JPS5827681B2 - Mounting structure of inductive wireless loop antenna for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mounting structure for an inductive wireless loop antenna for a vehicle running at high speed.

This antenna is for detecting the position of a vehicle traveling at a high speed. It is attached to the vehicle, and it emits radio waves from the antenna. Due to the twisted state of the twisted wire, a pulse-like output is generated in the twisted wire.

The driving state of the vehicle is detected based on the output, and the output is a highly directional guided wave.

Therefore, when attaching the antenna to a vehicle, if the loop antenna is directly attached to the outside of the vehicle, electrical effects may occur due to the vehicle outer panel, which is usually made of metal. , this image acts to cancel the current flowing through the loop antenna, resulting in a decrease in the output of the loop antenna.

Additionally, if a window is provided on the outer panel of the vehicle to prevent such images and a roof antenna is attached to the window, a current flows around the window in the opposite direction to the current flowing through the loop antenna. This also results in a decrease in output.

Furthermore, if an opening like the window is provided, it causes fluctuations in wind pressure, which is inconvenient for vehicles traveling at high speed. ), the coupling loss Lc between the loop antenna and the guided radio line increases, resulting in a decrease in the power input to the guided radio.

Lc=20 log − to −Q (d B ) −・”
..." = (1) Lc: Coupling loss: Constant determined by various constants of the transmitter loop antenna and the guided radio line. On the other hand, the outer panel of the vehicle is open at the bottom to attach the running wheels for running. It is covered with an equal average of 100% and has a complex shape.

For this reason, as described above, the back electromotive force generated is non-uniform, which has a non-uniform effect on the radio waves output from the antenna, resulting in a drawback that there is a risk of erroneous detection in detecting the position of the vehicle.

In view of the above points, the present invention provides an opening at a position corresponding to the guided wireless line on the outer panel of the vehicle, and provides an FRP cover that has no electrical influence on the opening to cut off the current flowing around the opening. By inserting an insulator as much as possible to form part of the area around the opening, a decrease in strength is prevented, and a decrease in the output of the loop antenna and a decrease in the resonance Q of the loop antenna are minimized, thereby preventing an increase in coupling loss Lc. At the same time, the purpose is to prevent the adverse effects of uneven back electromotive force.

Next, the present invention will be explained with reference to an embodiment shown in the drawings.

Figure 1 shows the reinforced plastic (F) covering the side opening.
RP) side view showing the state with the cover removed, 2nd
The figure is a cross-sectional view of the arch in FIG. 1, and FIG. 3 is a cross-sectional view of the arch in FIG.

In the figure, 1 is a vehicle body, 2 is an opening provided in a position corresponding to the guided radio line 9 of the vehicle body 1, and 3 is a ring 5 that connects the opening 2 with a ring 5.
The FRP cover has a sandwich structure made of FRP and is fixed with bolts, etc.

4 is a loop antenna, 5 is an antenna mounting bone that supports the loop antenna 4, and 6 is a lower stay forming the peripheral edge of the opening 2, which is supported in an electrically insulated state via an insulator 7. and is attached to the lower peripheral edge of the opening 2 with bolts 8.

The guided radio line 9 is for communicating with the loop antenna 4.

According to this configuration, since the lower stay 6 is attached to the vehicle body 1 with bolts 8 at the peripheral edge of the opening 20 via the insulator 7, an electrically open loop occurs and a back electromotive force is generated on the outer panel. There is no negative effect on the loop antenna 4.

In addition, since the front surface of the loop antenna 4 is covered with the FRP cover 3, there is no adverse effect such as electrical imaging on the loop antenna 4, and the strength of the lower stay 6 at the periphery of the opening 2 is reduced.
is firmly fixed with bolts 8 through an insulator 7, and the opening 2 is covered with an FRP cover 3 and fixed with bolts or the like, so it is strong.

Furthermore, since no back electromotive force is generated on the outer panel as described above, there is no risk of erroneous detection due to non-uniform back electromotive force that has conventionally been generated.

In the above embodiment, the structure in which the loop antenna 4 is provided inside the opening 2 and covered with the FRP cover 3 has been described, but the structure is not limited to this.
The structure may be such that the loop antenna 4 is attached at a position corresponding to the outer plate so as to double as the outer plate.

At this time, the opening 2 is configured to form an open loop as in the above embodiment.

As explained above, according to the present invention, the loop antenna is provided in the opening, the opening is covered with an insulating material such as FRP, and the insulating material is interposed in a part of the periphery of the opening. The electrical adverse effects of the loop antenna can be minimized without reducing its strength.

[Brief explanation of drawings]

Fig. 1 is a side view of a vehicle equipped with an inductive wireless loop antenna mounting structure according to an embodiment of the present invention, Fig. 2 is an arch sectional view of Fig. 1, and Fig. 3 is an Ei sectional view of Fig. 2. It is. 1... Vehicle body, 2... Opening, 3...
...FRP cover 4...Loop antenna, 5.
...Antenna mounting bone, 6...Lower stay, 7...Insulator, 8...Bolt, 9.
...Guided radio line.

Claims (1)

[Claims] 1. An opening is provided in the vehicle body at a position corresponding to the guided radio line, a loop antenna is attached to the opening, the opening is covered with an insulating cover, and the periphery of the opening is electrically connected to the periphery of the opening. A mounting structure for an inductive wireless loop antenna for a vehicle, characterized in that an insulating material is interposed to form an open loop.