Radome for vehicle-mounted radar device and manufacturing method thereof

Abstract

To provide a radome for a vehicle-mounted radar device, which secures water resistance, weather resistance, corrosion resistance, and scratch resistance required when a heater wire is installed, and offers improved manufacturing efficiency, more stable product quality, and enhanced yield.SOLUTION: A radome 1 for a vehicle-mounted radar device is provided, comprising an electromagnetic wave transparent base body 2 having a heater wire 5 wired along an in-plane direction thereof, the base body being formed by stacking and fixing a first base material 3 and a second base material 4. Recessed grooves 31 are formed along fixing surfaces of the first base material 3 and the second base material 4, and the heater wire 5 is fitted in the recessed grooves 31 and wired along the recessed grooves 31.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a radome for an in-vehicle radar device that is provided in front of the in-vehicle radar device, and more particularly to a radome for an in-vehicle radar device that has a snow-melting function and a method for manufacturing the same. [Background technology]

[0002] Conventionally, as a radome for an onboard radar device having a snow-melting function, a radome in which a heater wire is arranged to suppress a decrease in the transmission performance of millimeter waves has been known, and an example of such a radome is the radome disclosed in Patent Document 1.

[0003] This radome is composed of a front substrate and a rear substrate, a groove is formed on the surface of the front substrate, and a heater wire is fitted into this groove and wired so that the entire heater wire is housed in the groove. A transparent film is provided on the surface of the front substrate so as to cover the heater wire housed in the groove and is pressure-bonded to the front substrate, and by covering the heater wire with this transparent film, the weather resistance, corrosion resistance, and scratch resistance of the heater wire are improved (see Figure 6 and paragraphs

[0042] ,

[0044] to

[0046] of Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2020-139860 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, the radome in which the heater wire is fitted into the groove of Patent Document 1 has a transparent protective film attached to the front substrate to ensure the weather resistance, corrosion resistance, and scratch resistance of the heater wire, but since the work process of aligning and attaching the transparent protective film to the front substrate is required for each radome, there is a problem of poor manufacturing efficiency. Furthermore, the work of aligning and attaching the transparent protective film to the front substrate is difficult to perform repeatedly with high precision, which easily causes variations in product quality and reduces yield.

[0006] The present invention has been proposed in view of the above problems, and aims to provide a radome for an on-vehicle radar device, and a manufacturing method thereof, which can ensure the waterproofness, weather resistance, corrosion resistance, and scratch resistance required when the heater wire is installed, while also improving manufacturing efficiency, stabilizing product quality, and improving yield. [Means for solving the problem]

[0007] The radome for an automotive radar device of the present invention is characterized in that it comprises a heater wire wired in the surface direction of an electromagnetic wave transparent base, the base being formed by stacking and fixing a first base material and a second base material, a groove being formed on the side of the first base material that is fixed to the second base material, and the heater wire being fitted into the groove and wired along the groove. According to this, by fixing the first base material to the second base material, the heater wire fitted in the recessed groove is sealed inside the base body composed of the first base material and the second base material, so that it is possible to ensure the waterproofness, weather resistance, corrosion resistance, and scratch resistance required for the heater wire in an installed state. Also, since the radome can be formed without the work of attaching a protective film to cover the heater wire, it is possible to improve manufacturing efficiency, stabilize product quality, and increase yield.

[0008] The radome for an automotive radar device of the present invention is characterized in that a positioning recess for accommodating at least a portion of a wire harness connection portion electrically connected to the heater wire is formed on the fixing surface side of the first substrate. According to this, by positioning the wire harness connection part with the positioning recess, the wire harness connection part can be reliably fixed at a predetermined position inside the base body composed of the first base material and the second base material, thereby improving the stability of the electrical connection between the heater wire and the wire harness connection part. Also, it becomes possible to seal the wire harness connection part inside the base body composed of the first base material and the second base material, thereby ensuring the waterproofness, weather resistance, corrosion resistance, and scratch resistance required for the installed state of the wire harness connection part.

[0009] The radome for an automotive radar device of the present invention is characterized in that the heater wire is fitted into the groove of the first base material and another groove of the second base material and routed along the groove and the other groove, and the second base material made of injection molded material is fixed to the first base material by molding welding. This allows the second base material made of injection-molded material to be fixed to the first base material by molding welding, thereby further improving the waterproofness and weather resistance of the heater wire when it is installed, and further increasing the stability of these properties.In addition, the tolerance for dimensional errors in the width and depth of the grooves in the first base material relative to the diameter of the heater wire is increased, further improving yield.

[0010] The radome for an automotive radar device of the present invention is characterized in that the entire heater wire is embedded in the groove of the first base material, the convex stripes of the second base material are formed to fit into the groove of the first base material, and the second base material made of injection molded material is fixed to the first base material by molding welding. According to this, by fixing the second base material made of injection-molded material to the first base material by molding welding, it is possible to further improve the waterproofness and weather resistance of the heater wire when it is installed, and to further increase the stability of these properties. Also, by fitting the ridges of the second base material made of injection-molded material into the recessed grooves of the first base material, the recessed grooves are closed by the ridges, thereby further improving the waterproofness and weather resistance of the heater wire when it is installed, and also increasing the bonding strength between the first and second base materials by the anchor effect.

[0011] The radome for an automotive radar device of the present invention is characterized in that the heater wire is fitted into the groove of the first substrate and another groove of the second substrate and wired along the groove and the other groove, and the second substrate is bonded to the first substrate by welding or adhesive. This allows positioning by fitting the portion of the heater wire protruding out of the groove in the first substrate into another groove in the second substrate, thereby improving the positioning accuracy of bonding the first substrate and the second substrate together and facilitating the positioning of the first substrate and the second substrate, thereby improving manufacturing efficiency.

