JPH03150934A - Transmission system using rail - Google Patents

Abstract

PURPOSE:To constitute an economical transmission system with excellent work performance by using an unbalanced transmission circuit placed between a rail and ground to send a high frequency signal. CONSTITUTION:A rail mount metallic fixture 39 is provided to a hot line of two lead wires 8 for input and output to a transmitter 4 and a receiver 8 and one of the lead wires 8 connects to the rail 1. The cold wire of the lead wires 8 of the transmitter 4 and the receiver 6 connects to ground via an earth rod. Then the transmitter 4 sends a carrier signal modulated in 2-2.5MHz to the rail 1 at all times via an insulation capacitor 10. Thus, the high frequency signal is sent through the unbalanced transmission circuit between the rail and ground. Thus, a transmission system with economy and excellent job performance is realized.

Description

[Detailed Description of the Invention] (Field of Application of the Invention) The present invention can be applied to a transmission means used to notify workers who perform track maintenance work near or inside railway tracks of the approach of a train. , concerning the improvement of transmission systems using rails.

(Background of the Invention) Transmission systems that transmit signals using rails as electric circuits are widely used in the field of railway signals, and the necessary frequencies, voltages, etc. are selected and used depending on the purpose.

This transmission circuit is usually called a "track circuit", and unlike general communication lines, this electric circuit is free from line disconnections, crosstalk, etc., and has constant potential noise.
It has favorable characteristics as a transmission line, and is widely used for various signal transmissions necessary for railway operation, as it allows for economical construction of highly reliable transmission systems.

In this transmission system, if the supplied power can be used as is at low frequencies below the commercial frequency, it is relatively easy to increase the supplied power, and impedance matching between the transmitter/receiver and the track circuit is not particularly considered. However, sufficient transmission is possible.

However, when transmitting signals with frequencies higher than the audio frequency band, it is necessary to emphasize transmission efficiency, and impedance matching between the track circuit and the transmitter/receiver is as accurate as possible to achieve efficient and However, based on the structure and usage of such a transmission system, the transmission system must be fixedly installed, and it is not possible to use portable or mobile equipment. It was difficult to do so.

On the other hand, there are many accidents in which workers performing track maintenance work between or within railway tracks fail to notice an approaching train and come into contact with the train, resulting in death or injury. The 5-position system that accurately reports the approach of a train is extremely important for safe work, but when configuring this Q-worker train approach warning system, it is necessary to use the rail as a transmission line for the transmission system necessary for configuring the system. The effective use of line installation 4
This is extremely advantageous in constructing an economical and highly reliable transmission system, including the fact that it can be omitted. In this case, the transmitting/receiving end must be located at any necessary position determined by the current working situation, so the transmission system cannot be permanently installed and used effectively.

Therefore, it is composed of a portable transmitting/receiving 4M device that can be installed at the work site promptly at the required time to start work, and can be removed gracefully at the end of work, and can be used reliably even in non-electrical work. Transmission systems using rails have been in high demand as a means of transmission for train approach warning systems for workers, which ensure the safety of daily track maintenance work.

(Objective of the Invention) The object of the present invention is to solve the above-mentioned problems, to be easily usable at any point on a railway track, and to transmit signals using rails without considering impedance matching with the track circuit. The purpose of the present invention is to provide an economical and easy-to-operate transmission system that efficiently performs the following tasks.

(Features of the Invention) In order to achieve the above object, the present invention forms a transmission circuit with one or both sides of a pair of rails as the hot side of the transmission circuit, and the ground as the cold side of the transmission circuit, and The present invention is characterized in that signals are transmitted using a frequency of 2.0 to 2.5 MHz, and high-frequency signals are transmitted by an unbalanced transmission circuit between the rail and the ground.

(Embodiment of the Invention) FIG. 1 is a configuration diagram of a transmission system using rails, which is an embodiment of the present invention.

An embodiment of the present invention will be described as an example in which the present invention is used in a train approach warning device for workers.

In the track of the train signal system in which the transmission system according to the present invention is utilized, the rail 1, which is the negative side feeder wire for the direct current supplied to the train, is DC-insulated by the rail insulation 2. A closed section of the train signal is formed by feeding direct current through the impedance pound 3, and the length of this section is usually about 800 to 1200 m.

The transmitting device 4 of the transmission system of this method is located at any work site, at a required distance away from the work site in the direction in which the train is coming, together with a train detection device 5 (separately prepared) at the starting point. The receiving device 6 is attached to the rail l on one side, and the receiving device 6 is connected to a train detecting device 7 (separately prepared) at the terminal point.
and at a location near the work site in the direction of train departure.
It is also attached to rail 1.

