METHOD FOR CARRYING OUT A SOUND TEST AND ENDOSCOPE DEVICE

Abstract

A method is provided for carrying out a sound test for detecting and/or analyzing material faults and/or mounting faults of at least one component, in which the component is excited, by striking, to experience vibrations which generate soundwaves, after which the generated soundwaves are detected and conclusions are drawn about material faults and/or mounting faults on the basis of the detected soundwaves, wherein the striking of the component and the detection of the vibrations are carried out using an endoscope device. In addition, embodiments of the present invention relates to an endoscope device which is configured to carry out the method.

Claims

1. A method for carrying out a sound test for detecting and/or analyzing material faults and/or mounting faults of at least one component, in which the component is excited, by striking, to experience vibrations which generate soundwaves, after which the generated soundwaves are detected and conclusions are drawn about material faults and/or mounting faults on the basis of the detected soundwaves, wherein the striking of the component and the detection of the vibrations are carried out using an endoscope device.

2. The method as claimed in claim 1, wherein the at least one component is a component which is arranged inside a housing, in particular a guide blade or rotor blade arranged inside a turbine housing or compressor housing, and in that the method is carried out with a closed housing.

3. The method as claimed in claim 1, wherein the at least one component is a guide blade or rotor blade arranged inside a housing lower part of a turbine housing or compressor housing which is divided into a housing upper part and a housing lower part, and in that the method is carried out in a state in which the housing upper part is taken off and a rotor is arranged in the housing lower part.

4. The method as claimed in claim 1, wherein the detected vibrations are output via a loudspeaker and subsequently analyzed manually by trained personnel for the detection and/or analysis of material faults and/or mounting faults of the component, without further technical aids.

5. The method as claimed in claim 1, wherein the detected vibrations are transmitted to an evaluation device and compared therein automatically for the detection and/or analysis of material faults and/or mounting faults of the component with reference values stored in the evaluation device.

6. An endoscope device, in particular for carrying out a method as claimed in claim 1, which endoscope device has at least one handling unit and a shaft which is connected thereto and is of rigid or flexible design and in which an image transmission device and a light transmission device are integrated in such a way that the image signals and light signals can be transmitted from the free end of the shaft to the handling unit, wherein a pulse generator which can be activated by the handling unit is formed in the shaft in such a way that when it is activated a component which is present in the region of the free end of the shaft can be struck.

7. The endoscope device as claimed in claim 6, wherein a sensor device is provided in the region of the free end of the shaft and is formed in such a way that it generates signals representing received soundwaves and transmits them to the handling unit.

8. The endoscope device as claimed in claim 6, wherein the image transmission device, the light transmission device and the sensor device are arranged in channels which are separate from one another and extend through the shaft as far as the free end of the shaft.

9. The endoscope device as claimed in claim 6, wherein the image transmission device is provided in the form of a camera system.

10. The endoscope device as claimed in claim 6, wherein the pulse generator has a firing pin which can be activated mechanically, pneumatically or electromechanically, preferably by the handling unit.

11. The endoscope device as claimed in claim 6, wherein the sensor device has a microphone, a laser vibrometer or an acceleration pickup.

12. The endoscope device as claimed in claim 6, wherein an evaluation device is provided which is configured in such a way that it evaluates signals representing soundwaves transmitted by the sensor device, and compares the signal spectrum and/or impulse response of said signals with reference values stored in the evaluation device.

13. The endoscope device as claimed in claim 12, wherein the evaluation device is arranged on the handling device or integrated therein.

Description

BRIEF DESCRIPTION

[0020] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

[0021] FIG. 1 shows a schematic view of an endoscope device according to an embodiment of the present invention;

[0022] FIG. 2 shows a schematic view of a free end of a shaft of the endoscope device illustrated in FIG. 1;

[0023] FIG. 3 shows a schematic sectional view through a pneumatically activated pulse generator of the endoscope device illustrated in FIG. 1;

[0024] FIG. 4 shows a schematic sectional view through an alternative electromagnetically activated pulse generator according to an embodiment of the present invention;

[0025] FIG. 5 shows a schematic sectional view through an alternative mechanically activated pulse generator according to an embodiment of the present invention;

[0026] FIG. 6 shows schematic sectional views which show a further design of a mechanically activated pulse generator in various operating positions;

[0027] FIG. 7 shows schematic sectional views which show a further design of a mechanically activated pulse generator in various operating positions;

[0028] FIG. 8 shows schematic sectional views which show a further design of a mechanically activated pulse generator in various operating positions;

[0029] FIG. 9 shows a schematic sectional view through a turbine on the basis of which a method according to an embodiment of the present invention is described using an endoscope device; and

[0030] FIG. 10 shows a schematic sectional view of a turbine of a jointed design in which an upper housing half is removed, in which a rotor is arranged in a lower housing half, and on the basis of which a method according to a further embodiment of the present invention is described using an endoscope device according to embodiments of the invention.

