JP2009073247A - Vehicular wheel and its heat shielding and insulating coating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular wheel capable of reducing rolling friction by raising tire temperature with a simple structure. <P>SOLUTION: The whole outer peripheral surface 11d of a rim 11 is formed with an undercoat layer 13 of clear coating 5-40 μm thick. Further, a bead sheet part 11a and a rim flange part 11b which a bead part 21a of a tire 20 adheres to (adhesion parts) are masked. The whole outer peripheral surface 11d except the adhesion parts is provided with heat shielding and insulating coating 50-500 μm thick thereon to form a heat shielding/insulating layer 14. The heat shielding/insulating layer 14, for suppressing heat transmission from air in a tire air chamber MC and an inner surface of the tire 20 to the rim 11 in the outer peripheral surface 11d of the rim 11 which contacts air in the tire air chamber MC, is preferably excellent in reflexivity to heat radiation from those, heat insulation, and long wave radiation property for radiating the transmitted heat in long waves such as infrared rays and or far infrared rays while having high heat insulation properties. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rolling resistance reduction technique for a vehicle tire and a processing method thereof.

Conventionally, it is known that when the tire temperature of a vehicle is raised, rolling resistance is reduced, the fuel efficiency of the vehicle can be improved, and the grip strength of the tire tread portion is improved. And in patent document 1, the heat generating body over the circumferential direction perimeter of the rim outer peripheral surface of a vehicle wheel is located closer to the center in the wheel width direction, so that heat from the heat generating body is not released to the rim side. Techniques for placement through materials are described.
Japanese Patent Laid-Open No. 5-16623 (see FIG. 3, paragraphs 0020 and 0021)

However, the technique described in Patent Document 1 is a configuration in which power is supplied to a heating element from power supply means outside the tire air chamber, for example, a solar cell attached to a wheel cap, and has a complicated configuration. Further, even when the air in the tire air chamber is heated by the heating element attached to the outer peripheral surface of the rim, the heating element on the outer periphery of the rim is not disposed, and the vehicle wheel side from the outer peripheral surface of the rim that is in contact with the air in the tire air chamber However, there is a problem in that heat escapes and is dissipated into the atmosphere, resulting in poor heating efficiency.
In addition, there is a problem that the step of the well portion disappears and it is difficult to mount the tire.

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide a vehicle wheel that can increase rolling tire temperature and reduce rolling friction with a simple structure, and a method for manufacturing the same.

  In order to solve the above-mentioned problems, the present invention is characterized in that the entire surface of the rim outer peripheral surface contacting the air in the tire air chamber is coated with a heat insulating and heat insulating coating.

  According to the present invention, when the tire temperature rises due to friction with the road surface due to running of the vehicle, and the heat is further transferred to the air in the tire air chamber, the air temperature in the tire air chamber rises. Can be prevented from being dissipated into the atmosphere through the rim and the disk through the portion in contact with the rim outer peripheral surface portion of the vehicle wheel.

  Also, when applying thermal insulation coating to such vehicle wheels, masking is applied to the portion of the rim outer peripheral surface where the tire bead comes into contact, and after applying thermal insulation and thermal insulation coating, the masking treatment is removed. It is desirable to do.

  Masking the portion of the rim outer peripheral surface where the tire bead abuts and applying the heat insulating heat insulation coating, the portion where the tire bead abuts, that is, the bead seat portion of the rim outer peripheral surface is not subjected to the heat insulating heat insulating coating, The adhesion between the tire bead portion and the rim is maintained.

  According to the present invention, the tire temperature in the vehicle running state can be increased, the rolling resistance can be reduced, and the fuel efficiency can be improved.

  Hereinafter, a vehicle wheel according to an embodiment of the present invention will be described in detail with reference to the drawings.

A vehicle wheel in the present embodiment will be described with reference to FIG.
FIG. 1 is a front sectional view of a main part of a wheel in which a tire is mounted on a vehicle wheel according to the present embodiment.
As shown in FIG. 1, the vehicle wheel 10 includes a rim 11 for mounting a tire 20 and a disk 12 for connecting the rim 11 to a hub (not shown).

  As shown in FIG. 1, the rim 11 is bent in an L-shape toward the outer side in the wheel radial direction from the bead sheet portions 11 a and 11 a formed at both ends in the wheel width direction. Rim flange portions 11b and 11b, and well portions 11c that are recessed inward in the wheel radial direction between bead seat portions 11a and 11a.

