KR102731621B1 - Low noise pneumatic tire wheel including polyurethane sound-absorbing materials and manufacturing method thereof - Google Patents

Abstract

In a method for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material (S10), a method for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material (S10) is provided, the method including a polyurethane foam preparation step (S100) of preparing a polyurethane foam (100) by mixing a first reactant and a second reactant, a molding mold arrangement step (S200) of arranging a first mold (210) and a second mold (220) that are fitted together on an outer surface of a tire wheel to form an internal space, a polyurethane foam injection and foaming step (S300) of injecting polyurethane foam into the internal space of the mold, a polyurethane foam curing step (S400) of curing the foamed polyurethane foam, and a molding mold demolding step (S500) of demolding the mold.
Therefore, the present invention aims to solve all of the above-described problems.
According to the present invention, a method for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material in which a molding mold is arranged to face each other on the outer surface of a tire wheel to form an internal space between the tire wheels, and a molding mold (200) is divided into a first mold (210) and a second mold (220) and arranged to surround the entire outer surface of the tire wheel and inject polyurethane foam therein, so that after the molding mold (200) is arranged on the outer surface of the tire wheel, the polyurethane foam is foamed only into the internal space evenly formed when the polyurethane foam is foamed, thereby obtaining a sound-absorbing member having a uniform shape and quality at all times, and a low-noise tire wheel using the same is provided.
In addition, by separating the mold (200) for polyurethane foaming into pieces and arranging them, the mold is easily fixed and can be easily removed from the mold after work, compared to the mold of the prior art, which was difficult to remove from the mold, thereby providing a method for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material and a low-noise tire wheel using the same.
In addition, since the polyurethane foam is foamed immediately after injection, it has the effect of providing a method for manufacturing a low-noise tire including a polyurethane sound-absorbing material that is easy to demold after forming a sound-absorbing member with uniform quality, which is better than the conventional technology in which a foam rubber composition of consistent quality was not formed in the existing vulcanization and bonding process, and a low-noise tire wheel using the same.

Description

Method for manufacturing a low-noise tire wheel including polyurethane sound-absorbing materials and a low-noise tire wheel using the same {Low noise pneumatic tire wheel including polyurethane sound-absorbing materials and manufacturing method thereof}

The present invention relates to a method for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material and a low-noise tire wheel using the same, and more specifically, to a method for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material for manufacturing a low-noise tire wheel without a sound-absorbing material bonding process by directly injecting and foaming polyurethane foam onto the outer surface of a tire wheel, and a low-noise tire wheel using the same.

Pneumatic tires generate resonant noise around 200 Hz and radiated noise above 500 Hz, which originate from cavities created by the tire and rim structures.

The above-mentioned radiated noise is generated as a sound with sharp peaks inside the vehicle, causing discomfort to the driver and reducing ride comfort.

Recently, along with the expansion of electric vehicles, there is an increasing demand for improved ride quality and reduction of not only interior noise but also external noise generated by tires.

Therefore, in order to reduce tire resonance noise, a method of attaching sound-absorbing material to the outer surface of a tire wheel has been proposed.

However, when attaching sound-absorbing material to the outer surface of a tire wheel, an additional process of applying adhesive to the outer surface of the tire wheel and attaching the sound-absorbing material occurs, and there is a problem in that products of consistent quality are not produced because workers attach the sound-absorbing material manually.

In addition, there was the inconvenience of having to additionally produce sound-absorbing materials that fit the tire depending on the tire's specifications and intended use.

A prior art invention, Japanese Patent Laid-Open No. 2004-306660 A (2004.11. 04), relates to a vehicle wheel and a manufacturing method thereof, which comprises a vehicle wheel (10) having a rim (11) for mounting a tire and a sound-absorbing material (13) on the outer surface of the rim (11), wherein the sound-absorbing material (13) includes a process of fitting a mold into the rim (11), a process of filling the mold with a foamed rubber composition, and vulcanizing and bonding the foamed rubber composition to a well portion (11D) formed in the rim (11) to form a foamed rubber, and the sound-absorbing material (13) is formed in a shape that is continuous in the circumferential direction of the well portion (11D) and has a center that protrudes toward the outer side in the radial direction of the rim (11).

