Snow melting organizations

Abstract

The present invention provides a snow-melting mechanism provided on the outer cover of a radar unit, which suppresses false detection by the radar unit and suppresses the temperature rise of the radar unit due to the heat-generating element for snow melting. [Solution] The snow melting mechanism provides a radar unit that transmits and receives radar waves, an outer cover made of a colored material that transmits radar waves and is positioned in front of the radar unit to transmit radar waves, a heating element that generates heat when powered and is positioned in close contact with the inner surface of the outer cover, a cylindrical protective body that extends from the outer cover where the heating element is positioned toward the radar unit and has an internal hole that penetrates from front to back, and a synthetic resin foam placed in the internal hole of the protective body. By placing the synthetic resin foam, which transmits radio waves and has excellent heat insulation properties, between the outer cover to which the heating element is in close contact and the radar unit, the temperature rise is suppressed while ensuring radar characteristics.

Description

Technical Field

[0001] The present invention relates to a snow melting mechanism, particularly a snow melting mechanism provided on an outer cover of a radar unit that transmits and receives radar waves.

Background Art

[0002] Recently, vehicle radars capable of widely detecting objects around a vehicle have become widespread. However, when a radar unit is mounted on a vehicle, there is a problem that members inside the vehicle near the radar interfere with the transmitted and received waves of the radar, resulting in false detection of the radar unit. For this reason, in Patent Document 1, a standing wall is provided around the radar unit to surround the radar unit and suppress false detection.

[0003] By the way, like a vehicle lamp having an outer lens, the radar unit also has an outer cover that is disposed in front of the radar unit, defines the radar unit from the outside air, and transmits radar waves. Snow adhering to the outer lens of the vehicle lamp hinders appropriate light irradiation, and snow adhering to the outer cover of the radar unit adversely affects the characteristics of the radar unit. Therefore, it is desirable to provide a snow melting function also for the outer cover of the radar unit.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when the radar unit is surrounded by a standing wall to protect the characteristics of the radar unit as in Patent Document 1, if a snow melting function is provided for the outer cover, the temperature rise inside the standing wall becomes large due to the heat generating member for snow melting provided near the outer cover, and there is a problem that the temperature of the radar unit exceeds the operable temperature.

[0006] The present invention has been made in view of the above, and provides a snow melting mechanism provided on the outer cover of a radar unit, which suppresses false detection by the radar unit and suppresses the temperature rise of the radar unit due to the heating element for snow melting. [Means for solving the problem]

[0007] To solve the above problem, the snow melting mechanism of the present disclosure is configured to include a radar unit that transmits and receives radar waves, an outer cover made of a colored resin material that transmits the radar waves and is positioned in front of the radar unit and transmits the radar waves, a heating element that generates heat when power is supplied and is positioned in close contact with the inner surface of the outer cover, a cylindrical protective body that extends from the outer cover on which the heating element is positioned toward the radar unit and is positioned to cover the outer circumference of the radar unit when viewed from the direction of extension, and has an internal hole that penetrates from front to back, and a synthetic resin foam placed in the internal hole of the protective body.

[0008] In this embodiment, radar waves emitted from the radar unit pass through a synthetic resin foam placed in the inner cavity of a cylindrical protective body and are emitted from an outer cover on which a heating element is in close contact with the inner surface. Furthermore, the radar waves are reflected by the target object and returned to the radar unit via the reverse path for reception. Since the synthetic resin foam is composed mostly of air, it transmits radio waves but does not conduct heat well. Therefore, it transmits radar waves while insulating the heat from the heating element. The colored resin material hides the heating element from view even when it is placed inside, maintaining the aesthetic appearance. The cylindrical protective body suppresses false radar detection, and furthermore, a synthetic resin foam can be placed inside the cylindrical protective body as an insulating material. The synthetic resin foam allows radar waves to pass through the radar unit, and the temperature rise is suppressed.

