JP2019085083A - Vehicle electric wave transmission component - Google Patents

Abstract

To obtain a vehicle electric wave transmission component which enables reduction of attenuation when an electric wave is transmitted while securing aesthetic quality.SOLUTION: An ornament 10 includes: a surface layer part 12 forming a design surface 20; a rear layer part 16 provided at the rear side of the surface layer part 12 and having an attachment part 44 which is attached to a vehicle body; and an intermediate layer 14 which is provided adhering to a space between the surface layer part 12 and the rear layer part 16, is thinner than the surface layer part 12 and the rear layer part 16, and is formed by a sheet material S which is the same material as the surface layer part 12.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a radio wave transmission component for a vehicle mounted on a vehicle body of an automobile.

  Patent Document 1 discloses a vehicle radio wave transmitting component as a radome for protecting a radar that detects an obstacle around the vehicle. The radio wave transmission component for a vehicle includes a transparent member exposed on the surface of the vehicle, a decorative portion disposed on a part of the rear surface of the transparent member, and a base member covering the rear surface of the transparent member to hold the transparent member and the decorative portion And. Here, the radio wave transmission component for a vehicle is required to improve the design of the decorative portion, and the radio wave transmission component is required to cover the front of the radar.

JP, 2016-182866, A

  Here, in the radio wave transmission component for a vehicle of Patent Document 1, if the thickness of the layer through which radio waves are transmitted is reduced, the attenuation amount when the radio waves are transmitted is reduced, but on the other hand, the design is limited. There is a limit.

  An object of the present invention is to obtain a radio wave transmitting component for a vehicle which can reduce attenuation when transmitting a radio wave while securing the designability in consideration of the above fact.

  The radio wave transmission component for a vehicle according to the first aspect of the present invention is provided with a surface layer portion constituting a design surface, a back layer portion provided on the back side of the surface layer portion and having a mounting portion for a vehicle body, the surface layer portion and And a middle layer portion which is provided in close contact with the back layer portion and which is thinner than the surface layer portion and the back layer portion and which is formed of a sheet material of the same material as the surface layer portion.

  The first aspect is a radio wave transmitting component for a vehicle, which is composed of three layers of a surface layer part, a middle layer part and a back layer part. In this radio wave transmission component for a vehicle, the middle layer portion is formed of a sheet material made of the same material as the surface layer portion, and is formed thinner than the surface layer portion and the back layer portion. Here, in the back layer portion having the mounting portion, use of a resin having low radio wave permeability is assumed to obtain impact resistance and the like, but according to the first aspect, the thickness of the radio wave transparent component for a vehicle While reducing the proportion of resin with low radio wave permeability. That is, by securing the thickness of the radio wave transmission component for a vehicle, it is possible to suppress a decrease in designability, and by reducing the proportion of resin having low radio wave transmission, the attenuation when radio waves are transmitted is reduced. It can be done. Further, according to the first aspect, the strength of the radio wave transmitting component for a vehicle can be secured by the integrated middle layer portion and the back layer portion.

  The radio wave transmission component for a vehicle according to the second aspect of the present invention is provided on a surface layer portion constituting a design surface and on the back side of the surface layer portion, and also has a frame-shaped fixing portion connected to a vehicle body and the mounting portion And a middle layer portion made of the same material as the surface layer portion and provided in close contact with the surface layer portion and the fixing portion.

  A second aspect is a radio wave transmitting component for a vehicle, which is composed of three layers of a surface layer part, a middle layer part and a back layer part. In the radio wave transmission component for a vehicle, the middle layer portion is formed of the same material as the surface layer portion, and the portion in close contact with the middle layer portion in the back layer portion is formed as a frame-shaped fixed portion. Here, in the back layer portion having the attachment portion, use of a resin having low radio wave permeability is assumed to obtain impact resistance and the like, but resins of different materials and different dielectric constants are superimposed on the radio wave path. When this occurs, reflection and refraction of radio waves occur at the boundary between the two, and the amount of attenuation when radio waves pass increases. On the other hand, according to the second aspect, after the middle layer portion is formed of the same material as the surface layer portion, the reduction of the designability can be suppressed by securing the thickness of the radio wave transmission component for a vehicle. it can. Further, in the second aspect, the fixing portion is formed in a frame shape, so that resins having different materials and different dielectric constants do not overlap on the radio wave path. As a result, it is possible to suppress the reflection and refraction on the radio wave path to enhance the permeability to the radio wave, and to reduce the attenuation amount when the radio wave is transmitted.

