JP2022155277A - Electromagnetic wave transmission cover and manufacturing method of electromagnetic wave transmission cover - Google Patents

Abstract

To deter a heat generation part from being affected by chipping.SOLUTION: A mm-wave transmission cover 20 has a cover body part 22 disposed in front of a mm-wave radar device 13. A cover base material 23 of the cover body part 22 is formed from a resin material having mm-wave transmission properties. A heater film 25 is formed in a shape corresponding to a shape of a front surface of the cover base material 23 in front of the cover base material 23. The heater film 25 has: a film base material 26 formed from a resin material having mm-wave transmission properties; and a heat generation part 28 formed in a belt shape in a rear of the film base material 26. The cover body part 22 further has a protection part 35 that is positioned in front of the heater film 25 and protects a heat generation part 28 from shock when the shock is applied from the front. The protection part 35 has a resin sheet 36 that has mm-wave transmission properties, is formed in a shape corresponding to a shape of a front surface of the film base material 26, and covers the film base material 26 from the front.SELECTED DRAWING: Figure 3

Description

The present invention relates to an electromagnetic wave permeable cover and a method for manufacturing the electromagnetic wave permeable cover.

In a vehicle equipped with a device for transmitting and receiving electromagnetic waves such as millimeter waves, the device transmits electromagnetic waves to the outside of the vehicle. Electromagnetic waves reflected by objects outside the vehicle, including preceding vehicles, pedestrians, etc., are received by the device. The apparatus recognizes the object from the transmitted and received electromagnetic waves, and detects the distance between the vehicle and the object, the relative speed, and the like.

In the vehicle, an electromagnetic wave transmission cover that transmits electromagnetic waves is arranged in front of the device in the transmission direction of electromagnetic waves.
Here, when ice and snow adhere to the electromagnetic wave transmission cover, the electromagnetic waves are attenuated, and there is a problem that the detection performance of the device is lowered. Therefore, an electromagnetic wave transmission cover with a heater film added has been proposed (see, for example, Patent Document 1).

A heater film is formed by forming a heat-generating portion made of a conductive heat-generating material such as copper on one surface of a film substrate. The heat-generating portion is formed on the film substrate so as to be strip-shaped and wired in a predetermined pattern.

According to the electromagnetic wave transmission cover, the heat generating portion generates heat when energized. Therefore, even if ice and snow adhere to the electromagnetic wave transmitting cover, the heat generated by the heat generating portion melts the ice and snow, thereby suppressing attenuation of electromagnetic waves caused by the adhesion of ice and snow.

Japanese Patent No. 6719506

By the way, since the electromagnetic wave permeable cover is attached to the exterior of the vehicle, there is a problem that it may be damaged (chipped) by being hit by flying stones or the like while the vehicle is running. Then, when this chipping reaches the heat-generating portion, the heat-generating portion is affected. However, the electromagnetic wave transmission cover described in Patent Literature 1 does not consider such problems. Therefore, there is a demand for an electromagnetic wave transmission cover in which the heat generating portion is less susceptible to chipping, and a method for manufacturing the same.

An electromagnetic wave permeable cover that solves the above problems is an electromagnetic wave permeable cover that is applied to a vehicle equipped with a device that transmits and receives electromagnetic waves, and that has a cover main body disposed in front of the device in the transmission direction of the electromagnetic wave. The cover main body portion includes a cover base material molded from a resin material having electromagnetic wave permeability, and a shape corresponding to the shape of the front surface of the cover base material in the transmission direction at the front of the cover base material. a heater film formed into a shape, wherein the heater film is formed in a belt-like shape behind the film base in the transmission direction, and is formed of a resin material having electromagnetic wave permeability; a heat-generating portion that generates heat when energized, and the cover body portion is positioned further forward than the heater film and protects the heat-generating portion from an impact when an impact is applied from the front. a resin sheet having electromagnetic wave permeability and formed into a shape corresponding to the shape of the front surface of the film substrate in the transmission direction to cover the film substrate from the front. It has

According to the above configuration, the protective portion is positioned forward of the heat-generating portion of the heater film in the transmission direction of electromagnetic waves from the device. The resin sheet of the protection part is formed into a shape corresponding to the shape of the front surface of the film substrate in the transmission direction, and covers the film substrate from the front. The protective portion receives the impact when a stepping stone or the like collides with the cover body portion from the front and the impact is applied. The protection section prevents chipping reaching the heat generating section from occurring due to the collision.

In the electromagnetic wave transmitting cover, it is preferable that the film substrate is made of polyethylene terephthalate (PET), and the resin sheet is made of polycarbonate (PC).

According to the above configuration, PC is a resin material with higher impact resistance than PET. On the other hand, the film substrate is made of PET, which has excellent heat resistance and shrinkage resistance (dimensional stability). Therefore, since the resin sheet is made of PC, the impact is received by the resin sheet, and a great effect can be obtained as an effect of suppressing the occurrence of chipping reaching the heat-generating portion.

