JP5662126B2 - Load measuring method and load measuring apparatus - Google Patents

Description

  The present invention relates to a load measuring method and a load measuring apparatus for measuring a load such as a wheel load and a lateral pressure of a railway vehicle while traveling with a wheel shaft provided with a load detecting means, and particularly appropriately detecting an output peak of the load detecting means. Regarding what is possible.

Measures load (wheel-to-rail acting force) such as wheel load (P) and lateral pressure (Q) while running on an actual vehicle to check the running safety and various performances of railway vehicles. A load measuring wheel shaft (also referred to as a PQ wheel shaft) is known.
Such a load measuring wheel shaft is configured by attaching a plurality of strain gauges incorporated in a bridge circuit to the inner peripheral surface of a hole formed in a wheel or the surface of the wheel.
These strain gauges detect wheel compression strain and bending strain caused by wheel load, lateral pressure, etc., and the bridge circuit generates output according to these loads, so the correlation between load and output is known. Then, the load can be measured based on the output of the bridge circuit.
The output of the bridge circuit is pulled up on the vehicle via a slip ring and a cable, and is amplified by a dynamic strain amplifier.

  As a conventional technique related to a load measuring axle, for example, in Patent Document 1, for the purpose of improving the calibration error of the PQ axle, calibration is performed by statically loading the wheel weight while the PQ axle is supported by a bearing. The wheel load acting from the bearing is calculated from the difference between the running wheel load and the wheel load output by the own weight of the PQ wheel shaft when the PQ wheel shaft is rolled alone, and the wheel load by the own weight of the PQ wheel shaft is calculated. It is described that the wheel load is obtained by adding.

JP 2007-225413 A

The output signal of the load measuring wheel shaft described above is an intermittent so-called spike waveform that shows a peak when the rim portion closest to the strain gauge contacts the rail.
Such a peak is the point at which the strain sensitivity to the load is maximized. In the load measurement in the intermittent measurement method, the load such as the wheel load and the lateral pressure is obtained based on the peak value of such a spike waveform. .
However, when another peak occurs in the vicinity of such a peak due to, for example, a disturbance received from the rail, which peak value is used as data in the case of automatic measurement using the peak value as data, for example. It becomes difficult to distinguish. Here, if an inappropriate peak is read, an error in measurement data becomes large, so that automation is difficult and a complicated reading operation by a human may be required.

In order to deal with such a problem, for example, it is proposed to specify a peak in the wheel load measurement by providing another strain gauge for detecting the bend of the axle and matching the bend peak of the axle with the peak of the wheel load. Has been.
However, in this case, it is necessary to add a strain gauge for detecting the bending of the axle separately from the strain gauge for detecting the wheel load and the lateral pressure, and the configuration of the apparatus becomes complicated. In addition, since the output of the strain gauge that detects the bending of the axle is signal-processed, it is difficult to sufficiently increase the peak identification accuracy.
Also, by synthesizing the wheel load waveform of system 2 etc., the influence of the force due to disturbance etc. is offset, and a waveform with clear wheel load peak is generated, and the wheel load peak position is identified based on this waveform It has also been proposed to do.
However, even in this case, when a shocking peak is generated in the vicinity of the original peak, or when extremely small peaks are continuous, it is difficult to identify the original peak.
In view of the above-described problems, an object of the present invention is to provide a load measuring method and a load measuring apparatus that can easily and appropriately detect an output peak value of a load measuring wheel shaft.

The load measuring method of the present invention that solves the above-described problem has a pair of wheels fixed to both ends of an axle, and intermittently generates an output corresponding to a load acting on a contact portion between the wheel and the rail. A load measuring method using a load measuring wheel shaft provided with a load detecting means for detecting the rotational angle position of the load measuring wheel shaft sequentially while running a vehicle on which the load measuring wheel shaft is mounted. When the rotation angle position substantially coincides with the output reading position set in advance so as to correspond to the peak in the output history acquired by running the vehicle equipped with the load measuring wheel shaft in a smooth linear section in advance. The load is calculated based on the output of the load detection means.

In the load measuring method of the present invention, the rotational angle position is detected by an encoder provided on the axle of the load measuring wheel shaft and intermittently generating a pulse signal in accordance with a rotational direction displacement of the axle, and the output The load can be calculated based on the output of the load detection means detected substantially simultaneously with the pulse signal corresponding to the reading position.
Further, in the load measuring method of the present invention, the output reading position has a predetermined range, and the range of the output reading position is set wide according to the increase in the maximum curvature of the curved road included in the line on which the measurement is performed. It can be set as the structure to do.