[0009] In one embodiment, the synthetic resin foam is arranged to fill the internal cavity of the protective body, so as to close the front and rear openings of the protective body. In this embodiment, the thermal insulation performance is improved because the synthetic resin foam is densely filled inside the cylindrical protective body to close the openings. In addition, the synthetic resin foam is less likely to fall out of the protective body.

[0010] In one embodiment, the protective body is positioned such that one opening of the inner bore abuts against the outer cover, and the synthetic resin foam abuts against at least a portion of the heating element. In this embodiment, the abutment of one opening of the protective body against the outer cover facilitates the positioning of the protective body, the synthetic resin foam, and the radar unit. Furthermore, the abutment of the synthetic resin foam against the heating element allows the heating element to be pressed against the outer cover by the heat insulating material. This improves snow melting performance and heat insulating performance.

[0011] In one embodiment, the area in which the heating element is placed is smaller than one of the openings in the protective body, the entire heating element is placed inside the opening, and the electrical contacts of the heating element are placed outside the protective body. In this embodiment, when one of the openings in the protective body abuts against the outer cover, the entire heating element is placed inside the opening in the protective body. This makes it easier for heat from the heating element to be transferred to the outer cover, thereby improving snow melting performance, and also reduces the occurrence of false radar detections as radar waves pass through the opening. Since the electrical contacts are placed outside the protective body, it is easy to supply power to the heating element. [Effects of the Invention]

[0012] As is clear from the above explanation, a snow melting mechanism can be provided that is installed on the outer cover of a radar unit, which suppresses false detection by the radar unit and suppresses the temperature rise of the radar unit due to the heat-generating element for snow melting. [Brief explanation of the drawing]

[0013] [Figure 1] This shows the schematic configuration of the first embodiment. This is a perspective view of the snow melting mechanism provided on the outer cover of the radar unit. [Figure 2] Figure 1 is an exploded perspective view. [Figure 3] This is a horizontal cross-sectional view of Figure 1. [Figure 4] This is a schematic diagram illustrating the field of view of a radar unit. [Figure 5] The schematic configuration of the second embodiment is shown. This is a front view of a vehicle light fixture equipped with a snow melting mechanism. [Figure 6] This is a vertical cross-sectional view of Figure 5. [Figure 7] A modified example is shown. This is a horizontal cross-sectional view of a radar device equipped with a snow-melting mechanism. [Modes for carrying out the invention]

[0014] Specific embodiments of the present invention will be described below with reference to the drawings. These embodiments are illustrative and not limiting to the invention, and not all features or combinations thereof described in the embodiments are necessarily essential to the invention. In the following descriptions of embodiments and modifications, the same reference numerals are used for identical components, and redundant explanations are omitted as appropriate. In each figure, the dimensions and ratios do not reflect actual numerical values, but represent the configuration schematically. The colors used in the figures are not the actual colors themselves, but are chosen for clarity in explaining the state.

[0015] (First Embodiment) Figure 1 is a perspective view showing the schematic configuration of the present invention. Figure 2 is an exploded perspective view of Figure 1. Figure 2 is a horizontal cross-sectional view of Figure 1.

[0016] As shown in Figures 1 to 3, the snow melting mechanism 1 is installed on the outer cover 4. The snow melting mechanism 1 is installed on the outer cover of a device that transmits and receives radio waves and light, such as a radar unit 20.

[0017] The outer cover 4 is composed of members having the property of transmitting radio waves, and is provided in the radio wave transmission / reception direction (front direction) of the radar unit 20. It is a protective member and a light-blocking member that demarcates the radar unit 20 from the outside, and is composed of a colored resin member. With the outer cover 4, the radar unit 20 disposed inside the outer cover 4 can function without being visually recognized from the outside. The outer cover 4 may be the outer cover of a dedicated housing of the radar unit 20, or may be a part of the cover of a unit device including other devices such as a vehicle lamp.

[0018] The radar unit 20 is a detection sensor that transmits and receives radar waves. For example, it is mounted on a vehicle to detect obstacles in front of the vehicle.

