JPS6015508B2 - Railroad vehicle axle detection device - Google Patents

Description

[Detailed Description of the Invention] [Detailed Description of the Invention] The present invention relates to an axle detection device for a railway vehicle, and is particularly suitable for the axle load of a running vehicle and an axle load detection device, and shares a detection unit with these devices. This invention relates to an axle detection device.

[Background of the Invention] Recent freight yards detect the weight of freight cars running on arrival lines, detect overloaded or unbalanced cargo, and remove them from the train composition.

In this case, since the axle load value for each axle of the freight car is required, a measurement method is used in which an axle detection device is used to determine the order of the axles starting from the first car, and this is correlated with the axle load value of each order.
As an axle detection device for this purpose, as shown in Fig. 1, the metal proximity switch MtS operates near the saddle of the wheel.
W lights and photoelectric switches whose light beams were shielded by wheels were used.

As shown schematically in FIG. 1, a system has been developed in which the hammer weight signal is determined by measuring the shear strain produced on the rail by the wheels using a pickup such as a pair of strain gauges DsG bonded to the rail.

That is, 197 from the Japan Railway Cybernetics Council.
In the paper ``Automation of Freight Car Arrival Inspection (FIIS)'' on pages 442 to 445 of ``Collection of Papers from the Domestic Symposium on the Utilization of Cybernetics in Railways in Country IQ,'' published in November, 3 As explained,
If a pair of strain gauges are placed at a distance and the difference between the two outputs (one is inverted and summed) is taken, the peak value will be proportional to the wheel load. The output signal of this wheel load detector is
An axle detection device is required to ensure that the axle is removed once it has passed. By the way, the above-mentioned axle detection device is generally expensive due to the harsh environment in which it is used, and since wheel load measurement is performed at multiple points in order to reduce errors caused by the effects of the shaking of the freight car, these counterfeits are also expensive. In addition to increasing the price and complicating the overall configuration, this method also has the disadvantage that malfunctions due to noise cannot be avoided when detecting the axle.

For example, "
Proceedings of the 4th Domestic Symposium on Cybernetics Utilization in Railways, pages 202 to 205, ``Piezoelectric shaft position signal source 1'' describes how piezoelectric shaft position signal sources can be used as an axle detection device to detect vertical strain in the rails that appears due to stress using piezoelectric elements. In addition, it has been reported that the output voltage may be used to detect the axle or measure wheel weight.

However, since this method of axle detection obtains a pulse-like output voltage, if there is flat wear on the tread of the axle to be detected as it approaches, impact noise will appear in the output of the piezoelectric element, and the axle detection will be interrupted. There is a tinge that cannot be distinguished from a signal.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to provide an axle detection device for a railway vehicle that is resistant to noise without using a special axle detection element.

[Summary of the invention]

Therefore, in the present invention, the output of a pickup using a pair of strain gauges for wheel load detection is also used to obtain an axle signal, and is transmitted through a drift compensation circuit, a waveform shaping circuit, and a time width comparison circuit. The feature is that the axle signal is obtained by using the

[Embodiments of the invention]

FIG. 2 shows an embodiment of the present invention.

A pair of strain gauges DsG are arranged at intervals on the rail Rei, and a pickup PU is provided to extract the output difference between the two.
The power of this world is amplified by the amplifier AmP and the waveform shaping circuit W
F and converts a signal above a certain value into a square wave as an axle signal. In other words, when the axle of a freight car passes, a wheel load signal is generated whose peak value is proportional to the wheel load and whose width is proportional to the distance between the strain gauges/vehicle speed, as shown in Figure 3A, and this signal is shaped into a waveform. Then, an axle signal as shown in the circle in the same figure can be obtained. By the way, if there is flat wear on the tread of the wheel to be detected, impact noise may appear in the output of the pickup PU for detecting the weight of the vehicle, and the output of the pickup PU for detecting the wheel load may be affected by fluctuations in ambient temperature, etc. Drift due to influence may occur.