However, even in the case of the conventional invention, since the formwork is inserted between the rims and the formwork is dismantled, there are problems such as the height of the formwork may be different during the process, making it difficult to obtain a sound-absorbing material of a consistent shape; since the formwork is provided as an integral piece, the attachment and dismantling processes are difficult, and the foam rubber may be damaged during dismantling; and in the process of vulcanizing and bonding the foam rubber composition to form the foam rubber, there are problems such as the inability to obtain a foam rubber composition of consistent quality.

Accordingly, if a method for manufacturing a low-noise tire including a polyurethane sound-absorbing material is developed by arranging a mold facing the outer surface of a tire wheel to form an internal space between the wheel and the mold, and then injecting and foaming polyurethane foam into the internal space to produce the tire, the polyurethane foam will be foamed only into the internal space that has been evenly formed when the mold (200) is placed on the outer surface of the tire wheel and the polyurethane foam is foamed, so that a sound-absorbing material having a uniform shape and quality can always be obtained.

In addition, if the molding mold (200) for polyurethane foaming is placed in pieces separated, it is easy to fix and remove the molding mold, and thus it is easier to fix and remove the molding mold than the formwork of the prior art, which was difficult to fix and remove during work.

In addition, since the polyurethane foam is foamed immediately after injection, it will be possible to form a sound-absorbing member with more consistent quality than the conventional technology in which a foam rubber composition of consistent quality was not formed through conventional vulcanization and bonding.

Republic of Korea Patent Publication No. 10-1901399 (2018.09.17)

Therefore, the present invention aims to solve all of the above-described problems.

According to the present invention, the molding molds are mutually joined to face each other on the outer surface of the tire wheel to form an internal space between the tire wheels, the molding mold (200) is separated into a first mold (210) and a second mold (220), and arranged to surround the entire outer surface of the tire wheel, and polyurethane foam is injected into the interior thereof, so that after the molding mold (200) is arranged on the outer surface of the tire wheel, the polyurethane foam is foamed only in the internal space formed evenly when the polyurethane foam is foamed, thereby obtaining a sound-absorbing member having a uniform shape and quality at all times, and the present invention provides a method for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material and a low-noise tire wheel using the same.

In addition, when a molding mold (200) for polyurethane foaming is placed in pieces and separated, it is easy to fix the molding mold and can be easily removed from the mold after work, compared to the mold of the prior art, which was difficult to remove from the mold, and it is another purpose to provide a method for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material and a low-noise tire wheel using the same.

In addition, since the polyurethane foam is foamed immediately after injection, it is possible to form a sound-absorbing member with uniform quality, better than the conventional technology in which a foam rubber composition of consistent quality was not formed in the conventional vulcanization and bonding process, and it is another purpose to provide a method for manufacturing a low-noise tire including a polyurethane sound-absorbing material that is easy to demold after forming the sound-absorbing member, and a low-noise tire wheel using the same.

A representative configuration of the present invention to achieve the above purpose is as follows.

According to one aspect of the present invention, a method for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material (S10) is provided, comprising a polyurethane foam preparation step (S100) of preparing a polyurethane foam (100) by mixing a first reactant and a second reactant, a molding mold arrangement step (S200) of arranging a first mold (210) and a second mold (220) that are fitted together on an outer surface of a tire wheel and bonding and attaching them to form an internal space, a polyurethane foam injection and foaming step (S300) of injecting polyurethane foam into the internal space of the mold, a polyurethane foam curing step (S400) of curing the foamed polyurethane foam, and a molding mold demolding step (S500) of demolding the mold.

More specifically, a method for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material (S10) is provided, characterized in that the polyurethane foam preparation step (S100) includes a first reactant preparation step (S110) including an isocyanate component, a second reactant preparation step (S120) composed of a first polyol and a second polyol, and a reactant stirring step (S130) of stirring the first reactant and the second reactant to generate a polyurethane foam.

More specifically, a method for manufacturing a low-noise tire wheel (S10) including a polyurethane sound-absorbing material is provided, characterized in that the first reactant is mixed in an amount of 0.35 to 0.45 parts by weight based on 1 part by weight of the second reactant.

More specifically, a method for manufacturing a low-noise tire wheel (S10) including a polyurethane sound-absorbing material is provided, characterized in that the first reactant includes at least one selected from toluene diisocyanate, carbodiimide methylene diphenyl diisocyanate, monomeric methylene diphenyl diisocyanate, and polymeric diphenyl diisocyanate.