[0012] The radome for an automotive radar device of the present invention is characterized in that the entire heater wire is embedded in the groove of the first substrate, the convex stripes of the second substrate are formed to fit into the groove of the first substrate, and the second substrate is bonded to the first substrate by welding or adhesive. This allows positioning by fitting the portion of the groove in the first base material outside the heater wire into the ridge on the second base material, thereby increasing the positioning accuracy when bonding the first and second base materials together and facilitating positioning of the first and second base materials, thereby improving manufacturing efficiency. Also, by fitting the ridge on the second base material into the groove in the first base material, the groove is closed with the ridge, further improving waterproofness and weather resistance when the heater wire is installed and further increasing the bonding strength between the first and second base materials.

[0013] The radome for an on-vehicle radar device of the present invention is characterized in that either the first base material or the second base material is formed of a foamed resin. According to this, the insulating properties of the foamed resin make it possible to significantly reduce the power consumption of the heater that heats the radome, and also to suppress temperature unevenness in the radome, allowing the radome to be heated more uniformly, thereby enabling more uniform snow melting in the electromagnetic wave irradiation area. Furthermore, the dielectric loss tangent and real part of the non-dielectric constant of the foamed resin are closer to those of air than those of non-foamed solid synthetic resin, thereby reducing the attenuation of electromagnetic waves such as millimeter waves and achieving higher electromagnetic wave transmission performance.

[0014] The radome for an on-vehicle radar device of the present invention is characterized in that both the first base material and the second base material arranged on the viewing side are made of foamed resin. According to this, the heat insulating properties of the foam resins of both the first and second base materials enable a further significant reduction in the power consumption of the heater that heats the radome, and further suppresses temperature unevenness in the radome, allowing the radome to be heated more uniformly. Furthermore, electromagnetic wave attenuation is reduced, resulting in even higher electromagnetic wave transmission performance. Furthermore, in a configuration in which a non-transparent coating layer such as a colored coating layer is provided on the outer surface of the first base material located on the viewing side, for example, it is possible to reliably prevent a situation in which a local area of ​​the radome becomes significantly hot due to heater heating, causing the coating layer to deteriorate.

[0015] The radome for an automotive radar device of the present invention is characterized in that the first substrate placed on the viewing side is formed of a foamed resin, and the second substrate placed behind the first substrate is formed of a non-foamed synthetic resin. This makes it possible to reliably prevent a situation in which a localized area of ​​the radome becomes extremely hot due to heater heating, and the paint layer deteriorates, for example, when a non-transparent paint layer such as a colored paint layer is provided on the outer surface of the first base material located on the viewing side. Also, by forming the second base material located on the rear side from a non-foaming synthetic resin, the radome can be applied to vehicle-mounted components that require higher heat resistance inside the vehicle.

[0016] The radome for an automotive radar device of the present invention is characterized in that the first substrate placed on the viewing side is made of a non-foaming synthetic resin, and the second substrate placed behind the first substrate is made of a foamed resin. This ensures that snow and ice adhering to the viewing side of the radome can be melted reliably. Also, by using a non-foaming solid synthetic resin that has excellent waterproofness and durability for the first base material placed on the viewing side, the waterproofness of the radome can be improved and maintained for a long period of time.

[0017] The method for manufacturing a radome for an on-vehicle radar device of the present invention is a method for manufacturing a radome for an on-vehicle radar device of the present invention, characterized in that it comprises: a first step of positioning the first base material, the heater wire, and the wire harness connection portion inside a mold in a state in which a heater wire is fitted into the recessed groove of the first base material and fixed thereto, and at least a part of a wire harness connection portion is accommodated in the positioning recessed portion of the first base material and an end of the heater wire is in contact with a connection terminal of the wire harness connection portion; and a second step of injection molding by pouring molten resin into the mold, forming a second base material with the molten resin, fitting the heater wire into another recessed groove of the second base material, and molding and welding the second base material to the first base material. This molding and welding of the injection-molded second base material to the first base material further improves waterproofness and weather resistance when the heater wire is installed, and further enhances the stability of these properties. Furthermore, fitting the heater wire into a separate groove in the second base material widens the tolerance for dimensional errors in the width and depth of the groove in the first base material relative to the heater wire diameter, further improving yield. Furthermore, positioning the wire harness connection portion with the positioning recess securely fixes the wire harness connection portion in a predetermined position within the base body formed by the first and second base materials, thereby improving the stability of the electrical connection between the heater wire and the wire harness connection portion. Furthermore, it becomes possible to seal the wire harness connection portion within the base body formed by the first and second base materials, ensuring the waterproofness, weather resistance, corrosion resistance, and scratch resistance required for the wire harness connection portion when installed.

[0018] The method for manufacturing a radome for an on-vehicle radar device of the present invention is a method for manufacturing a radome for an on-vehicle radar device of the present invention, characterized in that it comprises a first step of positioning the first substrate, the heater wire, and the wire harness connection portion inside a mold in a state in which a heater wire is fitted into the recessed groove of the first substrate and fixed thereto, and at least a part of a wire harness connection portion is accommodated in the positioning recessed portion of the first substrate, and an end of the heater wire is in contact with a connection terminal of the wire harness connection portion; and a second step of injection molding by pouring molten resin into the mold, forming a second substrate with the molten resin, fitting the convex stripes of the second substrate into the recessed groove of the first substrate, and molding and welding the second substrate to the first substrate. According to this, by molding and welding the injection-molded second base material to the first base material, waterproofness and weather resistance can be further improved and their stability can be further enhanced when the heater wire is installed. Furthermore, by fitting the ridges of the second base material into the recessed grooves of the first base material, the recessed grooves can be blocked by the ridges, thereby further improving waterproofness and weather resistance when the heater wire is installed, and further increasing the bonding strength between the first base material and the second base material. Furthermore, by positioning the wire harness connection part using the positioning recess, the wire harness connection part can be reliably fixed in a predetermined position within the base body formed by the first base material and the second base material, thereby improving the stability of the electrical connection between the heater wire and the wire harness connection part. Furthermore, it is possible to seal the wire harness connection part within the base body formed by the first base material and the second base material, thereby ensuring the waterproofness, weather resistance, corrosion resistance, and scratch resistance required when the wire harness connection part is installed.

