JP6944415B2 - On-board communication device - Google Patents

Description

The present invention relates to an on-vehicle communication device, and is particularly suitable for an on-vehicle communication device mounted under the floor of a railway vehicle.

One of the means of communication between a railroad vehicle and ground equipment is non-contact communication using an on-board element and a ground element. In non-contact communication, the on-board child outputs a power wave for activating the ground element while the train is running, and the ground element activated by receiving the electric power wave sends and receives an information wave to and from the on-board child. , Communicate information between the ground and the vehicle. The on-board child uses a resonance loop antenna to improve the output efficiency of the power wave, and improves the output efficiency by matching the resonance frequency of the antenna with the frequency of the power wave.

However, when mounting the on-board element on a vehicle, if there is a metal object around the on-board element, the resonance frequency of the on-board element changes due to the electromagnetic influence of the metal object, and the output efficiency of the power wave decreases. do. Since the arrangement condition of the metal object is different for each vehicle, the amount of change in the resonance frequency is also different for each vehicle, which makes adjustment difficult.

In response to the above problems, for example, Patent Document 1 has the following items. That is, "a ground element equipped with a resonance circuit whose resonance frequency is controlled based on the signal information from the signal is installed on the ground outside a predetermined distance from the installation position of the signal that controls the operation of the train, and the train. An on-board child equipped with an oscillating circuit that oscillates at a constant frequency and a feedback circuit connected to the oscillating circuit is installed in the train so as to face the ground element, and the signal information from the signal device is used to obtain the above-mentioned. When allowing the train to travel, the resonance frequency of the resonance circuit is matched with the oscillation frequency of the oscillation circuit, and when the train is stopped, the resonance frequency is controlled to be different from the oscillation frequency. When the on-vehicle element faces the ground element, if the oscillation frequency is different from the resonance frequency, the oscillation frequency is caused by electromagnetic induction between the feedback circuit of the on-vehicle element and the resonance circuit of the ground element. In an automatic train stop system in which the train side detects the state of being oscillated to the resonance frequency and automatically stops the oscillator, it is located near the feedback circuit of the on-board element and has an electromagnetic effect on the feedback circuit. A shield plate made of a material having a high magnetic permeability and a high resistance is provided between the body and the feedback circuit. "

Japanese Unexamined Patent Publication No. 10-53135

According to the above-mentioned description of Patent Document 1, in order to provide the shield plate between the feedback circuit and the conductor that has an electromagnetic effect on the feedback circuit, there are a plurality of conductors around the feedback circuit. However, there is a problem that a shield plate corresponding to the number of conductors is required, which increases the mass and cost. Further, if the conductor is a metal cover for protecting the device from electromagnetic noise and flying objects, it may not be possible to secure a space for mounting the shield plate.

Further, the shield plate is a material having high magnetic permeability and high resistivity, and for example, ferrite of a sintered body containing iron oxide as a main component can be considered. However, among ferrites, Ni-Zn ferrite, which has a high resistivity, has a large magnetic core loss, so that the transmission efficiency of power waves is lowered. On the other hand, Mn-Zn ferrite having a small magnetic core loss cannot satisfy the condition shown in Patent Document 1 because of its low resistivity. Furthermore, ferrite is vulnerable to vibration and impact, and may be damaged when used in moving objects such as railroad vehicles. If it is damaged, its magnetism will be significantly reduced, and the desired shielding effect of the feedback circuit will not be sufficiently obtained. ..

As described above, there is a problem that it is difficult to investigate and obtain a high magnetic permeability material having high magnetic permeability, high resistivity, low loss, and strength that can be used for moving objects such as railway vehicles.

Therefore, the present invention is an on-board communication device capable of canceling an electromagnetic influence of surrounding conductors, that is, a change in resonance frequency, and suppressing a decrease in power wave output efficiency without using a shield plate and a high magnetic permeability material. I will provide a.
The present invention also provides an on-vehicle communication device in which the dimensions of the members used are suppressed and the increase in mass and cost is suppressed.