In the electromagnetic wave transmitting cover, the resin sheet preferably has a thickness of 0.3 mm or more.
As described above, when a resin sheet made of PC and having a thickness of 0.3 mm or more receives an impact due to a collision with a stepping stone or the like, the impact is received only by the resin sheet, and chipping reaches the heat-generating part. can be suppressed from occurring due to the collision.

A method for manufacturing an electromagnetic wave permeable cover for solving the above problems is applied to a vehicle equipped with a device for transmitting and receiving electromagnetic waves, and has a cover main body disposed in front of the device in the transmission direction of the electromagnetic wave. wherein the cover body includes a cover base material formed of a resin material having electromagnetic wave permeability, and a heater film adjacent to the front of the cover base material, wherein the heater film is made of a resin having electromagnetic wave permeability. a film substrate made of a material; and a strip-shaped heat-generating portion formed behind the film substrate in the transmission direction and generating heat when energized, wherein the cover main body portion further comprises a heater film. Manufacture of an electromagnetic wave permeable cover provided with a protective part located in the front and protecting the heat generating part from the impact when an impact is applied from the front, the protective part comprising a resin sheet having electromagnetic wave permeability. wherein the heater film formed into a shape corresponding to the shape of the front surface of the cover base material in the transmission direction is used as an insert member, and the cover base material is insert-molded behind the heater film. and a covering step of covering the film base with the resin sheet from the front by shaping the resin sheet into a shape corresponding to the shape of the front surface of the film base in the transmission direction. and

According to the above method, the cover base forming step and the covering step are performed in manufacturing the electromagnetic wave transmitting cover.
In the cover base forming step, a heater film formed into a shape corresponding to the shape of the front surface of the cover base in the transmission direction of electromagnetic waves from the apparatus is used as an insert member. A cover base material is insert-molded behind the heater film in the transmission direction. An intermediate body is obtained in which the cover base material is adhered to the heater film from behind.

Here, the following method is conceivable as another method for forming an intermediate body in which the cover base material and the heater film are integrated. That is, the heater film and the cover substrate are formed separately. The heater film is heated to soften the film substrate. Vacuum suction is applied to the heater film to adhere it to the front surface of the cover substrate. Then, the heater film is adhered to the cover base material while being deformed (shaped) following the shape of the front surface of the cover base material.

In this method, the film substrate is softened by heat and easily stretched. While the cover base material is positioned behind the heater film in the transmission direction, nothing corresponding to the cover base material is positioned in front of the heater film. Therefore, unevenness having a shape corresponding to the heat generating portion is generated on the front surface of the film substrate in the transmission direction.

On the other hand, in the insert molding, the heater film is arranged as an insert member in the mold, and in this state, the mold is filled with molten resin to mold the cover base material. At this time, the front surface of the film substrate only has a shape corresponding to the molding surface of the mold, and unevenness having a shape corresponding to the heat generating portion is not formed on the front surface.

Then, in the subsequent coating step, the resin sheet is formed into a shape corresponding to the shape of the front surface of the film substrate in the transmission direction. By this shaping, the intermediate film substrate is covered with the resin sheet from the front side to obtain the desired electromagnetic wave transmission cover.

In this electromagnetic wave permeable cover, the protective portion is positioned forward of the heat generating portion of the heater film. The resin sheet of the protection part is formed into a shape corresponding to the shape of the front surface of the film substrate, and covers the film substrate from the front. The protective portion receives the impact when a stepping stone or the like collides with the cover body portion from the front and the impact is applied. The protection section prevents chipping reaching the heat generating section from occurring due to the collision.

A method for manufacturing an electromagnetic wave permeable cover for solving the above problems is applied to a vehicle equipped with a device for transmitting and receiving electromagnetic waves, and has a cover main body disposed in front of the device in the transmission direction of the electromagnetic wave. wherein the cover body includes a cover base material formed of a resin material having electromagnetic wave permeability, and a heater film adjacent to the front of the cover base material, wherein the heater film is made of a resin having electromagnetic wave permeability. a film substrate made of a material; and a strip-shaped heat-generating portion formed behind the film substrate in the transmission direction and generating heat when energized, wherein the cover main body portion further comprises a heater film. Manufacture of an electromagnetic wave permeable cover provided with a protective part located in the front and protecting the heat generating part from the impact when an impact is applied from the front, the protective part comprising a resin sheet having electromagnetic wave permeability. a covering step of forming a cover covering the film base from the front with the resin sheet by attaching the resin sheet of the protective portion to the film base of the heater film; forming the covering body into a shape corresponding to the shape of the front surface of the cover base material in the transmitting direction, using the shaped covering body as an insert member, and placing the cover base material behind the heater film; and a cover base molding step for insert molding.

