CN112254807A

CN112254807A - Engine blade natural frequency testing system

Info

Publication number: CN112254807A
Application number: CN202011155495.7A
Authority: CN
Inventors: 陈东辉; 李威
Original assignee: Beijing Fanhua Hengxing Technology Co ltd; Beijing Zhongke Pansino Measurement & Control Co ltd
Current assignee: Beijing Fanhua Hengxing Technology Co ltd; Beijing Zhongke Pansino Measurement & Control Co ltd
Priority date: 2020-10-26
Filing date: 2020-10-26
Publication date: 2021-01-22

Abstract

The application relates to an engine blade natural frequency test system belongs to test system technical field, includes: carrying a machine table; the clamping device is used for clamping and fixing the measured blade; the knocking device is used for knocking the blade to be detected to generate vibration; the control device is connected with the knocking device and used for controlling the knocking device to knock the measured blade; the sound detection device is arranged close to the detected blade and used for detecting a vibration sound signal of the detected blade; the data acquisition device is connected with the sound detection device and used for acquiring data according to the vibration sound signal detected by the sound detection device; and the signal processing device is connected with the data acquisition device and is used for processing the data acquired by the data acquisition device to obtain the natural frequency of the blade to be detected. The engine blade natural frequency testing system has the advantages of being high in detection efficiency and strong in accuracy.

Description

Engine blade natural frequency testing system

Technical Field

The application relates to the technical field of test systems, in particular to an engine blade natural frequency test system.

Background

After the aeroengine blade is manufactured, a natural frequency test is required before assembly, and a plurality of blades mounted on an engine are ensured not to resonate. At present, a frequency sweep method is generally adopted for testing the inherent frequency of the blade of the aero-engine, namely, a vibration source is given to the blade of the aero-engine, the vibration frequency of the vibration source is continuously adjusted until resonance occurs, and the frequency of the vibration source at the moment is the inherent frequency of the blade of the aero-engine.

In view of the above-mentioned related art, the inventor believes that the testing of the natural frequency of the engine blade by the frequency sweep method has the defect of low testing efficiency.

Disclosure of Invention

In order to solve the problem of low testing efficiency in the prior art that the natural frequency of the engine blade is tested by a frequency sweeping method, the application provides a system for testing the natural frequency of the engine blade.

The application provides an engine blade natural frequency test system adopts following technical scheme:

an engine blade natural frequency testing system comprising:

carrying a machine table;

the clamping device is arranged on the bearing machine table and used for clamping and fixing the blade to be measured;

the knocking device is arranged on the bearing machine table, is adjacent to the clamping device and is used for knocking the blade to be detected to generate vibration;

the control device is connected with the knocking device and used for controlling the knocking device to knock the measured blade;

the sound detection device is arranged close to the detected blade and used for detecting a vibration sound signal of the detected blade;

the data acquisition device is connected with the sound detection device and used for acquiring data according to the vibration sound signal detected by the sound detection device;

and the signal processing device is connected with the data acquisition device and is used for processing the data acquired by the data acquisition device to obtain the natural frequency of the blade to be detected.

Through adopting above-mentioned technical scheme, beat the blade that is surveyed and make its vibration back, carry out data acquisition and processing to the vibration sound signal and can obtain the natural frequency of blade that is surveyed.

Furthermore, the clamping device comprises a base, a sliding table and a sliding block, wherein the sliding table is arranged on the base, a boss is fixedly arranged on the upper surface of one end of the sliding table, the sliding block can slide along the upper surface of the sliding table, and a space capable of accommodating the installation end of the measured blade is formed between the boss and the sliding block;

the end face of one side, facing the sliding block, of the boss is provided with a first clamping block, the end face of one side, facing the boss, of the sliding block is provided with a second clamping block, a bottom clamping block is arranged between the first clamping block and the second clamping block, and the first clamping block, the second clamping block and the bottom clamping block can clamp the mounting end of the blade to be tested.

Through adopting above-mentioned technical scheme, can press from both sides tightly and guarantee that the erection end of being surveyed the blade is not damaged to being surveyed the blade.

