SU420195A3 - - Google Patents

Description

(54) DEVICE FOR DEFECTOSCOPY OF FLAWS OF THE WHEELS OF RAILWAY MOBILE

passive element 2 or inductive coils 14 located in the magnetic field of the exciting circuit. The number of coils, their relative position, the distance between them, their installation relative to the rails is determined by the distance between the axles of the wheel pairs and the perimeter of the wheel flange, for example, the distance between the coils is provided less than the distance between the axles of the wheel pairs, as well as additional coils installed in zones 15 and 16, connected in series with UN coils to eliminate the influence of koleong pairs, the distance between the axes of which are smaller than the perimeter of the flange ECA; Installation of coils is also provided, the axis of which is located in a plane perpendicular to the plane of the rails, the coils being mounted along the axis of symmetry of the track.

The device works in the following, And | M way.

The current passing through the excitation circuit closed by the wheel pair is determined by the magnitude of the impedance of this co-tour. One of the components of the specified Dutchman is a transient resistance between a wheel flange and a rail. This resistance depends on the state of the flange and, in particular, on the absence of defects in it. Thus, the magnitude of the current in the excitation circuit is a signal about the state of the flange. As a consequence, the voltage on the passive element 2 is the ed. with. the signal about the state of the flange, which is registered by the indicator 5, while the strong channel passes through the amplifier 6, the detector and acts on the trigger 8 with a fixed response threshold, from the output of which the signal arrives the evaluation unit 9 to the defector indicator 10; the evaluation unit is essentially an electronic key, the transition of which from the "on," off positions is regulated by rail contacts 11 and 12, which are triggered at the moments of the passage of wheel sets, and the emf is determined in the evaluation unit. signal over the time interval between the iKOiHTaKTOB 11 and 12 trials, and also the emf derivative. a time signal in the presence of an iB defect on the wheel flange, and a signal to the defect indicator is issued for the indicated derivatives by the evaluation unit. Thus, in a wide range of rolling speeds, the readings of the defect indicator are practically determined by the size of the flange defect.

In order to increase the noise immunity of the device, an alternator of several kilohertz frequencies is provided, using a series resonance in the driving circuit. The moment of resonance occurs when the wheelset is located near the contacts, by means of which the rails are included in the exciting circuit, and the inductive component of the impedance of the exciting circuit is as high as the rails — the wheel — the axis reaches a predetermined value. The effect of insertion from adjacent wheelsets in series resonance in the driving circuit is significantly reduced.

When the circuit is excited by alternating current, induction coils 14 are used as communication elements in the recording circuit, mounted in the immediate vicinity of the rails or between the rails along the axis of symmetry of the path in the plane, perpendicular to the plane of the rails. In the latter case, the coils are predominantly affected by the field created by the current through the axis of the 1-wheel pair, and the field of currents in the relas.x has practically no effect on it.

When the wheel pairs are located at a distance smaller than the wheel perimeter, by means of additional coils installed in zones 15 and 16 and connected in series with the main influence of the adjacent wheel pairs on the results, co: ntrol is significantly reduced.

Subject invention

Claims (5)

1. A device for flaw detection of bald wheels of railway rolling stock, containing electromagnetic exciting and recording circuits, characterized in that, in order to increase the accuracy of control, the exciting circuit is designed as a two-pole between the rails of a series-connected current generator and a passive element, and the recording circuit configured as an electromotive force indicator (emf) and a communication element connected to its input. 2. Device 1P. 1, characterized in that the emf indicator. configured as a series-connected amplifier, signal detector, Schmitt trigger, evaluation unit, defect indicator, and rail contacts connected to the control inputs of the evaluation unit.  3. The device according to claim 1, of which there is a two-port device made in the form of an element of a series resonant circuit. 4. The device on c. 1, characterized in that the communication element is designed as a group of induction coils installed in the magnetic field of the exciting circuit. 5. The device according to claim 4, characterized in that the group of induction coils is made in the form of successively connected main and additional coils installed along the rail at a distance less than the perimeter of the wheel. L fPuZ.l - - five Phi 7 1 i3 Fig l