JPS5814347B2 - Defect measurement device for the top surface of the rail - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for measuring defects on the top surface of a rail.

In recent years, as railways have become faster and more dense, track structures have become stronger and rails have become heavier. It's happening all the time.

Therefore, it is strongly required for the upcoming track maintenance management of high-speed railways to regularly, quickly, and accurately detect and measure these various defects in the rails and to perform realignment management of the rail top surface based on the data. There is.

Traditionally, track rail wave wear has been measured by double integrating the data detected by an accelerometer from a feeler that is in direct contact with the rail, but with this method,
Since the feeler that detects acceleration picks up impact when the test vehicle is running at high speed, this must be removed by a filter, but currently the feeler can only remove impact at speeds of about 60 km/h at most.

Rail weld seam drop is also measured using the same method using accelerometers mounted under the vehicle's springs.

On the other hand, surface cracks on the top surface of the rail are detected using ultrasonic testing, but conventional ultrasonic measuring instruments are configured to be used solely for flaw detection, so they can only be used to measure wavy wear and surface cracks. It is not possible to simultaneously detect fissures and estimate the amount of grinding necessary to correct the parietal surface based on that data.

In view of the current situation, the present invention makes it possible to accurately detect and measure the wavelength and amplitude of the waveform of wave-like wear, as well as rail cracks at the same time, even when the measuring vehicle is at high speed. The aim is to provide a measurement method that can provide extremely effective data for estimating the

The present invention will be explained according to the embodiments shown in FIGS. 1 to 6.

In FIGS. 1 and 2, the measurement frame 6 includes an eddy current sensor 2 for measuring wear, an eddy current sensor 5 for measuring surface crack depth, an eddy current sensor 3 for detecting a horizontal reference line, and an eddy current sensor 4 for detecting lateral movement. Install.

The eddy current sensor 2 for measuring wear and the eddy current sensor 5 for measuring surface crack depth are mounted above the top surface 1a of the rail 1 so as to face the top surface 1a with a distance y between them.

The eddy current sensor 3 for horizontal reference line detection faces the rail upper neck 1c with a distance x in between, and the eddy current sensor 4 for lateral movement detection faces the rail head side 1b with the same distance x. Installed so that they face each other.

In this case, the distance between the lower surface of the horizontal reference line detection eddy current sensor 3 and the lower surface of the lateral movement detection eddy current sensor 4 is m, the wear measurement eddy current sensor 2, and the surface crack depth measurement eddy current sensor 5.
The distance between the lower surface and the lower surface of the horizontal reference line detection eddy current sensor 3 is set to l.

As shown in FIGS. 3 and 4, a guide wheel 7 is provided at the tip of the mounting arm 8 fixed to the axle box 10 of the wheel W of the measuring vehicle, and the measuring frame 6 is integrated with the inner ring of the bearing. It is configured to be slidable on the guide wheel shaft.

Since the guide wheel 7 is pressed so that its flange is always in contact with the rail 1 side by the spring 9, the sensors 2 and 5 are pressed against the rail top portions 1a and y, the sensor 3 is pressed against the rail top neck portion 1c, and the sensor 4 is pressed against the rail top portion 1a and y. is constructed so as to maintain the distance between the side surface of the rail head and x as much as possible.

When the measuring vehicle travels, each sensor 2-5 travels along the top surface 1a, upper neck portion 1c, and head side surface 1b of the rail 1 in a non-contact state while maintaining a constant interval.

During the traveling process, the output voltage of each sensor changes in accordance with the change in the distance between each sensor and the opposing rail surface, as is well known.

Therefore, the degree of unevenness of the top surface of the rail can be detected by a change in the output voltage of the sensor 2.

The sensor 3 outputs an output voltage value according to the change in the distance between the sensor 3 and the upper neck part 1c, but if the sensor 3 is not displaced in both the horizontal and vertical directions, the output will be in the horizontal direction, which is the longitudinal line of the upper neck part 1c. Since it can be expressed as a reference line, the output voltage of the sensor 2 can be used to detect the dimension t from the horizontal reference line to the rail top surface (when the rail top surface is normal), as well as the wavelength and wave height of the wavy wear.