[0019] The radar unit 20 is composed of, for example, a millimeter-wave radar using the FMCW (Frequency Modulated Continuous Wave) modulation method, and has a transmission antenna that transmits radar waves and a reception antenna that receives reflected waves from an object. The radar unit 20 transmits radio waves with excellent linearity from the transmission antenna, receives the reflected waves from an object in front with the reception antenna, and performs signal processing, thereby being able to measure the distance, speed, and angle to the object.

[0020] When snow adheres to the outer cover 4, the radar waves emitted from the radar unit 20 are absorbed / reflected / scattered by the snow, so the transmission / reception characteristics of the radar waves of the radar unit 20 deteriorate and the detection ability decreases. To prevent this, a snow melting mechanism 1 is provided on the outer cover 4.

[0021] The snow melting mechanism 1 has a sheet-like film heater 11 as a heating member. The film heater 11 that generates heat when powered is attached in close contact with the inner surface 4a of the outer cover 4, thereby implementing a snow melting function on the outer cover 4.

[0022] [[ID=The film heater 11 is a thin-film heating element composed of a material that has the property of transmitting radio waves and generates heat when power is supplied. The film heater 11 consists of, for example, multiple layers, and has at least a resin sheet and a heating layer. The resin sheet is a base member formed in sheet form from a resin material that has the property of transmitting radio waves. In this embodiment, the resin sheet is composed of a transparent resin material, but is not limited to this, and a colored resin material may be used as long as it has the property of transmitting radio waves. The heating layer is bonded to the resin sheet with an adhesive, and then a protective material containing a degradation inhibitor to prevent metal degradation is applied on top to form the film heater 11. The heating layer is a heating element composed of a conductive metal that generates heat when power is supplied. Conductive metals inhibit the transmission of radar waves, but in the case of the film heater 11, its form is a thin-film metal sheet using very small particles or extremely fine heating wires, so the effect on the radio wave transmission characteristics of the film heater 11 is small, and the radio wave transmittance of the film heater 11 is sufficiently ensured. The film heater 11 achieves both high heat generation and radio wave transparency, resulting in high flexibility and radio wave transparency, and can adhere closely to the inner surface 4a of the outer cover 4 even on curved surfaces. In this embodiment, the film heater 11 is laid in close contact with the outer cover 4 by being attached to the inner surface 4a of the outer cover 4 with a radio wave transparent adhesive.

[0023] The heating element of the snow melting mechanism 1 is not limited to the above, and may be a material such as a transparent PET film on which extremely fine wires are arranged in a mesh pattern, or a material on which fine metal particles are deposited, or a transparent heating film made of ITO film (indium tin oxide film), or a film heater such as an FPC using conductive ink on a transparent film, as long as it has sufficient radio wave transmission characteristics to transmit and receive radar waves so as to ensure the function of the radar unit 20.

[0024] A connector 12 is connected to the film heater 11 as an electrical contact. The connector 12 is the power supply unit for the film heater 11, and power is supplied to the film heater 11 via the connector 12. The power supply unit for the film heater 11 is not limited to the connector 12; any known method can be used as long as a cable connected to the vehicle battery is connected to the film heater 11 and power is supplied to the film heater 11.

[0025] The radar waves transmitted from the radar unit 20 pass through the outer cover 4 in the area where the film heater 11 is laid and illuminate a predetermined area in front of the outer cover 4. The radar waves reflected by the illuminated object pass through the outer cover 4 again and are received by the radar unit 20.

[0026] A cylindrical protective body 40 is positioned between the outer cover 4 and the radar unit 20. The protective body 40 extends from the outer cover 4 in the area where the film heater 11 is located toward the radar unit 20, and when viewed from this direction of extension, it is positioned to cover the outer circumference of the radar unit 20. The extension direction of the inner hole 41 is positioned so as to substantially coincide with the direction of transmission and reception of radar waves from the radar unit 20, and radar waves emitted from the radar unit 20 mainly pass through the inner hole 41 of the protective body 40 and are irradiated to the outside.

