

[0176] It should be noted that, in the third embodiment, the above steps S1 and S2 are performed in no particular order.

[0177] S3. Fix the inner tube 2 in the first filling cavity 82 by means of a plurality of positioning pins 87 so that an outer tube filling cavity 88 is formed between the inner wall of the first filling cavity 82 and the inner tube 2.

[0178] Among them, the outer annular surface 202 of the inner tube 2 does not contact the inner wall of the first pouring cavity 82, so as to allow the outer tube 1 that can completely cover the inner tube 2 to be formed in the outer tube pouring cavity 88. In this embodiment, the inner tube 2 is fixed in the first pouring cavity 82 by inserting the positioning pin 87 into the corresponding positioning hole 25. In this way, the inner tube 2 can be fixed in the first pouring cavity 82 more stably to prevent the inner tube 2 from moving in the first pouring cavity 82. Of course, in some other embodiments, the positioning hole 25 may not be provided on the inner tube 2, but a plurality of positioning pins 87 may be respectively inserted into the first pouring cavity 82 and respectively abutted against the surface of the inner tube 2 in the up and down directions, so as to fix the inner tube 2 in the first pouring cavity 82 of the first mold 8, and this application does not limit this.

[0179] S4, pouring the first material into the outer tire pouring cavity 88 through the first pouring hole 81 and curing the first material.

[0180] The first material body includes, for example, polyurethane (PU). A foaming agent is added to the first material body to form the tire 1 through foaming and curing.

[0181] S5. When the first material body is not completely solidified, the plurality of positioning pins 87 are completely withdrawn from the first pouring cavity 82 to allow the first material body to enter the space where the plurality of positioning pins 87 withdraw.

[0182] Wherein, “when the first material body is not completely solidified and formed” means that the outer tire 1 is not completely formed. There are different ways to implement steps S4 and S5, such as the following three ways:

[0183] The first method is that when the positioning pin 87 positions the inner tube 2, a portion of the first material is first poured to fill the space in the outer tube pouring cavity 88 except the space occupied by the positioning pin 87. When the first material in this portion has been foamed for a certain period of time but has not been completely foamed and completely solidified, all the positioning pins 87 are withdrawn from the first pouring cavity 82, and a portion of the first material is continued to be poured into the outer tube pouring cavity 88, so that the first material flows into the space originally occupied by the positioning pin 87, so that the hole left by the positioning pin 87 can be filled.

[0184] The second method is that when the positioning pins 87 position the inner tube 2, a portion of the first material body is first poured to fill the space in the outer tube pouring cavity 88 except the space occupied by the positioning pins 87. When the first material body of this portion is foamed for a certain period of time but not completely foamed and completely solidified, the plurality of positioning pins 87 are withdrawn from the first pouring cavity 82 in multiple times, and the first material body is poured into the outer tube pouring cavity 88 in multiple times until all the positioning pins 87 are withdrawn from the outer tube pouring cavity 88 and the first material body fills the space originally occupied by the plurality of positioning pins 87.

[0185] The third method is to first fill a portion of the first material into the outer tire filling cavity 88. When the portion of the first material has foamed for a certain period of time but has not yet been completely foamed, withdraw all or several positioning pins 87 from the outer tire filling cavity 88, so that the first material can fill the space originally occupied by the positioning pins 87 during the process of continuing foaming.

[0186] The above three methods are only illustrative examples, and the present application is not limited to using only one of the above three methods to implement steps S4 and S5.

[0187] like Fig.21 As shown, the method for preparing the wheel 100 in the third embodiment of the present application further includes the following step S6.

[0188] S6, after the first material body is completely solidified and formed, a tire casing 1 is obtained.

[0189] The outer tire 1 is wrapped around the inner tire 2 and connected to the inner tire 2 as a whole. This can prevent the inner tire 2 and the outer tire 1 from loosening. In this embodiment, the outer tire 1 has a plurality of positioning protrusions 15, which are formed by solidifying the first material body filled into the plurality of positioning holes 25 of the inner tire 2, and the plurality of positioning protrusions 15 are respectively accommodated in the corresponding positioning holes 25. In this way, the positioning holes 25 are filled, and the formation of depressions or holes on the outer surface 102 of the outer tire 1 can be avoided, making the outer tire 1 more beautiful.