According to the method described above, the coating step and the cover base material forming step are performed in manufacturing the electromagnetic wave transmitting cover.
In the covering step, the resin sheet of the protective portion is attached to the film substrate of the heater film. As a result, the film base is covered with the resin sheet from the front in the transmission direction of the electromagnetic wave from the device to form a cover.

In the cover base forming step, the cover is formed into a shape corresponding to the shape of the front surface of the cover base in the transmission direction. The shaped covering is used as an insert member, and the cover base material is insert-molded behind the heater film in the transmission direction. An electromagnetic wave transmitting cover is obtained in which the cover base material is attached to the heater film of the cover from the rear side.

In this electromagnetic wave permeable cover, the protective portion is positioned forward of the heat generating portion of the heater film. The resin sheet of the protective portion covers the film substrate from the front. The protective portion receives the impact when a stepping stone or the like collides with the cover body portion from the front and the impact is applied. The protection section prevents chipping reaching the heat generating section from occurring due to the collision.

According to the electromagnetic wave transmitting cover and the manufacturing method of the electromagnetic wave transmitting cover, it is possible to suppress the influence of chipping on the heat generating portion.

FIG. 4 is a partial front view showing the millimeter wave transmitting cover together with a part of the front grill in the first embodiment in which the electromagnetic wave transmitting cover is embodied as a millimeter wave transmitting cover for vehicles. FIG. 4 is a schematic front view of a heat generating portion in the heater film of the first embodiment; FIG. 2 is a partial plan cross-sectional view showing part of the millimeter wave transmission cover of the first embodiment together with part of the millimeter wave radar device; FIG. 4 is a partial plan cross-sectional view showing a form in the middle of manufacturing the millimeter wave transmission cover of the first embodiment; FIG. 6 is a partial plan cross-sectional view similarly showing a form in the middle of manufacturing the millimeter wave transmitting cover of the first embodiment; FIG. 6 is a partial plan cross-sectional view similarly showing a form (heater film) in the middle of manufacturing the millimeter wave transmission cover of the first embodiment; FIG. 6 is a partial plan cross-sectional view similarly showing a form in the middle of manufacturing the millimeter wave transmitting cover of the first embodiment; Similarly, FIG. 6 is a diagram showing a form in the middle of manufacturing the millimeter wave transmitting cover of the first embodiment, and is a partial plan cross-sectional view showing a state before attaching the protective portion to the intermediate body. FIG. 11 is a partial plan cross-sectional view showing a form in the middle of manufacturing the millimeter wave transmission cover of the second embodiment; FIG. 11 is a partial plan cross-sectional view of a millimeter wave transmission cover according to a third embodiment;

(First embodiment)
A first embodiment in which the electromagnetic wave transmission cover is embodied as a vehicle millimeter wave transmission cover will be described below with reference to FIGS. 1 to 8. FIG.

In the description below, the forward direction of the vehicle is defined as the front, and the reverse direction is defined as the rear. Also, in FIGS. 3 to 8, the scales of the parts of the millimeter wave transmission cover are appropriately changed so that the parts can be recognized. This point also applies to FIG. 9 showing the second embodiment and FIG. 10 showing the third embodiment.

As shown in FIGS. 1 and 3, a forward monitoring millimeter wave radar is installed behind the front grille 11 at the center of the front portion of the vehicle 10 in the vehicle width direction, as a device for transmitting and receiving electromagnetic waves. A device 13 is mounted. In FIG. 3, only part of the millimeter wave radar device 13 is illustrated. The millimeter-wave radar device 13 has a function of transmitting millimeter waves in electromagnetic waves toward the front outside the vehicle and receiving the millimeter waves reflected by objects outside the vehicle. Millimeter waves refer to radio waves having a wavelength of 1 mm to 10 mm and a frequency of 30 GHz to 300 GHz.

In the first embodiment, as described above, the millimeter wave radar device 13 transmits millimeter waves toward the front of the vehicle 10 . This is the direction from the rear to the front. The front in the transmission direction of the millimeter wave generally matches the front of the vehicle 10 , and the rear in the same transmission direction generally matches the rear of the vehicle 10 . Therefore, in the following description, the forward direction in the transmission direction of millimeter waves is simply referred to as "front", "front", etc., and the rearward direction in the same transmission direction is simply referred to as "rearward", "rear", etc.

The thickness of the front grille 11 is not uniform, like a general front grille. Moreover, in the front grille 11, a metal plating layer may be formed on the surface of the base material made of resin. The front grille 11 interferes with transmitted or reflected millimeter waves. For this reason, in the front grille 11, a window 12 is opened in front of the millimeter wave radar device 13 in the millimeter wave transmission direction.

The millimeter wave transmission cover 20 of the first embodiment is arranged in the window portion 12 . The millimeter wave transmission cover 20 is arranged in an upright state so that its front surface faces the front of the vehicle 10 and its rear surface faces the rear of the vehicle 10 . A front surface of the millimeter wave transmission cover 20 constitutes a design surface 21 .

