Radar antenna

Abstract

To provide a radar antenna capable of preventing freezing of the boundary between a radiation portion and a mount without using an electric heating wire.SOLUTION: A radar antenna 1 includes a radiating portion 2 rotatably mounted on a metal housing-shaped base 3, and further includes a heating coil 31 disposed at a predetermined location inside the base 3, and a heating control portion 32 that passes a current through the heating coil 31 and causes the base 3 to generate heat by electromagnetic induction heating.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a radar antenna to be mounted on a ship or the like, and particularly to a radar antenna that can withstand use in cold regions such as polar regions. [Background technology]

[0002] A radar antenna mounted on a ship or the like has a cylindrical, horizontally extending radiating section mounted on a housing-like base, and a motor installed inside the base causes the radiating section to rotate around its center. A radio (transmitter / receiver), which is an electronic circuit, is also installed inside the base, and this radio transmits radio waves from the radiating section and receives radio waves via the radiating section.

[0003] In recent years, the development of Arctic Ocean routes, which allow ships to sail without entering seawater, has progressed. As a result, the number of ships requiring polar-region compatibility has increased, and radar antennas installed on ships are also being required to be polar-region compatible. When a radar antenna is used in low-temperature or extremely cold environments such as polar regions, the boundary between the radiation unit and the mount may freeze, or ice and snow may accumulate on the underside of the radiation unit, preventing the radiation unit from rotating. In response to this problem, a conventional radar antenna 101, as shown in FIG. 5, has a heater using an electric heating wire 104 attached to the outside of the mount 103. The electric heating wire 104 is arranged to surround the boundary 105 between the radiation unit 102 and the mount 103, thereby heating the boundary 105 and preventing the boundary 105 from freezing (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-116675 Summary of the Invention [Problem to be solved by the invention]

[0005] However, heating using electric heating wires is inefficient because it radiates heat into the surrounding air. Furthermore, electric heating wires are consumables and must be replaced frequently. Furthermore, if a heater using electric heating wires is installed inside the mount, the radiant heat from the wires may cause the temperature inside the mount to rise too high, potentially interfering with the operation of the radio equipment, making it difficult to install the heater inside the mount. On the other hand, installing a heater using electric heating wires on the outside of the mount would hinder the miniaturization of the radar antenna. Furthermore, when a heater using electric heating wires is installed on the outside of the mount, waterproofing must be applied to prevent moisture such as seawater or rainwater from entering the interior through the installation area. Furthermore, replacing the heating wire requires redoing the waterproofing, which is time-consuming and costly.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a radar antenna that can prevent freezing of the boundary between the radiation part and the mount without using a heating wire. [Means for solving the problem]

[0007] In order to achieve the above object, the invention described in claim 1 is characterized in that a radar antenna has a radiating part rotatably mounted on a housing-shaped metal base, and is provided with a heating coil disposed at a predetermined location inside the base, and a heating control means for passing a current through the heating coil and causing the base to generate heat by electromagnetic induction heating.

[0008] The invention described in claim 2 is characterized in that it further comprises a heat dissipation means arranged between the radiation part and the base, which dissipates heat generated in the base toward the underside of the radiation part. [Effects of the Invention]

[0009] According to the invention described in claim 1, a heating coil is disposed inside a metal pedestal, and an electric current is passed through the heating coil to heat the pedestal by electromagnetic induction heating. Specifically, only the metal pedestal, through which the magnetic flux generated by the heating coil passes, generates heat, and the heat is transferred to the boundary between the radiation unit and the pedestal. This prevents the heat from radiating into the surrounding air, enabling efficient heating of the boundary. Furthermore, because the heating coil itself does not generate heat, it can be disposed inside the pedestal, enabling the device to be miniaturized and reduced in cost. Furthermore, because the heating coil is resistant to deterioration, it can be replaced less frequently. Furthermore, because the heating coil is disposed inside the pedestal, even if replacement of the heating coil becomes necessary, waterproofing is not required, making it easy to replace.