  In the radio wave transmission component for a vehicle according to the third aspect of the present invention, the surface layer portion is formed of a resin having higher radio wave permeability than the back layer portion, and the back layer portion is higher in impact resistance than the surface layer portion. It is formed of resin.

  According to the third aspect, in the mounting portion to the vehicle body, the shock resistance is secured, and the radio wave permeability is increased in the portion constituting the design to reduce the attenuation amount when the radio wave is transmitted. Can.

  In the radio wave transmitting component for a vehicle according to the fourth aspect of the present invention, the surface layer portion is formed of a resin that transmits light, and a surface on the back side is decorated.

  The radio wave transmission component for a vehicle according to the fourth aspect is made of a resin whose design surface is transparent. According to the fourth aspect, an emblem having a glossy design surface can be provided.

  In the radio wave transmission component for a vehicle according to the fifth aspect of the present invention, the design surface is coated with a material having a lower water absorbability than the surface layer portion.

  According to the fifth aspect, the deterioration of the radio wave transmittance due to the water absorption of the radio wave transmission component for vehicle due to rainfall or the like is suppressed. That is, it is possible to suppress an increase in the amount of attenuation when the radio wave passes.

  As mentioned above, according to the electromagnetic wave transmission parts for vehicles of the present invention, the amount of attenuation at the time of penetration of an electric wave can be reduced, securing designability.

It is a front view of the ornament of 1st Embodiment. It is side surface sectional drawing (AA sectional drawing of FIG. 1) of the ornament of 1st Embodiment. It is figure (A) and (B) explaining the manufacturing process of the ornament of 1st Embodiment. It is side surface sectional drawing of the ornament of 2nd Embodiment. It is side surface sectional drawing of the ornament of 3rd Embodiment.

  Next, embodiments of the present invention will be described based on FIGS. 1 to 5. In addition, the ornament 10 which is a radio wave transmission component for vehicles makes the vehicle front side the front side in the state attached to vehicles, and makes the vehicle back side the back side. Further, the vertical direction of the ornament 10 coincides with the vertical direction of the vehicle. Furthermore, in each figure, arrow F indicates the front side, and arrow U indicates the upper side.

First Embodiment
The ornament 10 of 1st Embodiment is shown to FIG. 1 and FIG. Although not shown, the ornament 10 is fixed to an opening provided at the center of the front grille of the vehicle. At the vehicle rear side of the ornament 10, a millimeter wave radar device (not shown) for detecting an obstacle around the vehicle is provided. This millimeter wave radar device emits radio waves (millimeter waves) toward the front of a vehicle and receives radio waves reflected by an obstacle. That is, the ornament 10 is disposed on the radio wave path.

(Constitution)
As shown in FIG. 1, the ornament 10 of the present embodiment has a horizontally long oval shape in a front view. In this ornament 10, a surface layer 12 having a design surface 20 has light permeability, and an emblem of a manufacturer, a vehicle type, etc. (in FIG. 1, the letter "R" in a round frame) It is displayed.

  FIG. 2 is a side sectional view of the ornament 10. As shown in FIG. 2, the ornament 10 has an arc shape in which the upper and lower centers protrude to the front in a side view, and the surface layer 12, the middle layer 14, and the back layer 16 are arranged in this order from the front.

  The surface layer portion 12 is formed of a transparent resin having high radio wave permeability, and the thickness thereof is about 3 mm to 4 mm. In the surface layer portion 12, the surface on the front side constitutes a design surface 20. The design surface 20 is smooth and glossy. Here, resin which comprises the surface layer part 12 of this embodiment is polycarbonate (PC) resin. The surface layer portion 12 may be formed of an acrylic resin represented by polymethyl methacrylate (PMMA). A recess 22 is formed in the surface on the back side of the surface layer 12 so as to be recessed toward the front side. The depth to the bottom of the recess 22 is about 0.5 mm. In addition, on the bottom of the recess 22 is formed a decorative layer 24 that has been decorated by coloring.

  The middle layer portion 14 is provided in close contact with the surface layer portion 12 and a back layer portion 16 described later. The middle layer portion 14 is formed of a sheet material S made of polycarbonate resin which is the same material as the surface layer portion 12. The thickness of the sheet material S constituting the middle layer portion 14 is about 0.5 mm. When forming the back layer portion 16, the middle layer portion 14 adheres to the back surface of the surface layer portion 12 by receiving pressure from the back side. That is, as shown in FIG. 2, the sheet material S constituting the middle layer portion 14 is in the recess 22.