[0019] The method for manufacturing a radome for an on-vehicle radar device of the present invention is a method for manufacturing a radome for an on-vehicle radar device of the present invention, in which at least one of the first substrate and the second substrate is formed of a transparent substrate or a light-transmitting substrate, and is characterized by comprising a step of imaging the base from the side of the first substrate or the second substrate, which is a transparent substrate or a light-transmitting substrate, comparing the captured image with a reference image to identify an improper base having an improper heater wire wiring state or an improper heater wire connection state, and removing the improper base. This makes it possible to recognize the internal state by utilizing the transparent or light-transmitting substrate, and to reliably remove inappropriate substrates having inappropriate heater wire wiring or connection states.Furthermore, it is possible to automatically remove inappropriate substrates having inappropriate heater wire wiring or connection states, thereby making it possible to improve the efficiency of the manufacturing process.

[0020] The method for manufacturing a radome for an on-vehicle radar device of the present invention is a method for manufacturing a radome for an on-vehicle radar device of the present invention, in which at least one of the first substrate and the second substrate is formed of a transparent substrate or a light-transmitting substrate, and is characterized by comprising a step of visually inspecting the substrate from the side of the first substrate or the second substrate, which is a transparent substrate or a light-transmitting substrate, and identifying and removing an inappropriate substrate having an inappropriate heater wire wiring state or an inappropriate heater wire connection state. This makes it possible to recognize the internal state by utilizing the transparent or light-transmitting substrate, and to reliably remove inappropriate substrates having inappropriate heater wire wiring or connection states.

[0021] The method for manufacturing a radome for an automotive radar device of the present invention is characterized in that the first substrate placed on the viewing side is a non-transparent substrate, and the second substrate placed on the side opposite to the viewing side is a transparent substrate or a translucent substrate. This makes it possible to ensure that radomes such as bumper covers, whose interiors are normally not visible, can be inspected using a transparent or translucent substrate, while eliminating the need for a separate painting process on the visible side, thereby streamlining the manufacturing process. [Effects of the Invention]

[0022] The radome for an on-vehicle radar device of the present invention can ensure the waterproofness, weather resistance, corrosion resistance, and scratch resistance required when the heater wire is installed, and can also improve manufacturing efficiency, stabilize product quality, and increase yield. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a front view of a radome for an on-vehicle radar device according to a first embodiment of the present invention; [Figure 2] Enlarged cross-sectional view of Figure 1 taken along line AA. [Figure 3] 5(a) to 5(d) are process explanatory diagrams illustrating a manufacturing process of the radome for the on-vehicle radar device according to the first embodiment. [Figure 4]FIG. 2 is an explanatory diagram showing a state in which a first base material, a heater wire, and a wire harness connection portion in the radome for an on-vehicle radar device according to the first embodiment are arranged inside a mold. [Figure 5] 3 is an enlarged cross-sectional view corresponding to FIG. 2 of a radome for an on-vehicle radar device according to a second embodiment of the present invention. [Figure 6] 6(a) to 6(d) are process explanatory diagrams illustrating a manufacturing process of the radome for an on-vehicle radar device according to the second embodiment. [Figure 7] 10 is an enlarged cross-sectional view corresponding to FIG. 2 of a radome for an on-vehicle radar device according to a third embodiment of the present invention. [Figure 8] 10 is an enlarged cross-sectional view corresponding to FIG. 2 of a radome for an on-vehicle radar device according to a fourth embodiment of the present invention. [Figure 9] 1 is a schematic explanatory diagram showing the configuration of an inspection system for a radome for an on-vehicle radar device according to the present invention; [Figure 10] FIG. 2 is a front view showing the radome for the vehicle-mounted radar device of the first embodiment in which a defective portion has occurred. [Figure 11] 3 is an enlarged cross-sectional view corresponding to FIG. 2 of a modified example of the radome for the on-vehicle radar device of the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0024] [Radome for an on-vehicle radar device according to the first embodiment] A radome 1 for an on-vehicle radar device according to a first embodiment of the present invention is used, for example, as a bumper cover attached to the bumper of a vehicle, and includes an electromagnetic wave-transmitting base 2 as shown in Figures 1 and 2. The base 2 is composed of a first base material 3 disposed on the viewing side and a second base material 4 disposed behind the first base material 3, and the first base material 3 and the second base material 4 are laminated and fixed together. The first base material 3 and the second base material 4 are each formed of an insulating, electromagnetic wave-transmitting synthetic resin.

[0025] The first substrate 3 and the second substrate 4 can be made of different or the same synthetic resin, and it is preferable from the viewpoint of improving the electromagnetic wave transmission performance to form the first substrate 3 and the second substrate 4 from materials whose refractive indexes n defined based on the complex dielectric constant match each other, or whose refractive indexes n are approximately the same or close to each other. As for the numerical range of close refractive indexes of the first substrate 3 and the second substrate 4, it is preferable that the difference in refractive index between the first substrate 3 and the second substrate 4 is within a range of 0 to 10%.

[0026] Here, the refractive index n is a quantity defined by the real part of the relative dielectric constant εr' and the imaginary part of the relative dielectric constant εr" as in Equation 1. From the perspective of transparency, it is preferable that the magnitude of the dielectric loss tangent tanδ, defined by Equation 2 from the ratio of the imaginary part to the real part at the applicable frequency, be 0.1 or less. It is also preferable that the magnitude of the real part of the relative dielectric constant be 3 or less. By keeping the magnitudes of the dielectric loss tangent and the real part of the relative dielectric constant at these values ​​or less, it is possible to ensure the reduction of the reflectivity and internal loss required for the radome.

