KR20180093574A - Tires using dual forming structure and the manufacturing method thereof - Google Patents

Abstract

The present invention relates to a bicycle tire formed by a double structured forming material, and a manufacturing method thereof. The manufacturing method comprises: a mold opening step of separating and opening an upper mold and a lower mold in which each recessed unit is formed to provide a tire shaped inner space; an arranging step of arranging an EVA foam first molded product having elasticity in an insert fixed pin which is projected to an upper part in the recessed unit of the lower mold; a mold adhering step of closing the upper mold and the lower mold after the arranging step, and allowing an insert fixed pin, which is projected to a lower part in the recessed unit of the upper mold, to support the EVA foam first molded product; a mold heating step of heating the closed mold in the mold adhering step at the temperature within a constant range; a raw material injecting step of injecting an EVA foam composition into a space provided by outer circumference surfaces of the recessed unit and the EVA foam first molded product through an injecting unit formed in one side of the upper mold or the lower mold; a hardening step of maintaining constant temperature during constant time to harden the EVA foam first molded product and the EVA foam composition of the mold; a de-molding step of removing a material hardened in the hardening step from the mold; and a ripening step of fixing a molded product, de-molded in the de-molding step, in a molded frame, and ripening the same. The present invention is provided to use an EVA foam by replacing a tube for injecting air pressure, thereby offering a bicycle tire to maintain the elasticity at a constant level or more.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle tire having a double-

The present invention relates to a bicycle tire formed of a foamed material having a double structure and a method of manufacturing the same. In order to prepare a primary molded product of an EVA foam having excellent elasticity instead of a tube in a tire, a primary molded product of the EVA foam is stably supported The present invention relates to a method for manufacturing a bicycle tire formed of a foamed material having a double structure by using a mold provided with an insert fixing pin.

Generally, a tire is coupled to the end of a moving object such as a vehicle, a bicycle, a motorcycle, a handcart, and the like, and is driven to rotate. The outer side surface of the tire is made of rubber having excellent abrasion resistance, and the inner side is provided with a tube filled with high-pressure air for relieving the external impact and raising the ride feeling by maintaining the elastic force.

However, the tire having the tube has a problem that the air pressure in the tube is reduced due to long-term maintenance and use, and the stable tire performance can not be exhibited.

In addition, there is a problem that when a hole is formed by a sharp material on the ground such as a nail or a glass piece, the tire can not function properly.

As a result, a tire with a built-in tube inconveniently periodically replenishes the air pressure to the tube, or the tube needs to be replaced or repaired if the tube is damaged.

In order to solve the above-described problems, the present applicant has filed Korean Patent No. 1663894 entitled " Multi-hardness bicycle tire and its manufacturing method ".

The prior art is formed of an upper mold and a lower mold for injecting a tire, an intermediate plate is inserted between the upper mold and the lower mold to inject and cure the outer EVA foam, and then the middle plate is removed to form a tube To a method of manufacturing a dual hardened bicycle tire by inserting an EVA foam primary molded product. In the prior art, the middle plate is positioned between the upper mold and the lower mold to form an outer EVA foam, and then the middle plate is separated between the upper mold and the lower mold so that the EVA foam primary molded product is positioned inside the outer EVA foam And the tire is cured.

However, in the prior art, there is a problem that the middle plate is placed between the upper mold and the lower mold and the middle plate is separated from the upper mold and the lower mold. Thus, the manufacturing process is troublesome and the working time is long, There was a decreasing Moon Jegem.

In addition, there is a problem that the production cost of the mold is increased as the middle plate is further required, including the upper mold and the lower mold.

Korea Patent No. 1663894

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing a bicycle tire that can produce a foam material that maintains an elastic force such as a tube even when the tube is not pneumatically injected, .

Another object of the present invention is to provide a bicycle tire which provides a function without puncturing even if the tire is damaged by nails or sharp materials.

It is still another object of the present invention to provide a method of efficiently manufacturing a tire using a mold formed to stably support the tire and manufacturing the tire with high quality.

It is a further object of the present invention to provide a bicycle tire which is cost-competitive by reducing the cost of manufacturing bicycle tires.

Meanwhile, the object of the present invention is not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood from the following description.