A main portion of the millimeter wave transmission cover 20 is configured by a cover body portion 22 . FIG. 3 shows a portion of the cover main body 22 in an enlarged manner. The cover body portion 22 includes a cover base material 23 , a heater film 25 and a protection portion 35 and is positioned in front of the millimeter wave radar device 13 .

The cover base material 23 is formed by resin molding using a resin material having millimeter wave permeability as electromagnetic wave permeability. The resin material used to form the cover base material 23 may be transparent or opaque. Although the cover base material 23 is made of PC (polycarbonate) in the first embodiment, it may be made of another resin material such as ABS (acrylonitrile-butadiene-styrene copolymer).

The heater film 25 is arranged between the cover base material 23 and the protective portion 35 and is positioned in front of and adjacent to the cover base material 23 made of resin. The heater film 25 is formed into a shape corresponding to the shape of the front surface of the cover base material 23 and is in close contact with the front surface. The heater film 25 includes a film substrate 26 , an adhesive layer 27 , a heat generating portion 28 and a resist layer 29 .

The film base material 26 is a portion forming a skeleton portion of the heater film 25 . The film substrate 26 is made of a resin material having millimeter wave permeability and having excellent heat resistance and shrinkage resistance (dimensional stability). In the first embodiment, the film substrate 26 is made of PET (polyethylene terephthalate). Further, in the first embodiment, the film substrate 26 has a thickness of approximately 0.1 mm.

The adhesive layer 27 has a function of adhering the heat generating portion 28 to the film substrate 26 . As the adhesive layer 27, for example, a colorless film-like optical adhesive sheet called OCA (OPTICAL CLEAR ADHESIVE) can be used. The term "transparency" as used herein includes not only colorless transparency but also colored transparency (colored transparency).

The heat generating portion 28 is made of foil made of a conductive heat generating material. The heat-generating portion 28 is formed in a belt-like shape behind the film substrate 26 and generates heat when energized. In the first embodiment, the heating portion 28 is made of copper foil. The heat generating portion 28 has a predetermined wiring pattern, for example, as shown in FIG. It is formed so as to be wired by a wiring pattern including and.

As shown in FIG. 3, the resist layer 29 is made of an insulating material, is formed on the adhesive layer 27, surrounds the heat generating portion 28, and covers the heat generating portion 28. As shown in FIG.
A binder layer 31 is formed between the resist layer 29 and the cover base material 23 . When the cover base material 23 is resin-molded, heat is transferred from the molten resin material and pressure is applied to the binder layer 31, thereby exhibiting adhesive strength and enhancing the adhesion between the cover base material 23 and the resist layer 29. It has the function of enhancing The binder layer 31 is made of a resin material that can be bonded to the cover base material 23, such as PMMA (polymethyl methacrylate), ABS, or the like.

The protective portion 35 includes a resin sheet 36 and an adhesive layer 37 , has a sheet shape, and is disposed forward of the film substrate 26 . The protective portion 35 has a role of protecting the heat-generating portion 28 from the impact when the cover body portion 22 is impacted from the front by flying stones or the like.

The resin sheet 36 is configured by a member separate from the film substrate 26 . The resin sheet 36 is made of a resin material having millimeter wave permeability, like the cover base material 23 . The resin material used to form the resin sheet 36 may be transparent or opaque, like the cover base material 23 . In the first embodiment, the resin sheet 36 is made of PC. The resin sheet 36 preferably has a thickness of 0.3 mm or more from the viewpoint of protecting the heat-generating portion 28 from the impact caused by collisions such as stepping stones. are used. The resin sheet 36 is formed into a shape corresponding to the shape of the front surface of the film substrate 26 .

The adhesive layer 37 is formed by the above OCA. The adhesive layer 37 is located between the resin sheet 36 and the film substrate 26 and adheres the resin sheet 36 to the front surface of the film substrate 26 in close contact.

The millimeter wave transmission cover 20 includes, in addition to the cover main body portion 22, an attachment portion (not shown) for attaching the cover main body portion 22 to the front grill 11, and the like.
Next, the operation of the first embodiment configured as described above will be described together with the manufacturing method of the millimeter wave transmission cover 20. FIG. In addition, effects caused by the action will also be described.

The millimeter wave transmission cover 20 is formed through a heater film forming process, a cover base material forming process, and a coating process.
<Heater film making process>
As shown in FIG. 4, in the heater film forming process, the adhesive layer 27 is formed by attaching the OCA to the rear surface of the film substrate 26 .

The film substrate 26 having the adhesive layer 27 formed thereon and the foil 38 made of a conductive heat-generating material, here copper foil, are pressed toward each other by a roller or the like. The foil 38 is attached to the film substrate 26 with the adhesive layer 27 .

Next, as shown in FIG. 5, the foil 38 is patterned. In the patterning process, photolithography and optical mask processes are performed to remove unnecessary portions of the foil 38 on the adhesive layer 27, thereby forming a band-shaped heat generating portion wired in a predetermined wiring pattern. 28 is a processing method.