In order to solve the above problems, the on-board communication device according to the present invention includes a loop coil, a capacitor connected in series or in parallel with the loop coil, a power supply unit for supplying power to the loop coil and the capacitor, and a loop coil. The loop coil radiates a magnetic field due to a current having a resonance frequency by a resonance circuit composed of a loop coil and a capacitor, which includes a housing for storing a capacitor and a power feeding unit and a conductor detachably fixed to the housing. The conductor is characterized in that it is arranged in a direction in which it intersects with the magnetic field.

According to the on-board communication device according to the present invention, the resonance frequency is adjusted in a state of being electromagnetically affected in advance by a metal plate which is a conductor included in the on-board communication device. For this reason, if there is a metal object around the vehicle when it is mounted on the vehicle and the resonance frequency changes due to the electromagnetic effect from this metal object, the metal plate is removed to remove the electromagnetic effect given in advance and the resonance frequency. Can cancel out the change in.

Further, by reducing the size of the metal plate and arranging it in the vicinity of the conducting wire of the loop coil having a high magnetic flux density, a high electromagnetic influence can be exerted on the small metal plate, and the mass and cost of the metal plate can be suppressed.

Also, when mounting on vehicles with different degrees of electromagnetic influence from surrounding metal objects, the electromagnetic influence of the metal plate can be adjusted by adjusting the distance between the metal plate and the loop antenna with a spacer according to the degree of influence. That is, since the amount of change in the resonance frequency can be adjusted, it can be applied to a vehicle having all the arrangement conditions of metal objects.

Further, since a high magnetic permeability material is not required, there is no concern that the members will be damaged even when used in an environment with severe vibration conditions such as a railway vehicle, and it is possible to prevent a decrease in power wave output efficiency due to magnetic core loss.
Issues, configurations and effects other than those described above will be clarified by the description of the following embodiments.

It is a perspective view which shows the structure of the on-vehicle communication device which concerns on Example 1 of this invention. FIG. 5 is a perspective view showing a configuration in which a metal plate is removed from the on-vehicle communication device according to the first embodiment. It is a perspective view which shows the structure of the on-vehicle communication device which concerns on Example 2 of this invention. It is a perspective view which shows the structure of the on-vehicle communication device which concerns on Example 3 of this invention. It is a top view which shows an example of the structure which arranges a metal plate inside a loop coil. It is a top view which shows an example of the structure which arranges a metal plate outside a loop coil. It is a top view which shows an example of the structure which makes a loop coil and a capacitor resonate in parallel. It is a top view which shows an example of the structure which makes a loop coil a figure eight shape. It is a top view which shows another example of the structure which makes a loop coil a figure eight shape. It is a side view which shows an example of the structure when the on-board child is mounted under the train floor where there is no metal object around. It is a side view which shows an example of the structure at the time of mounting under the train floor where a metal object exists at a position away from the on-board child. It is a side view which shows an example of the structure when the on-board child is mounted under the train floor where there is a metal object in the vicinity. It is a figure which shows an example of the structure of the system which applies the on-vehicle communication device which concerns on this invention. It is a top view which shows the structure which makes the shape of a metal plate U-shaped. It is a top view which shows the arrangement structure of the metal plate of the on-board communication device which concerns on Example 4 of this invention. It is a top view which shows the structure which arranges a metal plate on a loop coil. It is a side view which shows the structure which arranges the metal plate on the side surface of a housing.

Hereinafter, each of Examples 1 to 4 will be described in detail with reference to the drawings as a mode for carrying out the on-vehicle communication device according to the present invention.
Prior to explaining each embodiment, a system using an on-board communication device will be described.

FIG. 13 is a diagram showing an example of a configuration of a system to which the on-board communication device according to the present invention is applied.
As shown in the figure, the on-board element 100 mounted on the train 210 transmits and receives transmission / reception information from the on-board transmitter / receiver 110 from the on-board element 100 to the ground element 400 as electromagnetic waves, and the ground element 400 which is a ground side signal equipment. Communicate with.

In the case of a ground element called a "non-powered ground element" in which the ground element 400 does not have a power source by itself, it is necessary to wirelessly and non-contactly supply electric power for driving the ground element 400 from the train 210. The electric power transmitted by this radio is called a "power wave", and the electric power wave 410 is an unmodulated signal having a constant frequency.