Therefore, the output of the pickup PU is applied to the drift compensation circuit DfC via the amplifier AmP. The output of the amplifier is used on the one hand as wheel load data A. Then, the output from the drift compensation circuit D is given to the time width comparison circuit TvC (including the waveform shaping circuit WF), and any output from this is regarded as the axle signal F. Hereinafter, these operations will be explained by comparing them with the waveforms of each part shown in FIG.

The output of the pickup PU consisting of a pair of strain gauges DsG is as shown in FIG. 3A, which contains drift (changes over a very long period and is almost constant over a short period of time) and noise. When this signal is passed through the low-pass filter LpF with a low cutoff frequency shown in FIG. 2, the output becomes approximately constant and only a drift component appears as shown in FIG. 3B. Therefore, when the subtractor ADD takes the difference between the original signal A and the drift component B, the result is as shown in FIG. 3C, and the drift component is compensated for. Next, the waveform shaping circuit WF converts signals of a certain level or higher among the signals inputted from the drift compensation circuit into square waves.

At this time, if the noise component has a large level, it may appear as shown in the circle in FIG. 3. Therefore, by using the monostable multipipeter circuit MM triggered by the rising edge of the output ○ of the waveform shaping circuit WF, a pulse with a constant width as shown in FIG.
Take the logic of E (AND of D and (E NOT)). In this way, the output waveform of the monostable multivibrator ○
If the pulse width of is made larger than the width of the possible noise and 4 times smaller than the normal signal, the output of the logic circuit LC becomes like F, and only the normal signal appears. In general, the noise component is shocking and has a short time width. However, by placing a pair of strain gauges at a distance, and calculating the difference between the two, the normal wheel load value is determined by adjusting the pickup distortion so that the width is wider than this noise. Since it is possible to adjust the position of the gauge, noise and signal can be separated by such operations.

FIG. 4 shows another embodiment of the invention. In this system, the speed of a passing train is detected by the train speed detector TrW, and the pulse width of the waveform output from the monostable multipipulator MM is changed. In other words, when the train is running at high speed, the time width of both the normal logic signal and the noise becomes 4.0 mm, so the monostable multi-noise signal M is used for time width comparison.
The reference time width of the output of M is also made small.

In this way, stable axis detection becomes possible even when the passing speed range of the train to be measured is wide. In addition, in the above explanation, we did not take into account that the amplifier AmP attached to the pickup has frequency characteristics that are suitable for noise reduction, but it goes without saying that it is possible to improve the reliability of operation in this way. .

As described above, according to the present invention, it is possible to obtain an axle detection device that operates based on the signal from the axle load detection section, and it is possible to omit a dedicated device for axle detection, which allows the device to be configured simply and inexpensively, and to be reliable and resistant to noise. Axle detection becomes possible.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the slave, FIG. 2 is a diagram showing an embodiment of the present invention, FIG. 3 is an operation waveform diagram for explaining the present invention, and FIG. 4 is a diagram showing an embodiment of the present invention. It is a figure showing an example of. Rei...Rail, Gourd...Pair of strain gauges, PU...Pickup, DfC...Drift compensation circuit, TvC...Time width comparison circuit, LpF...Low pass filter, ADD... ...Subtractor, WF... Waveform shaping circuit, MM... Monostable multipipulator, LC... Logic circuit, TrV... Train speed detector. Polymorphism 2 bacteria Prediction J order polymycosis

Claims (1)

[Claims] 1. A pair of strain gauges installed at intervals on the rail to detect the shear strain generated on the rail when the wheels pass over the rail, a pick-up for extracting the output difference between the pair of strain gauges, and a pick-up for detecting the output difference between the pair of strain gauges. means for extracting the wheel axle load signal from the output; a circuit for compensating the drift of the axle load signal; a circuit for waveform shaping the output of the drift compensation circuit; and a time width of the output of the waveform shaping circuit being a reference value. 1. An axle detection device for a railway vehicle, comprising a time width comparison circuit that outputs an axle signal only when the width is larger than that of the axle signal.