[0027]

number

[0028]

number

[0029] Any suitable synthetic resin can be used within the scope of the present invention for the synthetic resin of the first substrate 3 and the synthetic resin of the second substrate 4. For example, acrylic resins such as polymethyl methacrylate (PMMA), polycarbonate (PC), acrylonitrile-butadiene-styrene copolymer (ABS), acrylonitrile-styrene-acrylate copolymer (ASA), acrylonitrile-ethylenepropyl rubber-styrene copolymer (AES), polypropylene (PP), etc. can be used alone or in combination, and additives may be added. Foams may also be used for these synthetic resins.

[0030] When foamed resin is used as the synthetic resin, it is preferable to form the first substrate 3 placed on the viewing side from foamed resin and the second substrate 4 placed behind the first substrate 3 from a non-foamed solid synthetic resin.It is also preferable to form the first substrate 3 placed on the viewing side from a non-foamed solid synthetic resin and the second substrate 4 placed behind the first substrate 3 from foamed resin.It is also preferable to form both the first substrate 3 and the second substrate 4 placed on the viewing side from foamed resin.

[0031] By forming both or either one of the first base material 3 and the second base material 4 from foamed resin, the heat insulating properties of the foamed resin can significantly reduce the power consumption of the heater that heats the radome 1, and also suppress temperature variations in the radome 1, allowing the radome 1 to be heated more uniformly, resulting in more uniform snow melting in the electromagnetic wave irradiation area R. Furthermore, the dielectric loss tangent and real part of the non-dielectric constant of the foamed resin are closer to those of air than those of non-foamed solid synthetic resin, thereby reducing the attenuation of electromagnetic waves such as millimeter waves and achieving higher electromagnetic wave transmission performance.

[0032] Furthermore, in a configuration in which a non-translucent coating layer 7 such as a colored coating layer is provided on the outer surface of the first substrate 3, etc., described below, by forming the first substrate 3 arranged on the viewing side, or both the first substrate 3 and the second substrate 4, etc., from foam resin, it is possible to more reliably prevent a situation in which a local area of ​​the radome 1 becomes significantly hot due to heater heating, thereby deteriorating the coating layer 7. Furthermore, by forming the first substrate 3 arranged on the viewing side from foam resin and the second substrate 4 arranged on the rear side from non-foaming synthetic resin, it is possible to apply the radome to vehicle-mounted components inside the vehicle that require higher heat resistance. Furthermore, in a configuration in which the first substrate 3 arranged on the viewing side is formed from non-foaming solid synthetic resin and the second substrate 4 arranged on the rear side of the first substrate 3 is formed from foam resin, the absence of insulating foam resin on the viewing side of the radome 1 reliably melts snow and ice adhering to the viewing side of the radome 1, and also improves the waterproofness of the radome 1 and enables the waterproofness of the radome 1 to be maintained for a long period of time.

[0033] Furthermore, with regard to the thicknesses of the first substrate 3 and the second substrate 4 in the electromagnetic wave transmission direction, the ratio of the thickness of the first substrate 3 to the thickness of the second substrate 4, the thickness of the first substrate 3, the thickness of the second substrate 4, and the total thickness of the base 2 composed of the first substrate 3 and the second substrate 4 are appropriate within a range that can ensure the required electromagnetic wave transmission as a radome 1 for an automotive radar device.

[0034] In the radome 1 for an on-vehicle radar device, a heater wire 5 is wired in the surface direction of an electromagnetically transparent substrate 2. Any appropriate conductive material can be used for the heater wire 3 within the spirit and scope of the present invention, and preferable examples include copper, silver, silver-plated copper, copper-silver alloy, copper-nickel alloy, nickel-chromium alloy, iron-chromium alloy, transparent conductive film such as ITO film, and carbon fiber. Furthermore, the heater wire can be in any form, and wire rod, conductive ink, conductive filler, etc. can be used.

[0035] The heater wire 5 in the illustrated example is formed as a continuous wire that meanders and folds back along the direction in which the plate-like base 2 expands, and the straight portions of the heater wire 5 are arranged side by side at intervals along the surface direction of the base 2 in and outside the electromagnetic wave irradiation region R of the base 2 by the on-board radar device, and the directions of current flowing in the straight portions of adjacent heater wires 5 are set to be approximately anti-parallel or anti-parallel to each other. Here, in the case of an on-board radar structure in which the straight portions of the heater wire 5 are arranged side by side so as to extend approximately perpendicular or perpendicular to the polarization plane of the linearly polarized electromagnetic waves irradiated by the on-board radar device, it is preferable to set the surface occupancy rate of the straight portions of the heater wire 5 in the electromagnetic wave irradiation region R to be 1% or more and 24% or less.

[0036] The heater wire 5 is embedded between the first substrate 3 and the second substrate 4, and is sandwiched between the first substrate 3 and the second substrate 4, and is disposed within and sealed in the base 2 formed of the first substrate 3 and the second substrate 4. In this embodiment, a recessed groove 31 is formed on the surface of the first substrate 3 that is fixed to the second substrate 4, and another recessed groove 41 is formed on the surface of the second substrate 4 that is fixed to the first substrate 3 so as to face the recessed groove 31. The heater wire 5 is fitted into the recessed groove 31 of the first substrate 3 and the other recessed groove 41 of the second substrate 4, and is routed along the recessed groove 31 and the other recessed groove 41 (see FIGS. 2 to 4).

[0037] Furthermore, a positioning recess 32 is formed on the fixing surface side of the first base material 3 so as to be continuous with the recessed groove 31, and the positioning recess 32 accommodates at least a part of a wire harness connection part 6 electrically connected to the heater wire 5. A connection terminal 61 of the wire harness connection part 6 and an end part 51 of the heater wire 5 are overlapped and electrically connected at a position corresponding to the recessed groove 31, for example, so that the connection terminal 61 of the wire harness connection part faces the second base material 4.

