CN100381782C - Electromagnetic Ultrasonic Transducer for On-line Dynamic Detection of Rolling Stock Wheelset Defects - Google Patents

Abstract

The invention discloses an electromagnetic ultrasonic transducer for on-line dynamic detection of defects in locomotive and vehicle wheelsets. Its skeleton (4) is formed by integral casting or milling of a medium, the notch of the E-shaped groove is downward, and the high-frequency coil ( 3) Wrap around the E-shaped groove of the frame (4); the upper surface (12) of the frame (4) is an arc-shaped concave surface adapted to the shape of the tread of the wheel (1); a bracket (9) is provided under the bottom plate (13) , the bottom plate (13) is connected to the support (9) through a damping spring (5). The high-frequency coil of the electromagnetic ultrasonic transducer has a long service life and is not easy to be damaged; at the same time, the electromagnetic coupling efficiency between the high-frequency coil and the tested wheel is high, the detection accuracy is high, and the reliability is strong.

Description

Electromagnetic Ultrasonic Transducer for On-line Dynamic Detection of Rolling Stock Wheelset Defects

Technical field

The invention relates to an electromagnetic ultrasonic transducer used in the field of non-destructive testing, in particular to an electromagnetic ultrasonic transducer used for on-line dynamic detection of wheel set tread defects of locomotives and vehicles.

Background technique

The wheel set is a key component of the locomotive running system, and whether there are defects and damages in the shape of the wheel set is directly related to the driving safety. The rapid development of railway speed and the high-density operation of rolling stock have accelerated the wear rate of wheel sets. Therefore, in order to avoid the situation that the wheelset is still in use due to defects and to ensure the safety of the train, it is necessary to perform non-destructive dynamic detection on the tread defects of the wheelset in time. The common wheel set detection method uses a piezoelectric ultrasonic transducer for detection. When the piezoelectric ultrasonic transducer generates body waves to detect the wheel set, it needs to scan point by point along the periphery of the tread for radial detection in the body, which cannot realize the wheel set surface. And the automatic retrace detection near the surface, so it is impossible to realize the dynamic detection of the wheelset in operation.

The structure and working principle of the electromagnetic ultrasonic transducer in the field of non-destructive testing is: a magnet is used to generate a static or quasi-static low-frequency magnetic field that is horizontal or vertical to the surface of the workpiece to be tested, and a high-frequency coil is placed in the magnetic field. The high-frequency coil is fixed by the frame and is parallel to the surface of the workpiece to be measured. The high-frequency signal from the external high-frequency signal generator flows into the high-frequency coil to generate a high-frequency magnetic field, which induces eddy currents on the surface and near the surface of the workpiece. The frequency range of the high-frequency magnetic field is within the ultrasonic frequency range. According to the principle of Lorentz force or the magnetostrictive effect, the eddy current forms ultrasonic surface waves under the action of the magnetic field, and the surface waves will propagate along the surface and near the surface of the workpiece, and the high-frequency coil simultaneously senses and receives the reflected ultrasonic surface wave signals . The transducer converts the ultrasonic surface wave signal into an electrical signal and outputs it, which is analyzed and processed by the analysis and processing equipment, so that the non-destructive testing of the surface and near-surface state of the workpiece can be realized. It can be seen that the electromagnetic ultrasonic transducer can generate surface waves that automatically propagate around the tread of the wheel set and its near surface, and can conveniently realize the dynamic detection of the wheel set in operation.

However, in the process of dynamic detection of wheel tread defects with electromagnetic ultrasonic transducers, the distance between the high-frequency coil and the wheel tread surface is required to be less than 1 mm to achieve good coupling of electromagnetic signals. However, due to pitting, continuous peeling and other phenomena on the tread surface of the wheel set, or the presence of other foreign objects, such physical boundary conditions limit the application of electromagnetic ultrasonic technology in wheel set inspection. Moreover, the coil winding of the electromagnetic ultrasonic transducer will also be damaged due to mechanical, chemical or thermal factors during the contact and coupling process of the wheel set.

The existing electromagnetic ultrasonic transducers for on-line dynamic detection of wheel-set defects of locomotives can solve the above problems by adding filling materials between the coil and the surface of the workpiece to protect the high-frequency coil. However, in the long-term use process, the filling material is easy to fall off due to the rolling effect of the wheels, which damages the high-frequency coil. At the same time, the top of the coil of the electromagnetic ultrasonic transducer is flat, and it is in line contact with the arc-shaped wheel tread. The contact effect is poor, the coupling efficiency is low, the detection accuracy is low, and the reliability is poor.

Contents of the invention

The purpose of the present invention is to provide an electromagnetic ultrasonic transducer for on-line dynamic detection of locomotive wheel defects. The high-frequency coil of the electromagnetic ultrasonic transducer has a long service life and is not easily damaged; The electromagnetic coupling efficiency is high, the detection accuracy is high, and the reliability is strong.

The present invention solves the technical problem, and the adopted technical scheme is: an electromagnetic ultrasonic transducer for on-line dynamic detection of locomotive wheelset defects, including a panel, a bottom plate and a magnet box between the panel and the bottom plate, and the magnet box is fixed There are magnets; the frame is set in the rectangular slot of the panel, and the high-frequency coil is wound on the frame. On the E-shaped groove of the skeleton; the upper surface of the skeleton is an arc-shaped concave surface adapted to the shape of the wheel tread; a bracket is provided under the bottom plate, and the bottom plate and the bracket are connected through a shock-absorbing spring.