The bead portion 21a of the tire 20 is attached to the bead seat portion 11a. As a result, a tire air chamber MC comprising an annular sealed space is formed between the outer peripheral surface 11 d of the rim 11 and the inner peripheral surface of the tire 20.
In addition, regarding the tire 20, the code | symbol 21 shows a tire main body, the code | symbol 22 shows an inner liner, and the code | symbol 21b shows a tread part.

  The well portion 11 c is provided for dropping the bead portions 21 a and 21 a of the tire 20 when the rim is assembled to the tire 20.

As shown in FIG. 1, the disc 12 is formed continuously from the end of the rim 11 on the vehicle outer side to the inner side in the wheel radial direction. The rim 11 and the disk 12 are manufactured from, for example, a lightweight high-strength material such as an aluminum alloy or a magnesium alloy.
These materials are not limited, and may be formed from steel (steel) or the like. The vehicle wheel 10 may be a spoke wheel.

  A clear coating undercoat layer 13 having a thickness of 5 to 40 μm is formed on the entire outer peripheral surface 11d of the rim 11 including the bead seat portion 11a, the rim flange portion 11b, and the well portion 11c. The bead sheet portion 11a and the rim flange portion 11b (contact portion) to which the portion 21a is in contact are masked, and the entire peripheral surface excluding the contact portion in the outer peripheral surface 11d has a thickness of 50 to 500 μm thereon. A thermal barrier thermal insulation coating 14 is formed by applying a thermal barrier thermal insulation coating.

  The undercoat layer 13 is formed to improve the corrosion resistance of the outer peripheral surface 11d of the rim 11 and to improve the adhesion between the bead portion 21a and the outer peripheral surface 11d, and is urethane-based, epoxy-based, acrylic-based, or fluorine-based. A coating material having a low thermal conductivity, such as, or a combination thereof is desirable. Electrocoating or powder coating is used for this coating.

The heat-insulating and heat-insulating layer 14 is for suppressing heat transfer from the air in the tire air chamber MC and the inner surface of the tire 20 to the rim 11 on the outer peripheral surface 11d of the rim 11 in contact with the air in the tire air chamber MC. It is desirable to have excellent reflectivity, heat insulation, and long wave radiation for radiating the transmitted heat at long wavelengths such as infrared rays and far infrared rays, and high heat insulation properties.
The heat-insulating / insulating layer 14 is formed of a coating material in which an inorganic material (filler) having heat-insulating properties and heat-insulating properties is blended with an organic material (resin or rubber). In order to minimize the increase in unsprung weight, it is desirable to use a hollow, fine inorganic filler for thinner and lighter coatings. In addition, it is necessary to select a hollow fine inorganic filler that can ensure the heat shielding and heat insulating performance and at the same time have sufficient strength and abrasion resistance to withstand impacts and scratches in the tire assembly process.

Below, the coating material which forms a thermal-insulation heat insulation layer is demonstrated in detail.
Here, a water-soluble paint will be described as an example. Table 1 shows the mixing ratio (%) of the coating material by volume ratio.
As described in Japanese Patent Application Laid-Open No. 11-323197, the coating material for forming the heat-insulating and heat-insulating layer 14 has hollow particles densely dispersed in order to achieve low thermal conductivity (high thermal insulation). Things are suitable. As hollow particles, those that have high strength and are not destroyed even during the kneading process with the paint, the painting process, and the tire incorporation process, and the paint does not enter the hollow particles (hollow bodies having no porous or open pore structure) are suitable. ing. Examples of the candidate include high-strength ceramic hollow particles (hereinafter referred to as ceramic balloons) as the above-described hollow fine inorganic filler. Examples of the ceramic composition include zirconia, titania composite, and silicon boride-based. Ceramic may be mentioned.

Incidentally, as the ceramic balloon used in the present embodiment, it is preferable from the viewpoint of heat insulation to use hollow particles whose hollow part is air or another gas, or vacuum hollow particles whose hollow part is vacuum. Among these, vacuum hollow particles are preferably used from the viewpoint of heat insulation.
Here, the vacuum means a state where the atmospheric pressure is lower than the atmospheric pressure, and does not mean an absolute vacuum.

Further, it is important that the ceramic balloon is transparent or translucent. By being transparent or translucent, light (infrared ray, far infrared ray, near infrared ray, etc.) incident on the balloon can be reflected.
Furthermore, it is more preferable to be transparent than translucent because it is more excellent in reflectivity. Moreover, if it is transparent or translucent, it does not need to be colorless and may be colored. Under such conditions, among the above-mentioned ceramics, a silicon boride ceramic is most suitable because it has high transparency. A ceramic balloon having a particle size of 5 to 150 μm is used. Based on experience, this particle size range is the optimum range from the viewpoints of coating film appearance, coating workability, coating film physical properties, and heat shielding functionality.