Furthermore, a first positioning groove and a second positioning groove are respectively arranged on two sides of the base, and the first positioning groove and the second positioning groove penetrate through the base along the thickness direction;

the bearing machine table is provided with a first positioning hole corresponding to the first positioning groove, a second positioning hole and a third positioning hole corresponding to the second positioning groove, the first positioning groove corresponds to the first positioning hole, and the second positioning groove corresponds to the second positioning hole or the third positioning hole so that the angle of the clamping device relative to the knocking device can be adjusted.

Through adopting above-mentioned technical scheme, can adjust clamping device for the angle of knocking the device, guarantee to strike the effect.

Further, the knocking device comprises a bottom plate, a bearing plate and a top plate, wherein a first guide pillar, a second guide pillar and a third guide pillar which are arranged in a triangular mode are arranged between the bottom plate and the top plate;

the bearing plate is positioned between the bottom plate and the top plate, sleeved on the first guide pillar, the second guide pillar and the third guide pillar and capable of sliding in the vertical direction;

the bearing plate is provided with a knocking component facing the clamping device, the knocking component comprises a driving mechanism and a hammer head mechanism, and the driving mechanism can drive the hammer head mechanism to do linear motion to knock a measured blade fixed on the clamping device;

the side of the bearing plate facing the clamping device is provided with a clamping assembly, and the clamping assembly is used for fixing the sound detection device.

Through adopting above-mentioned technical scheme, can realize the strike to being surveyed the blade to can fix sound detection device.

Furthermore, a first mounting hole is formed in one side, close to the clamping device, of the upper surface of the bottom plate, and a plurality of second mounting holes are uniformly formed in an arc with the first mounting hole as the center of circle;

the bearing machine table is provided with a fourth positioning hole corresponding to the first mounting hole and a fifth positioning hole corresponding to the second mounting hole, and the angle of the knocking device relative to the clamping device can be adjusted by corresponding the first mounting hole to the fourth positioning hole and corresponding the second mounting hole to the fifth positioning hole.

Through adopting above-mentioned technical scheme, can adjust the angle of knocking device for clamping device, guarantee to strike the effect.

Further, the driving mechanism comprises a push-pull electromagnet, and the push-pull electromagnet is provided with a push-pull rod extending towards the clamping device;

the hammer mechanism comprises a coupler, a positioning rod, a locking cap and a knocking rod, one end of the coupler is connected with a push-pull rod of the push-pull electromagnet, and the other end of the coupler is connected with the positioning rod;

the positioning rod is provided with a hollow cavity, the outer surface of one end, away from the coupler, of the positioning rod is a conical surface, a plurality of second cutting grooves extending along the length direction of the positioning rod are uniformly arranged in the circumferential direction of one end, away from the coupler, of the positioning rod, the second cutting grooves divide one end, away from the coupler, of the positioning rod into a plurality of parts, and the knocking rod can be inserted into the hollow cavity of the positioning rod;

the locking cap is provided with a first through hole through which the knocking rod can pass, and the locking cap can be installed at one end, far away from the coupler, of the positioning rod to lock the knocking rod inserted into the positioning rod.

By adopting the technical scheme, the knocking rods with corresponding lengths can be selected for the tested blades with different heights, and the replacement operation of the knocking rods is more convenient.

Further, linear bearings are arranged at the matching positions of the bearing plate and the first guide post, the second guide post and the third guide post, and the bearing plate slides relative to the first guide post, the second guide post and the third guide post through the linear bearings;

the linear bearing at the matching position of the bearing plate and the first guide pillar is a linear bearing with a clamping handle and used for limiting the position of the bearing plate in the vertical direction by clamping the first guide pillar.

Through adopting above-mentioned technical scheme, the activity of loading board on the vertical direction is more smooth and easy and can make the loading board fixed at certain position on the vertical direction.

Further, a cushion block is sleeved at the lower end of the first guide pillar;

a height column is arranged between the bottom plate and the bearing plate, and two ends of the height column are respectively abutted against the bottom plate and the bearing plate;

and the first guide pillar is provided with scale marks.