[0190] In other embodiments, the inner tube 2 may not have the positioning hole 25, and the positioning pin 87 abuts against the surface of the inner tube 2 to position the inner tube 2. When the positioning pin 87 is withdrawn and the first material fills the space originally occupied by the positioning pin 87, the outer tube 1 after curing and molding does not have the positioning protrusion 15. However, it is still possible to avoid leaving a notch at the position of the positioning pin 87 after the outer tube 1 is molded. This application does not impose any restrictions on this.

[0191] The present application also provides a child carrier, which is equipped with the wheels 100 in any of the above embodiments. The child carrier can be a child stroller, a crib, etc. The child carrier includes a carrier body (not shown in the drawings) and wheels 100 installed on the carrier body, and the child carrier can be conveniently moved by the wheels 100.

[0192] In the wheel preparation method, wheel and child carrier provided in the first to third embodiments of the present application, the connection strength between the inner tube and the outer tube of the wheel is good, which can avoid the problem of loosening between the inner tube and the outer tube of the wheel during use and improve the stability of the wheel operation.

[0193] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0194] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A method for preparing a wheel, characterized in that: The preparation method comprises: Using the first material body to solidify and form a tire, wherein the tire has a receiving groove; The inner tube is formed by centrifugally pouring a second material body into the containing groove of the outer tube to solidify it; and Take out the outer and inner tubes as a whole; Wherein, at least during the process of curing and molding the inner tube, negative pressure exhaust is performed.

2. The preparation method according to claim 1, characterized in that: The method of curing and molding the outer tire by using the first material body comprises: Providing a first mold, wherein the first mold is provided with a first infusion cavity and a first infusion hole communicating with the first infusion cavity; Centrifugally pouring the first material body into the first mold through the first pouring hole, so that the first material body is evenly covered on the inner wall of the first mold; and The outer tire is obtained after the first material body is cooled and solidified, wherein the outer tire is retained in the first mold.

3. The preparation method according to claim 2, characterized in that: The curing and molding of the inner tube comprises: Centrifugally pouring the second material body into the first mold through the first pouring hole, so that the receiving groove of the outer tire is filled with the second material body; and After the second material body is foamed and solidified, the inner tube is obtained, wherein the inner tube and the outer tube are connected as a whole.

4. The preparation method according to claim 2, characterized in that: In providing the first mold, a portion of the cavity wall of the first perfusion cavity covered by the first material body is used as a first cavity wall, another portion of the cavity wall of the first perfusion cavity not covered by the first material body is used as a second cavity wall, and the first perfusion hole penetrates the second cavity wall to communicate with the first perfusion cavity, The first mold is provided with a first exhaust hole for negative pressure exhaust, and the first exhaust hole penetrates the second cavity wall to communicate with the first pouring cavity.

5. The preparation method according to claim 2, characterized in that: During the process of centrifugally pouring the first material body into the first mold and cooling and solidifying the first material body, negative pressure exhaust is performed.

6. The preparation method according to claim 2, characterized in that: The first material body includes polyurethane, the second material body includes polyurethane, and the density of the outer tube formed by curing the first material body is greater than the density of the inner tube formed by curing the second material body.

7. The preparation method according to claim 1, characterized in that: The method of curing and molding the outer tire by using the first material body comprises: Provide tire molds; Injecting the first material into the tire mold through an injection molding machine; After the first material body is cooled and solidified, the outer tire is obtained; and The tire is removed from the tire mold.

8. The preparation method according to claim 7, characterized in that: The curing and molding of the inner tube comprises: Providing a second mold, wherein the second mold is provided with a second infusion cavity and a second infusion hole communicating with the second infusion cavity; Placing the outer tire in the second pouring cavity of the second mold, wherein the outer tire is in contact with the cavity wall of the second pouring cavity; Centrifugally pouring the second material body into the second pouring cavity through the second pouring hole, so that the receiving groove of the outer tire is filled with the second material body; and After the second material body is foamed and solidified, the inner tube is obtained, wherein the inner tube and the outer tube are connected as a whole.

9. The preparation method according to claim 8, characterized in that: In providing the second mold, a portion of the second infusion cavity wall that is in contact with the tire casing is used as a first cavity wall, another portion of the second infusion cavity wall that is not in contact with the tire casing is used as a second cavity wall, and the second infusion hole penetrates through the second cavity wall to communicate with the second infusion cavity. The second mold is provided with a second exhaust hole for negative pressure exhaust, and the second exhaust hole penetrates the second cavity wall to communicate with the second pouring cavity.

10. The preparation method according to claim 7, characterized in that: The first material body includes thermoplastic polyurethane, and the second material body includes polyurethane.

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