As shown in FIG. 6 , a resist layer 29 covering the heat generating portion 28 is formed by applying a solder resist or the like on the adhesive layer 27 and around the heat generating portion 28 .
Thus, the heater film 25 including the film substrate 26, the adhesive layer 27, the heating portion 28 and the resist layer 29 is produced.

<Cover Base Material Forming Process>
In the cover base material forming step, the heater film 25 is shaped so as to have a shape corresponding to (along with) the shape of the front surface of the cover base material 23 . For this shaping, for example, a jig (not shown) having a front surface similar in shape to the front surface of the cover base material 23 is used. The heater film 25 is heated and softened and placed in contact with or close to the jig. The softened heater film 25 is vacuum-sucked toward the jig. Then, the heater film 25 is brought into close contact with the front surface of the jig, so that the heater film 25 is formed into a shape corresponding to the shape of the front surface of the cover base material 23 .

The shaping may be performed with the binder layer 31 formed on the heater film 25 . Depending on the type of binder layer 31, the binder layer 31 may be formed after the shaping.

The binder layer 31 can be formed, for example, by performing powder coating, screen printing, or the like on the rear surface of the heater film 25 (resist layer 29).
As described above, the cover base material 23 is insert-molded using the heater film 25 shaped and formed with the binder layer 31 as an insert member. For this insert molding, a mold 60 having a fixed mold 61 and a movable mold 62 is used as shown in FIG. The movable mold 62 is separated from the fixed mold 61 and the heater film 25 with the binder layer 31 is placed on the fixed mold 61 . When the mold 60 is clamped, a cavity 63 is formed between the heater film 25 with the binder layer 31 and the movable mold 62 . A molten resin material for forming the cover base material 23 , in this case PC, is injected into the cavity 63 to fill the cavity 63 . By curing the molten resin, the cover base material 23 is resin-molded behind the heater film 25 with the binder layer 31 as shown in FIG. As a result, an intermediate body 64 is obtained in which the cover base material 23 is adhered to the heater film 25 via the binder layer 31 .

Here, as another method for forming the intermediate body 64 in which the cover base material 23 and the heater film 25 are integrated, the following method is conceivable. That is, the heater film 25 and the cover base material 23 are formed separately. The heater film 25 is heated to soften the film substrate 26 . The heater film 25 is vacuum-sucked and adhered to the front surface of the cover base material 23 . Then, the heater film 25 is adhered to the cover base material 23 while being deformed (shaped) following the shape of the front surface of the cover base material 23 .

In this method, the film substrate 26 is softened by heat and easily stretched. While the cover base material 23 is positioned behind the heater film 25, nothing equivalent to the cover base material 23 is positioned ahead. As a result, the front surface of the film substrate 26 is uneven in a shape corresponding to the heat-generating portion 28, and the front surface is not smooth.

In contrast, in the first embodiment, as described above, the intermediate body 64 is formed by insert molding. In insert molding, as shown in FIG. 7, when the cavity 63 is filled with the molten resin, the front surface of the film substrate 26 only assumes a shape corresponding to the molding surface of the fixed mold 61. Concavities and convexities having a shape corresponding to the heat generating portion 28 are not formed. The front surface of the film substrate 26 can be made smooth.

<Coating process>
As shown in FIG. 8, in the covering step, the heater film 25 is covered with the protective portion 35 from the front. More specifically, in the covering step, the protective portion 35 is heated by far infrared rays, contact heating, or the like. The protective portion 35 softened by heating is placed in contact with or close to the front surface of the film substrate 26 in the intermediate body 64 .

In this state, the protective portion 35 is vacuum-sucked toward the intermediate body 64 side. Then, the resin sheet 36 is adhered to the front surface of the film substrate 26 via the adhesive layer 37, and shaped into a shape corresponding to (along) the shape of the front surface. The resin sheet 36 shaped in this manner is attached to the front surface of the film substrate 26 with the adhesive layer 37 . The shaping may be performed by pressurizing with compressed air (compressed air molding).

Then, as shown in FIG. 3, the desired millimeter wave transmitting cover 20 is obtained, in which the protective portion 35 having the resin sheet 36 and the intermediate body 64 having the heater film 25 and the cover base material 23 are integrated. .

The millimeter wave transmission cover 20 thus obtained is attached to the front grille 11 at the attachment portion. In this millimeter wave transmission cover 20 , the sheet-like protection portion 35 is positioned forward of the heat generating portion 28 . The resin sheet 36 of the protective portion 35 is formed into a shape corresponding to the shape of the front surface of the film substrate 26 and covers the film substrate 26 from the front. The protection part 35 receives the impact when a flying stone or the like collides with the cover body part 22 from the front and the impact is applied. The protection portion 35 can suppress chipping reaching the heat generating portion 28 due to the collision, and can suppress the heat generating portion 28 from being affected by the chipping.