[0027] If other components are placed around the radar unit 20, the radar waves transmitted from the radar unit 20 may be reflected by these other components, preventing the radar unit 20 from accurately measuring the distance to the target object and potentially causing false detections. To suppress such problems, a cylindrical protective body 40 is provided.

[0028] Figure 4 is a schematic diagram illustrating the arrangement of the radar unit 20 and the protective body 40. Figure 4(A) is a horizontal cross-sectional view of Figure 1. Figure 4(B) is a rear view of Figure 1.

[0029] As shown in Figure 4(A), the cylindrical protective body 40, which has an internal bore 41 that is a through hole, is made of opaque resin and is positioned to cover the outer circumference of the radar unit 20 in a horizontal cross-section passing through the radar unit 20. That is, as shown in Figure 4(B), when viewed from the direction of extension of the internal bore 41 of the cylindrical protective body 40, the radar unit 20 is positioned inside the internal bore 41.

[0030] The cylindrical protective body 40 has openings at the front and rear through an inner hole 41, with the front opening being closed by contact with the outer cover 4. The radar unit 20 is located at the rear opening of the inner hole 41. The rear opening of the inner hole 41 may or may not be closed by the radar unit 20. In this embodiment, the protective body 40 is a rectangular cylinder composed of plate-like members for the upper wall, lower wall, right wall, and left wall. However, it is not limited to this, and the shape of the opening of the protective body 40 may be circular, semicircular, or free-form. Due to the straight-line propagation of radar waves, the shape of the inner hole 41 may correspond to the location where it is placed and the shape of the outer cover 4, as long as it is provided in a straight line. The front and rear openings of the protective body 40 do not have to be the same shape, and the cross-sectional shape in the extension direction does not have to be constant. For example, the upper wall of the rear opening may be a canopy type, or a conical / pyramidal shape that widens towards the front. The thickness of the protective body 40 does not have to be uniform.

[0031] A film heater 11 is positioned in the front opening of the inner bore 41, which is closed by the outer cover 4. Wiring 15 connected to the film heater 11 extends from the gap between the radar unit 20 and the outer cover 4, and a connector 12 provided at the end of the wiring 15 is positioned outside the protective body 40. The protective body 40 may be integrally formed with the outer cover 4, or it may have notches or holes through which the wiring 15 is inserted. The film heater 11 may be larger than the opening of the inner bore 41.

[0032] The protective body 40 is positioned in front of the radar unit 20, and is configured such that the radar unit 20, particularly the receiving surface 21, is located within the opening surface of the inner bore 41. Therefore, the inner bore 41 of the protective body 40 primarily serves as a path for radar waves. Specifically, as shown in Figure 4(A), if the normal direction of the receiving surface 21 of the reflected waves of the radar unit 20 is defined as axis Ax, then the field of view of the radar unit 20 is defined as θ×2. The FOV (Field of View) of the radar unit 20 extends outward by θ×2 from both ends of axis Ax at both ends of the receiving surface 21. At this time, the peripheral wall surface constituting the protective body 40 crosses the FOV at a position located in front of the radar unit 20. The rear end of the peripheral side surface of the protective body 40 (the rear opening of the inner bore 41) is located outside the FOV, and the front end of the peripheral side surface (the front opening of the inner bore 41) is located inside the FOV. In other words, at least a portion of the protective body 40 is located inside the field of view (FOV) of the radar unit 20.

[0033] As described above, if other components such as a lamp unit are located within the field of view (FOV) of the radar unit 20, it may lead to false detection by the radar unit 20. In this embodiment, when a protective body 40 is placed between the radar unit 20 and the outer cover 4, the protective body 40 closes off the space between the radar unit 20 and the outer cover 4, preventing other components from being placed there. Therefore, reflection of radar waves by other components is suppressed, and false detection by the radar unit 20 is suppressed.

[0034] In addition, a radio wave absorber 50 is provided on the inner surface of the protective body 40. The radio wave absorber 50 is made of a material with a transmittance of 50% or less in the wavelength range of radar waves. In this embodiment, the radio wave absorber 50 is attached to or applied to the entire inner surface of the protective body 40. However, it is not limited to this, and it is sufficient if the radio wave absorber 50 is provided on at least a part of the inner or outer surface of the protective body 40.

