JPS5945545B2 - Check-in/check-out type train detection circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a check-in/check-out type train detection circuit in which an inductive loop antenna into which a band-elimination filter is inserted is installed over the entire area of one block section. is obtained,
It is also an object of the present invention to provide a detection circuit of this type that is effective for rear blockage protection.

For rubber-tired rolling stock where the so-called track circuit-based train detection method, which detects trains by short-circuiting the rails with wheels, as is the case with general railways, cannot be applied, a train detection method called the check-in/check-out method is generally adopted. .

This type of detection method 6s stores that a train has entered a block section when a check-in signal wave transmitted from a car in front of the train is received by a loop antenna installed at the entrance of the block section. Furthermore, as the train progresses, the loop antenna installed at the entrance of the front block section receives a checkout signal wave transmitted from the rear car of the train, thereby clearing the memory of the presence of the train in the rear block section. be.

The present invention provides the above-mentioned check-in/check-out type train detection circuit, in which an inductive loop antenna is installed over the entire area of one block section, so that the presence of a train can be detected no matter where the train is within the section. By inserting a band-stop filter into the loop antenna, a short and small checkout induction loop is constructed to increase the effect of rear blockage protection.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of equipment for carrying out the present invention, in which an inductive loop antenna L is installed on the ground along the travel path T of the vehicle C so as to cover the entire block section 2T. to be laid.

The same applies to block sections IT and 3T, and henceforth, the equipment of section 2T will be representatively explained.

A band elimination filter BEF for blocking the passage of the checkout signal wave is inserted into the loop antenna L to form a short and small guidance section L for checking the opening of the rear block section.

When the vehicle C is not in the section 2T, a signal from the inspection signal transmission system 1 for checking the opening of the section 2T is received by the inspection signal reception system 2 via the loop antenna L.

That is, the reference signal transmission system 1 includes a modulator MD1 that modulates a carrier wave fc generated by an oscillator Gc with a modulation wave fm generated by an oscillator Gm, a band filter BPF1, an amplifier AMPL, etc., and modulates the carrier wave fc with a modulation wave fm. The reference signal is transmitted to the loop antenna L via the matching transformer ST1 of the transmission system 1 and the transmission cable TC1, the transmission cable TC, and the matching transformer ST2 of the loop antenna L.

In addition, the reference signal receiving system 2 includes a filter WBF having a required wide band, an amplifier AMP2, a limiter LIM1 and a detector DT.
, a bandpass filter BPFm for the modulated wave fm, a Schmitt circuit SM1, a rectifier RF1, a reference relay CHR, etc., which are transmitted to the loop antenna L, and a matching transformer RT1,
The reference signal received by the receiving system 2 via the transmission cable TC2 and the matching transformer RT2 has its noise removed by the broadband filter WBF, is amplified by the amplifier AMP2, passes through the limiter LIM, and is detected by the detector DT. be done.

In this case, the amplitude level of the amplified wave is set to be below the limit level of the limiter LIM.

Therefore, the limiter LIM does not operate.

The detected reference signal is passed through the bandpass filter BPF of the modulated wave fm.
m and is demodulated into a modulated wave fm, which is then sent to the Schmitt circuit SM1.
After the level is determined, the signal is rectified by the rectifier RF1 and the reference relay CHR is operated.

Next, talking about the on-board equipment, there is an oscillator GI for the check-in signal wave fi at the front of the vehicle C, an on-board antenna FA at the front that transmits this signal wave toward the loop antenna L on the ground, and an on-board antenna FA at the rear. The vehicle has a checkout signal wave f
There is an oscillator GU of vehicle C;

The induction levels of the signal waves fi and fu in the loop antenna L are set 4 to be higher than the reference signal.

Now, when the vehicle C enters the block section 2T from the block section 1T, the check-in signal wave fi transmitted from the on-board antenna FA to the ground antenna L is received by the reception system 2 superimposed on the reference signal, and both pass through the filter WBF. When the modulated inspection signal whose level has increased due to the superimposition is suppressed by the action of the limiter LIM, the component of the modulated wave fm is extremely reduced, the inspection relay CHR is restored, and the train entering section 2T is detected.

As vehicle C moves further and the rear vehicle enters section 2T, the rear antenna BA is located within short and small guidance section l, and the checkout signal wave fu guided by loop antenna L within section l is applied to its band-stop filter BEF. It is blocked and not transmitted to the receiving system 2, and the matching transformer ST2 and the transmission cable T
C1, is transmitted to the checkout receiving system 3 via the matching transformer ST1, passes through the bandpass filter BPF2 of the signal wave fu, the amplifier AMP2, the Schmitt circuit SM2, and the rectifier RF2 to operate the checkout relay 0UTR and block the rearward block. Detect the opening of section 1T.

However, when the rear antenna BA comes out in front of the cancellation filter BEF, the checkout signal wave fu is transmitted to the cancellation filter BEF.
Since transmission to receiving system 3 is blocked by EF, relay 0U
TR will be restored.

However, this signal wave fu is transmitted to the receiving system 2, and similar to the check-in signal fi mentioned earlier, the check relay CHR
work to restore.

The effect of this function is particularly noticeable when the train straddles the boundary of a block section, as shown by the dotted line diagram in FIG.