A method of manufacturing a bicycle tire formed of a foamed material having a dual structure according to the present invention includes a mold opening step of opening and separating an upper mold and a lower mold, in which depressions are formed so that a tire- A step of disposing an EVA foam primary molded product having an elastic force on an insert fixing pin provided so as to protrude upward from the upper mold; and after the arranging step, the upper mold and the lower mold are closely contacted and closed downward from the depression of the upper mold A mold pre-heating step of pre-heating the mold closed and closed in the mold close step to a pre-heating temperature, a mold pre-heating step of forming the EVA foam preform in one side of the upper mold or the lower mold, Of the EVA foam primary molded article through the injection port A curing step of keeping the EVA foam composition in a predetermined temperature range for a certain period of time to cure the EVA foam primary molded product and the EVA foam composition in the mold, A demolding step of demolding the material from the mold, and an aging step of immobilizing the shaped body demolded in the demolding step by fixing the molded body to a molding die.

The EVA foam composition according to claim 1, wherein the EVA foam primary composition and the EVA foam composition disposed at the outside of the EVA foam, which are injected in the arranging step and the raw material injecting step, are adhered to each other in the curing step, Is not required.

The EVA foam primary molded product disposed in the arranging step is a molded product mold preheating step in which the molded article mold composed of the upper mold and the lower mold having grooves is closely contacted and closed to preheat the molded article at a temperature of 80 to 100 DEG C, A step of injecting the EVA foam at a temperature of 80 to 110 DEG C into the mold through the injection port; a step of injecting the EVA foam in the step of injecting the material into the mold at a temperature of 20 to 30 DEG C A mold opening step for opening the molded article mold after the molded article cooling step and a molded article removal step for removing the molded EVA foam from the molded article mold in the molded article releasing step .

Wherein the EVA foam primary molded product in the batch step is preheated for 600 to 1,200 seconds in an oven at a temperature of 50 to 80 DEG C before being placed in the batch step.

The insert fixing pins are provided in different lengths and are detachably attached to the depressed portions of the upper mold and the lower mold so as to support the EVA foam primary molded product corresponding to the diameter of the EVA foam primary molded product .

A bicycle tire formed of a foamed material having a double structure produced according to the above method is characterized in that it is made of a primary molded product of EVA foam so as to absorb an impact applied to a bicycle tire and has an elastic part in a ring shape, A tire base having a relatively greater hardness than the elastic portion, and a wheel formed along an outer peripheral surface of the tire base and coupled with a rim fastening portion of the bicycle.

The tire base is formed with an elastic groove recessed inwardly from the outer circumferential surface so as to buffer external impact transmitted to the bicycle tire.

According to the present invention, the following effects can be expected.

1) By using the EVA foam instead of the tube for injecting air pressure, it is possible to provide a bicycle tire capable of maintaining the elastic force at a certain level or more.

2) It is possible to provide a bicycle tire which is composed entirely of EVA foam and can maintain its function even if it is damaged by nails or sharp materials.

3) By using the mold provided with the insert fixing pin capable of stably supporting the EVA foam, a high quality bicycle tire can be efficiently manufactured.

4) By reducing the mold cost by simplifying the number of molds used to manufacture bicycle tires, it is possible to lower the manufacturing costs of bicycle tires and manufacture the tires at a lower cost.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart of a method of manufacturing a bicycle tire formed from a foamed material having a dual structure according to the present invention.
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a bicycle tire manufacturing method.
FIG. 3 is a flow chart of a process for manufacturing a primary molded article of EVA foam in a bicycle tire manufacturing method formed of a foamed material having a dual structure according to the present invention.
4 is a cross-sectional view of a bicycle tire manufactured in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments described below, but may be embodied in various different forms, and these embodiments are not intended to be exhaustive or to limit the scope of the present invention to the precise form disclosed, It is provided to inform the person completely of the scope of the invention. And the terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. The singular forms herein include plural forms unless the context clearly dictates otherwise.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Brief Description of Drawings FIG. 1 is a block diagram of a computer system according to an embodiment of the present invention; FIG. 2 is a block diagram of a computer system according to an embodiment of the present invention; FIG.