  The back layer portion 16 is provided on the back side of the middle layer portion 14 and has a plate-like portion 40 having the same shape as the surface layer portion 12 in front view, and a plurality of attachment portions 44 formed on the back side from the outer edge portion of the plate-like portion 40. And. The mounting portion 44 has a columnar portion 44A which is a boss provided on the lower end side of the plate-like portion 40, and a claw portion 44B provided on the upper end side of the plate-like portion 40. The mounting portions 44 have a function of fixing the ornament 10 to the front grille of the vehicle.

  The back layer portion 16 is formed of a non-transparent resin having impact resistance, strength for mounting to a vehicle body, chemical resistance, and the like. Specifically, the resin constituting the back layer portion 16 of the present embodiment is an AES resin (acrylonitrile-ethylene-styrene copolymer). The back layer portion 16 may be formed of an ABS resin. The thickness of the plate-like portion 40 of the back layer portion 16 is about 1.2 mm to 1.7 mm.

(Manufacturing process)
Then, the manufacturing process of the ornament 10 of this embodiment is demonstrated. As shown in FIGS. 3A and 3B, the ornament 10 of the present embodiment is formed by injection molding. First, in the injection molding apparatus 100, the surface layer 12 made of polycarbonate resin is formed by the opposing injection molding die. And coloring is given to the bottom part of crevice 22 formed in the field on the back side of surface part 12.

  Next, as shown in FIG. 3A, the injection molds 110 and 112 are prepared in the injection molding apparatus 100. Here, the sheet material S made of polycarbonate resin is sandwiched between the injection mold 110 and the injection mold 112 to which the surface layer portion 12 is fixed. The sheet material S can be easily molded if it is heated by a heater (not shown) in advance. Then, as shown in FIG. 3B, an AES resin is injected into the inside of the injection mold 112. The sheet S is in close contact with the surface layer 12 by the pressure at the time of injection, whereby the middle layer 14 is formed, and the back layer 16 integrated with the middle layer 14 is formed.

  The ornament 10 formed as described above is taken out of the injection molding apparatus 100, cuts off the sheet material S which is a burr generated at the time of injection molding and protruding from the middle layer portion 14, and is further subjected to annealing (stress relief annealing). It will be. And the ornament 10 is completed.

(Summary of the first embodiment)
The ornament 10 of the first embodiment functions as a radome covering the front of a millimeter wave radar device provided in front of the vehicle. As described above, the ornament 10 is disposed on the radio wave path. Then, from the viewpoint of suppression of the output of the millimeter wave radar device and downsizing of the device, the ornament 10 is required to reduce the amount of attenuation when radio waves are transmitted. On the other hand, the ornament 10 also functions as a decorative member provided with an emblem. Here, although the ornament 10 can reduce the attenuation amount at the time of radio wave transmission by reducing the overall thickness, thinning reduces the three-dimensional effect and can not obtain a high-class feeling.

  Here, the surface layer portion 12 is preferably made of polycarbonate resin having high radio wave transparency among the resins in order to reduce the attenuation amount when radio waves are transmitted and to obtain the transparent design surface 20. However, polycarbonate resins are inferior in impact resistance, strength, chemical resistance and the like to AES resins and ABS resins. Therefore, in the back layer portion 16 having the mounting portion 44 to the vehicle body, the use of AES resin or ABS resin is suitable. On the other hand, AES resin and ABS resin have lower radio wave transmittance than polycarbonate resin.

  As described above, in the ornament 10 according to the present embodiment, the thickness of the plate-like portion 40 serving as an electric wave path is reduced and the plate-like portion 40 is made in the back layer portion 16 made of AES resin. The middle layer portion 14 was formed of a sheet material S made of polycarbonate resin for the reduced thickness. According to this embodiment, while securing the thickness of the ornament 10, it is possible to reduce the proportion of the AES resin with low radio wave permeability. That is, by securing the thickness of the ornament 10, it is possible to suppress a decrease in the designability, and reduce the amount of attenuation when the radio wave passes by reducing the proportion of the AES resin having low radio wave transparency. Can. Further, according to the present embodiment, the strength of the ornament 10 can be secured by the integrated middle layer portion 14 and the back layer portion 16.

