JPH0145001B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of a reference position setting target used for railway track inspection.

[Conventional technology]

Conventionally, on both the Tokaido and Sanyo Shinkansen lines, high-speed track inspection vehicles have been used to regularly inspect numerous measurement items in order to detect and manage the progress of track deviations. . In order to analyze this inspection data, an optical detection device using a laser beam installed on the inspection vehicle and an optical detection device using a laser beam installed on the inspection vehicle are used to record and display the fact that a certain reference point has been passed on a continuous data sheet. The position of the reference point was detected and recorded using a point detection reflector installed between the tracks.

However, the reflectors were expensive to maintain due to dirt and snow buildup, and in some cases, they had defects that made them completely unusable.

On the other hand, later Tohoku and Joetsu Shinkansen trains utilized the invention of the present inventor (see Japanese Patent Application Laid-Open No. 104460/1983) to improve the above-mentioned defects, and developed a system that is sensitive to magnetic lines of force based on high-frequency current. Targets that generate eddy currents are installed at reference positions along the track at fixed distances (for example, 1 kilometer), while a track inspection vehicle running at high speed on the track is equipped with a magnetic sensor drive control device and the above-mentioned target. A magnetic sensor that detects eddy currents is installed to sequentially measure the reference position, and the reference position is recorded on a data sheet along with signal waveforms that continuously detect and display numerous measurement items such as rail displacement and deformation. The items are filled in and displayed in order to facilitate examination of the measurement items.

[Problem to be solved by the invention]

The invention described in JP-A-57-104460 is all-weather and fully functional even under snow, but the target speed
In order to generate the above-mentioned eddy current for inspection vehicles traveling at high speeds of 200 km or more, a single flat magnetic metal body was installed, so branch rails,
If there are communication ground elements or other magnetic metal objects, they will all be detected by the magnetic sensor, and the distinction between the existing magnetic metal objects and the target will be difficult to record on the data paper that records the signal. There was a problem that it became difficult to distinguish between the entries and the display.

[Means to solve the problem]

This invention was developed to solve the above problems, and the configuration of the invention is described in the corresponding third to third embodiments.
Explaining this using FIGS. 7 and 9, the present invention includes a main body 1 which has mounting legs with bolts or the like on both the front and back sides and is made of a material with a low dielectric constant and good radio wave transparency.
In a railroad reference position setting target in which a flat magnetic metal body 2 that generates an eddy current in response to lines of magnetic force running in the left and right directions at high speed is buried close to the upper surface of the head portion of the target, the magnetic metal two left and right magnetic metal body pieces arranged perpendicularly to the running direction of the magnetic lines of force and having substantially the same width through which the lines of magnetic force pass;
3, 3:4, 4:5', 5', a non-conductive part 6 that does not generate eddy current is provided between the two parts, and the width of this part is set relative to the passage width. The double signal waveform 12 having an M-shaped portion at the top is generated by a magnetic sensor running at high speed across the two pieces.

[Effect]

Since the present invention has the above-described configuration, a magnetic sensor drive control device and a magnetic sensor are mounted on a track inspection vehicle running at high speed, and the target magnetic metal body 2 installed at a reference position is Two magnetic metal body parts 3, 3: 4, 4: 5, 5:
5', 5' when passed from side to side to the left and right, a non-inductive material exists between the two pieces and has a width that is approximately equal to or wider than the passing width of the piece. The presence of portion 6 allows the magnetic sensor to have M at the top.
A double signal waveform 12 having a character-shaped portion can be clearly generated.

〔Example〕

Embodiments of the target of the present invention will be explained based on the drawings. First, the target body 1 of the conventional type shown in FIGS. It is made of glass fiber-reinforced plastic made by impregnating glass fiber with saturated polyester resin, and is formed as an integrally molded product in the shape shown in the figure. Note that 7 is a bolt hole through which the mounting bolts provided on both the front and rear mounting legs are passed. In a place close to the upper surface of the head portion of the target body 1, there is a device of an appropriate size that is sensitive to the magnetic lines of force generated by the magnetic sensor drive control device of the track inspection vehicle that runs in the left and right directions in Fig. 1. A magnetic metal body 2 having a flat portion is provided.