[0038] The second base material 4 in this embodiment is made of an injection-molded material that is injection-molded so as to overlap the first base material 3, and the second base material 4 of the injection-molded material is fixed to the first base material 3 by molding welding. A heater wire 5 is embedded and sealed inside the second base material 4 of the injection-molded material and the first base material 3, and a wire harness connection portion 6 is also embedded and sealed inside. An electric cable 62 extending from the wire harness connection portion 6 is led out from the base body 2 composed of the first base material 3 and the second base material 4.

[0039] When manufacturing the radome 1 for an automotive radar device of the first embodiment, the first base material 3 is formed so as to have the recessed grooves 31 and the positioning recesses 32, as shown in Fig. 3(a). In forming the first base material 3, for example, the recessed grooves 31 and the positioning recesses 32 may be formed simultaneously with the formation of the overall shape by injection molding using a mold having protrusions corresponding to the recessed grooves 31 and the positioning recesses 32, or the recessed grooves 31 and the positioning recesses 32 may be formed by removing some members by cutting or the like after the overall shape is formed.

[0040] 3(b), the heater wire 5 is fitted into the groove 31 of the first base material 3 and fixed thereto. The heater wire 5 is preferably fixed to the groove 31 by vibration welding, in which pressure is applied to the heater wire 5 at the location of the groove 31 of the first base material 3 while applying vibration to the heater wire 5. However, heat welding, in which pressure is applied to the heater wire 5 at the location of the groove 31 while heating the heater wire 5, or adhesion with an adhesive can also be used. The heater wire 5 in this embodiment is fitted into the groove 31 so that a portion of it protrudes outside the groove 31 and fixed thereto.

[0041] 3(c) and 4, at least a part of the wire harness connecting portion 6 is accommodated in the positioning recess 32 of the first base material 3, and the end 51 of the heater wire 5 and the connection terminal 61 of the wire harness connecting portion 6 are brought into contact with each other. In this state, the first base material 3, the heater wire 5, and the wire harness connecting portion 6 are placed inside a mold 10 made of a split mold. The electric cable 62 of the wire harness connecting portion 6 is led out of the mold 10 from a lead-out port 12 formed in a part of the mold 10.

[0042] In this case, it is preferable to fix the wire harness connection portion 6 to the positioning recess 32 in which it is accommodated by, for example, vibration welding in which pressure is applied to the wire harness connection portion 6 at the positioning recess 32 of the first base material 3 while applying vibration to the wire harness connection portion 6, or by bonding with an adhesive. In order to more reliably establish electrical connection between the end 51 of the heater wire 5 and the connection terminal 61 of the wire harness connection portion 6, for example, by connection by twisting, connection by soldering, connection by wire bonding, or by crimping using a separate metal connection member, the end 51 and the connection terminal 61 may be brought into contact with each other so that electrical connection is ensured in advance before the second base material 4 is formed. However, from the viewpoint of efficiency of the manufacturing process, the end 51 and the connection terminal 61 may be simply placed one on top of the other and brought into contact with each other, and the electrical connection may be ensured by pressing the second base material 4 that is injection-molded, as described below.

[0043] Thereafter, as shown in FIGS. 3(d) and 4, molten resin MR is poured into the mold 10 through the injection port 11 of the mold 10 to perform injection molding, and the second base material 4 is formed from the molten resin MR. The second base material 4 is formed so as to cover the portion of the heater wire 5 that protrudes outside the groove 31, and the portion of the heater wire 5 that protrudes outside the groove 31 is molded and fixed to the second base material 4 by insert molding, so that the heater wire 5 or a part of it is fitted in another groove 41 of the second base material 4. In addition, the interface where the second base material 4 is laminated to the first base material 3 by injection molding is mold-welded. After the second base material 4 is formed, the mold 10 is demolded to obtain the radome 1 for an automotive radar device of the first embodiment.

[0044] According to the first embodiment, the heater wire 5 fitted in the recessed groove 31 is sealed inside the base body 2 formed by the first base material 3 and the second base material 4 by fixing the first base material 3 to the second base material 4, thereby ensuring waterproofness, weather resistance, corrosion resistance, and scratch resistance required for the installed state of the heater wire 5. Furthermore, since the radome 1 can be formed without performing the work of attaching a protective film to cover the heater wire 5, it is possible to improve manufacturing efficiency, stabilize product quality, and increase yield.

[0045] Furthermore, by positioning the wire harness connection part 6 with the positioning recess 32, the wire harness connection part 6 can be reliably fixed at a predetermined position inside the base 2 constituted by the first base material 3 and the second base material 4, thereby improving the stability of the electrical connection between the heater wire 5 and the wire harness connection part 6. Furthermore, it becomes possible to seal the wire harness connection part 6 inside the base 2 constituted by the first base material 3 and the second base material 4, thereby ensuring the waterproofness, weather resistance, corrosion resistance, and scratch resistance required for the wire harness connection part 6 in its installed state.

[0046] Furthermore, by fixing the second base material 4 made of an injection-molded material to the first base material 3 by molding welding, the waterproofness and weather resistance of the heater wire 5 in an installed state can be further improved, and these stability can be further enhanced. Furthermore, by fitting the heater wire 5 into the recessed groove 31 of the first base material 3 and another recessed groove 41 of the second base material 4 and wiring it along the recessed groove 31 and another recessed groove 41, the allowable range of dimensional errors in the width and depth of the recessed groove 31 of the first base material 3 relative to the diameter of the heater wire 5 can be expanded, and the yield can be further improved.

[0047] [Radome for an automotive radar device according to the second embodiment] 5, in the radome 1a for an on-vehicle radar device according to the second embodiment of the present invention, the entire heater wire 5 is embedded in the recessed groove 31a of the first base material 3a, and the ridges 42a of the second base material 4a are formed to fit into the recessed groove 31a of the first base material 3a, and the ridges 42a are formed to abut against and fix to the heater wire 5. That is, in place of the separate recessed groove 41 in the first embodiment, the second base material 4a has ridges 42a formed at locations corresponding to the separate recessed grooves 41, and the heater wire 5 is routed along the recessed grooves 31a and the ridges 42a.