[0035] The radio wave absorber 50 absorbs radar waves that are emitted from the side of the space (internal bore 41) between the radar unit 20 and the outer cover 4 and reflected by other components, thereby further suppressing false detections by the radar unit 20.

[0036] The radio wave absorber 50 may be a radio wave absorbing film in which a radio wave absorbing layer and an adhesive layer are laminated, or it may be a radio wave absorbing material coated with a binder that has been dispersed and kneaded. Preferably, the radio wave absorbing properties of the components of the protective body 40 are higher than those of the components of the outer cover 4. This allows radar waves emitted from the front of the radar unit 20 and emitted from the outer cover 4 to pass through, while radar waves emitted from the side and reflected by other components are absorbed by the protective body 40 and the radio wave absorber 50, further suppressing false detection by the radar unit 20. The protective body 40 and the outer cover 4 may be integrally constructed as a two-color molded product using the resin components with the above configuration. The protective body 40 and the outer cover 4 may also be integrally molded from the same component.

[0037] A synthetic resin foam 30 is placed in the inner cavity 41 of the protective body 40. The synthetic resin foam 30 is a foamed plastic containing air bubbles, such as polystyrene foam, and its composition is mostly air. For this reason, it is lightweight, has high thermal insulation performance, and has radio wave transparency that allows radar waves to pass through.

[0038] The synthetic resin foam 30 is positioned in the inner hole 41, filling it so as to close the front and rear openings. The synthetic resin foam 30 is approximately the same shape as the outer shape of the inner hole 41, and the inner hole 41 is filled with the synthetic resin foam 30 without any gaps. Because the synthetic resin foam 30 is elastic, it is preferable to push in a synthetic resin foam 30 that is larger than the inner hole 41, as this also suppresses its falling out. Since the synthetic resin foam 30 allows radar waves to pass through, the radar waves emitted from the radar unit 20 pass through the synthetic resin foam 30 and are irradiated to the outside from the outer cover 4 without any problems. Radar waves reflected by the target object also pass through the synthetic resin foam 30 and are received by the receiving surface 21.

[0039] The synthetic resin foam 30 is positioned up to the front opening of the protective body 40, and when the protective body 40 comes into contact with the outer cover 4, the synthetic resin foam 30 also comes into contact with the outer cover 4. As a result, the film heater 11 laid on the inner surface 4a is sandwiched between the synthetic resin foam 30 and the outer cover 4. The synthetic resin foam 30 has high thermal insulation performance, which improves the heat retention of the heat-generating film heater 11 and improves snow melting performance.

[0040] Furthermore, the thermal insulation properties of the synthetic resin foam 30 suppress the rise in ambient temperature caused by the heat generated by the film heater 11. The film heater 11 is positioned opposite the radar unit 20, and without the synthetic resin foam 30, the heat from the film heater 11 would be directed directly towards the radar unit 20, causing the radar unit 20 itself to easily overheat. In addition, since the protective body 40 is positioned to surround the film heater 11, the inner cavity 41 is also prone to overheating. Without the synthetic resin foam 30, the heat generated by the film heater 11 could exceed the operating limit temperature of the radar unit 20. For this reason, in this embodiment, the synthetic resin foam 30 is placed as a thermal insulation material to suppress the transfer of heat from the film heater 11 to the radar unit 20. Even if the protective body 40 is not placed, by placing the synthetic resin foam 30 between the radar unit 20 and the film heater 11, snow melting performance can be improved while ensuring the radar characteristics of the radar unit 20 and suppressing the temperature rise. By placing the protective body 40, false detection of radar waves is suppressed, improving radar characteristics. Furthermore, it facilitates the placement of the synthetic resin foam 30, allowing for more precise and efficient placement of the foam 30, and enabling thicker placement, compared to laminating it on the film heater. The synthetic resin foam 30 is an insulating material, and its thickness increases its insulating properties. The protective body 40 can also be placed in contact with both the radar unit 20 and the film heater 11, thereby improving both radar performance and snow melting performance.