The present invention relates to a method of manufacturing a bicycle tire formed of a foamed material having a double structure, and to manufacture a tire constituting a foam capable of replacing the function of a tube.

FIG. 1 is a flow chart of a method of manufacturing a tire according to the present invention, and FIG. 2 is a schematic cross-sectional view of a process of manufacturing the tire according to the present invention.

Hereinafter, the present invention will be described in detail with reference to FIGS. 1 and 2. FIG.

A tire having a double structure foam material according to the present invention is formed by a mold composed of an upper mold 110 and a lower mold 120. The upper mold 110 and the lower mold 120 are in close contact with each other so that a tire-shaped inner space is formed therein. The inner space is formed by depressions (not shown) formed in the upper mold 110 and the lower mold 120 111 and 121 are provided with insert fixing pins 112 and 122, respectively. The insert fixing pins 112 and 122 are for supporting the foamed material disposed in the inner space. An insert fixing pin 112 is provided on the depression 111 of the upper mold 110 so as to protrude downward and an insert fixing pin 122 is provided on the depression 121 of the lower mold 120 And can support the material disposed in the inner space so as to protrude upward.

The first step of the method for manufacturing a tire formed of a foamed material having a dual structure according to the present invention is a mold opening step (S10). In the mold opening step S10, the upper mold 110 and the lower mold 120 are isolated from each other.

Thereafter, a placement step S20 of arranging the EVA foam primary molded product 130 inside the upper mold 110 and the lower mold 120 separated from each other proceeds. The EVA foam primary molded product 130 can be disposed and supported on the insert fixing pin 122 provided on the lower mold 120. [

After the placing step S20, the mold close step S30 is performed. In the mold close step S30, the upper mold 110 and the lower mold 120 are brought into close contact with each other to close the mold. In the mold adhesion step S30, the upper mold 110 and the lower mold 120 are brought into contact with each other, and the insert fixing pin 112 provided on the upper mold 110 is inserted into the insert fixing pin 122 provided on the lower mold 120 Thereby preventing the EVA foam primary molded product 130 from being moved arbitrarily by being brought into contact with the disposed EVA foam primary molded product 130. [

Next, the mold preheating step S40 is performed. The mold preheating step (S40) is a step of preheating the metal mold closely closed in the metal mold closing step (S30) to a certain range of temperature, more specifically, a step of preheating to a temperature of 80 to 100 deg. This serves to maintain the liquid state when the EVA foam composition 140 injected in the material injecting step (S50), which will be described later, is injected into the mold.

After the mold pre-heating step S40, the raw material injecting step S50 is performed. The raw material injecting step S50 is performed through the depressions 111 and 121 through the injection port 113 formed at one side of the upper mold 110 or the lower mold 120 And the EVA foam composition 140 is injected into the space provided by the outer peripheral surface of the primary molded product 130 of the EVA foam. In the raw material injecting step (S50), the EVA foam composition 140 is injected to produce a tire base of a tire manufactured according to the present invention.

The EVA foam composition 140 injected in the raw material injecting step S50 may be injected at a temperature of 80 to 110 DEG C such that the EVA foam composition 140 is heated to a temperature similar to the temperature at which the mold is preheated in the mold preheating step S40 (140) is injected, it can be injected into the entire mold in a liquefied state.

After the raw material injecting step (S50), the curing step (S60) proceeds. The curing step S60 is a step of maintaining a certain range of temperature for a certain period of time so that the EVA foamed primary molded product 130 inside the mold and the EVA foamed composition 140 injected in the raw material injecting step S50 are cured.

The curing step (S60) is preferably maintained at a temperature of 150 to 200 DEG C for 1,000 to 1,500 seconds. The reason why the EVA foam primary molded product 130 and the EVA foam composition 140 are cured at a temperature of 150 to 200 DEG C in the curing step S60 is that the EVA foam primary molded product 130 and the EVA foam composition 140 So as to be hardened while expanding. In other words, when the EVA foam composition 140 in a liquid state at a temperature of 80 to 110 ° C is maintained at a temperature of 150 to 200 ° C, which is a higher temperature, the expanded EVA foam composition 140 exhibits excellent elasticity And the like. The EVA foam primary molded product 130 can also be expanded at a temperature of 150 to 200 DEG C, and such expansion can increase the elastic force.

