JPS6232652B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inductive radio device used in a third rail type (electric) railway.

Conventionally, the ground return method has been mainly used for guided radio communication on third-rail railways. In the ground return method, guide wires are generally installed at a height of 1 m to 4 m on both sides of the tram track, and a signal current is passed through the guide wires for transmission from the ground station, and the mobile station moves the magnetic field generated by the guide wire current. Receive with station antenna. Transmission from the mobile station is performed by transmitting signal power from the mobile station transmitter to the third rail from the collector shaft of the train connected via a capacitor, and causing a signal current to flow through the third rail. That is, by using the electromagnetic coupling between the third rail and the guide wire, the mobile station radio waves are transmitted to the guide wire and received by the fixed station. In this method, since the guided line returns to the ground, it is very easy to receive external radio waves, and if guided wireless communication or power line carrier is used in the vicinity, radio wave interference will occur, so it is not possible to use nearby frequencies. The drawbacks of such a conventional method will be explained in more detail.

FIG. 1 is a system diagram of a conventional ground-return type guidance radio device for a third-rail railway, and FIG. 2 is a cross-sectional view showing the relationship between a running vehicle (train), a rail, etc. In these figures, 1 is a mobile station transmitter, 2 is a coupling capacitor, 3 is a third rail, 4 is a running rail, and 5 is a coupling capacitor.
is the collector shoe, 6 is the terminating resistor, 7 is the guide wire, 8 is the line coupler, 9 is the receiver, 10 is the train,
11 is the rail level (RL). Now, the frequency transmitted from the transmitter 1 at the mobile station 10
The high frequency output of _{No. 1} is sent to the third rail 3 via the coupling capacitor 2 and the collector shoe 5, and flows to the third rail. The voltage induced in the guide wire 7 by the current in the third rail is transmitted to the receiver 9 through the line coupler 8. In addition, the guide line 7, the third rail 3,
The positional relationship of the rails 4 is as shown in FIG. 2, and one guide wire 7 is installed at a height of about 1 m to 4 m above the level 11 of the rails. Since the earth return guide line 7 is an open guide line, it receives not only the electromagnetic field from the third rail, but also all electromagnetic fields generated from sources other than the third rail. For this reason, interference occurs if guided radio equipment is operated nearby or power line carriers are used. In other words, it has the disadvantage of being weak against external noise.

An object of the present invention is to reduce the influence of external radio waves in a guidance radio device used in a third-rail railway, so that the device can be used in coexistence with other guidance radio equipment and power carrier equipment.

Figure 3 is a system diagram of a third-rail railway guidance radio embodying the present invention, and Figure 4 is a second diagram of Figure 3.
It is a sectional view similar to the figure. The transmitter 1 and coupling capacitor 2 of the mobile station are the same as those shown in FIG. 1, and send the mobile station transmission wave to the third rail.

The third rail 3 is located within a range of 0.1 to 0.5m near the third rail.
A metal circuit guiding wire 7' with a line width of about 0.1 to 0.3 m is installed parallel to the line. The mobile station transmission wave flows to the third rail 3 and generates an electromagnetic field in the vicinity of this, and the nearby metal circuit 7'
generates an induced voltage. This induced voltage is transmitted to the receiver 9 as in the earth return method.

On the other hand, with respect to external radio waves, the induced voltage is small because the guiding wire 7' has a metal circuit structure and the line width is narrow, and the guiding wire of the present invention is resistant to external noise.

The advantages of implementing the present invention as described above are:
The guided radio used in the third rail type railway transmits the mobile station on the third rail using capacitor coupling.
If reception is performed through narrowly spaced metal circuit induction wires, (a)
The parallel section between the third rail and the metal circuit guide line is approximately 1 km.
As mentioned above, the distance between the lines is narrow, less than 0.5m, so the coupling loss of radio waves is small. (b) Since the induction wire is a metal circuit that maintains balance with the ground, it is not easily affected by external radio waves. (c) Even if the power line and the third rail intersect or are parallel to each other for power line carrier communication at a height of about 15 meters above the ground, the distance between the guide line and the third rail is much closer than between the guide line and the power line. , even if the same frequency is used, a sufficient C/N ratio can be obtained, so the same frequency can be used, which is a significant practical advantage.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of a conventional ground-return type guidance radio device for third-rail railways, Fig. 2 is a sectional view showing the relationship between running vehicles and rails, etc., and Fig. 3 is a guidance radio device implementing the present invention. FIG. 4 is a sectional view of FIG. 3 similar to FIG. 2. 1...Mobile station transmitter, 2...Coupling capacitor,
3...Third rail, 4...Rail, 5...Collector shoe, 6...Terminal resistor, 7...Guiding wire, 7'
...Metal circuit guide wire, 8...Line coupler, 9...
Receiver, 10...train.

Claims (1)

[Claims] 1 A third method characterized in that a guide line connected to the third rail and connected to a ground fixed station at its end is installed as a metal circuit parallel to and within 0.5 m of the third rail with a line spacing of less than 0.5 m. Guidance radio equipment for rail railways.