[0048] The second base material 4a in the second embodiment is also made of an injection-molded material that is injection-molded so as to overlap the first base material 3a, and the second base material 4a made of the injection-molded material is fixed to the first base material 3a by molding welding. A heater wire 5 is embedded and sealed inside the second base material 4a made of the injection-molded material and the first base material 3a, and a wire harness connection portion 6 is embedded and sealed inside. The other configurations are the same as those in the first embodiment.

[0049] When manufacturing the radome 1 for an automotive radar device of the second embodiment, the first base material 3a is formed so as to have the recessed groove 31a and the positioning recess 32 in the same procedure as that for forming the first base material 3 of the first embodiment (see FIG. 6(a)). Then, as shown in FIG. 6(b), the heater wire 5 is fitted into the recessed groove 31a of the first base material 3a and fixed thereto, and the entire heater wire 5 is embedded in the recessed groove 31a of the first base material 3a. The heater wire 5 is fixed to the recessed groove 31a in the same procedure as that for fixing the heater wire 5 to the recessed groove 31 in the first embodiment.

[0050] Furthermore, at least a portion of the wire harness connecting portion 6 is accommodated in the positioning recess 32 of the first base material 3a, and the end 51 of the heater wire 5 and the connection terminal 61 of the wire harness connecting portion 6 are brought into contact with each other. In this state, the first base material 3a, the heater wire 5, and the wire harness connecting portion 6 are placed inside a mold 10 that is a split mold, as in the first embodiment. The electric cable 62 of the wire harness connecting portion 6 is led out of the mold 10 through an outlet 12 formed in a part of the mold 10 (see FIGS. 6(c) and 4). In the second embodiment as well, it is preferable that the wire harness connecting portion 6 is fixed to the positioning recess 32 in which it is accommodated. The end 51 of the heater wire 5 and the connection terminal 61 of the wire harness connecting portion 6 may be brought into contact with each other in advance so that an electrical connection is ensured before the second base material 4a is formed, or they may simply be placed in contact with each other so that an electrical connection is ensured by pressing the second base material 4a that is injection molded.

[0051] Thereafter, molten resin MR is poured into the mold 10 through the injection port 11 of the mold 10 to perform injection molding, and the second base material 4a is formed from the molten resin MR (see FIG. 6(d) and FIG. 4). The molten resin MR flows into the recessed grooves 31a and into contact with the heater wire 5, and the second base material 4a is formed so that the ridges 42a fit into the recessed grooves 31a of the first base material 3a, and the heater wire 5 is insert-molded to be molded and fixed to the recessed grooves 31a and the ridges 42a. Furthermore, the interface where the second base material 4a is laminated to the first base material 3a by injection molding is mold-welded. After the second base material 4a is formed, the mold 10 is demolded to obtain the radome 1a for an automotive radar device of the second embodiment.

[0052] According to the second embodiment, by fixing the second base material 4a made of injection-molded material to the first base material 3a by molding welding, it is possible to further improve waterproofness and weather resistance when the heater wire 5 is installed, and to further increase the stability of these properties. Also, by fitting the ridges 42a of the second base material 4a made of injection-molded material into the recessed grooves 31a of the first base material 3a, the recessed grooves 31a are closed by the ridges 42a, thereby further improving waterproofness and weather resistance when the heater wire 5 is installed, and further increasing the bonding strength between the first base material 3a and the second base material 4a due to the anchor effect. In addition, it is possible to obtain corresponding effects from the configuration corresponding to the first embodiment.

[0053] [Radome for an on-vehicle radar device according to the third embodiment] The radome 1b for an on-vehicle radar device of the third embodiment according to the present invention has a configuration in which a second base material 4b is bonded to the first base material 3 by welding or adhesive (see FIG. 7), instead of the configuration in the first embodiment in which the second base material 4 is injection molded so as to overlap the first base material 3, and the heater wire 5 is fitted into a groove 31 in the first base material 3 and another groove 41b in the second base material 4b, and is routed along the groove 31 and another groove 41b. The other configurations are the same as those of the first embodiment.

[0054] According to the third embodiment, the heater wire 5 protruding from the groove 31 of the first base material 3 can be positioned by fitting it into another groove 41b of the second base material 4b, which increases the positioning accuracy of bonding the first base material 3 and the second base material 4b and also makes it easier to position the first base material 3 and the second base material 4b, thereby improving manufacturing efficiency. In addition, the configuration corresponding to the first embodiment can provide corresponding effects.

[0055] [Radome for an on-vehicle radar device according to the fourth embodiment] The radome 1c for an on-vehicle radar device of the fourth embodiment according to the present invention has a configuration in which a second base material 4c is bonded to the first base material 3a by welding or adhesive, instead of the configuration in the second embodiment in which the second base material 4a is injection molded so as to overlap the first base material 3a (see FIG. 8). The heater wire 5 is entirely embedded in the recessed groove 31a of the first base material 3a, and the protruding strips 42c of the second base material 4c are fitted into the recessed groove 31a of the first base material 3a. The other configurations are the same as those of the second embodiment.

[0056] According to the fourth embodiment, positioning can be achieved by fitting the portion of the recessed groove 31a of the first base material 3a outside the heater wire 5 into the ridge 42c of the second base material 4c, thereby improving the positioning accuracy of the bonding of the first base material 3a and the second base material 4c and facilitating the positioning of the first base material 3a and the second base material 4c, thereby improving manufacturing efficiency. Furthermore, by fitting the ridge 42c of the second base material 4c into the recessed groove 31a of the first base material 3a, the recessed groove 31a is closed by the ridge 42c, thereby further improving waterproofness and weather resistance when the heater wire 5 is installed and further increasing the bonding strength between the first base material 3a and the second base material 4c. Other effects corresponding to those of the second embodiment can be achieved through a configuration corresponding to that of the second embodiment.

