JP7059867B2 - Decorative parts for vehicles - Google Patents

Description

The present invention relates to a vehicle decorative component that is attached to the front of the millimeter wave radar device in the direction of transmission of millimeter waves from the millimeter wave radar device to decorate the vehicle and has millimeter wave transmission.

In vehicles, millimeter-wave radar devices may be installed behind decorative parts for vehicles such as front grilles and emblems in order to measure the distance between vehicles and the distance to obstacles using millimeter waves.

However, when the above-mentioned decorative parts for vehicles are provided with a brilliant property by a metal film made of chrome plating to decorate the vehicle, and the metal film is formed in a continuous state over one surface, the metal film is formed. Blocks or greatly attenuates millimeter waves.

Therefore, for example, Patent Document 1 proposes decorative parts for vehicles having brilliance and millimeter wave transmission. The decorative parts for vehicles are formed between a transparent member formed of a resin material, a base material formed of the resin material and arranged behind the transparent member, and the transparent member and the base material. It has a decorative layer. The decorative layer is composed of a metal film formed by sputtering, vapor deposition, etc. on the rear surface of the transparent member, and a black pressing film formed by painting on the rear side of the metal film.

Here, since the metal film has millimeter wave permeability, it has a discontinuous structure, that is, the metal film is not continuous on one surface, and a large number of fine metal films are slightly separated from each other in an island shape or one. A structure that is spread out in contact with each other, the so-called sea island structure, is adopted.

Japanese Unexamined Patent Publication No. 2007-138270

However, in the decorative parts for vehicles described in Patent Document 1, a black pressing coating film is formed on the rear side of the metal film having a sea-island structure as a decorative layer. Therefore, the metal film can be seen through from the front of the decorative parts for vehicles, and the black pressing coating film on the rear side can be seen. Under the influence of this presser coating, the metal film looks darker than the metal film made of chrome plating. Further, due to the influence of the color of the transparent member and the metal film itself, the metal film looks more yellowish than the metal film made of chrome plating.

The present invention has been made in view of such circumstances, and an object thereof is to make a metal film shine with a brightness and a color closer to that of chrome plating than when the presser coating film is black. The purpose is to provide decorative parts for vehicles that can be made and can improve the design.

The vehicle decorative parts that solve the above problems are attached in front of the millimeter wave radar device in the direction of transmission of the millimeter wave from the millimeter wave radar device in the vehicle to decorate the vehicle and provide millimeter wave transparency. A transparent member formed of a resin material, a base material formed of the resin material and arranged behind the transparent member in the transmitting direction, and the transparent member and the base, which are decorative parts for a vehicle. A metal film having a decorative layer formed between the materials, the decorative layer formed so as to form a sea-island structure with respect to the rear surface of the transparent member in the transmitting direction, and the transmission thereof. The presser coating film formed on the rear side of the metal film in the direction is provided, and the L value of the presser film in the Lab color system is set to 42 to 95, and the b value is set to -48 to -2. Further, the light transmittance of the metal film is set to 1% to 9%.

Here, the Lab color system is one of the methods for expressing the color of an object numerically. The L value in the Lab color system represents brightness (brightness), and the a value and b value represent chromaticity. Saturation is a quantitative representation of a color in terms of hue and saturation, excluding lightness. It becomes darker as the L value becomes smaller, and becomes brighter as the L value becomes larger. The a value represents the chromaticity from green to red, and becomes greenish as the distance from 0 to the minus side and reddish as the distance from 0 to the plus side. The b value represents the chromaticity from blue to yellow, and becomes bluish as it goes away from 0 to the minus side, and becomes yellowish as it goes away from 0 to the plus side.

According to the above configuration, the millimeter wave transmitted from the millimeter wave radar device and the millimeter wave reflected by hitting an object such as a vehicle or an obstacle in front in the transmission direction are both base materials for decorative parts for vehicles. It penetrates the decorative layer and the transparent member. In the decorative layer, the metal film has a sea-island structure, so millimeter waves can pass through.

When light is applied to the decorative parts for vehicles from the front in the transmission direction, a part of the light is transmitted through the transparent member and then reflected by the metal film. Therefore, the metal film appears to shine through the transparent member.

Further, since the metal film has a sea-island structure, the metal film can be seen through from the front in the transmission direction of the decorative parts for vehicles, and the holding coating film on the rear side can be seen. Here, as described above, when the b value of the pressing coating film in the Lab color system is set to −48 to −2, the pressing coating film becomes a bluish to whitish color. Further, the L value of the presser coating film is set to 42 to 95, which is larger than the L value of black. Therefore, since the metal film can be seen through and the presser coating film can be seen, the metal film appears to be brighter than when the presser film is black, and to be bluish to whitish and shining. However, although the metal film is brighter than the case where the presser film is black, it may not be as bright as the chrome plating.

