The present invention relates to a device for measuring internal defects of railway tracks, and in particular an ultrasonic device for working on the track. Devices for analysing a body by means of an ultrasonic beam are well known and are used for measuring internal defects of railway tracks both on the track and in the workshop. According to this principle, an ultrasonic beam is emitted in the direction of the rail by a probe placed on the rail rolling table, the energy reflected by the rail and its defects are then detected and measured by suitable electronic circuits. US Patents 4.662.224 and 4.700.574 disclose methods and measurements of the devices.
The geometric position of the rails is never perfect and misalignment, point deformation or discontinuities on the rails cause the probes to burst on the rails and thereby lose the acoustic linkage pertaining to the measurements. These disturbances are all the more important as the working speed is high. Track devices, such as directional devices, for example, constitute important discontinuities and impose high stresses on the probes which may lead to the probes being torn away when the measuring vehicle passes.
The existing auscultation trolleys have about ten probes in rows of rails to ensure complete control of all rail defects. These probes are usually carried by a common beam which is pulled and guided along the rail by adequate means. Due to the required length of this support beam, its mass and the number of probes carried, it is extremely difficult to guarantee perfect probe-rail contact for all probes at all times and as a result these devices are not suitable for high-speed rail auscultation.
The purpose of the present invention is to overcome the disadvantages mentioned above. The patent holder proposes to this end an ultrasonic measuring device to be mounted under a railway vehicle which ensures perfect sound contact between each probe and the rail. This device also prevents the probes from being damaged when passing over large discontinuities on the rails.
The present invention concerns a measuring device equipped with ultrasonic probes which is distinguished by the features listed in claim 1. Further advantages are apparent from the features expressed in the dependent claims and from the detailed description of the invention.
The attached drawing shows two ways of making the measuring device according to the present invention.
Figure 1 is a partial cut side view of the measuring device according to the present invention.
Figure 2 is a partial top view of the device shown in Figure 1.
Figure 3 is a top view of the sole of the device shown in Figure 1.
Figure 4 is a side view of several measuring devices according to the present invention, mounted under a railway vehicle.
Figure 5 is a partial side view of a second embodiment of the lower part of the measuring device.
Figure 6 is a top view of the device shown in Figure 5.
Figure 7 is a schematic side view of a railway vehicle incorporating the measuring device described in this invention.
Figure 8 is a side view of a cleaning device of a railing in raised position.
Figure 9 is a side view of the device shown in Figure 8 in the working position.
Figure 1 shows the ultrasonic measuring device which consists of a skate 1 comprising two housing which can slide ultrasonic probes vertically 2. The top of skate 1 has a central mount 3 with two side arms 4.5 connecting the front mount 6 and the rear mount 7 of the skate respectively 1. Each probe 2 is mounted under a support plate 8. These support plates 8 are connected to the side arms 4.5 by means of pressure-adjustable cylinders 9. These cylinders 9 allow the probes 2 to be pressed against the rail with a determined force.The support pressure of these cylinders 9 can be adjusted to the speed of the device. The higher the speed, the greater the pressure with which the probes must be applied to the rail to prevent them from jumping. In place of the cylinders 9 there may be broken springs. The vertical running of the probes 8 is limited downwards by the support plates 8 whose dimensions are larger than those of the housing in which the probes slide 2.A sole 10 with cutouts that correspond to the housing of the skateboard 1 is fixed by screws (not illustrated) under the skateboard 1. This sole, usually made of plastic, allows the skateboard to slide on the rail reducing friction and wear.
The upper part of skate 1 is connected to a frame consisting of a support beam 12 on which are fixed two side plates, a front plate 21 and a rear plate 22. The vertical supports of skate 1 before 6 and rear plate 7 are connected by means of two cylinders 13 to the support beam 12. These cylinders 13 allow the sole 10 of skate 1 to be applied against the rail with a determined force and to lift the skate when walking up the foot, for example.These deformable rings 14 allow the skate to be driven in the direction of walking. They also allow the vibrations of probes 2 and skate 1 to be dampened when the device is moving forward. Deformable rings 14 can be replaced by any elastic organ, such as springs or silencer blocks. Pins 23 mounted in the front 6 and rear 7 supports of skate 1 slide vertically into housing practiced in the front 21 and rear 22 plates of the frame. These housing are in the form of a vertical slit whose width corresponds to the diameter of the pins 23. These pins 23 thus provide both latent guidance to the skate relative to the frame and limitation of the skate's movement towards the bottom when moving relative to the actual sound action of the frames 13.