[0057] [Scope of the invention disclosed herein] The inventions disclosed in this specification include, in addition to the individual inventions and embodiments listed as inventions, those specified by modifying partial contents of these with other contents disclosed in this specification, those specified by adding other contents disclosed in this specification to these contents, or those specified by deleting partial contents of these to the extent that partial effects are obtained and creating a generic concept. The inventions disclosed in this specification also include the following modifications and additions.

[0058] For example, in the above embodiment, an example of the radome 1 for an on-vehicle radar device in the form of a bumper cover has been shown, but the radome for an on-vehicle radar device of the present invention can be any type of vehicle mounting component, and is suitable as, for example, an emblem-shaped radome, etc. Furthermore, the heater wire 5 can be wired in the surface direction of the electromagnetic wave-transmitting base 2 in any suitable manner, such as by meandering wiring or by concentric wiring.

[0059] Furthermore, the first and second substrates in the radome for an automotive radar device of the present invention may each be a transparent substrate, a light-transmitting substrate, or a non-light-transmitting substrate. When the first substrate, the second substrate, or both the first and second substrates are transparent or light-transmitting substrates that allow the bonding surface between the first and second substrates to be visible from the outer surface, it is preferable to inspect the wiring state of the heater wire using an inspection system such as the one shown in Figure 9 as part of the manufacturing process.

[0060] The inspection system of Figure 9 is used when inspecting a radome 1 for an automotive radar device of the first embodiment, in which the second substrate 4 on the side opposite to the viewing side, or both the first substrate 3 and the second substrate 4, are transparent or translucent substrates that allow the bonding surface between the first substrate 3 and the second substrate 4 to be visible from the outer surface, and the radome 1 for an automotive radar device, which is transported sequentially at intervals on a conveyor, for example a conveyor 101, is imaged at a predetermined position from the second substrate 4 side, which is a transparent or translucent substrate, by an imaging unit 105 such as a camera (see the dashed dotted line in Figure 9).

[0061] The image captured by the imaging unit 105 and the time of capturing the image are input into the inspection device 110, which determines whether the wiring state and connection state of the heater wire 5 of the captured automotive radar device radome 1 are appropriate. The inspection device 110 includes an arithmetic processing unit such as a CPU, an MPU, etc., and a storage unit configured with a ROM, a RAM, a flash memory, an HDD, an SSD, etc., and the storage unit is provided with a control program storage unit 112 which stores a control program for executing an appropriateness determination process, an appropriate image storage unit 113 which stores reference images such as an overall image of an appropriate state or multiple partial images showing local appropriate states to be compared with the captured image, and a removal time storage unit 114 which stores a set time from the time of capturing the image of the automotive radar device radome 1 in which the wiring state and connection state of the heater wire 5 are inappropriate to the time to operate a removal processing unit 120 such as a robot arm which removes the inappropriate automotive radar device radome 1 at a predetermined position.

[0062] The appropriateness determination unit 111 of the inspection device 110 is composed of a calculation processing unit that cooperates with the control program of the control program storage unit 112, and compares the captured image with a reference image, and determines whether the captured image shows an appropriate wiring or connection state of the heater wire 5 by, for example, existing template matching, pattern matching that detects characteristic edges and calculates similarity, or machine-learned standards of an artificial intelligence program, and thereby determines whether the captured image shows an appropriate base or an appropriate radome 1 for an on-board radar device. For example, as shown in Figure 10, if the heater wire 5 has a twisted portion 52, or if the end 51 of the heater wire 5 and the connection terminal 61 of the wire harness connection portion 6 are not connected, the captured image and the on-board radar device radome 1 are determined to be appropriate.

[0063] When the appropriateness determination unit 111 of the inspection device 110 determines and recognizes an imaging image of the inappropriate vehicle-mounted radar dome 1, it uses the set time in the removal time storage unit 114 and adds the set time to the imaging time of the imaging image of the inappropriate vehicle-mounted radar dome 1, and outputs the removal time and the removal command to the removal processing unit 120 such as a robot arm via the removal command output unit 115 such as a communication interface. The removal processing unit 120 removes the inappropriate vehicle-mounted radar dome 1 from the production line at the corresponding removal time. According to this inspection system, the internal state can be recognized by utilizing a substrate of a transparent substrate or a translucent substrate, and an inappropriate substrate having an inappropriate wiring state or connection state of the heater wire can be surely removed. In addition, an inappropriate substrate having an inappropriate wiring state or connection state of the heater wire can be automatically removed, and the manufacturing process can be made more efficient.

[0064] In addition, instead of the automated inspection system as shown in FIG. 9, visual inspection is performed in the direction of the dashed line in FIG. 9, and an inappropriate substrate having an inappropriate wiring state or connection state of the heater wire 5 and an inappropriate vehicle-mounted radar dome 1 are manually removed. This is also good. Thereby, the internal state can be recognized by utilizing a substrate of a transparent substrate or a translucent substrate, and an inappropriate substrate having an inappropriate wiring state or connection state of the heater wire can be surely removed. Further, these inspection systems are suitably used for the vehicle-mounted radar domes 1, 1a, 1b, 1c, etc. of the first to fourth embodiments having a transparent substrate or a translucent substrate, and the vehicle-mounted radar dome of the present invention having a transparent substrate or a translucent substrate.

[0065] When using the above-described inspection system, for a vehicle-mounted radar dome such as a bumper cover where the inside is usually not visible, it is preferable to use a non-translucent substrate such as a colored substrate for the first substrates 3, 3a, etc. on the visual side because the painting process can be omitted. However, when the first substrates 3, 3a, etc. are made of a transparent substrate or a translucent substrate, it is preferable to provide a non-translucent coating layer 7 such as a colored coating layer on the outer surface of the first substrates 3, 3a, etc. (see FIG. 11).