The ground element 400 receives the unmodulated power wave 410 transmitted from the train 210, rectifies it, activates the circuit in its own ground element with the DC-converted power, and supplies the power wave 410 from the train 210 to itself. The control information 420 is transmitted from the ground element 400 to the on-board element 100 while the circuit of the above is activated (that is, while the train 210 is approaching the vicinity of the ground element 400). The electromagnetic wave of the control information 420 is called an "information wave". The control information 420 is also transmitted from the train 210 side.
As described above, in order to activate the unpowered ground element 400, it is necessary to supply electric power (electric power wave 410) from the train 210 via the on-board element 100.

FIG. 1 is a perspective view showing a configuration of an on-board communication device according to a first embodiment of the present invention.
FIG. 1 shows an on-vehicle element 100 of a transponder transmission / reception system as an example of an on-vehicle communication device. The on-board child 100 stores a loop coil 20, a capacitor 21, a power feeding unit 22, a mounting wire (on-board child connecting cable) 11 for supplying electric power to the power feeding unit 22, and these. The housing 1 is provided with a vehicle connecting portion 3 and a bracket 5 for connecting the housing 1 to the vehicle.

The on-board communication device according to the first embodiment is applicable to the on-board child used in the transponder transmission / reception system, and is a railway security system ATS-P (Automatic Train Stop-Pattern) using the transponder transmission / reception system and an automatic operation system. It can also be applied to ATO (Automatic Train Operation) and digital ATC (Automatic Train Control).

The loop coil 20 of the on-board element 100 constitutes an LC resonance circuit with L (inductance) of the loop coil 20 and C of the capacitor 21, and adjusts the resonance frequency to one specific power wave frequency to make the power wave more efficient. Send well. However, in the case of this configuration, if a metal object (conductor) is present around the vehicle body element 100, an eddy current is generated in the metal object due to the magnetic field output by the loop coil 20.

Since this eddy current generates a magnetic field in a direction that interferes with the output magnetic field of the loop coil 20, the L (inductance) of the loop coil 20 decreases, and the resonance frequency changes to the high frequency side. If the deviation between the resonance frequency and the power wave frequency becomes large, the power wave output efficiency of the on-board element 100 decreases, and the starting power required for the ground element 400 cannot be supplied.

Therefore, when the present invention is not used, care should be taken not to place a metal object around the on-board element 100, or when a metal object must be arranged around the vehicle body element 100, the resonance frequency due to the influence of the metal object is taken. It is necessary to take measures such as predicting the amount of change in the above and adjusting the resonance frequency of the LC resonance circuit to the low frequency side in advance.

The on-vehicle communication device according to the first embodiment has, as components, a loop coil 20 for transmitting an electric power wave, a capacitor 21, a power feeding unit 22, and a mounting wire for supplying electric power to the electric power supply unit 22 (on-vehicle child connection). A cable) 11 and a housing 1 for storing the housing 1, a vehicle connecting portion 3 for connecting the housing 1 to a vehicle, a bracket 5, and a metal plate 2 provided between the bracket 5 and the housing 1 are provided. At this time, the metal plate 2 is arranged in the vicinity of the conducting wire of the loop coil 20.

In the on-board child 100, the electric power input from the train side is supplied to the power feeding unit 22 via the mounting line 11. The power feeding unit 22 resonates with a resonance circuit composed of the loop coil 20 and the capacitor 21, and supplies a current having the same frequency as the power wave to the loop coil 20. When a current flows through the loop coil 20, a magnetic field is radiated, which becomes a power wave.

The method of adjusting the resonance frequency of the on-board element 100 will be described in two stages: when the on-board element 100 is manufactured and when it is mounted on the train 210.

First, a method of adjusting the resonance frequency of the on-board element 100 at the time of manufacturing will be described.
Since the vehicle head element 100 includes the metal plate 2 in a direction interlinking with the magnetic field output by the loop coil 20, an eddy current is generated in the metal plate 2 to generate a magnetic field in a direction that cancels the output magnetic field of the loop coil 20. .. As a result, the L (inductance) of the loop coil 20 becomes smaller than that in the case where the metal plate 2 is not provided. In this state, that is, with the metal plate 2 attached, the capacitance of the capacitor 20 is adjusted so that the resonance frequencies of the loop coil 20 and the capacitor 21 match the power wave frequency.