  Moreover, it is preferable that the ceramic balloon used has a wide particle size distribution. That is, it is preferable to use a ceramic balloon having a wide range of different particle sizes from a large particle size to a small particle size. In such a case, the dense lamination state of the ceramic balloons in the coating film causes the ceramic balloons having a small particle diameter to enter the gaps between the ceramic balloons having a large particle diameter, thereby further reducing the gaps between the ceramic balloons. That is, the ceramic balloons can be arranged more densely. Therefore, the reflectivity and heat insulation as a coating film can be further improved.

  Furthermore, ceramic balloons have a high long wave emissivity. The long wave emissivity is the conversion efficiency when the absorbed heat is radiated again as infrared rays. Therefore, a coating film in which such ceramic balloons are densely stacked and arranged emits infrared rays with high efficiency.

In order to disperse such a ceramic balloon densely in the coating film, an acrylic polymer and silica particles are used as a structure holding material. As the acrylic polymer, copolymers of various acrylic monomers designed as synthetic resins for paints can be used. The acrylic polymer is used in the form of an emulsion mixed with the coating film forming material.
As described in paragraphs [0026] and [0027] of Japanese Patent Application Laid-Open No. 11-323197, these acrylic polymers and silica particles as a structure-retaining material are intermolecular when dispersed in a solution. When a so-called scaffold structure is formed by a non-covalent bond such as a hydrogen bond, a coordination bond, or van der Waals force, and particles such as a ceramic balloon are present in the solution in which the scaffold structure is formed, the ceramic balloon becomes a scaffold structure. In this state, the bubbles are uniformly distributed in the solution.

  Since the solvent evaporates while the uniform distribution state of the ceramic balloons is continuously maintained, finally, a state in which the ceramic balloons are densely laminated in the coating film is obtained. Here, the dense stacked arrangement means a state in which the ceramic balloons are close to each other in a three-dimensional manner and are densely fixed. Therefore, the undercoat layer 13 is covered with multiple ceramic balloons.

The coating material in the present embodiment can contain various commonly used coating film forming materials, solvents, pigments, and additives in addition to the above structure-retaining agent and ceramic balloon. As the film forming material, here, for example, acrylic resin is used, water is used as a solvent, titanium dioxide (titanium white), which is an inorganic pigment, is used as a masking agent, and an additive is used as an additive. , Dispersants, antifoaming agents, viscosity modifiers and the like are used.
Infrared reflective composite oxide black pigments such as (Co, Fe) (Fe, Cr) ₂ O ₄ and Cr ₂ O ₃ may be added.

  As described in Table 1 above, by using a ceramic balloon as a raw material for the coating material, a heat shielding and heat insulating performance of 0.03 W / m · K can be obtained.

Incidentally, the heat-insulating and heat-insulating layer 14 is a masking process in which a masking tape (not shown) is applied to the outer peripheral surface 11d from the bead seat portion 11a to the rim flange portion 11b of the rim 11 in the vehicle wheel 10 in which the coating of the undercoat layer 13 has been completed. After that, the coating material shown in Table 1 is applied.
At this time, it is necessary to prevent the coating film from being biased to one side in the wheel circumferential direction or one side in the wheel width direction. For example, a vehicle wheel 10 with a wheel center axis kept horizontal using a jig is applied while slowly rotating around the wheel center axis, and the rotation is maintained until the dry state progresses to some extent and no dripping occurs. A process of forming a more uniform layer is preferable, for example, by a method of performing coating or by dividing the coating into several times and drying the applied surface and then performing the next coating.
Alternatively, the vehicle wheel 10 may be placed horizontally, the coating may be divided into several times, and the applied surface may be dried before the next coating is performed.
By doing in this way, the coating material is biased to one side in the wheel circumferential direction and one side in the wheel width direction, or the rising portion is applied to the outer side in the wheel radial direction from the well portion 11c to the bead seat portion 11a. It is possible to prevent the film from becoming thin and being biased toward the well portion 11c.

  The masking tape described above is peeled off in a semi-dry state where the surface has been dried to some extent, the coating treatment of the heat-insulating and heat-insulating layer 14 is completed, and then complete drying is performed.

