FI78984B - ANORDINATION OF PROFILMAETNING AV RAELSHJUL. TRANSFERRED PAEIVAEMAEAERAE - FOERSKJUTET DATUM PL 14 ç 26.11.85 - Google Patents

Description

Device for measuring the profile of rail wheels - Anordning för profilmätning av rälshjul.

1 78984

The invention relates to a device for determining the profile shape of a rail wheel and the dimensions of a profile in accordance with standards. Such a device is needed both for quality control of new rail wheels and for monitoring the wear of existing wheels.

Special mechanical thrust gauges are commonly used to determine the profile shape of a rail wheel and its standard dimensions. Drawing devices are also known for obtaining a drawing of a rail wheel profile. To determine the wear depth, the drawn profile is compared to a theoretical or previously similarly determined profile.

The disadvantage of these known measuring methods is that the measurement accuracy is too low, which makes it easy to make erroneous assessments, e.g. of wheel wear. In addition, known devices are cumbersome to use. Such measurement methods do not provide reliable results, e.g. when attempting to wear time after relatively short driving kilometers.

The measuring device according to the invention is intended to eliminate the disadvantages of these known methods and its object is to provide a measuring method with which the accurate determination of the dimensions and standards according to the rail wheel is easy and fast even in difficult field conditions. To achieve this, the measuring device according to the invention is characterized by what is apparent from the characterizing part of the first claim.

The greatest weakness, inaccuracy, of the prior art is avoided in the device according to the invention and in the measurement with it, so that the measurement of the examined profile and the comparison of the obtained measurements with the standard profile take place simultaneously during the measurement. To enable this, a desired standard profile is attached to the measuring device, which is followed by another follower member during the measurement. The monitoring element following the measured profile generates a difference signal if the measured profile differs from the standard profile. This difference signal can be e.g. a change in inductance in the induction coil. The difference signal can be amplified and registered with a plotter. When the device is reset at the beginning of the measurement at the highest point of the flange, the difference signal directly indicates the amount of wear. The monitoring of the standard profile and the profile to be measured during the measurement may be by mechanical, optical, electrical, magnetic or pneumatic means.

One embodiment of the device according to the invention is shown in Figures 1 and 2.

Figure 1 shows a measuring device according to the invention seen from the side and mounted on a rail wheel.

Figure 2 shows a measuring device according to the invention seen in a direction perpendicular to the plane of the rail wheel to be measured. The following shows the structure and operation of the measuring device according to the invention with reference to the figure numbers.

The measuring device is attached to the rail wheel (1) to be measured by means of a magnet placed on the base plate (2) so that the guide pins (3) rest on the outer edge of the flange and the base plate on the flange side side of the rail wheel. Since the outer circumference of the flange on which the pins (3) rest is not in use, the radius of the outer circumference of the flange also serves as a reference dimension. The body (4) of the measuring device is fixed in a position perpendicular to the base plate (2). The measuring carriage (5) moves along the slide rails in the body of the measuring device by means of a nut (7) rotated by a nut placed on the carriage and a stepper motor (6).

3 78984 On the conductors of this horizontally moving carriage, a second measuring carriage (8) moves vertically, the tracking member (9) following the shape of the upper surface of the reference profile (11) fixed to the measuring device body by two pins (10). In this case, the vertically moving measuring slide / to which the monitoring member is fixedly attached also moves in the vertical plane following the shape of the reference profile (11). The vertically moving carriage has a vertically moving measuring sensor (12), at the lower end of which a tracking member (13) follows the shape of the profile of the rail wheel to be measured when the horizontally moving carriage is moved. The tracking members (9) and (13) are in the same vertical, so that at the moment of measurement they are both equally far from the reference surface. The measuring sensor located in the vertically moving measuring slide works in such a way that the magnitude of the signal given by it is proportional to the distance between the monitoring members. When the measurement is started, the monitoring members are moved by moving the horizontal carriage to the starting position at the highest point of the flange. The sensor signal is reset at this point. The measurement is done by moving the horizontal sled so that the tracking members move the desired distance from the starting point. (The distance marked in Figure 1 corresponds to a UIC standard circle). The signal given by the measuring device is then directly proportional to the height difference between the reference profile and the profile to be measured, i.e. the wear depth of the profile to be measured. According to the program, the measurement can be repeated at the desired points in the profile and repeated at different points in the circumference of the rail wheel, giving a clear idea, e.g. of the distribution of wear at different points on the rail wheel. When moving to measuring a rail wheel according to another standard, you only need to change the reference profile. in accordance with the standard.

With the measuring device according to the invention, the measurement and the registration of the results can be automated, e.g. using a microcomputer, and the results of the measurements made under field conditions can be stored in the computer's memory for later analysis.

4,78984

In another embodiment of the invention, the reference profile (11) can be replaced by a mathematical function describing the shape of its upper surface, which is stored in the computer's memory. The measuring carriage (8) is then moved vertically by means of a guide screw rotated by a computer-controlled stepper motor and a nut in the carriage so that the position of the carriage corresponds to the - reference profile at each measuring distance from the reference surface.

With the measuring device according to the invention, a large number of accurate measurement results can be easily obtained, e.g. on the wear of a rail wheel. For example, when the wear depth is between 0 ... 10 mm, the measurement accuracy is 0.03 mm. Based on such measurement results, the rehabilitation turning of the rail wheel can be performed considerably more economically and accurately than was possible using previously known measurement methods.

Claims (2)

5,78984 Claim A measuring device for accurately determining the profile shape of rail rails by comparing the measured values of model model (11) and rail wheel profile tracking members (9, 13), characterized in that the tracking members (13.9) following the profiles to be measured (1,11) are on the same vertical, of which two one of the means monitors the shape of the profile to be measured and the other simultaneously the shape of the reference profile and generates a measuring signal proportional to the variation of the vertical distance differences of said monitoring members and the measuring device is provided with a base plate (2) for attaching the measuring device to the rail.