The water supply duct 15 is drawn through 17.17' channels in front of the probes 2 into a chamber formed by the sleeve cutting 10. The water supply duct 16 is drawn through 18.18' channels in the rear of each probe 2 into a chamber formed by the sleeve cutting 10. It is thus possible to bring water through the 17.17' channels into the chamber in front of the probes so that a film of water forms between the probe 2 and the rail, thus ensuring excellent sound contact between the probe and the rail.
Figure 3 shows the shape of the cuts made in the sole 10 and thus the configuration of the chambers they define at the front and rear of the probes. These cuts 19,20 reproduce the rectangular shape of the probes in their central part to allow the passage of the probe 2 and extend forward and backward through a triangular cut. The sorting shape of these cuts promotes a uniform distribution of water at the front of the probes and allows the water to be concentrated to the recovery channels 18,18' at the rear of the probes.
Figure 4 is a profile view of an auscultation trolley mounted under a railway vehicle and comprising several units of measurement covered by the present invention.
In order to save the water required for the operation of the measuring system and thereby increase its autonomy and to improve the contact between the probe and the rail, a second design of the measuring device bearing the probes is proposed. This second design is described in Figures 5 and 6. The drainage ducts 15 and 16 supply water to the 24 splash nozzles.The water cone thus formed has an opening of about 35° and the distance between the base of the cone and the opening of the nozzle 24 is about 15 mm. The dimensioning and orientation of these nozzles 24 makes it possible to form the water film required for the correct probe-rail contact in an optimal way.This allows the formation of an optimal water film, which further reduces water consumption compared to the first implementation shown in Figures 1 to 3.
Figure 7 shows a schematic of a railway vehicle carrying a test trolley 26 with a set of measurement units 1. This trolley 26 also has lifting means consisting of hydraulic cylinders 27 which allow the installation to run up-to-the-foot. This trolley 26 is also connected to the railway vehicle chassis by means of rudders 29 which allow the train to be driven in the desired direction. This test trolley 26 is extensible transversely and has transverse (non-locked) means for placing the inside cylinders 28 against the side of the rail to provide an adequate lateral and transverse guide to the test trolley 26.On either side of the device containing the measuring units 1 there is a 30.30' rail cleaning device which will be described in more detail below. Located in front of the 3030' rail cleaning devices in the direction of travel and mounted on wagon 26 are 31.31' cleaning nozzles. These 31.31' cleaning nozzles are fed with water at a pressure of about 100 bar and allow the removal of debris or dust on the rail before the passing of the measuring units 1.
The general water supply system consists of a piston pump capable of delivering the water required at a maximum pressure of about 180 bar from a water tank on the railway vehicle. The water supply system directly feeds a first high pressure circuit which delivers water to the 31.31' cleaning nozzles and, via a pressure reducer, a second supply system which feeds the 24 splash nozzles to form the water film on the rail surface at a pressure of about 15 bar.
Tests in progress have shown that it is not possible to completely remove the waste on the rail with the help of the 31.31' cleaning nozzles alone, so the 30.30' cleaning devices have been arranged behind the 31.31' cleaning nozzles.
The cleaning device shown in Figure 8 consists of a claw 32 with 33 slots, mounted by means of pressure-adjustable cylinders 34 in a cradle 35. The cylinders 34 allow the contact force between claw 32 and the rail to be precisely adjusted. This claw 32 is driven in the direction of travel by means of deformable rings 36 which also have the function of dampening the vibrations of the claw 32. The cradle 35 is connected to a mounting plate 37 which is mounted under the carriage 26 by means of two 38.39 pivoting handles at one end in the upper part of the cradle 35 and at their other end in the mounting plate 37.A hydraulic cylinder 40, the cylinder body of which is connected to the base of the mounting plate 37 and the rod to the top of the mounting 38 allows the entire cradle 35 with the cleaning claw 32 to be lifted, as shown in Figure 9, for example, the entire cleaning device for up-to-the-foot walking.