CS258399B1 - Means for oriented adhesive characteristics determination - Google Patents

Abstract

The tool is designed for designers rolling stock. Allows directly from the graphics the measured or calculated adhesive characteristics to determine the desired values oriented adhesion coefficients. Aids forms a grid mat, at the beginning of which is a pivot pin a rotating ruler attached.

Description

The invention relates to the determination of oriented adhesion characteristics, at a variable lead angle, based on the basic characteristic determined by calculation or experimentally.

In practice, the rail vehicle designer often needs to know the course of the adhesion characteristics in contact of the wheel with the rail. Longitudinal adhesion characteristics are known from experiments which determine the dependence of the coefficient of adhesion in the longitudinal direction on the slip in the longitudinal direction. From this characteristic, the values of the oriented coefficients of adhesion in the longitudinal direction and the coefficients of adhesion in the transverse direction cannot be deducted if the wheel is approaching the rail at an angle of attack, i.e. when a lateral slip occurs between the wheel and rail.

Analytical calculation of oriented adhesion characteristics requires digitization of the measured dependencies, which is disadvantageous.

This disadvantage is overcome by the device according to the invention, characterized in that the plate-shaped washer is provided at the beginning of a rectangular coordinate grid with a fastening pin on which the ruler is rotatably mounted. The device allows determination of oriented adhesion characteristics directly from the measured characteristic, provided that the dependence of the total adhesion coefficient on the total slip is the same for any direction, which is confirmed with good accuracy by many experiments.

An exemplary embodiment of the device of the invention is shown in the drawing, in which Fig. 1 shows an overall view of the device and Fig. 2 shows a method for evaluating a record.

The device for determining based adhesive characteristics of FIG. 1 is formed by two plate-shaped washer, which is deposited on a rectangular grid 2. Next, the substrate 2 provided with a rotatable ruler rychlovázacím 2 ^and pin 1 of the ruler is pivotally mounted to the substrate 2 ^{in the} left lower corner of the grid 2, that is, at its origin.

The procedure for determining oriented adhesion characteristics is as follows:

It is preferable to use a transparent, eg tracing paper or foil, to record the adhesive characteristic 2, since the coordinate screen 2 on the substrate 2 facilitates the identification of the coordinate systems of the coordinate screen 2 and the recording of the adhesive characteristic 6, further facilitates the transmission and reading of values.

A rotary ruler 2 is applied ^{and the} parts 2 'A ^and 2 ^are fastened by a pivot pin 6.

The graph of FIG. 2 shows the values of the oriented coefficients of adhesion for the longitudinal chute S and the transverse chute S, as follows: x y

- on the horizontal axis with the slip Sy, that is the point plots the values of the longitudinal slip δ _χ , that is the point A, and the transverse B, and the points parallel to the vertical axis

- the transverse slip value is plotted on a vertical axis, parallel to the horizontal axis of the same scale, that is, point C, and

- a pivot ruler 2 is rotated to the point of intersection of the plotted parallel lines ^{and the} distance OD is transferred to the horizontal axis where point E is obtained

- parallel to the vertical axis at point E, which intersects with the original adhesion characteristic 6 at point F.

This point F is connected by a ruler 2 ^{with the} origin 0 and a point G of the oriented adhesion characteristic Ί_ = f Ο _χ ) is obtained on the comic at point A for the lateral slip = const.

At the point of intersection with the perpendicular point B, the point H of the oriented adhesion characteristic = f (Sy) is obtained for the longitudinal slip _{χ χ} = const. By transferring the distance BH to point A, point 2 is obtained, which is the point of the oriented adhesion characteristic J9 ju ^ = f (Ξ _χ ) for transverse slip

Sy = const.

The process is repeated until the required number of points of the desired oriented adhesive characteristic T, 2 or 9 is obtained.

The method of determining oriented adhesion characteristics from the measured adhesion characteristic by means of the present invention is advantageous in particular in that it is fast and at the same time easy to use and based directly on the graphical record of the measured adhesion characteristic.

Claims (1)

SUBJECT OF THE INVENTION Apparatus for determining oriented adhesion characteristics from a measured adhesion characteristic, characterized in that the plate-shaped plate (1) is provided at the beginning of a rectangular coordinate grid (2) with a fastening pin (4) on which the ruler (3) is rotatably mounted.