In contrast, the targets of the present invention are
As shown in the figure, a magnetic metal body 2 in the head part of the main body 1
is divided into two left and right parts that are arranged perpendicularly to the running direction of the track inspection vehicle and have approximately the same width of passage of magnetic lines of force, and a non-conductive part 6 in which no eddy current is generated is placed between these two parts. It is effective to make the width of the non-conductive portion 6 as wide as possible, and to make it approximately equal to or wider than the passage width. That is, in the case shown in FIG. 3, two rectangular magnetic metal pieces 3 of the same shape are arranged side by side, and a non-conductive part 6 is placed between them.
It is embedded in the target body 1 made of the above-mentioned plastic or the like so that the target body 1 is made of plastic or the like. Fourth
In the figure, the two magnetic metal pieces 4, 4 are U-shaped with their ends facing each other, and appropriate perforated portions 8 are provided at both ends. In this case, the magnetic metal pieces 5, 5 are connected at a narrow connection part to form a U-shape as a whole, and a suitable perforated part 8 is provided at the connection part. In the one shown in FIG. 6, both ends of the magnetic metal body pieces 5, 5 are connected by a narrow connection part,
The overall shape is square-shaped, and appropriate perforated portions 8 are provided at the connecting portions. The perforated portion 8 is provided in the target body 1 made of plastic or the like.
This is to strengthen the bond with. In the one shown in FIG. 7, two magnetic metal body pieces 5', 5' are arranged side by side without being limited to the same rectangular shape, and the non-conductive part 6 is made as wide as possible, and the width of the piece 5', that is, the passage width is The width is arbitrary as long as it is at least the minimum width that allows detection of lines of magnetic force, and both ends are connected by a thin connection part to form a rectangular shape or an oval shape as a whole. In this case, the perforated portion 8 is not necessary because the connection is made by a thin linear portion.

To explain the effects of the structure shown in Figures 3 to 7 using the signal waveform shown on the track inspection car, noise 9 is generally constantly generated in the signal waveform as shown in Figure 8. The signal waveform 10 produced by the conventional magnetic metal body 2 shown in FIGS. Although it was possible to accurately fill in and display, if there is another magnetic metal object in the orbit, the signal waveform 1
There was a problem in that a pseudo waveform 11 similar to 0 was generated, resulting in misidentification as the target position.

On the other hand, by dividing the magnetic metal body into two magnetic metal pieces 3, 4, 5, 5' as in the present invention and providing a non-conductive part 6 between these pieces, as shown in FIG. A double signal waveform 12 having an M-shaped portion at the top as shown in FIG.

Here, as the material for the magnetic metal body, pure iron is superior in terms of performance, and by making the material an alloy such as iron-cobalt, it is possible to connect the magnetic sensor on the conventional inspection vehicle to the top surface of the target. For example, a distance between the magnetic field lines of about 50 mm was the maximum sensitivity for reaching magnetic field lines, but now we have obtained a sensor that is suitable for high-sensitivity magnetic sensors that can reach magnetic lines of force from a height of about 200 mm or more. Note that these magnetic metal pieces may not only be buried in the head portion of the target, but may also be simply buried flush with the upper surface of the head portion.

〔Effect of the invention〕

This invention has the above-mentioned structure and operation, and therefore it uses a special structure of the magnetic metal body inside the target, especially two magnetic metal bodies arranged in parallel at right angles to the traveling direction of the magnetic field lines traveling at high speed. The width through which the lines of magnetic force pass through the magnetic metal piece is approximately equal to or wider than the width of the non-conductive part interposed between the two pieces,
A double signal waveform having an M-shaped portion at the top can be reliably generated in a magnetic sensor running at high speed.

Therefore, according to the present invention, a clear double signal waveform with no variation can be obtained, and it is possible to distinguish the presence of a target from other magnetic metal objects existing in the orbit. This eliminates the need for constant correction and checking as with conventional targets, making it extremely effective for high-speed railway track inspection.

[Brief explanation of drawings]

Figure 1 is a top view of a conventional target; Figure 2 is a top view of a conventional target;
3 is a plan view showing one embodiment of the target of the present invention, FIGS. 4 to 7 are plan views showing other embodiments of the present invention, and FIG. 8 is a plan view of a conventional target. Signal Waveform Diagram FIG. 9 is a signal waveform diagram of the present invention. 1: target body, 2: magnetic metal body, 3,
4, 5, 5': magnetic metal body piece, 6: non-conductive part, 7: bolt hole, 8: perforated part, 9: noise waveform, 10: conventional signal waveform, 11: analogous waveform, 12: Double signal waveform.

Claims (1)

[Scope of Claims] 1. A main body that has mounting legs with bolts etc. on both the front and back sides and is made of a material with a low dielectric constant and good radio wave transparency, and is mounted in the left and right direction close to the top surface of the head part. In a railroad reference position setting target in which a flat magnetic metal body that generates an eddy current in response to magnetic lines of force traveling at high speed is buried, the magnetic metal body is juxtaposed at right angles to the running direction of the magnetic lines of force so that the lines of magnetic force pass through the target. Consisting of two left and right magnetic metal body pieces with approximately equal widths, a non-conductive part that does not generate eddy current is provided between the two pieces, and the width of the part is set relative to the passage width. For setting a reference position for railways, the magnetic sensor is made substantially equal in width or wider in width, and generates a double signal waveform having an M-shaped portion at the top on a magnetic sensor that travels at high speed across the two pieces. Target. 2. A railway reference position setting target as claimed in claim 1, wherein two juxtaposed magnetic metal pieces are each shaped like a U-shape and are embedded in the main body with their ends facing each other. 3. The railway reference position setting target according to claim 1, wherein one or both ends of two juxtaposed magnetic metal pieces are connected to each other and embedded in the main body. 4. A railway reference position setting target according to claim 1, wherein both ends of two juxtaposed magnetic metal pieces are connected in a linear manner and embedded in the main body.