In particular, in the first embodiment, the film substrate 26 is made of PET, and the resin sheet 36 is made of PC. PC is a resin material with higher impact resistance than PET. Therefore, the impact is received by the resin sheet 36, and a greater effect can be obtained as an effect of suppressing the occurrence of chipping reaching the heat generating portion 28 due to the collision.

Further, in the first embodiment, the resin sheet 36 made of PC has a thickness of about 0.4 mm. Therefore, when a stepping stone or the like collides and impacts the resin sheet 36, the impact is received only by the resin sheet 36, and chipping reaching the heat generating portion 28 can be suppressed.

By the way, when ice and snow adhere to the designed surface 21 of the millimeter wave transmission cover 20, the heat generating portion 28 is energized and generates heat. Part of the heat generated by the heat-generating portion 28 is transferred to the design surface 21 via the adhesive layer 27 , the film substrate 26 and the protective portion 35 . This heat melts the ice and snow adhering to the design surface 21, thereby suppressing the attenuation of millimeter waves due to the ice and snow.

Also, when millimeter waves are transmitted from the millimeter wave radar device 13 shown in FIG. The transmitted millimeter waves are reflected by objects in front of the vehicle, including preceding vehicles and pedestrians, and then transmit through the cover body 22 again and are received by the millimeter wave radar device 13 . The millimeter wave radar device 13 recognizes an object based on the transmitted and received millimeter waves, and detects the distance between the vehicle 10 and the same object, the relative speed and the like.

According to the first embodiment, the following effects are obtained in addition to the above.
- As one form of the heater film, a type in which heater wires are wired on a film substrate is known, unlike the first embodiment. The heater wire is composed of a linear heat-generating portion made of a conductive heat-generating material such as copper, and a covering portion made of a resin material such as urethane resin and covering the heat-generating portion.

In the production of the heater film of the above type, it is difficult to run the heater wire on the film base material, resulting in high cost.
In contrast, in the first embodiment, a foil 38 made of a conductive heat-generating material is adhered to the film substrate 26 with an adhesive layer 27, and the foil 38 is patterned to form a heat-generating material wired in a predetermined wiring pattern. It forms part 28 . Therefore, the heat generating portion 28 can be formed at a lower cost than in the case where the heater wire is wired on the film substrate.

Moreover, the degree of freedom in designing the wiring pattern can be increased as compared with the case of wiring the heater wire.
- The film base material 26 may be formed of a PC film material having a large thickness of about 0.4 mm, unlike the first embodiment.

On the other hand, as one method for efficiently mass-producing electronic devices, there is a method called a roll-to-roll method. When the heater film is mass-produced by this method, the film material is wound into a roll. In making the heater film, the film material is drawn from the roll. Processing such as application of adhesive, adhesion of foil, patterning, etc., is sequentially performed on the pulled out film material. The film material after each of the above processes is wound again into a roll. The thinner the film material, the longer the number of turns of the roll, that is, the length that can be wound per roll.

In this regard, in the first embodiment, the film base material 26 of the heater film 25 is made of a PET film material having a thickness of about 0.1 mm. Therefore, when the heater film 25 is rolled, as described above, the number of windings per roll is increased compared to the case where the film base 26 is formed of a PC film material having a thickness of about 0.4 mm. be able to. Therefore, the production efficiency can be improved, and the manufacturing cost of the heater film 25 and the millimeter wave transmission cover 20 can be reduced.

- Moreover, when the film base material 26 is formed of a PC film material having a large thickness of about 0.4 mm as described above, there is the following concern.
When the foil 38 is adhered to the film substrate 26 by the adhesive layer 27, when photolithography for patterning is performed, the film substrate 26 is greatly deformed and shrunk due to the heat generated by the chemical reaction. In contrast, the foil 38 does not deform and shrink as much as the film substrate 26 . Therefore, there is a possibility that the heat-generating portion 28 is separated from the film substrate 26 .

In this regard, in the first embodiment, the film substrate 26 is formed of a PET sheet material having a thickness of about 0.1 mm. Therefore, deformation and shrinkage of the film substrate 26 can be suppressed during photolithography. It is possible to prevent the exothermic part 28 from peeling off from the film substrate 26 .

- In the first embodiment, the protective portion 35 adjacent to the front of the heater film 25 is in the form of a sheet having a thickness of about 0.4 mm, and the front surface thereof constitutes the design surface 21 . Therefore, the distance from the heat generating portion 28 to the design surface 21 is short, and the heat generated by the heat generating portion 28 is easily transferred to the design surface 21 . Ice and snow adhering to the design surface 21 can be efficiently melted.

(Second embodiment)
Next, a second embodiment in which the electromagnetic wave transmission cover is embodied as a millimeter wave transmission cover for vehicles will be described with reference to FIG.

The millimeter wave transmission cover 40 of the second embodiment has the same configuration as the millimeter wave transmission cover 20 of the first embodiment. Therefore, elements similar to those described in the first embodiment are denoted by the same reference numerals, and overlapping descriptions are omitted.