However, according to the above configuration, the light transmittance of the metal film is set to 1% to 9%. When the light transmittance is set in the above range, the amount of light reflected by the metal film increases and the brightness increases. Therefore, it is possible to make the metal film shine brighter than when the light transmittance of the metal film is larger than 9%.

As a result, when the decorative parts for vehicles are viewed from the front in the transmission direction, the metal film appears to shine with a brightness and color closer to that of chrome plating than when the presser coating film is black.

When the light transmittance is set in the above range, the influence of the metal film on the millimeter wave transmittance is small, and good millimeter wave transmittance can be obtained.
In the decorative parts for vehicles, it is preferable that the a value of the presser coating film in the Lab color system is set to -1 to 9.

By setting the a value of the presser coating film in the Lab color system to a value satisfying the above conditions, the presser film becomes a slightly reddish color. Therefore, when the decorative parts for vehicles are viewed from the front in the transmission direction, the metal film appears to shine with a color closer to that of chrome plating.

According to the above-mentioned decorative parts for vehicles, the metal film can be made to shine with a brightness and color close to those of chrome plating, as compared with the case where the presser coating film is black, and the design can be improved.

The front view which shows the emblem in one Embodiment which embodied a decorative part for a vehicle into an emblem. A side sectional view showing an emblem in one embodiment together with a millimeter wave radar device and a front grill. A partial side sectional view showing a part of FIG. 2 in an enlarged manner. The graph which shows the setting range of the L value and the b value in the Lab color system about the holding film of one Embodiment. The graph which shows the setting range of the L value and a value in the Lab color system about the holding film of one Embodiment. The graph which shows the result of having measured the L value and b value in the Lab color system when the metal film was seen through a transparent member for a plurality of emblems having different light transmittances of a metal film.

Hereinafter, an embodiment in which a decorative part for a vehicle is embodied in an emblem will be described with reference to the drawings. In each figure, the scale of each member is appropriately changed in order to make each member recognizable.

As shown in FIG. 2, a front grill 11 for introducing outside air such as running wind into the engine room to cool the radiator is attached to the front portion of the engine room of the vehicle 10. Further, on the rear side of the front grill 11 and on the front side of the radiator, A. C. C. A millimeter-wave radar device 12 that functions as a sensor in (adaptive cruise control) is attached. The millimeter wave radar device 12 transmits millimeter waves to the front of the vehicle and receives millimeter waves reflected by hitting an object. The millimeter wave radar device 12 measures the inter-vehicle distance and the relative speed between the vehicle in front and the own vehicle (vehicle 10) based on the transmitted millimeter wave (transmitted wave) and the received millimeter wave (received wave). The millimeter wave is a radio wave having a wavelength of 1 to 10 mm and a frequency of 30 to 300 GHz. A. C. C. Controls the throttle opening and the brake of the engine based on the measurement result by the millimeter wave radar device 12, accelerates and decelerates the own vehicle (vehicle 10), and controls the inter-vehicle distance.

The thickness of the front grill 11 is not constant like a general front guru. Further, in the front grill 11, a metal plating layer may be formed on the surface of the resin base material, as in the case of a general front guru. Therefore, the front grill 11 interferes with the transmitted or reflected millimeter waves. Therefore, in the front grill 11, a window portion 13 is provided at a position serving as a millimeter wave path of the millimeter wave radar device 12, specifically, a position in front of the millimeter wave radar device 12.

As shown in FIGS. 1 and 2, the emblem 20 is arranged in the window portion 13. The emblem 20 includes a transparent member 21, a base material 26, and a decorative layer 31, and has a substantially elliptical plate shape as a whole.

The transparent member 21 is a member that constitutes the front side portion of the emblem 20. The transparent member 21 is transparently formed of a resin material such as PC (polycarbonate) resin, which is a resin material having a small dielectric loss tangent (an index value indicating the degree of electrical energy loss in the dielectric). The dielectric loss tangent of the PC resin is 0.006. If the dielectric loss tangent is small, the millimeter wave is difficult to be converted into thermal energy, so that the attenuation of the millimeter wave can be suppressed.

FIG. 3 shows a part of FIG. 2 in an enlarged manner. As shown in FIG. 3, a general portion 22 substantially orthogonal to the front-rear direction and a recess 23 recessed forward from the general portion 22 are formed in the rear portion of the transparent member 21. The recess 23 has a pair of facing wall surfaces 24 and a bottom wall surface 25 facing each other. The facing wall surfaces 24 are inclined in the front-rear direction so that the distance between them becomes smaller toward the front side.