Next, a method of correcting the resonance frequency of the on-board element 100 according to the arrangement of surrounding metal objects when the on-board element 100 is mounted on the train 210 will be described.

FIG. 10 is a side view showing an example of a configuration when the on-board element 100 is mounted on the underfloor 200 of a train where there is no metal object around it. The on-board child 100 is connected to the underfloor 200 of the train by using the bracket 5. At this time, since there is no metal object in the surroundings, the resonance frequency of the on-board element 100 does not change, and the vehicle can be used in the state at the time of manufacture (the state in which the metal plate 2 is attached).

FIG. 12 is a side view showing an example of a configuration when the on-board element 100 is mounted on the underfloor 200 of a train in which a metal object 10 is present in the vicinity. As the metal object 10 in the vicinity of the on-board element 100, a shield or the like that protects the on-board element 100 from flying objects such as electromagnetic noise and ballast is assumed. Due to the influence of the metal 10 surrounding the on-board element 100, a part of the magnetic field output by the on-board element 100 is interlinked with the metal object 10, so that an eddy current is generated in the metal object 10 and the output magnetic field of the on-board element 100 is generated. Generates a magnetic field in the direction that cancels out. As a result, the L (inductance) of the loop coil 20 decreases, and the resonance frequency of the on-board element 100 changes to the high frequency side.

At this time, as shown in FIG. 2, when the metal plate 2 is removed from the on-board element 100, the magnetic field in the canceling direction generated in the metal plate 2 disappears, and the L (inductance) of the loop coil 20 increases (manufacture). L (inductance), which was sometimes lowered by the metal plate, is restored), and the resonance frequency changes to the low frequency side. Thereby, the change to the high frequency side due to the influence of the metal object 10 can be canceled out, and the resonance frequency of the on-board element 100 can be made to match the frequency of the power wave.

As described above, the technical concept that is the basis of the method for adjusting the resonance frequency of the on-vehicle element according to the present invention is that the metal plate 2 is detachably attached to the on-vehicle element 100 in advance and the loop coil 20 is L (inductance). ) Is lowered to adjust the resonance frequency of the on-board element 100, and when the on-board element 100 is mounted on the train 210, depending on the installation status of the metal object 10 around the on-board element 100. By removing the metal plate 2, the L (inductance) of the loop coil 20 is adjusted to correct the resonance frequency of the on-board element 100 so that it matches the power wave frequency.

This eliminates the need to predict the installation status of the metal object 10 of the train 210 on which the on-board element 100 is mounted and adjust the resonance frequency in advance at the time of manufacturing the on-board element 100, so that the on-board element 100 having the same specifications can be used. It can be applied to both the case where there is a metal object around the installation position of the on-board child 100 and the case where there is no metal object.

Further, since the magnetic flux density is higher as the position closer to the conductor of the loop coil 20, by arranging the metal plate 2 near the conductor of the loop coil 20, even if the size of the metal plate 2 is small, a large amount of magnetic flux is chained. It can be crossed and a large eddy current is generated. As a result, a sufficient amount of frequency change can be obtained, and an increase in mass and cost due to mounting of the metal plate 2 can be suppressed.

Here, a metal plate 2 is assumed as a member used in the method for adjusting the resonance frequency of the on-board element according to the present invention, but this is a high magnetic permeability material in a moving body such as a railroad vehicle. This is because there is a high risk of damage to a member that is vulnerable to vibration and impact, and the reliability of the device cannot be ensured. As long as there is no high possibility that such a risk is involved, the present invention is not limited to a metal plate, and a conductor may be used, and a high magnetic permeability is more preferable.

As for the method of fixing the metal plate 2 in the first embodiment, any means such as screws, bolts and springs that can be easily attached and detached may be used.