FIG. 2 shows a heat transfer path from a running tire air chamber. (A) shows a case of a vehicle wheel without a heat insulation heat insulation layer of a comparative example, and (b) a book with a heat insulation heat insulation layer. It is a figure explaining the case of the wheel for vehicles in an embodiment. FIG. 3 is a diagram for explaining the time transition of the temperature of the tread portion of the tire after the vehicle starts traveling.
In FIG. 2, the clear coating undercoat layer 13 is omitted from the display.

When the vehicle starts running, the tread portion 21b generates heat due to friction with the road surface, and the shoulder portion, side portion, and the like of the tire 20 repeatedly bend due to rolling friction and is heated by heat conduction.
In the case of the vehicle wheel 10A that does not have the heat-insulating and heat-insulating layer of the comparative example, heat due to self-heating of the tire 20 is radiated through the following three paths.
(1) Heat is released from the surface of the tire 20 to the atmosphere as indicated by arrow A. (2) Heat is released from the bead portion 21a to the atmosphere via the bead seat portion 11a and the rim 11 and the disk 12 as indicated by arrow B. (3) As indicated by the arrow C, the air in the tire air chamber MC is heated and radiated to the atmosphere via the rim 11 and the disk 12.

  On the other hand, in the vehicle wheel 10 of the present embodiment, the heat dissipation paths of (1) and (2) are the same as in the case of the vehicle wheel 10A, but the path of (3) is heat shielded. Since the heat insulating layer 14 reflects heat transfer from the tire air chamber MC as indicated by an arrow RC and exhibits high heat insulating performance, the temperature of the tire air chamber MC is higher than that of the vehicle wheel 10A of the comparative example. To increase.

This can also be simulated by calculation. In the graph of FIG. 3, the vertical axis represents the temperature of the tread portion 21 b of the tire 20, and the horizontal axis represents the elapsed time from the start of traveling of the vehicle, and the curve 11 has the heat insulating and heat insulating layer 14. In this case, the curve l2 indicates a case where the thermal barrier heat insulating layer 14 is not provided. Here, the conditions of the heat-insulating and heat-insulating layer 14 are such that those shown in Table 1 have a thickness of 400 μm, and the heat-insulating and heat-insulating performance is 0.03 W / m · K or less.
In this case, it was found that the tire tread portion temperature could be higher than the curve l2 of the comparative example of 2 to 3 ° C.
As a result, rolling resistance is reduced by that amount, and fuel efficiency is improved.

  Moreover, the heat insulation heat insulation layer 14 is not provided in the part which the bead part 21a of the tire 20 of the bead seat part 11a contact | abuts. Since the bead part 21 also moves so as to bend on the bead sheet part 11a during traveling, the thermal insulation thermal insulation layer 14 is peeled off when the thermal insulation thermal insulation layer 14 including the ceramic balloon is coated to the part where the bead part 21a abuts. Or the ceramic balloon contained therein may be destroyed, and the adhesion between the rim 11 and the bead portion 21a is impaired, causing air leakage. In this embodiment, since the heat insulation heat insulation layer 14 is not coated to the part which the bead part 21a contact | abuts, such inconvenience does not arise.

  Incidentally, the heat around the bead wire (not shown) of the tire 20 is radiated to the atmosphere via the bead seat portion 11a and the rim 11 and the disk 12, so that the temperature of the bead portion 21a can be avoided from becoming too high. .

  Further, unlike the technology of Patent Document 1 described in the paragraph of the background art, the heat insulating material does not occupy the well portion 11c, and therefore, tire replacement or the like can be easily performed.

It is principal part front sectional drawing of the wheel which mounted | wore the tire for the vehicle wheel which concerns on this embodiment. The heat transfer path from the running tire air chamber is shown, (a) shows the case of a vehicle wheel having no heat insulation heat insulation layer of the comparative example, and (b) the vehicle in the present embodiment having the heat insulation heat insulation layer. It is a figure explaining the case of a wheel. It is a figure explaining the time transition of the temperature of the tread part of the tire after vehicles start a run.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle wheel 11 Rim 11a Bead seat part 11b Rim flange part 11c Well part 11d Outer peripheral surface 12 Disc 13 Undercoat layer 14 Thermal insulation heat insulation layer 20 Tire 21a Bead part (tire bead part)
21b Tread part MC Tire air chamber

Claims (2)

  A vehicle wheel characterized in that the entire surface of the rim outer peripheral surface contacting the air in the tire air chamber is coated with a heat insulating and heat insulating coating.   2. The masking process is performed after removing the masking process after performing a masking process on a portion of the outer peripheral surface of the rim where the tire bead portion comes into contact during the thermal barrier thermal insulation coating. The thermal-insulation heat insulation coating method in the vehicle wheel as described.

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