More specifically, a method for manufacturing a low-noise tire wheel (S10) including a polyurethane sound-absorbing material is provided, characterized in that the second reactant is composed of a first polyol having a hydroxyl value (OH Value) of 20 to 40 mgKOH/g in an amount of 85 to 95 wt%, and a second polyol having a hydroxyl value (OH Value) of 20 to 60 mgKOH/g in an amount of 5 to 15 wt%.

More specifically, a method for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material (S10) is provided, characterized in that the second reactant includes 0.01 to 0.1 weight part of a chain extender having a hydroxyl value (OH Value) of 900 to 1,200 mgKOH/g based on 1 weight part of the first polyol and second polyol mixed composition.

More specifically, a method for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material (S10) is provided, characterized in that the molding die has an overall semi-circular shape, a cross-section in the shape of the letter 'ㄷ', and has an opening and a plurality of folded portions, the openings being arranged to face the outer surface of the tire wheel to form an internal space between the tire wheels.

More specifically, a method (S10) for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material is provided, characterized in that the molding mold further has a plurality of protrusions (214) on the inner wall of the molding mold.

The above molding mold placement step (S200) includes a first mold placement step (S210) of arranging a first mold having at least one fitting groove on a side surface on an outer surface of a tire wheel, and a second mold placement step (S220) of arranging a second mold having at least one protrusion on a side surface on an outer surface of a tire wheel by fitting it with a side surface of the first mold. A low-noise tire wheel manufacturing method (S10) including a polyurethane sound-absorbing material is provided.

More specifically, the polyurethane foam injection and foaming step (S300) provides a method (S10) for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material, characterized in that the polyurethane foam is injected through an injection port provided at a predetermined position in the mold.

According to one embodiment of the present invention, a low-noise tire (10) wheel including a polyurethane sound-absorbing material is provided, manufactured by a method (S10) for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material.

According to the present invention, a method for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material in which a molding mold is arranged to face the outer surface of a tire wheel to form an internal space between the tire wheels, the molding mold (200) is divided into a first mold (210) and a second mold (220) and arranged to surround the entire outer surface of the tire wheel, and polyurethane foam is injected into the interior thereof, so that after the molding mold (200) is arranged on the outer surface of the tire wheel, the polyurethane foam is foamed only into the internal space evenly formed when the polyurethane foam is foamed, thereby obtaining a sound-absorbing member having a uniform shape and quality at all times, and a low-noise tire wheel using the same is provided.

In addition, by separating the mold (200) for polyurethane foaming into pieces and arranging them, the mold is easily fixed and can be easily removed from the mold after work, compared to the mold of the prior art, which was difficult to remove from the mold, thereby providing a method for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material and a low-noise tire wheel using the same.

In addition, since the polyurethane foam is foamed immediately after injection, it has the effect of providing a method for manufacturing a low-noise tire including a polyurethane sound-absorbing material that is easy to demold after forming a sound-absorbing member with uniform quality, better than the conventional technology in which a foam rubber composition of consistent quality was not formed in the conventional vulcanization and bonding process, and a low-noise tire wheel using the same.

FIG. 1 is an overall flow chart of a method (S10) for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material according to one embodiment of the present invention.
Figure 2 is a detailed flowchart of a polyurethane foam preparation step (S100) according to one embodiment of the present invention.
Figure 3 is a detailed flowchart of a mold placement step (S200) according to one embodiment of the present invention.
Figure 4 is a combination sequence diagram of a mold (200) according to one embodiment of the present invention.
Figure 5 is a perspective view of a combined mold (200) according to one embodiment of the present invention.
FIG. 6 is a drawing showing an injection method of a polyurethane foam injection and foaming step (S300) according to one embodiment of the present invention.
Figure 7 is a cross-sectional view of a polyurethane foam (100) according to one embodiment of the present invention.
FIG. 8 is a cross-sectional view of a polyurethane foam (100) according to an additional embodiment of the present invention.
FIG. 9 is a perspective view of a low-noise tire wheel (10) including a polyurethane sound-absorbing material according to one embodiment of the present invention.

The detailed description of the present invention set forth below refers to the accompanying drawings which illustrate specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention, while different from one another, are not necessarily mutually exclusive. For example, specific shapes, structures, and features described herein may be implemented in other embodiments without departing from the spirit and scope of the invention. It should also be understood that the positions or arrangements of individual components within each disclosed embodiment may be changed without departing from the spirit and scope of the invention. Accordingly, the following detailed description is not intended to be limiting, and the scope of the invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled, if any. Like reference numerals in the drawings designate the same or similar functionality throughout the several aspects.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings so that a person skilled in the art to which the present invention pertains can easily practice the present invention.