FIG. 2 is an explanatory diagram showing a method of attaching the transmitting device 4 and the receiving device 6 to the rail 1.

Both the transmitting device 14 and the receiving device 6 are equipped with a rail mounting bracket 9 at the end of the hot side of the two lead wires 8 for human output, which makes it easy to connect the lead wires 8. Connect to rail 1.

The other wires on the cold side of the lead wires 8 of the transmitting device 4 and the receiving device 6 are grounded to the earth by a grounding rod or the like.

The frequency band of the carrier signal used in the transmission system of the present invention avoids the signal frequency band and medium wave broadcasting frequency band already used in the track circuit, so there are 2 to 2 vacant usable frequency bands. Uses the 5MHz band.

The transmitting device 4 constantly sends out a modulated carrier signal of 2 to 2.5 M) Iz to the rail l via an insulating capacitor [0 (about several μF). When a train approaches and the train detection device 5 at the starting point operates, train approach information is transmitted to the transmitting device 4, and the transmitting device 4 stops transmitting the carrier signal that is constantly being transmitted for a certain period of time.

The carrier signal is transmitted by rail 1 and isolated capacitor 1
1 (on the order of several μF), but when it detects a state in which the carrier signal cannot be received for a certain period of time, the receiving device 6 self-maintains that state,
At the same time, the status is sent as an output to the alarm device 12, and the alarm device 12 issues a train approach warning to the worker.

When the train passes the work site, the train detection device W7 at the terminal point
operates, and the information is transmitted to the receiving device 6. Based on this information, the receiving device 6 cancels the self-holding state caused by detecting the interruption of the carrier signal for a certain period of time, and thereby the alarm device 1
2 automatically stops the train approach warning.

Experiments on actual railway lines have confirmed the practicality of the unbalanced transmission system between one side rail l and the ground according to the present invention.

Furthermore, the potential noise is limited to the induction of commercial frequencies and the radiation of medium-wave broadcast waves, and can be easily addressed in the actual implementation of the device.

In addition, if the work site is at the end of a train signal block section where impedance bond 3 is installed,
As shown in the figure, by connecting the transmitting device 4 and the receiving device 6 to the balanced midpoint 13 of the impedance bond 3, the signal can be transmitted by the rails l on both sides, and the transmission level of the carrier signal can be improved. Can be done.

In addition, if it is necessary to transmit a carrier signal across a train signal block section depending on the work site, the rail insulation 2 can be connected by short-circuiting both ends of the rail insulation 2 of one rail l used as a transmission circuit with a capacitor. Can be bypassed.

If the railway track is double-track, the transmitter 4 can be installed in both directions around the work site, and in this way, the present transmission system can easily and economically configure a transmission system between arbitrary locations. becomes possible.

By effectively using the rails on one or both sides as signal transmission circuits, it is possible to lay contact lines and check line conditions, especially in line sections with high train density and when sufficient work time is not available. It is possible to configure a practical transmission system such as the ability to omit confirmation.

(Effects of the Invention) As explained above, according to the present invention, a transmission circuit is formed with one or both sides of a pair of rails serving as the hot side of the transmission circuit, and the ground being the cold side of the transmission circuit, and the carrier frequency of the signal is Since the signal is transmitted using 2.0 to 2.5 MHz, and the high frequency signal is transmitted to the unbalanced transmission circuit between the rail and the ground, it can be transmitted at any point on the railway line. It is possible to provide an economical and highly workable transmission system that can be easily used for the purpose of the present invention and efficiently transmits signals using rails without considering impedance matching with the track circuit.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a transmission system using a rail on one side and grounding, which is an embodiment of the present invention, and Fig. 2 is an explanatory diagram of connecting a transmitting/receiving device to a rail in an embodiment of the present invention.
FIG. 3 is a block diagram of a transmission system using rails on both sides and grounding, which is another embodiment of the present invention. ■61. Rail, 286. Rail insulation, 3. . Impedance bond, 4. , , transmitting device , 5129
Train detection device, 611. Receiving device, 7°00 train detection device, 8.1. Lead wire, 91. . Rail mounting bracket, 10. Il, , insulation capacitor, +
2. ,,alarm device,13. ,,Equilibrium midpoint. Patent patent applicant East Japan Railway Company Toho Electric Industry Co., Ltd. Minoru Nakamura Figure 1

Claims (1)

[Claims] (1) A transmission system that uses the rails of a railway track as a signal transmission circuit, in which one or both sides of a pair of rails is the hot side of the transmission circuit, and the ground is the cold side of the transmission circuit, forming a transmission circuit, A transmission system that transmits signals using a carrier signal frequency of 2.0 to 2.5 MHz.