Compared with the prior art, the beneficial effect of the technical solution of the present invention is: the use of an integral frame with the E-shaped groove notch downwards, so that the rolled part of the frame and the entire frame are an integral structure, compared with the existing The rolled part of the filling has a significantly enhanced ability to withstand pressure, is not easy to be crushed, and the high-frequency coil is not easy to fall off, and has a long service life. The upper surface of the skeleton is an arc-shaped concave surface adapted to the shape of the wheel tread, so that the contact between the ultrasonic transducer and the wheel tread is changed from line contact to surface contact, the contact area is greatly increased, the electromagnetic coupling efficiency is improved, and the detection accuracy is high and reliable. Strong. The shock-absorbing spring between the base plate and the bracket can weaken the impact force of the wheel tread on the electromagnetic ultrasonic transducer during the dynamic rolling process, effectively protect the electromagnetic ultrasonic transducer and prolong the service life; The contact between the transducers is tighter and better, further improving the electromagnetic coupling efficiency.

The distance between the bottom of the above-mentioned E-shaped groove and the arc-shaped concave surface is ≤1mm. This can ensure good electromagnetic coupling between the ultrasonic transducer coil and the tread of the wheel set.

The above-mentioned bracket is fixed on the deck, and the deck is clamped and fixed on the bottom of the rail by bolts. The installation and fixation between the present invention and the track is realized by adopting the mode of the card seat, and the damage to the existing structure of the track is minimal.

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is a front view structural schematic diagram of an embodiment of the present invention.

FIG. 2 is a side view of FIG. 1 .

FIG. 3 is a top view of FIG. 1 .

FIG. 4 is an enlarged partial cross-sectional view of the panel and its internal framework and coils of this embodiment (enlarged partial cross-sectional view of B in FIG. 1 ).

FIG. 5 is an enlarged sectional view of the panel of this embodiment (an enlarged sectional view taken along the line A in FIG. 3 ).

FIG. 6 is a schematic diagram of the circuit principle of the preamplifier circuit inside the preamplifier box 10 of this embodiment.

Detailed ways

Example

Figures 1-5 show that a specific embodiment of the present invention is: an electromagnetic ultrasonic transducer for on-line dynamic detection of vehicle wheelset defects, including a panel 2, a base plate 13, and a magnet between the panel 2 and the base plate 13 Box 8, magnet 11 is fixed inside the box 8; the skeleton 4 is set in the rectangular slot of the panel 2, and the high-frequency coil 3 is wound on the skeleton 4, and the skeleton 4 is made by integral casting or milling of the medium, and its E-shaped The notch of the groove is downward, and the high-frequency coil 3 is wound on the E-shaped groove of the frame 4; the upper surface 12 of the frame 4 is an arc-shaped concave surface adapted to the shape of the tread surface of the wheel 1; Support 9 is connected by shock-absorbing spring 5 .

The distance between the bottom of the E-shaped groove and the arc-shaped concave surface 12 is ≤1mm. The bracket 9 is fixed on the deck 6, and the deck 6 is clamped and fixed on the bottom of the rail by bolts 14. Of course, in actual use, holes can also be drilled on the rail waist of the track 7, and the bracket is mounted on the track 7 in a bolt mode without using a clamp.

A preamp box 10 connected to the high frequency coil 3 is also fixed on the bracket 9 of this embodiment. Of course, the preamp box 10 and its internal preamplifier circuit can also be placed in other positions, such as the top of the deck 6 . The input end of the preamplifier circuit inside the preamplifier box 10 is connected with the lead end of the high frequency coil 3, and the circuit can adopt various preamplifier circuits of existing ultrasonic frequency band electric signals, as shown in Figure 6 Pre-amplification circuit.

The radius of curvature R of the arc-shaped concave surface 12 of the frame 4 of the present invention is equivalent to the radius of curvature R of the tread rolling circle of the wheel set 1, and the value range is usually 400mm-700mm. The material of the panel 2 can be selected from steel or other wear-resistant metal materials. The magnet 11 used in the electromagnetic ultrasonic transducer can be either a DC electromagnet or a permanent magnet.

The present invention can also be applied to the drop wheel detection system by improving the appearance structure of the installation support 9 and the electromagnetic ultrasonic transducer. Remove the mounting support 9 and the damping spring system 5, and add a handle, then it can be applied to the wheel set static defect detection system.

When the present invention is implemented, except that the upper surface of the skeleton 4 is an arcuate concave surface 12, part of the upper surface of the panel 2 adjacent to the skeleton 4 also forms an arcuate concave surface 12 with the same radius of curvature and center of circle as the skeleton 4 . Certainly, only the upper surface of the framework 4 may be the arc-shaped concave surface 12 , while the upper surface of the panel 2 is not higher than the highest point of the arc-shaped concave surface 12 .

Claims (3)

1. a rolling stock wheel comprises the magnet casing (8) between panel (2), base plate (13) and panel (2) and the base plate (13) to electromagnet ultrasonic changer of on-line dynamic detection for defect, and magnet casing (8) internal fixation has magnet (11); Skeleton (4) is located in the rectangular channel of panel (2), radio-frequency coil (3) is on skeleton (4), it is characterized in that: integrated poured or Milling Process forms described skeleton (4) by medium, and the breach of its E shape groove is downward, and radio-frequency coil (3) is on the E shape groove of skeleton (4); The upper surface (12) of skeleton (4) is and the adaptive arc-shaped concave of wheel (1) tread contour; Base plate (13) below is provided with support (9), and base plate (13) links to each other by damping spring (5) with support (9).

2. electromagnet ultrasonic changer according to claim 1 is characterized in that: the distance≤1mm of the bottom of described E shape groove and arc-shaped concave (12).

3. electromagnet ultrasonic changer according to claim 1 is characterized in that: described support (9) is fixed on the deck (6), and deck (6) then is fixed on the bottom of rail by bolt (14) chucking.

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