FIG. 1 is an overall flow chart of a method (S10) for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material according to one embodiment of the present invention.

Referring to FIG. 1, a method (S10) for manufacturing a low-noise tire wheel including a polyurethane sound-absorbing material may be composed of a polyurethane foam preparation step (S100), a mold placement step (S200), a polyurethane foam injection and foaming step (S300), a polyurethane foam curing step (S400), and a mold release step (S500).

More specifically, the polyurethane foam preparation step (S100) is a step of preparing a polyurethane foam (100) formed by mixing a first reactant and a second reactant. The first reactant and the second reactant will be described in detail in the detailed flowchart of Fig. 2.

The above mold placement step (S200) is a step in which a first mold (210) and a second mold (220) that can be fitted together are placed on the outer surface of a tire wheel and joined together to form an internal space into which polyurethane foam can be injected.

The above polyurethane foam injection and foaming step (S300) is a step of injecting the polyurethane foam (100) formed in the polyurethane foam preparation step (S100) into the internal space formed by the mold (200).

The above polyurethane foam curing step (S400) is a step in which the polyurethane foam injected into the internal space is cured by leaving it at room temperature for 30 seconds to 1 minute.

The above mold demolding step (S500) is a step of demolding the mold that is mutually bonded to the outer surface of the tire wheel when the curing of the polyurethane foam (100) is complete.

Figure 2 is a detailed flowchart of a polyurethane foam preparation step (S100) according to one embodiment of the present invention.

Referring to FIG. 2, the polyurethane foam preparation step (S100) may be composed of a first reactant preparation step (S110), a second reactant preparation step (S120), and a reactant stirring step (S130).

In the first reactant preparation step (S110), the first reactant may include an isocyanate component. The isocyanate component may include one or more isocyanate components selected from toluene diisocyanate, carbodiimide methylene diphenyl diisocyanate, monomeric methylene diphenyl diisocyanate, and polymeric diphenyl diisocyanate.

In the second reactant preparation step (S120), the second reactant may be composed of a first polyol and a second polyol.

The first polyol can be composed of 85 to 95 wt% of a component having a hydroxyl value of 20 to 40 mgKOH/g, and the second polyol can be composed of 5 to 15 wt% of a component having a hydroxyl value of 20 to 60 mgKOH/g.

When the ratio of the first polyol component in the mixing ratio of the first polyol and the second polyol is less than 85 wt%, the ratio of the second polyol increases, which may cause problems such as deformation of the urethane foam and reduction in permanent compression set ratio. When it exceeds 95 wt%, the ratio of the second polyol decreases, which may cause problems such as increased vibration transmission ratio.

When the hydroxyl value (OH value) of the second polyol is less than 20 to 60 mgKOH/g and less than 5 wt% of the polyol, there is a problem of increased vibration transmission from the tire, and when it exceeds 15 wt%, problems of foam deformation and decreased permanent compression set rate may occur.

In addition, the second reactant may be formed by including 0.01 to 0.1 weight part of a chain extender having a hydroxyl value (OH value) of 900 to 1,200 mgKOH/g based on 1 weight part of the first polyol and second polyol mixed composition.

If the proportion of the above chain extender is less than 0.01 part by weight, there is a problem of reduced tensile strength and tear strength, and if it exceeds 0.1 part by weight, there is a problem of flowability during foaming, so the foam does not form into a consistent shape.

The reactant stirring step (S130) is a step of forming a polyurethane foam by stirring the first reactant and the second reactant, which are composed as described above. In the stirring step, the ratio of the first reactant and the second reactant is such that the first reactant is mixed at 0.35 to 0.45 parts by weight based on 1 part by weight of the second reactant, and stirring is performed for about 3 to 10 seconds to form a polyurethane foam (100).

When the first reactant is less than 0.30 parts by weight based on 1 part by weight of the second reactant, the foaming speed and crosslinking time become longer, and when it exceeds 0.50 parts by weight, problems such as increased hardness and reduced formability due to shortened curing time may occur.

Figure 3 is a detailed flowchart of a mold placement step (S200) according to one embodiment of the present invention.

Figure 4 is a combination sequence diagram of a mold (200) according to one embodiment of the present invention.

Figure 5 is a perspective view of a combined mold (200) according to one embodiment of the present invention.