[0010] According to the invention described in claim 2, the heat generated in the mount is dissipated by the heat dissipation means toward the underside of the radiation part, thereby melting the ice and snow adhering to the underside of the radiation part and more reliably preventing the boundary between the radiation part and the mount from freezing. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a perspective view showing a radar antenna according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic block diagram of the interior of the radar antenna mount of FIG. 1. [Figure 3] FIG. 2 is a schematic cross-sectional view showing the configuration of the radar antenna of FIG. 1 in a state where a heating coil is disposed. [Figure 4] FIG. 10 is a schematic cross-sectional view showing the configuration of a radar antenna according to a second embodiment of the present invention, in which a heating coil and heat dissipation fins are disposed. [Figure 5] FIG. 10 is a schematic cross-sectional view showing a conventional radar antenna in which a heating wire is disposed. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described below based on the illustrated embodiments.

[0013] (Embodiment 1) Fig. 1 is a perspective view showing a radar antenna 1 according to a first embodiment of the present invention, in which a radiating section 2 is rotatably mounted on a housing-like (case-like) mount 3. This radar antenna 1 is a radar antenna to be mounted on a ship or the like, and as shown in Fig. 2, a heating coil 31 and a heating control section (heating control means) 32 are mainly provided within the mount 3. Here, the radar antenna 1 has the same configuration and function as a conventional radar antenna except for the heating coil 31 and the heating control section 32, and therefore detailed description of the same points as conventional radar antennas will be omitted, but the radar antenna 1 has the following general configuration, etc.

[0014] That is, the radiation unit 2 has an elongated radome 21 that is cylindrical in shape with a horizontally long cross section (oval shape that is long in the horizontal direction) and extends horizontally, and antenna components including a radiation waveguide, a radio wave shaping plate, and a flare are disposed inside the elongated radome 21. The center of the radome 21 is connected to the upper end of a rotary joint (not shown) inside the mount 3.

[0015] This rotary joint is a hollow cylindrical shaft that extends vertically and is disposed within the pedestal 3 so as to be rotatable around its axis. A motor (not shown) is also disposed within the pedestal 3. The motor is an electric motor for rotating the radiation part 2, and when the motor is started and rotates, the rotary joint rotates, and in conjunction with this rotation, the radiation part 2 rotates within a horizontal plane around its center.

[0016] A radio (not shown) is also provided within the mount 3. The radio is a transceiver for transmitting and receiving radio waves and signals to and from the outside, and is made up of electronic circuits, and is connected to the radiation unit 2 so that signals can be transmitted.

[0017] In addition to this conventional configuration, a heating coil 31 and a heating control unit 32 are further provided inside the gantry 3. The gantry 3 is made of metal, and in this embodiment, is made of an aluminum alloy.

[0018] FIG. 3 is a schematic cross-sectional view showing the arrangement of a heating coil 31 in the radar antenna 1 according to this embodiment. The heating coil 31 is a device that generates a magnetic flux m required for electromagnetic induction heating to heat the boundary portion 5 between the radiation portion 2 and the pedestal 3, and is arranged at a predetermined location inside the pedestal 3. Here, the predetermined location is a location close to the upper surface of the pedestal 3, as shown in FIG. 3. The closer the distance between the heating coil 31 and the upper surface of the pedestal 3, the easier it is to heat the upper surface of the pedestal 3, which is preferable. Note that, for convenience, the number of heating coils 31 is set to 12 in FIG. 3, but the number of heating coils 31 is not limited to this and may be changed as appropriate depending on the size, shape, etc. of the pedestal 3.

[0019] The heating control unit 32 is a mechanism that controls electromagnetic induction heating. The heating control unit 32 performs control as follows: When starting electromagnetic induction heating, the heating control unit 32 passes a current from a power supply (not shown) to the heating coil 31. When a current flows through the heating coil 31, a magnetic flux m is generated around the heating coil 31, and this magnetic flux m passes through the metal base 3, causing an eddy current to flow on the metal surface of the base 3. This generates Joule heat, causing the base 3 (particularly the top surface of the base 3 through which the magnetic flux m passes) to heat up. The heat generated in the top surface of the base 3 is then transferred to the boundary portion 5 between the radiation unit 2 and the base 3, heating the boundary portion 5.