  In addition, in order to suppress the attenuation amount of the radio wave when the ornament 10 absorbs water due to rainfall or the like, in the present embodiment, the sheet material S made of a material having a small decrease in radio wave permeability at the time of water absorption may be selected.

  Further, in the present embodiment, in order to avoid reflection and refraction of radio waves at the boundary between the middle layer portion 14 and the back layer portion 16 of different materials, it is desirable that the dielectric constants of the middle layer portion 14 and the back layer portion 16 be close.

Second Embodiment
The ornament 10A of 2nd Embodiment is shown in FIG. Hereinafter, differences from the first embodiment will be described. The same components as in the first embodiment are given the same reference numerals.

  The middle layer portion 14A of the present embodiment is provided in close contact with the surface layer portion 12 and a back layer portion 16A described later. The middle layer portion 14A is made of polycarbonate resin which is the same material as the surface layer portion 12. The middle layer portion 14 is formed by injection molding after the surface layer portion 12 is decorated such as coloring. Therefore, the middle layer portion 14A is in close contact with the concave portion 22 of the surface layer portion 12. The thickness of the middle layer portion 14 is about 1.7 mm to 2.2 mm.

  The back layer portion 16A is provided on the back side of the middle layer portion 14A, and is formed so as to protrude from the outer edge portion of the fixing portion 42 to the back side from a frame shaped fixing portion 42 surrounding the outer edge portion of the surface layer portion 12 and the middle layer portion 14A in front view And a plurality of mounting portions 44. The fixing portion 42 includes a ring-shaped annular portion 42A and a tubular tube portion 42B extending from the outer peripheral portion of the annular portion 42A to the front side. Here, the fixing portion 42 of the present embodiment is formed outside the path of radio waves. That is, the frame-shaped fixed portion 42 is formed so that radio waves pass through the frame. The mounting portion 44 has a columnar portion 44A which is a boss provided on the lower end side of the fixed portion 42, and a claw portion 44B provided on the upper end side of the fixed portion 42.

  The back layer portion 16A is made of a non-transparent resin having impact resistance, strength for mounting on a vehicle, resistance to chemicals, and the like. Specifically, it is formed of an AES resin as in the first embodiment. In addition, since the fixing part 42 is formed out of the path | route of an electromagnetic wave, it can be formed with the thickness which can ensure intensity.

  In the ornament 10A of the present embodiment configured as described above, the surface layer portion 12 and the middle layer portion 14A are formed by an injection molding apparatus. The back layer portion 16A may be previously molded separately from the surface layer portion 12 and the middle layer portion 14A, and then fixed to the back side of the middle layer portion 14A later. As a fixing method, the annular portion 42A of the fixing portion 42 may be attached to the middle layer portion 14A with a double-sided tape, and a claw is provided on the inner peripheral surface of the pipe portion 42B in the fixing portion 42, and this is used as the outer peripheral surface of the middle layer portion 14A. It may be locked. The back layer portion 16A may be injection molded after inserting the integrated surface layer portion 12 and the middle layer portion 14A into an injection molding apparatus.

(Summary of the second embodiment)
As described above, in consideration of the characteristics of each resin material, the surface layer 12 having the design surface 20 preferably uses polycarbonate resin or acrylic resin, and the back layer 16A having the attachment 44 to the vehicle body It is desirable to use AES resin or ABS resin. On the other hand, when resins of different materials and different dielectric constants are superimposed on the radio wave path, radio waves are reflected or refracted at the boundary between the two, and the attenuation when transmitting the radio waves increases. In addition, when resins of different materials are superimposed, the degree of change of the dielectric constant due to water absorption is also different, and there is a possibility that the radio wave permeability may be further reduced during rainfall or the like.

  Based on the above problems, in the ornament 10A of the present embodiment, after the middle layer portion 14A is formed of the same polycarbonate resin as the surface layer portion 12, the decrease in the designability is suppressed by securing the thickness of the ornament 10A. be able to. In addition, the back layer portion 16A having the mounting portion 44 is formed of an AES resin and is formed separately from the surface layer portion 12 and the middle layer portion 14A, thereby securing impact resistance, strength, and chemical resistance. Then, in the present embodiment, by providing the frame-like fixing portion 42 in the back layer portion 16A, the resin having different material and dielectric constant is prevented from overlapping on the radio wave path. As a result, it is possible to suppress the reflection and refraction on the radio wave path to enhance the permeability to the radio wave, and to reduce the attenuation amount when the radio wave is transmitted. Furthermore, compared with the case where the resin from which a material differs differs, degradation of the electromagnetic wave permeability in the time of rain etc. can be controlled.