[0041] In this embodiment, the synthetic resin foam 30 is positioned up to the rear opening of the protective body 40, and the radar unit 20 is also positioned in contact with the synthetic resin foam 30. This positions the radar unit 20 and ensures stable placement. However, the protective body 40 does not necessarily have to have its front and rear openings in contact with the outer cover 4 or the radar unit 20; it is sufficient that the synthetic resin foam 30 is positioned in at least the inner bore 41.

[0042] (Second Embodiment) A second embodiment will be described with reference to Figures 5 and 6. Figure 5 is a front view of a vehicle lighting fixture 199 equipped with a snow melting mechanism 101 and a radar unit 20. Figure 6 is a longitudinal cross-sectional view of Figure 5. Components with equivalent mechanisms are denoted by the same reference numerals, and detailed explanations are omitted as appropriate.

[0043] The vehicle lighting fixture 199 is a headlight and is mounted on both the left and right sides of the front of the vehicle. The vehicle lighting fixture 199 comprises a lamp housing consisting of a lamp body 102 and an outer lens 104.

[0044] The outer lens 104 is a two-color molded product and consists of a transparent portion 104b made of a light-transmitting transparent resin material and a colored portion 104c made of a colored resin material having radio wave transmission properties, forming the outer edge of the transparent portion 104b and integrally formed with the transparent portion 104b. The outer lens 104 is a so-called transparent lens, and neither the transparent portion 104b nor the colored portion 104c has the function of an optical lens, and it serves as the outer cover of the vehicle lamp 199. The colored portion 104c is made of an opaque resin, and it is not possible to see inside the lamp chamber through the colored portion 104c.

[0045] The lamp body 102 is a housing with an open front, and the outer lens 104 is attached to the front opening of the lamp body 102, forming a lamp chamber S inside. The lamp unit LU and the radar unit 20 are housed inside the defined lamp chamber S. Specifically, the lamp unit LU is positioned on the back of the transparent part 104b, and the radar unit 20 is positioned on the back of the lower edge of the colored part 104c, approximately in the center. Since the radar unit 20 is positioned on the back of the colored part 104c, it is hidden by the colored part 104c and cannot be seen from the outside. The colored part 104c corresponds to the outer cover of this configuration.

[0046] The lamp unit LU is an optical unit configured to project light forward and form a predetermined light distribution in front of the vehicle. A conventionally known configuration may be used, and a detailed explanation will be omitted.

[0047] The vehicle light fixture 199 is equipped with a snow melting mechanism 101. A transparent film heater 111 is laid on the inner surface 104a of the outer lens 104 (the back surface of the outer lens 104 and the inner surface of the light chamber S). The transparent film heater 111 is a sheet-shaped heating element that generates heat when power is supplied, and is made of a transparent resin material that has light transmission and radio wave transmission properties. The transparent film heater 111 is mainly made of transparent resin and has the same configuration as the film heater 11 except that it has light transmission in addition to radio wave transmission properties.

[0048] The transparent film heater 111 is laid in close contact with the inner surface 104a so as to cover the transparent portion 104b and extend over the lower end of the colored portion 104c. The transparent film heater 111 has a power supply mechanism (not shown), which is connected to the vehicle battery. When powered, the transparent film heater 111 generates heat, and this heat melts the snow adhering to the outside of the outer lens 104, ensuring proper illumination by the lamp unit LU and the detection function of the radar unit 20 using radar waves.

[0049] A cylindrical protective body 40 is positioned between the radar unit 20 and the colored section 104c inside the lamp chamber. A radio wave absorber 50 is laid on the inner wall surface of the inner hole 41 of the protective body 40, and synthetic resin foam 30 is packed further inside. Except for the use of the colored section 104c instead of the outer cover 4, and the use of a transparent film heater 111 larger than the inner hole 41 instead of the film heater 11, the arrangement and shape of the radar unit 20, protective body 40, radio wave absorber 50, and synthetic resin foam 30 are the same as those of the snow melting mechanism 1.