The reason why the curing step (S60) is maintained for 1,000 to 1,500 seconds is that the EVA foam primary molded product 130 and EVA foam composition 140, which are made of different materials, adhere to each other and adhere to each other. If the curing step S60 is maintained at less than 1,000 seconds, the EVA foam composition 140 may not completely cure, and if the curing step S60 is maintained for more than 1,500 seconds, the temperature of the curing step S60 There may occur a problem that some of the EVA foamed primary molded product 130 and the EVA foamed composition 140 are melted and mixed with each other without a boundary line. Thus, the curing step S60 is maintained for a period of 1,000 to 1,500 seconds.

In the curing step S60, the EVA foam primary molded product 130 and the EVA foamed composition 140 can be cured and cured, and no separate bonding process is required.

Next, the demolding step S70 is performed. The de-molding step S70 is a step of separating the EVA foam composition 140, which has been inflated and cured in the curing step S60, and the EVA foam primary molded product 130 from the mold.

Finally, the aging step (S80) proceeds. In the aging step (S80), in the demolding step (S70), the molded product sprayed from the mold is aged at room temperature. Here, the molded product refers to a tire-shaped product composed of the EVA foam composition 140 and the EVA foam primary molded product 130. In the aging step (S80), the molding is fixed to a molding die and is hardened and hardened at room temperature. The molded product obtained in the aging step (S80) can maintain the shape of the tire semi-permanently.

The aforementioned EVA foam primary molded product 130 and the EVA foam composition 140 have different paths. The EVA foam composition 140 has a relatively higher hardness than the EVA foam primary molded article 130. More specifically, the EVA foam composition 140 has a hardness of 70 [Asker C] or more and the EVA foam primary molded product 130 has a hardness of about 30 to 50 [Asker C]. More preferably, the EVA foam primary molded product 130 may have a hardness of 45 [Asker C] or less. Since the EVA foam composition 140 is formed on the outer side of the bicycle tire and directly abuts against the ground, the hardness must be relatively high to prevent damage and serve as a support. The EVA foam primary molded product 130 has a relatively low hardness and elasticity so that it can buffer external impacts. And it is possible to provide an elastic force such that air is mixed in the EVA foamed primary molded product 130.

The EVA foam composition 140 has a tensile strength of 4.0 MPA or more, a tear strength of 1.5 MPa or more, a wear resistance of 100 NBS or more, and a shelf life of more than EVA foam primary molded product 130 250% or more.

The EVA foam primary molded product 130 is characterized in that the rebound resilience is 60% higher than that of the EVA foam composition 140. The EVA foam primary molded product 130 may have a modulus of elasticity of 55% or more.

Thus, the bicycle tire composed of the EVA foam primary molded product 130 and the EVA foam composition 140 can have a specific gravity of about 0.45 g / cc and can be manufactured in a light weight.

The EVA foam primary molded product 130 can be manufactured to have various colors, and the EVA foam composition 140 can be manufactured in various colors by adding a pigment or the like when it is in a liquid state. Thus, bicycle tire buyers can be provided with customized color tires.

The EVA foam primary molded product 130 and the EVA foam composition 140 can be injected into a mold through a direct injection molding method.

FIG. 3 is a flow chart for explaining a method of manufacturing a primary molded article of EVA foam according to the present invention. Hereinafter, a method of manufacturing a primary molded article of EVA foam will be described with reference to FIG.

The EVA foam primary molded product 130 according to the present invention includes a molded article mold preheating step S110, a molded article injection step S120, a molded article mold cooling step S130, a molded article mold opening step S140, ). ≪ / RTI >

The molded article mold preheating step (S110) is a step of closely closing and closing the molded article mold composed of the upper mold and the lower mold having grooves to mold the EVA foam primary molded product 130, and preheating the molded article to a temperature of 80 to 100 캜. This is to allow the EVA foam in the liquid state to flow into the inside of the molded article mold to fill the inside of the molded article mold while maintaining the liquid state.

Next, the step of injecting the molded article (S120) is a step of injecting the EVA foam at a temperature of 80 to 110 ° C inside the molded article mold through the injection port formed at one side of the molded article mold. The reason for injecting the EVA foam at a temperature of 80 to 110 占 폚 is to keep it in a liquid state.

