JP2940122B2 - Receiving antenna device for vehicles - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular receiving antenna device used in a vehicle that travels while being supplied with power from an overhead line.

B. Summary of the Invention The present invention has a vehicle receiving antenna device used in trains, trolleys, buses, etc.,
By mounting a bar antenna so as to be parallel to the overhead line that supplies power to the train, good reception sensitivity can be obtained while having a simple and small configuration.

C. Prior Art Conventionally, vehicles that are supplied with power from an overhead line, ie, so-called AM broadcasts (medium-wave band broadcasts) can be listened to in vehicles such as trains and trolleys / buses. There has been proposed a receiving antenna device for a vehicle configured to be used by being attached to an outer portion of a vehicle body.

As this vehicle receiving antenna device, a so-called bar
Some antennas have at least one pair of antennas.

That is, as shown in FIG. 1, the receiving antenna device for a vehicle has a pair of bar antennas 101 and 102 housed and held in an outer casing 103 made of an insulating material. The bar antennas 101 and 102 are respectively made of high-frequency magnetic cores 104 and 105 formed in a rod shape from a metal material such as ferrite.
And coils 106 and 107 wound around the high-frequency magnetic cores 104 and 105, respectively.
And is configured.

The bar antennas 101 and 102 are attached to the bottom surface of the outer casing 103 with their axes at right angles to each other.

The receiving antenna device for a vehicle configured as described above is mounted on a train or the like by mounting the outer casing 103 on an outer portion of a vehicle body such as a train, for example, on a roof 108.

The bar antennas 101 and 102 receive, for example, radio waves transmitted and propagated from a broadcasting station or the like. Both ends of the coils 106 and 107 of the bar antennas 101 and 102 are connected to a receiving device (not shown) provided on the train or the like via an antenna code (not shown). That is, the bar antenna 101,102
Sends the received radio waves to the receiving device. This receiving device generates sound according to the radio wave received by each of the bar antennas 101 and 102, or amplifies the radio wave and emits it as a radio wave into the interior of a train or the like.

The reception sensitivity of each of the bar antennas 101 and 102 is
Each of the high-frequency magnetic cores 104 and 105 has a so-called 8-shaped directivity in which a direction orthogonal to the axis of the magnetic cores 104 and 105 has the highest sensitivity. In this vehicular receiving antenna device, since the axes of the high-frequency magnetic cores 104 and 105 of the bar antennas 101 and 102 are oriented in directions orthogonal to each other, almost all of them are indicated by arrows a and b in FIG. Directivity receiving sensitivity can be obtained.

D. Problems to be Solved by the Invention Incidentally, as described above, the pair of bar antennas 101 and 10
In the vehicular receiving antenna device having 2, even if the receiving state of each of the two bar antennas 101 and 102 changes due to a change in the direction of the body of the train or the like, good reception can be performed. Therefore, it is necessary to use a coupling circuit such as a detuning circuit. Therefore, the configuration cannot be simplified.

Further, in this vehicular receiving antenna device, since the pair of bar antennas 101 and 102 are disposed such that the axes of the high-frequency magnetic cores 104 and 105 are arranged in directions orthogonal to each other,
At least an area corresponding to a rectangle having one side as the length of each of the bar antennas 101 and 102 is occupied, and it is not possible to reduce the size of the device configuration.

Furthermore, since the receiving antenna device for a vehicle has a substantially omnidirectional receiving sensitivity, a pantograph-type contact slid on the overhead wire to receive power supply from the overhead wire and the overhead wire. The noise generated by the friction with the user is likely to be received. Also, noise due to mutual interference between the bar antennas 101 and 102 is likely to occur. When such noise occurs, good reception cannot be performed.

Therefore, the present invention has been proposed in view of the above-described circumstances, and while the size and size of the configuration have been reduced,
It is an object of the present invention to provide a vehicular receiving antenna device capable of obtaining good receiving sensitivity.

E. Means for Solving the Problems In order to solve the above-mentioned problems and achieve the above-mentioned object, the vehicle receiving antenna device according to the present invention is provided with a vehicle receiving power supplied from an overhead wire and traveling in a direction along the overhead wire. It has a bar antenna attached to the car body, this bar antenna,
The axis of the high-frequency magnetic core is parallel to the overhead wire.