[0050] The radar waves emitted from the radar unit 20 pass through the synthetic resin foam 30, the transparent film heater 111, and the colored portion 104c, and are irradiated onto a predetermined area in front of the vehicle.

[0051] In this embodiment, the radar unit 20 is mounted on the vehicle lighting fixture 199 together with the lamp unit LU, the outer lens 104 serves as the outer cover for both the lamp unit LU and the radar unit 20, and the snow melting mechanism 101 is a snow melting mechanism common to both the lamp unit LU and the radar unit 20. The snow melting mechanism 101 may not be a dedicated device for the radar unit 20, but may be used in conjunction with the lighting fixture or other detection devices or light transmission devices.

[0052] (modified version) The configuration of this disclosure is not limited to that described above. Figure 7 shows a modified radar device 299. The radar device 299 comprises a housing body 202 with an opening at the front and an outer cover 204 as a housing. The radar unit 20 is arranged in the inner space defined by the attachment of the outer cover 204 to the front opening of the housing body 202.

[0053] The outer cover 204 has the same configuration as the outer cover 4 and is made of a colored material that allows radar waves to pass through.

[0054] The radar device 299 is equipped with a snow melting mechanism 1, and a film heater 11 is laid on the inner surface of the outer cover 204. A radar unit 20 is positioned behind the area of ​​the outer cover 204 where the film heater 11 is laid, and a cylindrical protective body 40 is positioned between the radar unit 20 and the outer cover 204. A radio wave absorber 50 is laid on the inner wall surface of the inner hole 41 of the protective body 40, and synthetic resin foam 30 is packed inside thereof. Since these are the same configuration as in the first embodiment, a detailed explanation is omitted.

[0055] The housing body 202 is made of a resin material that absorbs radio waves. By housing the radar unit 20 in a dedicated enclosure, the likelihood of false detections caused by radar waves being reflected by other materials is reduced. Furthermore, the protective body 40, radio wave absorber 50, and synthetic resin foam 30 further reduce the occurrence of false detections and improve the radar characteristics of the radar unit 20. Thus, the radar unit 20 may be housed in a dedicated enclosure, or it may be mounted on various other devices as part of the radar device 299.

[0056] Although preferred embodiments and variations of the present invention have been described above, these embodiments are merely examples of the present invention, and it is possible to combine them based on the knowledge of those skilled in the art, and such embodiments are also included within the scope of the present invention. [Explanation of Symbols]

[0057] 1:Snow melting mechanism 4: Outer cover 4a: Inner surface (of the outer cover) 11: Film heater (heating element) 12: Connector (electrical contact) 20: Radar Unit 21: (Radar wave) receiving surface 30: Synthetic resin foam 40: Protective body 41: Internal bore 50: Radio wave absorber

Claims

1. A radar unit that transmits and receives radar waves, An outer cover made of a colored resin material that transmits radar waves, positioned in front of the radar unit and transmitting the radar waves, A heating element that generates heat when power is supplied and is positioned in close contact with the inner surface of the outer cover, A cylindrical protective body having a through-hole extending from front to back extends from the outer cover on which the heat-generating element is located toward the radar unit, and is positioned to cover the outer circumference of the radar unit when viewed from the direction of extension. A synthetic resin foam disposed in the inner hole of the protective body, Equipped with, A snow melting mechanism characterized by the following features.

2. The synthetic resin foam is disposed in the inner hole of the protective body so as to fill the openings at the front and rear of the protective body. The snow melting mechanism according to feature 1.

3. The protective body is positioned such that one opening of the inner hole abuts against the outer cover, and the synthetic resin foam abuts against at least a portion of the heating element. A snow melting mechanism according to claim 1 or 2.

4. The region in which the heating element is placed is smaller than the one opening of the protective body, the entire heating element is placed within the one opening, and the electrical contacts of the heating element are placed on the outside of the protective body. The snow melting mechanism according to claim 3, characterized in that

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