Although Fig. 1 shows a case where the reference signal transmission system 1 is installed on the entrance side and the reception system 2 is installed on the exit side with respect to the traveling direction of the vehicle C in the block section 2T, the installation locations of both the transmission and reception systems can be reversed. It works the same way though.

However, the position of the band-stop filter BEF is changed to rear antenna B.
The difference is that once A has passed, the checkout signal fu does not become an input to the reference signal receiving system.

FIG. 2 shows each signal wave fi in the band of frequency f.

Frequency positions of fu and fc and bandpass filter WBF.

This shows the relationship with the pass frequency band of BPF2. Filter WBF is a filter that passes three signal waves fi, fc, and fu, and filter BPF2 passes only checkout signal wave fu among the three signal waves. Filter.

As already mentioned, the band elimination filter BEF conversely eliminates the checkout signal wave fu.

However, the cancellation filter BEF can be replaced by a band pass filter, a low pass or high pass filter, a series resonator, or the like.

For example, as shown in Fig. 3, a bandpass filter BPF allows signal waves fi and fc to pass through but the signal wave fu is outside the pass frequency band.
x, etc. In this case also a low pass filter may be used which produces the same effect.

Figure 4 shows an example of a memory circuit for the presence of a train.
TTR is a train presence memory relay in block section 1T.
The symbols ITTR of the contacts constituting the circuit are the contacts of the relays with the same symbol, 1TCHR is the contact of the check relay in section 1T, and 2TOUTR is the contact of the checkout relay in section 2T.

While the train is in section 1T, the inspection relay ITCH for that section
Since R has been restored, the memory relay ITTR is de-energized and restored, and stores the presence of the train in that section.

When the tail of the train passes through section 1T and enters section 2T, the section opening check relay 1TcHRjJK of section 1T is activated, and the checkout detection relay 2TOUTR of section 2T is activated, so an excitation circuit is configured and relay ITTR is activated. The memory of the train's existence is cleared.

After that, relay 1TTR is self. Its operation is maintained by an excitation circuit via a holding contact ITTR.

The embodiments of the present invention have been described above, but to discuss the effect of inserting the band-stop filter BEF, which is a feature of the present invention, first, the section check relay CHR is restored even if the train is in the position of the blocked section. The presence of trains is memorized and the configuration has sufficient train detection functionality.

Furthermore, the present invention forms a short and small induction loop Jl for a checkout signal at the entrance end of the induction loop antenna L by a band elimination filter BEF, and receives a checkout signal from onboard the vehicle in the short and small induction loop I. Since the system is configured to perform checkout detection, the block release operation becomes safer and the security function can be improved.

In other words, in check-in/check-out type train detection, the block is released by checking relay 1TCHR and checkout relay 2T, as explained in the example in Figure 4.
This is done by the operation of OUTR.

Therefore, if there are vehicles in both section 1T and section 2T, the on-board transmitter of the vehicle traveling in section 1T will fail and check-in/check-out signals will no longer be transmitted from the vehicle. Then, the inspection relay ITCHR in section 1T operates.

If checkout relay 2TOUTR is operating at this time, train presence memory relay ITTR will be activated, and the block in section 1T will be forcibly canceled even though there are vehicles in section 1T. There is a risk that the above serious problem may occur.

Therefore, it is safer to perform the reception loop for checkout detection, which detects the advance of a vehicle from a block section by activating checkout relay 0UTR, within a small and limited range as much as possible. .

The present invention uses a band elimination filter BEF to form a short and small loop antenna l for receiving a checkout signal at the entrance end of an inductive loop antenna L that spans the entire width of the section, and performs checkout detection only in this short and small loop antenna portion. With this configuration, the above-mentioned safety problems can be solved as much as possible, and the safety of vehicle operation can be further improved.

In addition, since it is a short and small loop antenna, it is resistant to noise, and furthermore, a short and small induction loop can be installed by simply providing a band-stop filter, and the economical effect is also significant.

[Brief explanation of the drawing]

The drawings relate to an embodiment of the check-in/check-out type train detection circuit according to the present invention. Fig. 1 is a schematic diagram of the equipment implementing the present invention, and Figs. 2 and 3 show the signal waves and bandpass filters used. FIG. 4 is an example diagram of a train detection storage circuit. IT, 2T, 3T...Block section, 1TTR・
...Memory relay, L...Induction loop antenna, BEF...Band elimination filter, L...
...Short guidance section, fu...Checkout signal.

Claims (1)

[Claims] 1. By superimposing the check-in signal from the train on the check signal for opening the block section, the check signal is suppressed and the entry of a train into the block section is detected, and at the same time, the check-out signal from the train is received. In a check-in/check-out type train detection circuit that detects departure from a block section using A check signal transmission system for transmitting is connected to the other end, and a check signal receiving system for receiving the check signal is connected to the other end, and furthermore, the end of the induction loop antenna on the block section entrance side is connected to a checkout system from onboard the vehicle. A checkout signal receiving system for receiving signals is connected, and a band elimination filter for blocking only passage of the checkout signal is inserted at a position a short distance from the entrance end, and a band elimination filter for blocking only passage of the checkout signal is connected to the entrance side of the induction loop antenna. A check-in/check-out type train detection circuit characterized by forming a short inductive loop at the end for a check-out signal.