Third Embodiment
The ornament 10B of 3rd Embodiment is shown in FIG. Hereinafter, differences from the first embodiment will be described. The same components as in the first embodiment are given the same reference numerals.

  The ornament 10B of the third embodiment is different from the first embodiment in that the middle layer portion made of the sheet material S is not provided, and the back layer portion 16B having the attachment portion 44 adjacent to the back side of the surface portion 12 Is formed. The back layer portion 16B is made of a mixed resin of polycarbonate and AES. The back layer portion 16B is formed by injection molding after the surface layer portion 12 is decorated such as coloring. Therefore, the back layer portion 16B is in close contact with the recess 22 of the surface layer portion 12.

  In the present embodiment, the following effects can be obtained by using the back layer portion 16B as a mixed resin of polycarbonate and AES. That is, the dielectric constant can be made closer to the surface layer 12 made of polycarbonate. In addition, in the mounting portion 44, impact resistance, strength, and chemical resistance can be secured. Furthermore, the deterioration of radio wave permeability at the time of water absorption can be suppressed. From the above, according to the ornament 10B of the present embodiment, it is possible to suppress reflection and refraction of radio waves at the boundary between the surface layer 12 and the back layer 16B. Moreover, compared with the case where the resin from which a material differs differs, degradation of the electromagnetic wave permeability in the time of rain etc. can be suppressed.

  Further, as shown in FIG. 5, in the third embodiment, a coating (hard coat) layer 20A made of a material having a lower water absorbency than the surface layer 12 is provided on the design surface 20. Here, the coating layer 20A is preferably a silicon-based or fluorine-based material. When the surface layer 12 is formed of polycarbonate resin, it is necessary to apply a coating to prevent damage and to suppress deterioration by ultraviolet light, but when acrylic coating is applied, it is likely to absorb water and once it absorbs water, it dries Since it takes time to finish, the radio wave transmission performance may be degraded.

  On the other hand, the water absorption of the surface layer portion 12 can be suppressed by providing the coating layer 20A made of a silicon-based or fluorine-based material having a water absorption lower than that of acrylic as in the present embodiment. Further, even if the surface layer portion 12 absorbs water due to long-term inundation, the water can be drained in a short time if placed in a dry state. From the above, according to the coating layer 20A of the present embodiment, it is possible to suppress the deterioration of the radio wave transmission performance at the time of rainfall or the like.

  Also in the first and second embodiments, a coating layer made of a silicon-based or fluorine-based material may be provided.

  The ornaments 10, 10A, and 10B of each embodiment are mounted on the front grille on the front of the vehicle, but the present invention is not limited to this. The front of the millimeter wave radar device provided on the trunk or back door of the vehicle rear ) May be attached.

10 Ornament (radio wave transmission parts for vehicles)
10A ornament (radio wave transmission parts for vehicles)
10B ornament (radio wave transmission parts for vehicles)
12 surface portion 14 middle layer portion 14A middle layer portion 16 back layer portion 16A back layer portion 16B back layer portion 20 design surface 44 attachment portion 42 fixing portion

Claims (5)

A surface portion constituting a design surface,
A back layer portion provided on the back side of the surface layer portion and having a mounting portion for a vehicle body;
An intermediate layer portion which is provided in close contact with the surface layer portion and the back layer portion, is thinner than the surface layer portion and the back layer portion, and is formed of a sheet material of the same material as the surface layer portion;
Radio wave transmission parts for vehicles equipped with. A surface portion constituting a design surface,
A back layer portion provided on the back side of the surface layer portion and having a mounting portion for a vehicle body and a frame-like fixing portion connected to the mounting portion;
An intermediate layer portion of the same material as the surface layer portion, provided in close contact with the surface layer portion and the fixing portion.
Radio wave transmission parts for vehicles equipped with.   The vehicle according to claim 1 or 2, wherein the surface layer portion is formed of a resin higher in radio wave permeability than the back layer portion, and the back layer portion is formed of a resin higher in impact resistance than the surface layer portion. For radio wave transmission parts.   The radio wave transmission component for a vehicle according to any one of claims 1 to 3, wherein the surface layer portion is formed of a resin that transmits light, and a surface on the back side is decorated.   The radio wave transmission component for a vehicle according to any one of claims 1 to 4, wherein the design surface is coated with a material having a lower water absorbability than the surface layer portion.