The general portion 22 corresponds to the background region 20a of the emblem 20 in FIG. 1, and the recess 23 corresponds to the pattern region 20b of the emblem 20. Here, the pattern region 20b is formed by the letter (A) and the annular portion around it. The transparent member 21 may be formed of a PMMA (polymethylmethacrylate) resin, which is a resin material having a small dielectric loss tangent, like the PC resin.

As shown in FIGS. 2 and 3, the base material 26 is a member constituting the rear portion of the emblem 20, and is a resin such as AES (acrylonitrile-ethylene-styrene copolymer) resin, which is a resin material having a small dielectric loss tangent. Depending on the material, it is formed in a colored color such as black. The dielectric loss tangent of the AES resin is 0.007, and the relative permittivity is substantially the same as the relative permittivity of the PC resin. The front portion of the base material 26 is formed in a shape corresponding to the shape of the rear portion of the transparent member 21. That is, a general portion 27 that is substantially orthogonal to the front-rear direction is formed in the front portion of the base material 26 and behind the general portion 22 of the transparent member 21. A convex portion 28 is formed in the front portion of the base material 26 and behind the concave portion 23 of the transparent member 21 so as to project forward from the general portion 27.

A mounting portion 30 for mounting the emblem 20 to the front grill 11 projects rearward from a plurality of locations on the rear surface of the base material 26 and outside the millimeter wave irradiation region.
Instead of the AES resin, the base material 26 is a resin having a relative dielectric constant close to that of the transparent member 21, for example, ASA (acrylonitrile-styrene-acrylate copolymer) resin, PC resin, PC resin and ABS (acrylonitrile-butadiene-). It may be formed by a polymer alloy of a resin (styrene copolymer) or the like.

The decorative layer 31 is formed between the transparent member 21 and the base material 26, and has millimeter wave transmission. The decorative layer 31 is composed of a colored layer 32, a metal film 33, and a pressing coating film 34.

The colored layer 32 is formed on the rear surface of the general portion 22 of the transparent member 21, and is black in the present embodiment.
The metal film 33 is formed so as to form a sea-island structure with respect to both the opposing wall surfaces 24 and the bottom wall surface 25 in the recess 23 of the transparent member 21 and the entire rear surface of the colored layer 32. The sea-island structure is a structure in which the metal film 33 is not continuous on one surface, and a large number of fine metal film 33 are spread in an island shape slightly separated from each other or partially in contact with each other. By adopting this structure, the metal film 33 has a discontinuous structure, high electrical resistance, and millimeter wave transmission.

In this embodiment, indium (In), which has a property of easily forming a discontinuous structure, is used as the metal material. If the metal film 33 is formed of a metal material having poor properties instead of indium, it becomes a continuous structure and becomes electric when it reaches a film thickness region where sufficient brilliance is obtained in appearance. The resistance becomes low and the millimeter wave transmission becomes insufficient.

The light transmittance of the metal film 33 is set to 1% to 9%. By setting the light transmittance to belong to the above range, both millimeter wave transmittance and brilliance can be obtained satisfactorily.
The pressing coating film 34 is formed on the rear side of the metal coating film 33. The pressing coating film 34 improves the corrosion resistance of the metal film 33 in the decorative layer 31, improves the adhesion to the base material 26 formed on the metal film 33 in a later step, and forms the base material 26. It has a function of protecting the metal film 33 from stress and the like at the time. In the present embodiment, the L value, the a value, and the b value of the presser coating film 34 in the Lab color system are set to values belonging to the region surrounded by the frame of the two-dot chain line in FIGS. 4 and 5. That is, the L value is set to 42 to 95, the a value is set to -1 to 9, and the b value is set to −48 to -2. The corresponding colors are white to blue and include light blue.

Further, assuming that the dimension of the emblem 20 in the anteroposterior direction at least in the irradiation region of millimeter waves is the thickness T, the thickness T is uniformly set to a value substantially equal to the value satisfying the following equation 1. Here, the "substantially equal thickness" means a thickness included in an error range of ± 0.2 mm.

T = {(λe / 2) / √ (εp)} n ... (Equation 1)
The meaning of each symbol in the above formula 1 is as follows.
λe: Wavelength of millimeter wave εp: Relative permittivity of transparent member 21 (or base material 26) n: Integer Thus, the thickness T of the emblem 20 is an integer obtained by dividing the half wavelength by the square root of the relative permittivity. It is set to double.