DETAILED DESCRIPTION

[0031] FIG. 1 shows an endoscope device 1 according to an embodiment of the present invention. The endoscope device 1 comprises a handling unit 2 which is defined on the outside by a housing which defines a grip region 3, and a shaft 4 which is embodied in a flexible way here. Within the shaft 4, Bowden cables 5 are arranged in a known fashion, which Bowden cables 5 can be activated in order to move the shaft 4 by means of the handling unit 2, here by means of a switching lever 6 which is arranged on the handling unit 2 and can move in all directions. In addition to the Bowden cables 5, an image transmission device 7, a light transmission device 8, a pulse generator 9 and a sensor device 10 are integrated into the shaft 4, which image transmission device 7, light transmission device 8, pulse generator 9 and sensor device 10 are each arranged in the present exemplary embodiment in channels which are separate from one another and which extend through the shaft 4 from the handling unit 2 as far as the free end of the shaft 4. However, it should be clear that it is basically also possible to arrange at least some of the specified components in a common channel, such as, for example, the image transmission device 7 and the light transmission device 8.

[0032] The image transmission device 7 is embodied here in such a way that image signals are transmitted from the free end of the shaft 4 to a monitor 11 arranged on the handling unit 2, in the manner of a video endoscope. Even if a digital image transmission is preferred, it is alternatively also possible to implement the image transmission device optically, for example by means of a lens system and an eyepiece which is arranged on the handling unit 2, in particular when the shaft 4 is embodied as a rigid shaft.

[0033] The light transmission device 8 comprises here a glass fiber cable bundle 12 which guides light from a light source 13 which is positioned within the handling unit 2 and is embodied here as an LED light source, to the free end of the shaft 4.

[0034] The pulse generator 9 is embodied in such a way that when it is activated the switches 14 which are provided on the handling unit 2 can be struck by means of a component which is provided in the region of the free end of the shaft 4, as is also explained in more detail below with reference to FIG. 9. The pulse generator 9 has for this purpose a firing pin 15 which can be activated pneumatically or electromagnetically or else mechanically depending on the design. These examples of the implementation unit of the various types of activation are illustrated in FIGS. 3 to 8, to which reference is made in more detail below.

[0035] The sensor device 10 is embodied in such a way that it generates signals representing received soundwaves and transmits them to the handling unit 2. For this purpose, the sensor device 10 has here a microphone 16 which transmits received signals to a loudspeaker 17 which is provided on the handling unit 2. Alternatively, the signals can, however, also be transmitted to an evaluation device 18 which is also integrated here into the handling unit 2, but can alternatively also be provided separately. The evaluation device 18 is configured in such a way that it evaluates signals representing soundwaves transmitted by the sensor device 10 by comparing the signal strength of said signals with, in particular, reference values stored in the evaluation device 18. At this point it is to be noted that instead of a microphone 16, the sensor device 10 can also have other suitable sensors, in particular in the form of a laser vibrometer, an acceleration pickup or the like.

[0036] FIGS. 3 to 5 show various activation principles of the firing pin 15 of the pulse generator 9.

[0037] FIG. 3 shows a sleeve 19 which is inserted into the shaft channel of the pulse generator 9 starting from its free end, in the direction of the arrow 20. The sleeve 19 has two annular projections 21 and 22 which are arranged spaced apart from one another, protrude radially inward and define a receptacle space 23 for the firing pin 15, wherein the annular projection 21 which is provided at the free end is provided here as a separate component, while the other annular projection 22 is embodied in an integral fashion with the sleeve 19. The firing pin 15 is provided at its free end with a radially outwardly protruding annular shoulder 24 and its other free end with a semispherical head 25. Within the receptacle space 23 a pressure spring 26 is accommodated which is supported, on the one hand, against the annular projection 21 and, on the other hand, against the annular shoulder 24 of the firing pin 15. In order to accelerate the firing pin 15 to strike a workpiece in the outward direction, the outer end face 27 of the annular projection 24 of the firing pin 15 can be acted on in the direction of the arrow 28 with compressed air, with the result that the firing pin 15 is moved with a predetermined impulse counter to the restoring force of the compression spring 26.