If the additional frame 6 makes a slight horizontal displacement and the distance x between the sensor 3 and the upper neck portion 1c changes slightly, that change will correspond to the change in the distance x between the head side surface 1b and the sensor 4. Since this appears as a change in the output voltage, the amount of change is calculated, and the output voltage value of the sensor 3 is corrected by adding or subtracting the output change due to the horizontal displacement from the output voltage value of the sensor 3.

If the mounting frame 6 makes a small vertical displacement, the output voltage value of the sensor 2 will be an output change due to the combined displacement of the uneven displacement of the top surface of the rail and the vertical displacement of the sensor 2. It is expressed as a change in output voltage, so
By adding or subtracting the output voltage change amount due to the vertical displacement of the sensor 3 to the output voltage value of the sensor 2, it is possible to calculate the output voltage value of the sensor 2 due only to the uneven displacement.

In this way, the changes in the distances between the sensor 2 and the sensors 3 and 4 and the opposing surfaces of the respective rails are corrected and calculated, so the following description will be made assuming that the sensors do not displace in the vertical and horizontal directions.

It is assumed that when the measuring wheel reaches position B from the position shown as A in FIG. 1, there is wavy wear 1w on the top of the rail head.

In such a case, the sensor 2 detects the distance y' from the top surface of the corrugated wear 1w by using its output voltage as 1.

Since the output voltage corresponding to the distance y when the sensor 2 faces the flat crown surface is fixed, the peak value of the wave-like wear can be detected as y-y'=a, and the horizontal reference line The thickness t' from to the valley can also be measured.

a = t - t' (where t is the thickness from the upper neck to the flat top of the head) Note that it is necessary to vertically displace the measuring frame 6 from a place where a joint plate, guard rail, etc. are provided on the track. In some cases, a hydraulic or electric lift mechanism may be attached, and it is preferable to lift and lock when not measuring.

In the above embodiment, an example was described in which wave-like wear of a rail is detected, but cracks on the crown surface can also be measured in exactly the same manner.

5 and 6 show an example of an arithmetic recording mechanism according to the present invention.

In Fig. 5, the outputs from the eddy current sensors 2, 3, 4, and 5 are input to the calculation processing unit 11, where they are amplified and subjected to calculation correction to calculate the amount of wave-like wear and surface cracks on the top surface of the rail. , output to the recording section 12 along with the distance pulse signal 13 inputted at the same time, and output to the recording tape 14 or directly to the recording paper 1.
5. The phrase recorded in FIG. 6 shows the arithmetic processing unit 11 in FIG.
details are shown.

A portion surrounded by a dotted line and indicated as 11 indicates an arithmetic processing section, and 12 is a recording section.

In the arithmetic processing unit 11, 21, 31, 41 and 51
1 is an amplifier circuit, 22, 32, 42 and 52 are known linearizers, 13 is a speed generator, and 131 is, for example, a crystal oscillator.

The output voltages of the sensors 3 and 4 are output by an amplifier circuit 31, respectively.
and 41, the output of the amplification circuit 31 is directly sent to the vertical displacement amount detection circuit 111, and the output of the amplification circuit 41 is given linearity to the output by the linearizer 42, and is then input to the vertical displacement amount detection circuit 111. 111, and the corresponding detection circuit 1
At step 11, the output voltage of sensor 3 is subtracted from the output voltage of sensor 4.

Looking at the amount of displacement in the horizontal direction for sensors 3 and 4, they are the same, and for sensor 4, the displacement in output voltage due to vertical displacement remains within the position facing the side surface of the rail head on the same vertical line. Therefore, since the sensor 3 is vertically displaced passing through the opposing surface of the upper neck of the rail, a change in the output voltage corresponding to the vertical displacement occurs.

Therefore, the output voltage of sensor 3 (vertical change and horizontal change)
By subtracting the horizontal change of the sensor 4 (same as the horizontal change of the sensor 3) from the above, the vertical change of the measurement frame can be obtained.

On the other hand, the output of the linearizer 42 is also given to a horizontal displacement detection circuit 112 comprising a comparator or the like.

The horizontal displacement amount detection circuit 112 records the standard output voltage of the sensor 4 when the sensor 4 is separated from the side surface of the rail head by the distance x, and the standard output voltage and the output of the linearizer 42 are recorded. The voltages are compared, and the difference voltage is given to the displacement amount composite circuit 113.