Then, as shown in FIGS. 1 and 2, the emblem 20 is attached to the front grill 11 at the attachment portion 30 in an upright state. Here, the means for attaching the emblem 20 to the front grill 11 is not particularly limited. The emblem 20 is attached to the front grill 11 by, for example, a clip, a screw, a claw engagement or the like.

The emblem 20 having the above configuration is manufactured as follows.
First, as shown in FIGS. 2 and 3, a transparent member 21 having a general portion 22 and a recess 23 at the rear portion is formed by injection molding. The colored layer 32 is formed by performing printing such as screen printing, hot stamping, or the like on the rear surface of the general portion 22. Indium as a metal material is sputtered or vapor-deposited on both the facing wall surface 24 and the bottom wall surface 25 in the recess 23 and the entire colored layer 32 to form a metal film 33 forming a sea-island structure. A pressing coating film 34 is formed on the entire metal film 33 by coating from the rear side. In this way, the decorative layer 31 composed of the colored layer 32, the metal film 33 having a sea-island structure, and the pressing coating film 34 is formed on the rear side of the transparent member 21. The base material 26 is formed by insert molding. That is, an intermediate molded body in which the decorative layer 31 is formed on the rear surface of the transparent member 21 is used as an insert and placed in the mold. A molten resin material made of AES resin is injected into a mold and cured. When the base material 26 having the general portion 27 and the convex portion 28 is integrally formed on the rear side of the transparent member 21 and the decorative layer 31, the desired emblem 20 can be obtained.

Next, the action and effect of the emblem 20 of the present embodiment obtained as described above will be described.
When a millimeter wave is transmitted forward from the millimeter wave radar device 12 shown in FIG. 2 in order to measure the inter-vehicle distance and the relative speed between the vehicle in front and the own vehicle (vehicle 10), the millimeter wave is transmitted in the emblem 20. It penetrates the base material 26, the decorative layer 31, and the transparent member 21, respectively. The millimeter wave reflected by hitting an object such as a vehicle or an obstacle in front in the transmission direction also passes through the emblem 20 in the same manner as described above. Since the metal film 33 has a sea-island structure and is discontinuous, it has high electrical resistance and millimeter-wave transmission.

As shown in FIGS. 2 and 3, in the emblem 20, the decorative layer 31 formed between the base material 26 and the transparent member 21 has a function of decorating the front portion of the vehicle 10 including the front grill 11. Demonstrate. When light hits the emblem 20 from the front side, a part of the light passes through the transparent member 21 and then is reflected by the metal film 33. Therefore, when the emblem 20 is viewed from the front, the metal film 33 appears to shine through the transparent member 21. Since the metal film 33 is formed on the inclined facing wall surface 24 and the bottom wall surface 25 in the recess 23, a pattern including characters having a metallic luster can be seen three-dimensionally on the rear side thereof through the transparent member 21.

Further, since the metal film 33 has a sea-island structure, the metal film 33 can be seen through from the front of the emblem 20, and the pressing coating film 34 on the rear side can be seen. Here, as shown in FIG. 4, since the b value of the pressing coating film 34 in the Lab color system is set to −48 to -2, the pressing coating film 34 has a bluish to whitish color. Will be. Further, the L value of the presser coating film 34 is set to 42 to 95, which is larger than the L value of black. Therefore, since the pressing coating film 34 can be seen through the metal film 33, the metal film 33 appears to be brighter than when the pressing coating film 34 is black, and to be bluish to whitish and shining. However, although the metal film 33 is brighter than the case where the presser film 34 is black, it may not be as bright as the chrome plating.

However, in the present embodiment, the light transmittance of the metal film 33 is set to 1% to 9%. This setting is possible by adjusting the ratio of the island portion to the sea island structure and the film thickness in the metal film 33. When the light transmittance is set in the above range, the amount of light reflected by the metal film 33 increases and the brightness increases. Therefore, it is possible to make the metal film 33 shine brighter than when the light transmittance of the metal film 33 is larger than 9%.

As a result, when the emblem 20 is viewed from the front, the metal film 33 appears to shine with a brightness and color closer to that of chrome plating than when the presser coating film 34 is black.

Further, in the present embodiment, as shown in FIG. 5, since the a value of the pressing coating film 34 in the Lab color system is set to -1 to 9, the pressing coating film 34 has a slightly reddish color. Will be. Therefore, when the emblem 20 is viewed from the front, the metal film 33 appears to shine with a color closer to that of the chrome plating.