Industrial Applicability

[0066] The present invention can be used in a radome for an on-vehicle radar device. [Explanation of symbols]

[0067] DESCRIPTION OF SYMBOLS 1, 1a, 1b, 1c...Radome for on-vehicle radar device 2...Base 3, 3a...First base material 31, 31a...Groove 32...Positioning recess 4, 4a, 4b, 4c...Second base material 41, 41b...Another groove 42a, 42c...Convex strip 5...Heater wire 51...End 52...Wire twisted portion 6...Wire harness connection portion 61...Connection terminal 62...Electrical cable 7...Paint layer 10...Mold 11...Injection port 12...Outlet R...Electromagnetic wave irradiation area MR...Molten resin 101...Conveyor 105...Imaging unit 110...Inspection device 111...Adequacy determination unit 112...Control program storage unit 113...Adequate image storage unit 114...Removal time storage unit 115...Removal command output unit 120...Removal processing unit

Claims

1. a heater wire wired in the surface direction of an electromagnetic wave-transmitting substrate; the base body is constructed by stacking and fixing a first base material and a second base material, a recessed groove is formed on the first substrate on a surface thereof that is fixed to the second substrate; The radome for an on-vehicle radar device is characterized in that the heater wire is fitted into the recessed groove and routed along the recessed groove.

2. 2. The radome for an on-vehicle radar device according to claim 1, wherein a positioning recess for accommodating at least a portion of a wire harness connection portion electrically connected to the heater wire is formed on the fixing surface side of the first base material.

3. the heater wire is fitted into the groove of the first base material and another groove of the second base material and wired along the groove and the other groove; 3. The radome for an on-vehicle radar device according to claim 1, wherein the second base material made of an injection-molded material is fixed to the first base material by molding welding.

4. the heater wire is entirely embedded in the groove of the first substrate, The protrusions of the second base material are formed to fit into the recessed grooves of the first base material, 3. The radome for an on-vehicle radar device according to claim 1, wherein the second base material made of an injection-molded material is fixed to the first base material by molding welding.

5. the heater wire is fitted into the groove of the first base material and another groove of the second base material and wired along the groove and the other groove; 3. The radome for an on-vehicle radar device according to claim 1, wherein the second base material is attached to the first base material by welding or adhesive.

6. the heater wire is entirely embedded in the groove of the first substrate, The protrusions of the second base material are formed to fit into the recessed grooves of the first base material, 3. The radome for an on-vehicle radar device according to claim 1, wherein the second base material is attached to the first base material by welding or adhesive.

7. 3. The radome for an on-vehicle radar device according to claim 1, wherein either the first base material or the second base material is made of a foamed resin.

8. 8. The radome for an on-vehicle radar device according to claim 7, wherein both the first base material and the second base material arranged on the viewing side are made of foamed resin.

9. 8. The radome for an automotive radar device according to claim 7, wherein the first base material arranged on the viewing side is formed of a foamed resin, and the second base material arranged behind the first base material is formed of a non-foamed synthetic resin.

10. 8. The radome for an on-vehicle radar device according to claim 7, wherein the first base material arranged on the viewing side is made of a non-foaming synthetic resin, and the second base material arranged behind the first base material is made of a foamed resin.

11. A method for manufacturing a radome for an automotive radar device as described in claim 3, wherein a positioning recess for accommodating at least a part of a wire harness connection part electrically connected to the heater wire is formed on the fixing surface side of the first substrate, a first step of fixing the heater wire so as to be fitted into the recessed groove of the first base material, accommodating at least a part of a wire harness connecting portion in the positioning recess of the first base material, and arranging the first base material, the heater wire, and the wire harness connecting portion inside a mold in a state in which an end of the heater wire and a connecting terminal of the wire harness connecting portion are in contact with each other; A second step of injection molding a molten resin into the mold, forming a second base material from the molten resin, fitting the heater wire into another recessed groove of the second base material, and molding and welding the second base material to the first base material. A method for manufacturing a radome for an on-vehicle radar device, comprising:

12. A method for manufacturing a radome for an automotive radar device as described in claim 4, wherein a positioning recess for accommodating at least a part of a wire harness connection part electrically connected to the heater wire is formed on the fixing surface side of the first substrate, a first step of fixing the heater wire so as to be fitted into the recessed groove of the first base material, accommodating at least a part of a wire harness connecting portion in the positioning recess of the first base material, and arranging the first base material, the heater wire, and the wire harness connecting portion inside a mold in a state in which an end of the heater wire and a connecting terminal of the wire harness connecting portion are in contact with each other; A second step of injection molding a molten resin into the mold, forming a second base material from the molten resin, fitting the convex strips of the second base material into the concave grooves of the first base material, and molding and welding the second base material to the first base material. A method for manufacturing a radome for an on-vehicle radar device, comprising:

13. 8. The method for manufacturing a radome for an on-vehicle radar device according to claim 1, wherein at least one of the first base material and the second base material is formed of a transparent base material or a light-transmitting base material, A method for manufacturing a radome for an automotive radar device, comprising the steps of: capturing an image of the substrate from the side of the first substrate or the second substrate, which is a transparent substrate or a light-transmitting substrate, comparing the captured image with a reference image to identify an inappropriate substrate having an inappropriate heater wire wiring state or an inappropriate heater wire connection state, and removing the inappropriate substrate.

14. 8. The method for manufacturing a radome for an on-vehicle radar device according to claim 1, wherein at least one of the first base material and the second base material is formed of a transparent base material or a light-transmitting base material, A method for manufacturing a radome for an automotive radar device, comprising a step of visually inspecting the substrate from the side of the first substrate or the second substrate, which is a transparent substrate or a light-transmitting substrate, and identifying and removing an inappropriate substrate having an inappropriate heater wire wiring state or an inappropriate heater wire connection state.

15. 15. The method for manufacturing a radome for an automotive radar device according to claim 13, wherein the first substrate arranged on the viewing side is a non-transparent substrate, and the second substrate arranged on the opposite side to the viewing side is a transparent substrate or a translucent substrate.

Images