[0038] FIG. 4 shows an electromagnetic variant for activating the firing pin 15. In this variant, the annular shoulder 24 is attached approximately centrally to the firing pin 15, wherein the compression spring 26 which is arranged within the receptacle space 23 is supported against the annular shoulder 24 of the firing pin 15, on the one hand, and against the annular projection 22, on the other. Arranged opposite the firing pin 15 on the other side of the annular projection 22 is an electromagnet which holds the ferromagnetically embodied firing pin 15 counter to the actuating force of the compression spring 26 in the pulled-back position. If the electromagnet is switched off, the compression spring 26 presses against the annular shoulder 24 of the firing pin 15 in such a way that the firing pin 15 shoots forward with a predetermined impetus.

[0039] FIG. 5 shows a first embodiment of a mechanically activated firing pin 15. The design illustrated in FIG. 5 corresponds essentially to the design in FIG. 3, only that the firing pin 25 is not activated by means of compressed air but instead by means of a wire 30 with which the firing pin 15 can be pressed outward with a predetermined impetus counter to the restoring force of the compression spring 26.

[0040] FIGS. 6 to 8 show a second variant of a mechanically activated firing pin 15 in various positions. In this variant, the compression spring 26 is supported between the annular projection 22 and the annular shoulder 24 which is arranged in the front half of the firing pin 15. The rear end of the firing pin 15 which extends beyond the annular projection is arranged in a rear receptacle space 31 of the sleeve 19 and has a radially extending drilled hole 32 in which two spheres 33 which lie opposite each other are accommodated which engage radially outward, via a spring 34 arranged between the spheres 33, into an annular groove 35 of a guide element 36 which engages around the free end of the firing pin 15 and is accommodated in an axially movable fashion within the rear receptacle space 31 of the sleeve 19. A wire 37 which extends as far as the handling unit 2 is secured to the free end of the guide element 36. In the relaxed state, illustrated in FIG. 6, the compression spring 26 presses the annular shoulder 24 of the firing pin 15 against the annular projection 21. In order to tension the system, the wire 37 is pulled back counter to the restoring force of the compression spring 26 according to FIG. 7 as long as the spring force of the spring 34 is sufficiently large in order to maintain the connection between the firing pin 15 and the guide element 36 via the spheres 33. If the spring force of the compression spring 26 exceeds the horizontal force component between the spheres 33 and the guide element 36, the connection between the firing pin 15 and the guide element 36 is released, after which the firing pin 15 is accelerated impulsively as far as the annular projection 21 by the restoring force of the compression spring 26.

[0041] A method for carrying out a sound test for detecting and/or analyzing material faults and/or mounting faults of guide or rotor blades 39, 40 arranged within a turbine housing 38 using an endoscope device 1 of the type described above is described below with reference to FIG. 9. For this purpose, the shaft 4 of the endoscope device 1 is introduced through an already present or additionally provided flange opening 41 in the turbine housing 38 and pushed forward as far as the guide blade 39 or rotor blade 40 which is to be tested. As soon as the free end of the shaft 4 comes into contact with the guide blade 39 or rotor blade 40 which is to be tested, the firing pin 15 is activated, depending on the embodiment variant of the endoscope device 1, pneumatically, electromagnetically or mechanically by means of the switch 14, in such a way that the blade is excited to experience vibrations which generate soundwaves. The vibrations are then detected by means of the sensor device 10, after which conclusions are drawn about the material fault and/or mounting fault on the basis of the detected soundwaves. The detection of the soundwaves can be carried out, for example, by means of the microphone 16, after which the detected soundwaves are output via the loudspeaker 17 and are then analyzed by trained personnel without further technical aids. Alternatively, the detected soundwaves can, however, also be conveyed to the evaluation device 18 within which the analysis takes place automatically by comparing the signals representing the detected soundwaves with limiting values stored within the evaluation device 18.

[0042] The method described above is distinguished, in particular, by virtue of the fact that a sound test can be carried out on the guide blade 39 and rotor blade 40 without previously exposing the guide blade 39 and rotor blade 40, that is to say without having to disassemble the turbine housing 38. Correspondingly, the method according to embodiments of the invention can also be carried out quickly and economically without a large amount of expenditure.

[0043] It is to be noted that the sensor device 10 can basically also be arranged on a separate endoscope device (not illustrated here). In this case, the previously described method is carried out by guiding the shafts of the two endoscope devices into the region of the blade to be tested.

[0044] FIG. 10 shows the execution of the previously described method in a turbine housing 38 of a jointed design which is divided into a housing upper part and a housing lower part 42, wherein the housing upper part which is not illustrated here is taken off the housing lower part 42, and the rotor 43 is still arranged on the housing lower part 42. Here, thanks to the use of the endoscope device 1 it is possible to dispense at least with the removal of the rotor 43.

[0045] Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0046] For the sake of clarity, it is to be understood that the use of ‘a’ or ‘an’ throughout this application does not exclude a plurality, and ‘comprising’ does not exclude other steps or elements.