GB2045925A

GB2045925A - Measuring axle bearing temperature

Info

Publication number: GB2045925A
Application number: GB8006787A
Authority: GB
Original assignee: Industrie Automation GmbH and Co
Current assignee: Industrie Automation GmbH and Co
Priority date: 1979-03-01
Filing date: 1980-02-28
Publication date: 1980-11-05
Also published as: FR2450188A1; JPS55149815A; DE2907945A1; GB2045925B; FR2450188B3

Abstract

Apparatus for the measurement of the temperature of axle bearings in rail vehicles comprises a detector (5), which generates an electrical signal in response to infrared rays, an optical system (1), which is arranged alongside a rail track and - when a rail vehicle travels past - receives radiation energy from part of the surface of an axle bearing, a modulator (3) arranged in the ray path and an electronic system for evaluating the signals of the detector. A deflecting mirror is positioned in front of the optional system (1) so that it deflects into the axis of system (1) the infrared rays emitted substantially vertically downwards from a narrow strip of the underside of the axle bearing. A ray-conducting element (7), especially constructed for the conduction of infrared rays is inserted between the modulator (3) and the detector (5). <IMAGE>

Description

SPECIFICATION Improvements in or relating to apparatus for measurement of the temperature of rail vehicle axle bearings The present invention relates to apparatus for the measurement of the temperature of axle bearings in rail vehicles.

Apparatus of this kind is described in United Kingdom patent specification No: 1482955 and clarifica- tion of the general construction and purpose of apparatus of the kind to which the present invention relates may be obtained by reference to specification No: 1482955. In the apparatus of No: 1482955, the fins or webs of the modulator of the apparatus have an infrared-reflecting coating on the side facing the detector and are shaped in such a mannerthatthe detector is largely mirrored in these webs or fins. It is furthermore explained in specification No: 1482955 thatthetemperature of the detectorcan be utilized as a comparison temperature.

This arrangement or construction of the component has, however, the disadvantage that background radiation, which impairs the actual reference radiation and leads to falsification thereof, can get into the ray path on the travel between the web or fin surfaces and the detector.

It also has the disadvantage that the fins or webs for purely mechanical reasons cannot be so exactly shaped that the detector is imaged even in only an approximately form. Rather, the shape of the fins or webs is always such that an appreciable part of the rays emanating from the detector are not reflected back to it, but are radiated away into the surroundings. There is accordingly a need for improvement of this apparatus so that firstly the afore-mentioned background radiation can no longer getto the detector and that secondly all rays emanating from the detector as far as possible get back to the detector.

According to the present invention there is provided apparatus for measurementofthe temperature of rail vehicle axle bearings, the apparatus comprising a deflecting element locatable adjacent to a rail track to receive infrared radiation radiated from the axle bearings of rail vehicles passing along the track and to deflect such radiation towards a given ray path, an optical system arranged to receive the deflected radiation and to direct the radiation along the ray paths, a modulator arranged in the ray path to modulate radiation passing therethrough, an infrared ray detector arranged to detect modulated radiation and to generate an electrical signal in response to detection of radiation, a radiation conducting element arranged between the modulator and detector to conduct radiation therebetween, and electronic processing means for processing signals generated by the detector.

Preferably, the ray-conducting element is a tube, the inside of which is constructed to be reflective of infrared rays, preferably gilded.

Such a ray-conducting element, which is comparable with a light-conducting element in the range of the visible light, fulfils a double purpose. Firstly, it screens the space between the modulator and the detector against background radiation. This therefore prevents background radiation from being picked up by the detector and leading to falsification of the reference temperature. Secondly, it prevents the rays, which emanate from the detector and are reflected at fins or webs of the detector, from being scattered into the surroundings. Rather, these rays are reflected at the inside walls of the ray-conducting element due to the inexact shaping, for example of the fins, into the rays reflected into the surroundings and get, in some cases after multiple reflection, back to the detector.Such a ray-conducting element may thus appreciably increase the efficiency of the mirrored fins or webs.

In addition, the structuring of this element apparently acts as a cold background, since the bodyspecific radiation is negligible in this region.