The second embodiment is slightly different from the first embodiment in terms of manufacturing method. In the second embodiment, when manufacturing the millimeter wave transmission cover 40, the covering step is performed before the cover base forming step is performed.

In the covering step, the resin sheet 36 of the protective portion 35 is adhered to the film substrate 26 of the heater film 25 with the adhesive layer 37 . As a result, a cover 41 in which the film substrate 26 is covered from the front with the resin sheet 36 is formed.

In the cover base forming step, the cover 41 is formed into a shape corresponding to the shape of the front surface of the cover base 23 . That is, the covering 41 is heated and softened, and placed in contact with or close to a jig (not shown) having a shape similar to that of the front surface of the cover base 23 on its front surface. be done. The softened coating 41 is vacuum-sucked toward the jig. Then, the cover 41 is brought into close contact with the front surface of the jig, thereby forming a shape corresponding to the shape of the front surface of the cover base material 23 .

The shaping in this case may be performed in a state where the binder layer 31 is formed on the heater film 25 of the cover 41, as in the first embodiment. Depending on the type of binder layer 31, the binder layer 31 may be formed after the shaping.

The shaped covering 41 is used as an insert member. As indicated by a two-dot chain line in FIG. 9 , the cover base material 23 is insert-molded behind the cover 41 . As a result, the intended millimeter wave transmitting cover 40 is obtained, in which the cover base material 23 is adhered to the heater film 25 of the cover 41 via the binder layer 31 .

Therefore, although the second embodiment is slightly different from the first embodiment in terms of the manufacturing process, it has the same configuration. A suppressing effect is obtained.

(Third embodiment)
Next, a third embodiment in which the electromagnetic wave transmission cover is embodied in a vehicle millimeter wave transmission cover 50 will be described with reference to FIG.

In the third embodiment, a heater film 51 is used instead of the heater film 25 . The film base material 52 of the heater film 51 is made of PC, which is the same resin material as the resin material forming the resin sheet 36, instead of PET.

The film substrate 52 has a thickness greater than that of the film substrate 26 in the second embodiment, for example, the thickness of the film substrate 26 plus the thickness of the resin sheet 36 .

In this way, the film base 52 is made of PC, which is the same resin material as the resin sheet 36 , and the thickness of the film base 52 is greater than the thickness of the film base 26 . Therefore, when the cover main body 22 is hit by a flying stone or the like from the front, the film base 52 receives the shock and suppresses the occurrence of chipping reaching the heat generating portion 28 due to the collision. It has the function to That is, the film base material 52 has a function of protecting the heat-generating part 28 from impact, similarly to the protective part 35 . Therefore, in the third embodiment, the protective portion 35 made of a member separate from the film substrate 52 is not provided.

The heater film 51 includes an adhesive layer 27 , a heating portion 28 and a resist layer 29 in addition to the film substrate 52 . Among the plurality of members constituting the heater film 51 , members different from the film substrate 52 are the same as those in the heater film 25 .

As described above, since the millimeter wave transmission cover 50 has a configuration different from that of the millimeter wave transmission cover 40, the manufacturing process is also different from that of the second embodiment.
In the third embodiment, the cover base forming step is performed without performing the covering step.

In the cover base material forming step, the heater film 51 is formed into a shape corresponding to the shape of the front surface of the cover base material 23 . That is, the heater film 51 is heated and softened, and placed in contact with or close to a jig (not shown) having a shape similar to that of the front surface of the cover base material 23 on its front surface. be. The softened heater film 51 is vacuum-sucked toward the jig. Then, the heater film 51 is brought into close contact with the front surface of the jig, so that the heater film 51 is formed into a shape corresponding to the shape of the front surface of the cover base material 23 .

The shaping in this case may be performed in a state where the binder layer 31 is formed on the heater film 51 as in the second embodiment. Depending on the type of binder layer 31, the binder layer 31 may be formed after shaping.

The shaped heater film 51 is used as an insert member, and the cover base material 23 is insert-molded behind the heater film 51 as in the second embodiment. As a result, the desired millimeter wave transmitting cover 50 is obtained, in which the cover base material 23 is attached to the heater film 51 via the binder layer 31 .

Therefore, although the third embodiment is slightly different from the second embodiment in terms of the manufacturing process, it is possible to obtain the effect of suppressing the chipping of the heat generating portion 28 as in the second embodiment.
In addition, each embodiment can also be implemented as a modified example which changed this as follows. The above embodiments and the following modifications can be combined with each other within a technically consistent range.

- As the film substrate 26 in the first and second embodiments, a material other than PET may be used that is formed of a material that satisfies the following conditions.
Conditions: Must be a resin material that has millimeter wave transmittance and is excellent in heat resistance and shrinkage resistance (dimensional stability).