[0020] On the other hand, when electromagnetic induction heating is to be terminated, the heating control unit 32 stops the supply of current from the power supply to the heating coil 31. Here, the heating control unit 32 may automatically control the electromagnetic induction heating by setting the timing for starting and ending the electromagnetic induction heating based on temperature information sent from a temperature sensor provided in the gantry 3, for example.

[0021] As described above, according to the first embodiment, the heating coil 31 is disposed inside the metal pedestal 3, and a current is passed through the heating coil 31 to heat the pedestal 3 by electromagnetic induction heating. That is, only the metal pedestal 3, through which the magnetic flux generated by the heating coil 31 passes, generates heat, and the heat is transferred to the boundary portion 5 between the radiation portion 2 and the pedestal 3. This prevents the heat from being radiated into the surrounding air, enabling efficient heating of the boundary portion 5. Furthermore, because the heating coil 31 itself does not generate heat, it can be disposed inside the pedestal 3, enabling the device to be miniaturized and reduced in cost. Furthermore, because the heating coil 31 is resistant to deterioration, it can be replaced less frequently. Furthermore, because the heating coil 31 is disposed inside the pedestal 3, even if replacement of the heating coil 3 becomes necessary, waterproofing is not required, and replacement can be easily performed.

[0022] (Embodiment 2) Next, a radar antenna 1 according to a second embodiment of the present invention will be described. Note that the same components as those in the first embodiment will be denoted by the same reference numerals and detailed description thereof will be omitted.

[0023] Fig. 4 is a diagram for explaining the radar antenna 1 according to this embodiment. As shown in Fig. 4, the radar antenna 1 according to this embodiment differs from the first embodiment in that heat dissipation fins (heat dissipation means) 4 are disposed between the radiation unit 2 and the mount 3. Note that in Fig. 4, the number of heating coils 31 is set to 12 for convenience, but the number of heating coils 31 is not limited to this and may be changed as appropriate depending on the size, shape, etc. of the mount 3.

[0024] The heat dissipation fins 4 have high thermal conductivity and high thermal emissivity and dissipate heat generated in the pedestal 3 by electromagnetic induction heating toward the underside of the radiation unit 2, and are disposed between the radiation unit 2 and the pedestal 3. In this embodiment, the heat dissipation fins 4 are attached to the outside of the upper surface of the pedestal 3, as shown in FIG. 4 . The heat dissipation fins 4 are preferably made of a metal with particularly high emissivity, such as iron, which has a higher emissivity than the aluminum alloy that constitutes the pedestal 3. This allows the heat generated on the upper surface of the pedestal 3 by electromagnetic induction heating to be dissipated and reach the underside of the radiation unit 2, which is located away from the boundary 5 between the radiation unit 2 and the pedestal 3, and to melt ice and snow that has adhered to the underside of the radiation unit 2.

[0025] As described above, according to this second embodiment, the heat generated in the mount 3 is dissipated by the heat dissipation fins 4 toward the underside of the radiation section 2, so that the ice and snow adhering to the underside of the radiation section 2 can be melted, and it becomes possible to more reliably prevent the boundary portion 5 between the radiation section 2 and the mount 3 from freezing.

[0026] The above describes an embodiment of the present invention, but the specific configuration is not limited to the above embodiment, and even if there are design changes or the like within the scope of the gist of the present invention, they are included in the present invention. [Explanation of symbols]

[0027] 1. Radar antenna 2 Radiant part 3 Mounting stand 31 Heating coil 32 Heating control unit (heating control means) 4. Heat dissipation fins (heat dissipation means) 5 Boundary part 101 Radar Antenna 102 Radiant part 103 Mounting stand 104 Heating wire 105 Boundary part m magnetic flux

Claims

1. A radar antenna in which a radiating part is rotatably mounted on a housing-shaped metal base, a heating coil disposed at a predetermined position inside the frame; a heating control means for passing a current through the heating coil to heat the pedestal by electromagnetic induction heating; A radar antenna comprising:

2. The device further includes a heat dissipation means disposed between the radiation unit and the base, for dissipating heat generated in the base toward a lower surface of the radiation unit.

2. The radar antenna according to claim 1, wherein:

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