When the light transmittance is set in the above range, the effect of the metal film 33 on the millimeter wave transmittance is small, and good millimeter wave transmittance can be obtained.
FIG. 6 shows the L value in the Lab color system when the metal film 33 of the decorative layer 31 is viewed through the transparent member 21 for the emblems 20 of Examples 1 to 4 in which the light transmittances of the metal film 33 are different from each other. And the result of measuring the b value are shown. The color of the presser coating film 34 in each embodiment is blue, and the light transmittance is set as follows. In Example 1, it is set to "1%", in Example 2, it is set to "2%", in Example 3, it is set to "6%", and in Example 4, it is set to "9%". The comparative example shows the measurement results when the presser coating film 34 is black and the light transmittance of the metal film 33 is set to 6%.

From FIG. 6, it can be seen that when the metal film 33 of the decorative layer 31 is viewed through the transparent member 21, it looks brighter and brighter with a brightness and color generally closer to that of chrome plating than when the presser coating film 34 is black. ..

Here, in Example 4, the L value is smaller than that in Comparative Example. However, due to variations in the film thickness of the metal film 33, the light transmittance of the metal film 33 usually varies by about 4%. Considering this variation, it cannot be said that the L value is necessarily smaller than that of the comparative example in Example 4, and it is not denied that the metal film 33 shines with a brightness and color close to those of chrome plating. not.

It should be noted that the above embodiment can also be implemented as a modified example in which this is modified as follows.
As shown in FIG. 3, since both facing wall surfaces 24 are inclined in the front-rear direction in the recess 23 of the transparent member 21, indium (In) is formed on the facing wall surface 24 as compared with the bottom wall surface 25 when the metal film 33 is formed. ) Is hard to adhere. On the facing wall surface 24, the film thickness of the metal film 33 tends to be thinner than that of the bottom wall surface 25. On the facing wall surface 24, the metal film 33 is transparent and the color of the pressing coating film 34 is easier to see than on the bottom wall surface 25. Assuming that the color depth of the pressing coating film 34 is uniform, the metal film 33 looks different from the bottom wall surface 25 on the facing wall surface 24.

Therefore, when it is possible to paint with a different color depending on the portion, the pressing coating film 34 is formed on the facing wall surface 24 with a paint having a different color from the bottom wall surface 25. Is desirable. By doing so, the color depth of the metal film 33 becomes about the same on the facing wall surface 24 and the bottom wall surface 25.

-The metal film 33 may be formed of a metal material other than indium.
A hard coat layer may be formed on the front surface of the transparent member 21, or water repellency may be imparted. As a means for imparting water repellency, for example, a water repellent film may be formed on the front surface of the transparent member 21. Further, the molding surface of the mold used for molding the transparent member 21 may be textured or nano-processed.

The emblem 20 may be formed in a plate shape having a shape different from that of an ellipse.
-The emblem 20 may be attached to the vehicle body instead of the front grill 11.
-Vehicle decorative parts are attached in front of the millimeter wave radar device 12 in the direction of transmission of millimeter waves from the millimeter wave radar device 12 in the vehicle 10 to decorate the vehicle 10 and provide millimeter wave transmission. It may be applied to a vehicle decorative part different from the emblem 20, for example, a front grill, provided that it has.

In addition, the technical ideas that can be grasped from the above embodiments will be described together with their effects.
(A) In the vehicle decorative part according to claim 1 or 2, the metal film is formed of indium.

According to the above configuration, indium (In) has a property of easily forming a discontinuous structure. Therefore, by using indium, it is possible to form a metal film having a sea-island structure.

10 ... vehicle, 12 ... millimeter wave radar device, 20 ... emblem (decorative part for vehicle), 21 ... transparent member, 26 ... base material, 31 ... decorative layer, 33 ... metal film, 34 ... pressing coating film.

Claims (2)

In a vehicle, it is a decorative component for a vehicle that is attached in front of the millimeter wave radar device in the direction of transmission of millimeter waves from the millimeter wave radar device to decorate the vehicle and has millimeter wave transmission.
A transparent member formed of a resin material, a base material formed of the resin material and arranged behind the transparent member in the transmission direction, and a decoration formed between the transparent member and the base material. With layers,
The decorative layer has a metal film formed so as to form a sea-island structure with respect to the rear surface of the transparent member in the transmission direction, and a presser coating formed on the rear side of the metal film in the same transmission direction. With a membrane,
The L value of the presser coating film in the Lab color system is set to 42 to 95, and the b value is set to -48 to -2.
Further, a decorative component for a vehicle in which the light transmittance of visible light in the metal film is set to 1% to 9%. The decorative component for a vehicle according to claim 1, wherein the a value of the presser coating film in the Lab color system is set to -1 to 9.

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