Referring to FIGS. 3 to 5, the mold placement step (S200) may be composed of a first mold placement step (S210) and a second mold placement step (S220).

First, to explain the mold (200), the mold (200) has an overall semi-circular shape, a cross-section in the shape of the letter 'ㄷ', and a surface composed of an opening and a plurality of folded parts. The opening is arranged to face the outer surface of the tire wheel, and when the first mold and the second mold are mutually joined, an internal space can be formed between the tire wheel.

The first mold may have at least one fitting groove (211) on the side surface, and the second mold may have at least one protrusion (212) on the side surface.

The arrangement order of the mold (200) can be as shown in Fig. 4.

First, a first mold (210) and a second mold (220) are prepared at the center of the tire.

Thereafter, a first mold placement step (S210) is performed to place a first mold (210) equipped with a fitting groove (211) on the outer surface of the tire wheel.

After the placement of the first mold is completed, a second mold (220) equipped with a protrusion (212) is placed and fitted into the fitting groove (211) of the first mold, and a second mold placement step (S220) is performed to couple them together.

The mold (200) in which mutual bonding is completed on the outer surface of the tire wheel can be provided in a form that completely surrounds the outer surface of the tire wheel, as shown in FIG. 5, and the internal space can be provided in the form of a hollow portion penetrating both side cross sections of the mold, so that the entire shape can be formed in a circular shape.

This type of fitting structure has the effect of making it easier and more convenient to fix and remove the mold than the conventional invention where the formwork was fitted and removed as a whole.

In addition, since no adhesive is used, natural demolding is possible, which has the effect of preventing damage to the polyurethane foam (100) during demolding.

FIG. 6 is a drawing showing an injection method of a polyurethane foam injection and foaming step (S300) according to one embodiment of the present invention.

Referring to FIG. 6, the polyurethane foam injection and foaming step (S300) may inject polyurethane foam (100) through an injection port provided at a predetermined location in the mold (200).

The above injection port may be formed at one location selected from the side of the mold (200) and the inner wall of the mold (200).

It will be possible to inject polyurethane foam (100) by additionally providing a polyurethane foam injector (300) comprising a polyurethane foam storage unit (310) and an injection nozzle (320).

A spray nozzle (320) having a bent shape is inserted into the injection port of the mold (200) to inject polyurethane foam (100) into the internal space at high speed.

The injected polyurethane foam (100) is foamed in the internal space formed between the tire and the mold, thereby filling the internal space. Since foaming is performed immediately after injection, no additional heating process for foaming is required, thereby saving the time required for production.

In addition, since the polyurethane foam is foamed immediately after injection, it is possible to produce a sound-absorbing material with more uniform quality than the conventional technology in which a foam rubber composition of consistent quality was not formed during the existing vulcanization and bonding process.

In addition, since polyurethane foam is foamed only in the inner space, the entire area always has a uniform height, and a sound-absorbing material of uniform shape and quality can be obtained, making it easy to maintain quality during production.

In the polyurethane foam curing step (S400), the foamed polyurethane foam is completely cured when left at room temperature for 30 seconds to 1 minute.

After the polyurethane foam has been cured, a mold demolding step (S500) is performed to demold the mold.

When the first or second mold is demolded, the remaining molds that were fitted and fixed can be demolded naturally, so the molds can be safely demolded without damage to the manufactured polyurethane foam (100).

Figure 7 is a cross-sectional view of a polyurethane foam (100) according to one embodiment of the present invention.

FIG. 8 is a cross-sectional view of a polyurethane foam (100) according to an additional embodiment of the present invention.

Referring to Figures 7 and 8, they are cross-sectional views of polyurethane foam (100) after completion of mold demolding. The polyurethane foam (100) may be applied in various thicknesses depending on the shape of the mold (200).

In addition, by additionally providing a protrusion on the inner wall of the mold, the shape of the polyurethane foam (100) can be changed, so that a sound-absorbing tire wheel can be produced without delay in the production process by only replacing the mold according to the specifications and purpose of the tire.

FIG. 9 is a perspective view of a low-noise tire wheel (10) including a polyurethane sound-absorbing material according to one embodiment of the present invention.

Through the polyurethane foam preparation step (S100), the mold placement step (S200), the polyurethane injection and foaming step (S300), the polyurethane foam curing step (S400), and the mold demolding step (S500), it will be possible to manufacture a low-noise tire wheel including a polyurethane sound-absorbing material in the tire wheel as shown in FIG. 10.