Applicable resin materials include, for example, polyamide (PA).
- The resin sheet 36 may be made of a material other than PC that satisfies the following conditions.

Condition: Even if chipping occurs due to impact from the front due to a collision such as a stepping stone, it is suppressed from reaching the heat generating part 28.
- The above millimeter wave transmission covers 20, 40, 50 can be embodied in vehicle emblems, ornaments, marks, and the like.

- The electromagnetic wave permeable cover can be applied to any vehicle equipped with a device for transmitting and receiving electromagnetic waves for detecting objects outside the vehicle. In this case, electromagnetic waves transmitted and received by the device include electromagnetic waves such as near-infrared rays in addition to millimeter waves.

A device for transmitting and receiving electromagnetic waves for detecting an object outside the vehicle may be a device for rear monitoring, front side monitoring, or rear side monitoring, in addition to forward monitoring. In this case, the electromagnetic wave transparent cover is arranged in front of the device in the transmission direction of the electromagnetic waves.

- The electromagnetic wave permeable cover can also be applied when a device that transmits and receives electromagnetic waves is mounted on a vehicle other than a vehicle, such as a train, an aircraft, or a ship.

10... vehicle (vehicle)
20, 40, 50 ... millimeter wave transmission cover (electromagnetic wave transmission cover)
DESCRIPTION OF SYMBOLS 22... Cover main-body part 23... Cover base material 25, 51... Heater film 26, 52... Film base material 28... Heat generating part 35... Protective part 36... Resin sheet 41... Covering body

Claims (5)

An electromagnetic wave transmission cover applied to a vehicle equipped with a device for transmitting and receiving electromagnetic waves, and having a cover main body disposed in front of the device in a transmission direction of the electromagnetic wave,
The cover main body includes a cover base formed of a resin material having electromagnetic wave permeability, and a front surface of the cover base formed into a shape corresponding to the shape of the front surface of the cover base in the transmission direction. and a heater film;
The heater film includes a film substrate made of a resin material having electromagnetic wave permeability, and a heat generating portion formed in a belt shape behind the film substrate in the transmission direction and generating heat when energized,
The cover main body further includes a protection portion located in front of the heater film and protecting the heat-generating portion from an impact when an impact is applied from the front,
The protective portion includes a resin sheet that has electromagnetic wave permeability and is formed into a shape corresponding to the shape of the front surface of the film substrate in the transmission direction to cover the film substrate from the front. Electromagnetic transmission cover. 2. The electromagnetic wave permeable cover according to claim 1, wherein the film substrate is made of polyethylene terephthalate (PET), and the resin sheet is made of polycarbonate (PC). 3. The electromagnetic wave transmission cover according to claim 2, wherein said resin sheet has a thickness of 0.3 mm or more. Applied to a vehicle equipped with a device for transmitting and receiving electromagnetic waves, and having a cover main body disposed in front of the device in the transmission direction of the electromagnetic waves,
wherein the cover main body includes a cover base material made of a resin material having electromagnetic wave permeability, and a heater film adjacent to the front side of the cover base material,
The heater film includes a film substrate made of a resin material having electromagnetic wave permeability, and a strip-shaped heat generating portion formed behind the film substrate in the transmission direction and generating heat when energized,
The cover main body further includes a protection portion located in front of the heater film and protecting the heat generating portion from an impact when an impact is applied from the front, wherein the protection portion receives electromagnetic waves. A method for manufacturing an electromagnetic wave transmission cover comprising a transparent resin sheet,
A cover base material forming step of insert-molding the cover base material behind the heater film using the heater film formed in a shape corresponding to the shape of the front surface of the cover base material in the transmission direction as an insert member. When,
forming the resin sheet into a shape corresponding to the shape of the front surface of the film substrate in the transmission direction, thereby covering the film substrate from the front with the resin sheet. Method. Applied to a vehicle equipped with a device for transmitting and receiving electromagnetic waves, and having a cover main body disposed in front of the device in the transmission direction of the electromagnetic waves,
wherein the cover main body includes a cover base material made of a resin material having electromagnetic wave permeability, and a heater film adjacent to the front side of the cover base material,
The heater film includes a film substrate made of a resin material having electromagnetic wave permeability, and a strip-shaped heat generating portion formed behind the film substrate in the transmission direction and generating heat when energized,
The cover main body further includes a protection portion located in front of the heater film and protecting the heat generating portion from an impact when an impact is applied from the front, wherein the protection portion receives electromagnetic waves. A method for manufacturing an electromagnetic wave transmission cover comprising a transparent resin sheet,
a covering step of forming a cover in which the resin sheet of the protective portion is attached to the film base of the heater film to cover the film base with the resin sheet from the front;
The cover is formed into a shape corresponding to the shape of the front surface of the cover base material in the transmission direction, the shaped cover is used as an insert member, and the cover base material is positioned behind the heater film. A method for manufacturing an electromagnetic wave transmission cover, comprising a cover base material molding step of insert molding.

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