Next, the mode and mutual relationship of each component will be described.
Regarding the positional relationship between the metal plate 2 and the loop coil 20, when the metal plate 2 is arranged inside the loop coil 20 shown in FIG. 5, the metal plate 2 is arranged outside the loop coil 20 shown in FIG. Either, or the case where the metal plate 2 is arranged on the loop coil 20 shown in FIG. 16 may be used. In short, the metal plate 2 is arranged at a position symmetrical with respect to the center of the loop coil 20 (including the arrangement of the metal plate 2 in Examples 3 and 4 described later).

Regarding the length (dimension) relationship between the metal plate 2 and the loop coil 20, the length (dimension) of the metal plate 2 in the lateral direction is the length of the loop coil 20 in the lateral direction of the metal plate 2. Make it less than half of (dimensions).

The connection method between the loop coil 20 and the capacitor 21 may be either the series resonance type shown in FIG. 5 or the parallel resonance type shown in FIG. 7.

The shape of the loop coil 20 may be the figure 8 shape shown in FIGS. 8 or 9, or any other shape.

The shape of the metal plate 2 is not limited to the rectangular shape shown in FIG. 1 as long as it can be installed in the vicinity of the loop coil 20, and may be, for example, a U-shaped shape shown in FIG. Further, the number of the metal plates 2 may be one or a plurality of two or more.

The material of the metal plate 2 may be selected according to desired characteristics, such as inexpensive and high-strength stainless steel, high-conductivity copper, or low-density aluminum. Further, the amount of change in the frequency related to the resonance frequency may be adjusted by changing the material of the metal plate 2 according to the arrangement state of the metal object 10 of the train on which the on-board element 100 is mounted.

FIG. 3 is a perspective view showing the configuration of the on-board communication device according to the second embodiment of the present invention.
The structural difference from the first embodiment is that the spacer 4 is provided between the metal plate 2 and the housing 1, and the other configurations are the same as those of the first embodiment.

According to the second embodiment, when the on-board element 100 is mounted on the train 210, the correction amount of the resonance frequency of the on-board element 100 can be selected from a plurality of stages.
The resonance frequency adjusting method at the time of manufacturing the on-board element 100 is the same as that of the first embodiment. At this time, the spacer 4 is not attached to the on-board element 100.

FIG. 11 is a side view showing an example of the configuration when the metal object 10 is mounted on the underfloor 200 of the train in which the metal object 10 is present at a position away from the vehicle top element 100.
In the figure, as in the first embodiment, a part of the magnetic field output by the on-board element 100 interlinks with the metal object 10, so that an eddy current is generated in the metal object 10 and the L (inductance) of the loop coil 20 decreases. Then, the resonance frequency of the on-board element 100 changes to the high frequency side. However, since the distance between the metal object 10 and the on-board element 100 is larger than that in the case of the first embodiment, the eddy current generated in the metal object 10 and the amount of change in the resonance frequency of the on-board element 100 are different from those in the first embodiment. It will be smaller than the case.

In such a case, a spacer 4 is inserted between the housing 1 and the metal plate 2 to increase the distance between the two. When the distance between the metal plate 2 and the housing 1 is increased by using the spacer 4, the magnetic field interlinking with the metal plate 2 decreases, and the L (inductance) of the loop coil 20 increases (L (decreased at the time of manufacture). Inductance) recovers) and the resonance frequency changes to the low frequency side. Since the amount of change at this time can be adjusted by arbitrarily selecting the thickness (height) of the spacer 4 and changing the distance between the metal plate 2 and the housing 1, the spacer is adjusted according to the degree of influence of the metal object 10. If the thickness (height) of 4 is set, it is possible to handle all the arrangement situations of the metal object 10 with the on-board child having the same specifications.

FIG. 4 is a perspective view showing the configuration of the on-board communication device according to the third embodiment of the present invention.
In the first and second embodiments, the metal plate 2, the bracket 5, and the housing 1 are collectively fixed by the vehicle connecting portion 3, but in the third embodiment, the metal plate 2 is molded as shown in FIG. A metal plate fixing portion 6 for fixing to the body 1 is separately provided, and the metal plate 2 and the bracket 5 are individually fixed to the housing 1.