Further, the load measuring device of the present invention has a pair of wheels fixed to both ends of the axle, and a load detecting means for intermittently generating an output corresponding to a load acting on a contact portion between the wheel and the rail. Load measuring wheel axle, position detecting means for sequentially detecting the rotational angle position of the load measuring wheel axle, and an output history of the load detecting means, and the load measuring wheel detected by the position detecting means. The rotational angle position of the wheel shaft substantially coincides with a preset output reading position so as to correspond to a peak in an output history obtained by running a vehicle equipped with the load measuring wheel shaft in a smooth linear section in advance. Output data processing means for calculating the load based on the output of the load detecting means at the time.

In the load measuring apparatus according to the present invention, the load measuring device includes recording means for synchronously recording the output history of the load detecting means and the output history of the position detecting means, and the output data processing means includes the load recorded by the recording means. The load may be calculated using the output history of the detection means and the output history of the position detection means.
Note that the output data processing means for reading the output of the load detection means offline in this way may be provided on the vehicle or on the ground such as a laboratory.
Further, in the load measuring device according to the present invention, the position detecting unit includes an encoder that is provided on the axle of the load measuring wheel and intermittently generates a pulse signal in accordance with a rotational displacement of the axle. The output data processing means may be configured to calculate the load based on the output of the load detection means detected substantially simultaneously with the pulse signal corresponding to the output reading position.
Further, in the load measuring apparatus according to the present invention, the output reading position has a predetermined range, and the output data processing means has a maximum curvature of a curved road included in a line on which the range of the output reading position is measured. The range of the output reading position can be set wide according to the increase.

According to the present invention, the rotation angle position of the load measuring wheel shaft is sequentially detected while the vehicle is running, and the load detecting means when the detected rotation angle position substantially coincides with the preset output reading position. By calculating the load based on the output, even if other peaks are formed in the vicinity of the original peak due to disturbance or the like, the original peak value can be read appropriately, and the load measurement accuracy can be improved. Can be improved.
Further, the rotation angle position is detected by an encoder that intermittently generates a pulse signal in accordance with the displacement in the rotation direction of the axle, and the output of the load detection means detected substantially simultaneously with the pulse signal corresponding to the output reading position. By calculating the load based on this, the above-described effects can be obtained more reliably.
In addition, the output reading position has a predetermined range, and the range of the output reading position is set wide according to the increase in the maximum curvature of the curved road included in the line on which the measurement is performed, so that the wheel axis is inclined when passing the curve. Even when the contact position between the wheel and the rail is shifted in the rail longitudinal direction, the peak value can be detected appropriately, and the measurement accuracy can be ensured.

It is a mimetic diagram showing composition of an embodiment of a load measuring device to which the present invention is applied. 2 is an enlarged view of a main part of a PQ wheel shaft in the load measuring apparatus of FIG. 1, FIG. 2 (a) is an external view seen from the axle direction, and FIG. 2 (b) is a bb part of FIG. 2 (a). It is arrow sectional drawing. It is a figure which shows the structure of the bridge circuit for the wheel load measurement in the PQ axle of FIG. It is a figure which shows the structure of the bridge circuit for the lateral pressure measurement in the PQ wheel axis | shaft of FIG. 4 is a graph showing an example of output history of the wheel load measurement bridge circuit of FIG. 3 and the encoder of FIG. 1.

Hereinafter, embodiments of a load measuring method and a load measuring device to which the present invention is applied will be described with reference to the drawings.
The load measuring method and the load measuring apparatus according to the embodiment use a plurality of strain gauges constituting a bridge circuit, and use a PQ wheel shaft that generates a pulsed output corresponding to the wheel load and the lateral pressure. The pressure is measured.
Drawing 1 is a mimetic diagram showing the composition of the load measuring device of an embodiment.
The load measuring device includes a PQ wheel shaft 1, an encoder 110, a dynamic strain amplifier 120, an encoder amplifier 130, a data recording / analysis PC (hereinafter simply referred to as “PC”) 140, and the like.