Although the invention has been described with reference to specific details, such as specific components, and limited embodiments and drawings, these have been provided only to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains may make modifications and variations based on this description.

Therefore, the idea of the present invention should not be limited to the embodiments described above, and not only the claims described below but also all modifications equivalent to or equivalent to the claims are included in the scope of the idea of the present invention.

10: Low-noise tire wheel with polyurethane sound-absorbing material
S10: Method for manufacturing low-noise tire wheel including polyurethane sound-absorbing material
S100: Polyurethane foam preparation step S110: First reactant preparation step
S120: Second reactant preparation step S130: Reactant stirring step
S200: Mold placement step S210: First mold placement step
S220: Second mold placement stage S300: Polyurethane injection and foaming stage
S400: Polyurethane foam curing stage S500: Mold removal stage
100: polyurethane foam 110: first reactant
120: Second reactant 200: Mold
210: 1st mold 220: 2nd mold
211 : Insertion groove 212 : Protrusion
213: Inlet 214: Protrusion
300: Polyurethane foam injector 310: Polyurethane foam storage unit
320 : Injection nozzle

Claims (11)

In a method for manufacturing a low-noise tire wheel (S10) including a polyurethane sound-absorbing material,
A polyurethane foam preparation step (S100) of preparing polyurethane foam (100) by mixing the first reactant and the second reactant;
The overall cross-section is in the shape of the letter 'ㄷ', and is a surface having an opening and a plurality of folded portions. The molding mold is composed of a first mold and a second mold that are fitted together and are attached so that the openings face each other on the outer surface of the tire wheel to form an internal space between the tire wheels.
A polyurethane foam injection and foaming step (S300) of injecting polyurethane foam into the internal space of a mold through an injection port provided at a predetermined position in the mold;
Polyurethane foam curing step (S400) for curing expanded polyurethane foam;
After the polyurethane foam is hardened, a mold demolding step (S500) for demolding the first mold or the second mold;
Including,
The above mold placement step (S200) is
A first mold placement step (S210) of placing a first mold having at least one fitting groove on a side surface on the outer surface of a tire wheel, a second mold placement step (S220) of placing a second mold having at least one protrusion on a side surface on the outer surface of a tire wheel by fitting it with a side surface of the first mold;
A method for manufacturing a low-noise tire wheel including polyurethane sound-absorbing material (S10).

In paragraph 1,
The above polyurethane foam preparation step (S100) is
Step of preparing a first reactant containing an isocyanate component (S110);
Step of preparing a second reactant composed of a first polyol and a second polyol (S120);
A reactant stirring step (S130) of stirring the first reactant and the second reactant to produce polyurethane foam;
A method for manufacturing a low-noise tire wheel (S10) comprising a polyurethane sound-absorbing material characterized by including a.
In the second paragraph,
A method for manufacturing a low-noise tire wheel (S10) including a polyurethane sound-absorbing material, characterized in that the first reactant is mixed in an amount of 0.35 to 0.45 parts by weight based on 1 part by weight of the second reactant.
In the second paragraph,
The first reactant is,
A method for manufacturing a low-noise tire wheel (S10) comprising a polyurethane sound-absorbing material, characterized in that it comprises at least one selected from toluene diisocyanate, carbodiimide methylene diphenyl diisocyanate, monomeric methylene diphenyl diisocyanate, and polymeric diphenyl diisocyanate.
In the second paragraph,
The second reactant is,
The first polyol contains 85 to 95 wt% of a component having a hydroxyl value (OH Value) of 20 to 40 mgKOH/g,
A method for manufacturing a low-noise tire wheel (S10) including a polyurethane sound-absorbing material, characterized in that the second polyol is composed by mixing 5 to 15 wt% of a component having an OH value of 20 to 60 mgKOH/g.
In the second paragraph,
The second reactant is,
Based on 1 part by weight of the first polyol and second polyol mixed composition,
A method for manufacturing a low-noise tire wheel (S10) including a polyurethane sound-absorbing material, characterized in that it contains 0.01 to 0.1 weight part of a chain extender having an OH value of 900 to 1200 mgKOH/g.
delete In paragraph 1,
The above molding mold is,
A plurality of protrusions (214) on the inner wall of the mold;
A method for manufacturing a low-noise tire wheel (S10) comprising a polyurethane sound-absorbing material characterized by further comprising:
delete delete A low-noise tire wheel comprising a polyurethane sound-absorbing material manufactured by the method of claim 1.