F. Function In the vehicular receiving antenna device according to the present invention, the bar antenna that is supplied with power from the overhead wire and is attached to the vehicle body of the vehicle traveling in the direction along the overhead wire has an axis of the high-frequency magnetic core that is connected to the overhead wire. Since they are parallel to each other, secondary radiated radio waves from the overhead wire can be satisfactorily received.

G. Examples Hereinafter, specific examples of the present invention will be described with reference to the drawings.

As shown in FIG. 1, a receiving antenna device for a vehicle according to the present invention includes first to sixth bar antennas 1, 2, 3, 4, 5, 6,
have. Each of these bar antennas 1,2,3,4,5,6
Are high frequency magnetic cores 7 each formed in a rod shape from a metal material such as ferrite, and first to sixth coils 8, 9, 10, 11, 12, 13 and 13 wound corresponding to these high frequency magnetic cores 7, respectively. And is configured.

Each of the bar antennas 1, 2, 3, 4, 5, and 6 has a frequency of a radio wave to be received, for example, a frequency band of about 300 kHz to 3000 kHz in the case of so-called AM broadcasting (medium-wave band broadcasting). According to the predetermined frequency in the above each coil 8, 9,
The number of turns of 10,11,12,13 is defined. That is, in this vehicular receiving antenna device, one bar antenna corresponds to one frequency band, so that a plurality of bar antennas do not receive radio waves in the same frequency band. ing.

Each of the bar antennas 1, 2, 3, 4, 5, and 6 is a first antenna.
As shown in FIG. 2 and FIG.
Are mounted in parallel on each other on a support plate 14 arranged and supported therein by a joining means using an adhesive or the like. The support plate 14 is mounted in the housing 15 by a plurality of stop screws 16. In addition, a cover 17 formed in a shape corresponding to the case 15 is attached to the open upper surface of the case 15 and closed.

Further, a pre-amplifier device 23 is attached to the support plate 14. The coils 8, 9, 10, 11, 12, and 13 of the bar antennas 1, 2, 3, 4, 5, and 6 are connected to the preamplifier device 23.

The receiving antenna device for a vehicle configured as described above is supplied with power from an overhead wire 25 via a pantograph-type contact 24 as shown in FIGS. It is attached to a vehicle traveling in a direction along the overhead wire 25 indicated by an arrow A in FIG. 4, that is, a vehicle body 20 such as a train or a trolley bus. The receiving antenna device for a vehicle is mounted on the vehicle body 20 by mounting the housing 15 on the roof portion 19 of the vehicle body 20 via the support member 18.

At this time, as shown in FIGS. 3 and 4, the receiving antenna device for a vehicle has the above-described bar antennas 1, 2, 3, 4,
The axes of the high frequency magnetic cores 5 and 6 are arranged in such a direction as to be parallel to the overhead wire 25.

As shown in FIG. 6, each of the bar antennas 1, 2, 3, 4, 5, and 6 directly receives a radio wave transmitted and propagated from a broadcast station or the like, and receives the pre-amplifier. Send to device 23.
Each of the bar antennas 1, 2, 3, 4, 5, and 6 receives a secondary radiated radio wave of the radio wave received by the overhead wire 25 and sends it to the pre-amplifier device 23. The signals received by the bar antennas 1, 2, 3, 4, 5, 6 and amplified by the preamplifier device 23 are transmitted through a transmission code 22, as shown in FIGS. 2 and 6. Is sent to the main amplifier device 21 provided in the vehicle body 20. This main
The amplifier device 21 further amplifies the transmitted signal and sends it to the transmitting device 27, the receiving device 28, and the like. The transmitting device 27 radiates the signal transmitted from the main amplifier device 21 as a radio wave into the vehicle interior of the vehicle body 20. Therefore, in the vehicle interior of the vehicle body 20, the above-described bar antennas 1, 2, 3, 4, 5, 6
Can receive the received radio wave. Also,
The receiving device 28 is a so-called radio receiver, and generates sound in the vehicle interior based on a signal transmitted from the main amplifier device 21.

In this vehicle receiving antenna device, the signals received by the bar antennas 1, 2, 3, 4, 5, and 6 are transmitted to the vicinity of the bar antennas 1, 2, 3, 4, 5, and 6. The signal is amplified by the pre-amplifier device 23 arranged in the above. Therefore, in this vehicular receiving antenna device, the amplification factor of the main amplifier device 21 disposed in the vehicle body 20 can be suppressed low, and noise mixed in the transmission cord 22 is amplified. It is suppressed.