During vertical and horizontal displacement, the sensor 4 maintains a position facing the opposing surface of the side of the rail head which is in the same vertical plane, so the differential voltage indicates a voltage corresponding to the amount of horizontal displacement of the measurement frame.

The displacement compound circuit 113 combines the voltage corresponding to the vertical displacement output from the vertical displacement detection circuit 111 and the voltage corresponding to the horizontal displacement output from the horizontal displacement detection circuit 112. It is outputted and given to the arithmetic circuit 114 via the linearizer 32.

On the other hand, the output voltages from the sensors 2 and 5 are amplified by the amplifier circuits 21 and 51, given linearity by the linearizers 22 and 52, and input to the arithmetic circuit 114. By adding and subtracting the voltage corresponding to the composite change of the vertical change and the horizontal change input from the linearizer 32, the arithmetic circuit 114 calculates the output voltage of the sensors 2 and 5 in the vertical direction. The voltage corrected for the variation and the horizontal variation is input to the recording section 12,
The relationship is recorded in advance with the output voltage when facing a flat top surface, and by comparing the two, it is possible to measure the voltage corresponding to wear and surface cracks on the rail top surface.

On the other hand, reference numeral 13 denotes a known speed generator that is attached to the wheels of a vehicle and is used to generate one pulse per rotation of the wheel to measure the distance traveled by the vehicle. mounted on the wheel, and its output is transmitted to a crystal oscillator 1, for example.
31.

The crystal oscillator 131 is input to the speed generator 13
If the crystal oscillator 131 is set to output one pulse every predetermined number of pulses, the crystal oscillator 131 outputs a pulse to the arithmetic circuit 114 every predetermined travel distance of the measuring vehicle.

Therefore, if the speed generator 13 and the crystal oscillator 131 are activated at the same time as the measurement by the sensors 2, 5, 3, and 4 is started, the measurement result by the arithmetic circuit 114 is determined by comparing the distance traveled by the measuring vehicle. Recording section 12
The measurement results corresponding to the distance traveled by the measuring vehicle are recorded.
After measurement, worn and cracked areas on the top surface of the rail can be easily found, making maintenance and replacement work of the rail extremely easy after measurement.

According to the present invention, in addition to surface defects such as wavy wear, cracks, and dropped weld seams on the top of the rail head, it is also possible to detect and measure the head thickness and the finish condition of the head milled surface. There was a three-point method on each side based on chord length as a standard, but the present invention has remarkable technical effects, such as being able to measure wavy wear with a single point method and providing data essential for crown wear management. It is.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of the present invention, FIG. 2 is a side view of FIG. 1, FIG. 3 is a front view showing the mounting mechanism of the measuring frame in the present invention, and FIG. A side view, FIG. 5 is a block diagram showing an example of the calculation and recording mechanism of the present invention, and FIG.
FIG. 2 is a block diagram showing details of the arithmetic processing unit in the figure. 1a...Rail top surface, 1b...Rail head side surface, 1c...Rail top neck, 2...
...Eddy current sensor for wear measurement, 3...Eddy current sensor for horizontal reference line detection, 4...Eddy current sensor for lateral movement detection, 5...Surface Eddy current sensor for crack depth measurement.

Claims (1)

[Claims] 1. An eddy current sensor 2 for wear measurement and a sensor 5 for surface crack depth measurement are installed on opposing surfaces above the top surface of the rail at predetermined intervals, and on opposite surfaces extending from the side surface of the rail head and the top neck of the rail at predetermined intervals, respectively. The eddy current sensor 4 for detecting lateral movement and the eddy current sensor 3 for detecting horizontal reference line are fixedly arranged, and the output voltage due to the horizontal displacement of the eddy current sensor 3 for detecting horizontal reference line is applied to the eddy current sensor 4 for detecting lateral movement. It is corrected by changes in output voltage due to displacement, and also includes an eddy current sensor 2 for measuring wear and an eddy current sensor 5 for measuring surface crack depth.
A method for measuring defects on the top surface of a rail, characterized in that the output voltage due to the vertical displacement of the horizontal reference line detection eddy current sensor 3 is corrected by a change in the output voltage due to the vertical displacement of the horizontal reference line detection eddy current sensor 3.