Such an increase in efficiency also occurs when the temperature inherent in the detector is not utilized as a reference temperature, but when the temperature of the cooled fins and webs is used for this purpose. In this case, there is also prevention of partial loss into the surroundings of the rays emanating from the fins and webs.

For preference, a further ray-conducting element of that kind is arranged in the region between the optical system and the modulator. The further element can also serve in this region to keep unwanted background radiation from getting to the detector and falsifying the measurement result.

An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawing, which is a cross-sectional view of part of apparatus embodying the invention.

Referring now to the drawing there is shown part of an apparatus for measuring the temperature of rail vehicle axle bearings, the-apparatus comprising an entry optical system 1 with a dirt protection diaphragm 2 arranged in front of the optical system 1. In front of the diaphragm 2 there is arranged a deflecting mirror (not shown) for deflecting to the axis of the optical system infrared radiation radiated downwardly from a narrow strip of the underside of an axle bearing of a rail vehicle travelling past the mirror. The positioning of the mirror in relation to a rail track on which such vehicle travels is described in more detail in the aforementioned specification No: 1482955.

The optical system directs the deflected infrared radiation along a ray path, in about the centre of which is a tuning fork modulator 3, the mode of construction and manner of function of which is described in specification No: 1482955 and therefore not explained in more detail here.

Disposed at the end of the ray path is an exit optical system 4, directly behind which is arranged a detector 5 on a Peltier cooler 6.

Inserted between the modulator 3 and the optical system 4 is a first ray-conducting tube 7, which in the present embodiment is expediently also constructed as a mount for the optical system 4 at its end downstream in the ray path. Adjoining the optical system 4, almost without any space therebetween, is the mount of the detector 5 so that background radiation cannot penetrate to the detector at this point.

The ray-conducting tube 7 is provided at its inside with an infrared-reflecting coating. Thereby, the rays reflected by or radiated from the fins of the tuning fork modulator 3 towards the side are reflected at the inside of the tube 7 and conducted to the detector.

On the other hand, background radiation coming from outside is reflected back and does not get into the ray path.

In addition, a second ray-conducting tube 8, the inside wall of which is also constructed to be infrared-reflecting, is inserted between the entry optical system 1 and the modulator 3. While it is the main purpose of the first ray-conducting tube 7 to avoid impairment of the reference temperature emanating from the fins or webs of the modulator, it is the particular purpose of this second rayconducting tube 8 to conduct the signal radiation free of interference.

Claims

1. Apparatus for measurement of the temperature of rail vehicle axle bearings, the apparatus comprising a deflecting element locatable adjacent to a rail track to receive infrared radiation radiated from the axle bearings of rail vehicles passing along the track and to deflect such radiation towards a given ray path, an optical system arranged to receive the deflected radiation and to direct the radiation along the ray path, a modulator arranged in the ray path to modulate radiation passing therethrough, an infrared ray detector arranged to detect modulated radiation and to generate an electrical signal in response to detection of radiation, a radiation con ducting element arranged between the modulator and detector to conduct radiation therebetween, and electronic processing means for processing signals generated by the detector.

2. Apparatus as claimed in claim 1, wherein the deflecting element is adapted to be mounted to receive and deflect radiation radiated downwardly.

3. Apparatus as claimed in either claim 1 or claim 2, wherein the radiation conducting element comprises a tube having an infrared ray reflective internal surface.

4. Apparatus as claimed in claim 3, wherein the internal surface of the tube is gilded.

5. Apparatus as claimed in any one of the preceding claims, further comprising a further radiation conducting element arranged between the optical system and the modulator to conduct radiation therebetween.

6. Apparatus as claimed in claim 5, wherein the further radiation conducting element comprises a tube having an infrared ray reflective internal surface.

7. Apparatus as claimed in any one of claims 3,4 and 6, wherein the internal surface of the tube or at least one of the tubes is so shaped as to provide a substantial conical formation of infrared rays conducted therethrough.

8. Apparatus for measurement of the temperature of rail vehicle axle bearings, the apparatus being substantially as hereinbefore described with refer encetothe accompanying drawing.