Further, the metal plate 2 may be arranged at any position as long as it is oriented so as to interlink with the magnetic field output by the loop coil 20. Therefore, for example, as shown in FIG. 17, it may be arranged and fixed on the side surface of the housing 1. At that time, the shape of the metal plate 2 may be a flat plate or a U-shape as shown in the figure.

According to the third embodiment, since the bracket 5, the metal plate 2, and the bracket 5 are individually fixed to the housing 1, only the metal plate 2 can be attached and detached even after the on-board child 100 is mounted on the train. Therefore, workability is improved.

FIG. 15 is a top view showing an arrangement configuration of a metal plate of the on-board communication device according to the fourth embodiment of the present invention.
As shown in FIG. 15, if the loop coil 20 has a rectangular shape, if the metal plates 2 are arranged inside the four corners of the loop coil 20, the magnetic flux density interlinking with the metal plate 2 becomes even denser. The size of the plate 2 can be further reduced.

Further, for each component constituting the on-board communication device according to each of the above embodiments, for example, a metal plate is shown as a typical conductor, but the material is appropriately changed if it is in the category of the conductor. It is possible, and the materials and the like of other components can be changed as appropriate.

In the above, Examples 1 to 4 have been described as embodiments for carrying out the present invention, but the present invention is not limited to the above-mentioned Examples, and includes various modifications. For example, the present invention is not necessarily limited to those having all the configurations described above. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add / delete / replace other configurations with respect to a part of the configurations of each embodiment.

1 housing, 2 metal plates, 3 vehicle connections, 4 spacers, 5 brackets,
6 Metal plate fixing part, 10 metal objects, 11 mounting wires, 20 loop coils,
21 capacitors, 22 power supply, 100 on-board child, 110 on-board transmitter / receiver,
200 trains underfloor, 210 trains, 400 ground elements, 410 power waves, 420 information waves

Claims (11)

With a loop coil
A capacitor connected in series or in parallel with the loop coil,
A power supply unit that supplies power to the loop coil and the capacitor,
A housing for storing the loop coil, the capacitor, and the power feeding unit,
It is provided with a conductor that is detachably fixed to the housing.
The loop coil radiates a magnetic field due to a current having a resonance frequency due to a resonance circuit composed of the loop coil and the capacitor.
An on-vehicle communication device, wherein the conductor is arranged in a direction in which the conductor intersects with the magnetic field. The on-board communication device according to claim 1.
An on-vehicle communication device characterized in that the conductor is a metal plate. The on-board communication device according to claim 1 or 2.
An on-vehicle communication device characterized in that the position where the conductor is arranged is in the vicinity of the conducting wire of the loop coil. The on-board communication device according to claim 3.
An on-vehicle communication device characterized in that the vicinity of the conducting wire is any of a position inside the loop coil, a position outside the loop coil, and a position on the loop coil. The on-board communication device according to claim 3.
An on-vehicle communication device characterized in that the vicinity of the conducting wire when the loop coil has a rectangular shape is a position inside the four corners of the loop coil. The on-board communication device according to any one of claims 1 to 5.
An on-vehicle communication device characterized in that the dimension of the conductor in the lateral direction is one half or less of the dimension of the loop coil in the lateral direction of the conductor. The on-board communication device according to any one of claims 1 to 6.
An on-vehicle communication device characterized in that the loop coil has a shape including a figure eight shape. The on-board communication device according to any one of claims 1 to 7.
An on-vehicle communication device characterized in that the conductor is installed at a position symmetrical with respect to the center of the loop coil. The on-board communication device according to any one of claims 1 to 8.
An on-vehicle communication device, characterized in that a spacer having an arbitrary thickness is provided between the housing and the conductor. The on-board communication device according to any one of claims 1 to 9.
A bracket for installing the housing in a vehicle is provided.
In the case of the on-board communication device according to any one of claims 1 to 8, the conductor is installed between the housing and the bracket, and the on-board communication device according to claim 9 is provided. In the case of a vehicle-mounted communication device, the spacer and the conductor are installed in order from the housing side. The on-board communication device according to claim 10.
The vehicle is a railroad vehicle and
The on-board communication device is an on-board communication device characterized by transmitting at least one of information of train control and driving support.

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