When the EVA foam is injected in the mold material injection step to fill the inside of the molded article mold, the molded article mold cooling step (S130) for cooling the molded article mold so that the temperature of the injected EVA foam becomes a temperature of 20 to 30 캜 is proceeded. The molded article mold cooling step (S130) serves to prevent the EVA foam from foaming until the curing step (S60).

After the molded article mold cooling step (S130), the molded article mold opening step (S140) proceeds. The molded article mold releasing step S140 is a step of releasing the upper mold and the lower mold apart from each other and serves to demold the EVA foam primary molded article 130 in the molded article mold.

Next, the molded article deburring step S150 is performed. In the step S150, the EVA foamed primary molded article 130 is separated from the molded article mold after the molded article open step S140.

The EVA foam primary molded article 130 according to one embodiment of the present invention may be preheated for 600 to 1200 seconds in an oven at a temperature of 50 to 80 캜 before being placed in the placing step S20. This serves to prevent the EVA foam from hardening by preheating it to a temperature similar to the temperature inside the mold.

The primary molded product 130 of the EVA foam according to the present invention may be composed of an environmentally friendly polymer, and toxic gas is not generated during disposal or incineration, so that it may not adversely affect the natural environment.

Referring to FIG. 2 again, the EVA foam primary molded product 130 according to the embodiment of the present invention can be manufactured in various sizes, that is, different diameters of the cross section, depending on the type of tire to be manufactured. Accordingly, the insert fixing pins 112 and 122 of the present invention can be provided in various lengths corresponding to the sizes of the EVA foam primary molded product 130, and the recessed portions 111 of the upper mold 110 and the lower molds 120 may be detachably fixed to each of the depressed portions 121.

More specifically, when the EVA foam primary molded product 130 is formed to have a small cross-sectional diameter, insert fixation pins 112 and 122 having relatively long lengths are provided in the depressions 111 and 121 so that the EVA foam primary molded product 130 The insert fixing pins 112 and 122 having relatively short lengths are provided on the depressions 111 and 121 so that the EVA foam primary molded product 130 and the EVA foam primary molded product 130 can be stably supported. (130) can be stably supported.

Hereinafter, a bicycle tire manufactured according to the manufacturing method of the present invention will be described with reference to FIG. 4 is a sectional view of a bicycle tire according to the present invention.

The bicycle tire may be largely composed of the elastic portion 210, the tire base 220, and the wheel 230.

First, the elastic portion 210 is formed into a primary molded product of EVA foam so as to absorb impact applied to the bicycle tire, and is formed into a ring shape.

The tire base 220 is formed to enclose the elastic portion 210 and is formed to have a relatively greater hardness than the elastic portion 210. The inner circumferential surface of the tire base 220 and the outer circumferential surface of the elastic portion 210 are in close contact with each other.

The tire base 220 is a portion that directly contacts the ground and directly receives an external impact. It is preferable that the abrasion resistance, the hardness, the tensile strength and the tear strength are larger than the elastic portion 210 provided inside the tire base 220 have.

More specifically, the tire base 220 has a hardness of 70 [Asker C] or more, and the elastic portion 210 has a hardness of about 30 to 50 [Asker C].

The tire base 220 may have a tensile strength of 4.0 MPA or more, a tear strength of 1.5 MPa or more, a wear resistance of 100 NBS or more, and a storage ratio of 250% or more higher than that of the elastic portion 210.

The resilient part 210 has a rebound resilience of 60% higher than that of the tire base 220.

The tire base 220 according to the embodiment of the present invention may have an elastic groove 221 formed therein. The elastic grooves 221 are recesses formed inwardly from the outer circumferential surface of the tire base 220, and may be formed as a pair at opposite positions. In particular, the elastic grooves 221 may be formed on both sides of the tire base 220. Further, the shape of the elastic groove 221 may be formed in various shapes such as a circular shape, a square shape, and a pentagon shape, and may be formed in a plurality of shapes.