The PQ wheel shaft 1 uses a wheel provided with a strain gauge constituting a bridge circuit, and the wheel load (P) acting in the vertical direction between the wheel and the rail, and the lateral pressure acting in the sleeper direction (Q ).
The PQ wheel shaft 1 includes a pair of left and right wheels 10 and an axle 20 that couples the wheels.
The axle 20 is rotatably supported by journal boxes formed at both ends by an unillustrated axle box. The axle box is attached to the carriage frame via an axle box support device having a primary spring system.
2 is an enlarged view of the main part of the PQ wheel shaft 1, FIG. 2 (a) is an external view seen from the axle direction, and FIG. 2 (b) is a view taken along the line bb in FIG. 2 (a). It is sectional drawing.
The wheel 10 is an integrally rolled wheel having an integrally formed rim portion 11, a wheel seat 12, a plate portion 13, and the like.
The rim portion 11 is a portion constituting the outer peripheral edge portion of the wheel 10, and is formed with a tread surface 11 a and a flange 11 b that come into contact with the rail.
The wheel seat 12 is disposed at the center of the wheel 10 and has an opening into which the end of the axle 20 is inserted and fixed.
The plate portion 13 is a flat plate-like portion that connects the inner peripheral surface portion of the rim portion 11 and the outer peripheral surface of the wheel seat 12.

In addition, openings O1, O2 and the like to which strain gauges P1 to P4 for wheel load measurement are attached are formed in the plate portion 13.
The openings O <b> 1 and O <b> 2 are through holes formed, for example, through the plate portion 13 in the axial direction of the wheel 10. The openings O <b> 1 and O <b> 2 are formed in a circular shape when viewed from the axial direction of the wheel 10.
The opening O <b> 1 is disposed at an intermediate portion between the rim portion 11 and the wheel seat 12.
Strain gauges P1 and P2 are provided on the inner peripheral surface of the opening O1.
The strain gauges P <b> 1 and P <b> 2 are arranged apart from each other in the circumferential direction of the wheel 10.

The opening O2 is disposed symmetrically with respect to the central axis of the wheel 10 with respect to the opening O1, and is formed in substantially the same manner.
Strain gauges P3 and P4 are provided on the inner peripheral surface of the opening O2.
The strain gauges P3 and P4 are spaced apart from each other in the circumferential direction of the wheel 10.

The plate portion 13 is provided with strain gauges Q1a to Q4a and Q1b to Q4b for measuring lateral pressure.
The strain gauges Q1a and Q1b are provided on the surface portion on the outer side in the vehicle width direction of the plate portion 13 in the intermediate portion between the opening O1 and the wheel seat 12.
The strain gauges Q1a and Q1b are arranged side by side in the circumferential direction of the wheel 10.
The strain gauges Q2a and Q2b are provided on the surface portion on the inner side in the vehicle width direction of the plate portion 13 so that the positions when viewed from the central axis direction of the wheel 10 overlap with the strain gauges Q1a and Q1b, respectively.
The strain gauges Q3a and Q3b are arranged symmetrically with respect to the central axis of the wheel 10 with respect to the strain gauges Q1a and Q1b.
The strain gauges Q4a and Q4b are arranged symmetrically with respect to the central axis of the wheel 10 with respect to the strain gauges Q2a and Q2b.

The above-described strain gauges P1 to P4 for wheel load measurement are incorporated in the bridge circuit Bp as shown in FIG.
Further, the strain gauges Q1a to Q4a and Q1b to Q4b for measuring the lateral pressure are incorporated in the bridge circuit Bq as shown in FIG.
The input voltage Vin of each bridge circuit Bp, Bq is supplied from the vehicle via a slip ring SL provided in the axle box portion. Further, the output voltage Vout of each bridge circuit Bp, Bq is supplied to the dynamic strain amplifier 120 provided on the vehicle via the slip ring SL.
A plurality of such strain gauges and bridge circuits are provided by shifting the angle around the central axis of the wheel 10. For example, a plurality of openings that are substantially the same as the openings O1, O2, etc. are arranged at predetermined intervals in the circumferential direction, and a strain gauge for measuring the wheel load is arranged in each opening, and a lateral side is disposed around the circumference. A strain gauge for pressure measurement may be arranged.