As described above, in the vehicle receiving antenna device, since the bar antennas 1, 2, 3, 4, 5, and 6 also receive the radio waves captured by the overhead wire 25, good reception sensitivity is obtained. . Further, in this vehicle receiving antenna device, since the axis of each high-frequency magnetic core 7 of each of the bar antennas 1, 2, 3, 4, 5, and 6 is parallel to the overhead wire 25, The antennas 1, 2, 3, 4, 5, and 6 do not receive so-called sliding noise generated by the sliding of the overhead wire 25 and the contact 24, so that good reception can be performed.

In this vehicular receiving antenna device, a substantially omnidirectional receiving sensitivity can be obtained. That is, as shown in FIG. 5, each of the bar antennas 1, 2, 3, 4, 5, 6 and the axis of each high-frequency magnetic core 7 are indicated by arrows H and V in FIG. If the bar antennas 1, 2, 3, 4, 5, and 6 are arranged in a direction perpendicular to the overhead line 25, the reception sensitivity of the bar antennas 1, 2, 3, 4, 5, and 6 will be Is the so-called eight-character directivity centered at. In this case, each of the bar antennas 1, 2, 3, 4, 5, and 6 is connected to the overhead wire 25.
And the sliding noise with the contact 24 is easily received. On the other hand, like the receiving antenna device for a vehicle according to the present invention, each of the bar antennas 1, 2, 3, 4, 5, and 6 is indicated by an arrow A in FIG. When the antenna is arranged in a direction parallel to the overhead wire 25,
The receiving sensitivities of 1,2,3,4,5,6 become almost omni-directional, so that good reception can be performed regardless of the difference in the direction in which radio waves propagate.

In the vehicular receiving antenna device according to the present invention, the number of the bar antennas can be appropriately set according to the frequency band of the radio wave to be received.

H. Effects of the Invention As described above, in the vehicular receiving antenna device according to the present invention, the bar antenna attached to the body of the vehicle that is supplied with power from the overhead line and travels in the direction along the overhead line has a high-frequency magnetic core. Is made parallel to the overhead wire. Therefore, the bar antenna can satisfactorily receive the secondary radiated radio wave from the overhead wire.

The bar antenna does not receive sliding noise between the overhead wire and a contact that comes into contact with the overhead wire to receive power supply from the overhead wire, and has a substantially omnidirectional reception sensitivity. Having.

That is, the present invention can provide a vehicular receiving antenna device capable of obtaining a good receiving sensitivity while achieving downsizing and simplification of the configuration.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing the configuration of a vehicular receiving antenna device according to the present invention and a state in which the vehicular receiving antenna device is mounted on a vehicle body of a train. FIG. 2 is a front view, partially broken away, showing the configuration of the above-described vehicle receiving antenna device and a state in which the vehicle receiving antenna device is attached to the train body. FIG. 3 is a plan view, partially broken away, showing the configuration of the above-described vehicle receiving antenna device and a state in which the vehicle receiving antenna device is mounted on the train body. FIG. 4 is a side view, partially broken away, showing the configuration of the vehicular receiving antenna device and the state in which the vehicular receiving antenna device is mounted on the train body. FIG. 5 is a perspective view for explaining the direction of the axis of the high-frequency magnetic core of the bar antenna of the receiving antenna device for a vehicle and the direction of the overhead wire. FIG. 6 is a block diagram schematically showing a configuration of an amplifying device used together with the above-described vehicle receiving antenna device. FIG. 7 is a perspective view, partially cut away, showing the configuration of a conventional vehicular receiving antenna device. 1 1st bar antenna 2 2nd bar antenna 3 3rd bar antenna 4 4th bar antenna 5 5th bar antenna 6 6th Bar antenna 7: High-frequency core 20: Body 25: Overhead wire

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01Q 1/32

Claims (1)

(57) [Claims] 1. A bar antenna which is supplied with power from an overhead wire and is attached to a vehicle body of a vehicle traveling in a direction along the overhead wire, wherein the bar antenna has an axis of a high-frequency magnetic core parallel to the overhead wire. Vehicle receiving antenna device.