The resilient groove 221 may serve to relieve the external impact on the ground when the tire is pressed from the ground or is uneven and rugged. In other words, the space created by the provision of the elastic grooves 221 can be flexibly expanded and contracted during the pressing or external impact, so that the impact can be dispersed.

The wheel 230 is formed along the outer circumferential surface of the tire base 220 so as to allow the tire to be engaged with the rim fastening portion formed on the bicycle. The wheel 230 and the tire base 220 may be made of the same material and formed integrally or may be made of different materials.

The bicycle tire according to the present invention may further include a tread portion having a predetermined concavo-convex pattern on the outer circumferential surface of the tire base 220. The tread portion serves to reduce the contact area with the ground, thereby minimizing damage to the bicycle tire.

The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the claims of the invention to be described below may be better understood. It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the foregoing detailed description, and all changes or modifications derived from the appended claims and their equivalents should be construed as being included within the scope of the present invention.

110: upper mold
120: Lower mold
111, 121:
112, 122: insert fixing pin
113: inlet
130: Primary molded product of EVA foam
140: EVA foam composition
210:
220: tire base
221: Elastic groove
230: Wheat

Claims (7)

A mold opening step of separating the upper mold and the lower mold, in which the depressions are formed, so as to provide a tire-shaped inner space;
Disposing an EVA foam primary molded product having an elastic force on an insert fixing pin provided so as to protrude upward from a depression of the lower mold;
A die attaching step of supporting the EVA foam primary molded article by an insert fixing pin provided so as to protrude downward from the depressed portion of the upper mold while the upper mold and the lower mold are closely closed after the arranging step;
A mold preheating step of preheating the mold closed and closed in the mold close step to a temperature within a predetermined range;
A raw material injecting step of injecting an EVA foam composition into a space provided by the depressions and the outer circumferential surface of the EVA foam primary molded product through an injection port formed on one side of the upper mold or the lower mold;
A curing step of keeping the EVA foam primary molded article and the EVA foam composition in the mold at a constant temperature range for a certain period of time;
A demolding step of demolding the cured material in the mold in the curing step; And
And a step of aging the molded article, which is demolded in the demoulding step, by immobilizing the molded article on a molding frame, thereby forming a bicycle tire. The method according to claim 1,
The EVA foam primary composition and the EVA foam composition disposed outside the EVA foam primary molded product of different properties injected in the arranging step and the raw material injecting step,
Wherein the curing step is performed by bonding and hardening the cemented rubber material so that a separate bonding process is not required. The method according to claim 1,
In the EVA foam primary molded product disposed in the arranging step,
A mold preheating step of preheating the molded article mold composed of the upper mold and the lower mold with grooves in close contact with each other to a temperature of 80 to 100 캜;
A molding material injection step of injecting the EVA foam at a temperature of 80 to 110 ° C into the molding material mold through an injection port formed at one side of the molding material mold;
Cooling the molded article mold so that the EVA foamed article injected in the step of injecting the molded article is cooled to a temperature of 20 to 30 ° C after a predetermined time;
A mold opening step of opening the molded article mold after the step of cooling the molded article mold; And
And a step of removing the molded EVA foam from the molded article mold at the step of opening the molded article mold. The method according to claim 1 or 3,
In the EVA foam primary molded product in the arranging step,
Wherein the preheating is carried out in an oven at a temperature of 50 to 80 DEG C for 600 to 1,200 seconds before being placed in the batching step. The method according to claim 1,
The insert fixing pin
Characterized in that the upper mold and the lower mold are detachably attached to the depressed portions of the upper mold and the lower mold so as to support the EVA foam primary molded product corresponding to the diameter of the EVA foam primary molded product, A method of manufacturing a bicycle tire formed from a material. A bicycle tire formed from a foamed material having a dual structure produced according to any one of claims 1 to 5,
An elastic part formed as an EVA foam primary molded product so as to absorb the impact applied to the bicycle tire and having a ring shape;
A tire base formed to enclose the elastic portion and having a relatively greater hardness than the elastic portion; And
And a wheel formed along an outer peripheral surface of the tire base and coupled with a rim fastening portion of the bicycle. The method according to claim 6,
In the tire base,
Characterized in that an elastic groove recessed inward from the outer circumferential surface is formed so as to buffer an external impact transmitted to the bicycle tire.

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