The encoder 110 is a rotary encoder that is provided in an axle box that supports one end of the axle 20 and detects a rotational angle position around the central axis of the PQ wheel shaft 1. The encoder 110 generates an intermittent pulse signal according to the rotational displacement of the PQ wheel shaft 1.
As such a pulse signal, for example, about 600 to 1200 pulses are output per rotation of the PQ wheel shaft 1. The encoder 110 outputs an origin pulse signal once per rotation when the PQ wheel shaft 1 reaches a predetermined rotation angle position. With such a configuration, the current rotation angle position of the PQ wheel shaft 1 can be detected by counting the number of pulses after the origin pulse signal is output.

The dynamic strain amplifier 120 receives the output voltage Vout of the bridge circuit Bp for wheel load measurement and the bridge circuit Bq for lateral pressure measurement, and amplifies them with a predetermined gain and transmits them to the PC 140 in real time. is there.
The encoder amplifier 130 receives the output of the encoder 110, amplifies it with a predetermined gain, and transmits it to the PC 140.

The PC 140 includes information processing devices such as a CPU, RAM, ROM, HDD, and other storage means, various input / output units, and a bus that connects these.
The PC 140 includes an A / D board 141 and a counter board 142.
The A / D board 141 performs analog-digital conversion on the output of the dynamic strain amplifier 120.
The counter board 142 counts up the number of pulses based on the output signal of the encoder 110 amplified by the encoder amplifier 130.

FIG. 5 is a graph showing an example of the output history of the bridge weight measurement bridge circuit Bp and the encoder 110 in the embodiment.
FIG. 5A shows the output history of the bridge circuit Bp, the vertical axis shows the output voltage, and the horizontal axis shows time.
FIG. 5B shows the output history of the encoder 110, the vertical axis shows the output voltage, and the horizontal axis shows time.

The PC 140 adopts the output of the bridge circuits Bp and Bq as measurement data when the rotational angle position of the PQ wheel shaft 1 detected based on the output of the encoder 110 is a predetermined output reading position set in advance. To calculate wheel load and lateral pressure.
The reading of the outputs of the bridge circuits Bp and Bq and the calculation of the wheel load P and the lateral pressure Q may be performed in real time using, for example, a PC mounted on the vehicle. On the vehicle, only the output of the bridge circuits Bp and Bq and the output of the encoder 110 are synchronously recorded. The output of the bridge circuits Bp and Bq and the calculation of the wheel load P and the lateral pressure Q are stored in a storage medium. You may perform by offline processing on the ground etc. using the recorded data, for example.

The output reading position is obtained, for example, by acquiring the output history of the bridge circuits Bp and Bq while driving a vehicle equipped with the PQ wheel shaft 1 at a low speed in a smooth straight section for the purpose of obtaining an output with less disturbance. Then, it is set as a range having a predetermined width as necessary before and after the rotation angle position corresponding to the peak in the output history.
By such preliminary traveling, it is possible to acquire a wheel load waveform and a lateral pressure waveform that are not affected by fluctuations or other forces. By correlating such wheel load waveform, lateral pressure waveform, and wheel rotation angle information, the pulse position (number of pulses from the origin) of the encoder 110 at which the output of the bridge circuits Bp, Bq peaks can be recorded. The PC 140 sets this pulse position as an output reading position. Further, the output reading position may include a plurality of pulse positions.
Then, the PC 140 reads the output peak values of the bridge circuits Bp and Bq detected substantially simultaneously with the pulses of the encoder 110 included in the output reading position, and calculates the wheel load P and the lateral pressure Q based on this. .

Further, it is known that the wheel axis of a railway vehicle is inclined relative to the rail when passing through a curve, and an attack angle is generated. Specifically, the outer turning wheel is relatively displaced forward, and the inner turning wheel is relatively displaced rearward.
In such a case, the peak positions of the bridge circuits Bp and Bq are shifted in the front-rear direction with respect to the normal peak positions.
Therefore, in the present embodiment, as the maximum curvature of the curved road on the route to be measured increases, the range included in the output reading position described above is expanded before and after the peak position during straight running, The peak positions of the bridge circuits Bp and Bq are prevented from deviating from the output reading position.

As described above, according to the present embodiment, the rotational angle position of the PQ wheel shaft 1 is sequentially detected while the vehicle is running, and the detected rotational angle position substantially coincides with the preset output reading position. By calculating the wheel load P and the lateral pressure Q based on the outputs of the bridge circuits Bp and Bq at the time, even if another peak is formed in the vicinity of the original peak due to disturbance or the like, the original peak The value can be read appropriately.
In addition, the rotation angle position is detected by the encoder 110 that intermittently generates a pulse signal in accordance with the rotation direction displacement of the axle 20, and the bridge circuit Bp detected substantially simultaneously with the pulse signal corresponding to the output reading position, By calculating the wheel load P and the lateral pressure Q based on the output of Bq, the above-described effects can be obtained more reliably.
In addition, the output reading position has a predetermined range, and the range of the output reading position is set wide according to the increase in the maximum curvature of the curved road included in the route on which the measurement is performed, so that the wheel and the rail are passed when the curve passes. Even if the contact position with the position shifts in the rail longitudinal direction, the peak value can be detected appropriately.

(Other embodiments)
In addition, this invention is not limited only to above-described embodiment, Various application and deformation | transformation can be considered.
For example, the load measuring wheel shaft is not limited to the one having the integrally rolled wheel as in the embodiment, and may have a different configuration, for example, one having a spoke wheel.
Further, the arrangement of strain gauges and the configuration of the bridge circuit are not particularly limited.
The configuration of the load measuring device is not limited to that of the above-described embodiment, and can be changed as appropriate.

1 PQ wheel shaft (load measuring wheel shaft) 10 wheel 11 rim portion 11a tread surface 11b flange 12 wheel seat 13 plate portion O1, O2 opening P1 to P4 strain gauge (for wheel load detection)
Q1a to Q4a, Q1b to Q4b Strain gauge (for detecting lateral pressure)
SL Slip ring Bp Wheel load measurement bridge circuit Bq Lateral pressure measurement bridge circuit Vin Input voltage Vout Output voltage 110 Encoder 120 Dynamic strain amplifier 130 Encoder amplifier 140 PC
141 A / D board 142 Counter board

Claims (7)

A load measuring wheel shaft having a pair of wheels fixed at both ends of the axle and having load detecting means for intermittently generating an output corresponding to a load acting on a contact portion between the wheel and the rail is used. A load measuring method,
While driving the vehicle equipped with the load measuring wheel shaft, the rotational angle position of the load measuring wheel shaft is sequentially detected, and the detected rotational angle position is a straight line that is smooth in advance for the vehicle equipped with the load measuring wheel shaft. The load is calculated based on the output of the load detecting means when substantially matching the preset output reading position so as to correspond to the peak in the output history obtained by traveling the section. Measuring method. The rotational angle position is detected by an encoder that is provided on the axle of the load measuring wheel axle and intermittently generates a pulse signal in accordance with the rotational displacement of the axle.
The load measurement method according to claim 1, wherein the load is calculated based on an output of the load detection unit detected substantially simultaneously with the pulse signal corresponding to the output reading position. The output reading position has a predetermined range, and the range of the output reading position is set wide according to an increase in the maximum curvature of a curved road included in a route on which measurement is performed. The load measuring method according to claim 2. A load measuring wheel shaft having a pair of wheels fixed to both ends of the axle, and load detecting means for intermittently generating an output corresponding to a load acting on a contact portion between the wheel and the rail;
Position detecting means for sequentially detecting the rotational angle position of the load measuring wheel axle;
The output history of the load detection means is captured, and a vehicle in which the rotational angle position of the load measuring wheel shaft detected by the position detecting means is mounted on the load measuring wheel shaft is caused to travel in a smooth linear section in advance. Output data processing means for calculating the load based on the output of the load detection means when substantially matching the preset output reading position so as to correspond to a peak in the acquired output history , Load measuring device. A recording means for recording the output history of the load detection means and the output history of the position detection means synchronously;
5. The load measurement according to claim 4, wherein the output data processing means calculates the load using the output history of the load detection means and the output history of the position detection means recorded by the recording means. apparatus. The position detecting means includes an encoder that is provided on the axle of the load measuring wheel axle and intermittently generates a pulse signal in accordance with a displacement in the rotational direction of the axle.
The output data processing means calculates the load based on the output of the load detection means detected substantially simultaneously with the pulse signal corresponding to the output reading position. 5. The load measuring device according to 5. The output reading position has a predetermined range;
The output data processing means widens the range of the output reading position in accordance with an increase in the maximum curvature of a curved road included in a route on which the range of the output reading position is measured. The load measuring device according to any one of claims 4 to 6.

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