Through adopting above-mentioned technical scheme, the cushion can support the backup pad under the free fall state, and the setting of scale mark and high post is convenient for adjust the height of loading board according to different blade height.

Further, the clamping assembly comprises a first supporting rod arranged on the side surface, facing the clamping device, of the bearing plate, and the first supporting rod is perpendicular to the side surface, facing the clamping device, of the bearing plate;

the first support rod is sleeved with a fixing clamp, one end of the fixing clamp is provided with an adjusting knob, and the clamping degree of the fixing clamp on the first support rod can be adjusted by rotating the adjusting knob;

the other end of the fixing clamp is provided with a second supporting rod, the second supporting rod is arranged in parallel with the first supporting rod, and a fixing seat used for installing a sound detection device is arranged at one end, far away from the bearing plate, of the second supporting rod.

Through adopting above-mentioned technical scheme, can fix and adjust the distance of sound detection device and surveyed blade to sound detection device.

Further, the sound detection device is a sound pressure sensor;

the signal processing device comprises an industrial personal computer, wherein a signal processing module and a dispersion degree calculating module which are built based on LabVIEW are arranged in the industrial personal computer, the signal processing module is used for processing data collected by the data collecting device to obtain the natural frequency of the blade to be measured, and the dispersion degree calculating module is used for calculating the dispersion degree of the natural frequency of a plurality of same blades to be measured.

By adopting the technical scheme, the vibration sound signals of the detected blade can be detected, and the natural frequency and the dispersion degree of the detected blade can be obtained.

In summary, the present application includes at least one of the following beneficial technical effects:

1. knocking the tested blade and obtaining the natural frequency of the tested blade according to the vibration sound signal, so that the efficiency of testing the natural frequency of the tested blade is improved;

2. the angle of the knocking device and the angle of the clamping device on the bearing machine table are adjustable, so that the knocking effect is guaranteed, high-frequency signals can be excited, and the accuracy of inherent frequency testing is high.

Drawings

FIG. 1 is a functional block diagram of an engine blade natural frequency testing system;

FIG. 2 is a schematic view of the structure of the clamping device;

FIG. 3 is a schematic view showing the arrangement of positioning holes on the carrier;

FIG. 4 is a schematic view of the knocking device from one perspective;

FIG. 5 is a schematic view of the alternative perspective of the rapping device;

FIG. 6 is a schematic structural view of the rapping assembly;

fig. 7 is an exploded view of the hammer mechanism;

fig. 8 is a schematic view of the knocking device from a further perspective.

Description of reference numerals: 1. a machine platform; 2. a clamping device; 3. a knocking device; 4. a control device; 5. a sound detection device; 6. a data acquisition device; 7. a signal processing device; 8. a blade to be tested; 11. a first positioning hole; 12. a second positioning hole; 13. a third positioning hole; 14. a fourth positioning hole; 15. a fifth positioning hole; 21. a base; 211. a first positioning groove; 22. a sliding table; 23. a slider; 24. a boss; 25. a lead screw; 26. a first clamping block; 27. a second clamp block; 28. a bottom clamp block; 29. a limiting block; 31. A base plate; 311. a first mounting hole; 312. a second mounting hole; 313. cushion blocks; 314. a height post; 32. a carrier plate; 33. a top plate; 34. a first guide post; 341. scale lines; 35. a second guide post; 36. a third guide post; 37. a linear bearing; 371. a linear bearing with a clamping handle; 38. A knocking component; 381. a drive mechanism; 3811. pushing and pulling the electromagnet; 3812. a fixing plate; 382. a hammer head mechanism; 3821. a coupling; 38211. a first dividing groove; 38212. a third slitting groove; 38213. a first threaded fastener hole; 3822. positioning a rod; 38221. a second dividing groove; 3823. a locking cap; 3824. a knock bar; 39. a clamping assembly; 391. a first support bar; 392. a fixing clip; 393. adjusting a knob; 394. a second support bar; 395. a fixed seat; 3951. a fourth dividing groove; 3952. a second threaded fastener hole.

Detailed Description

The present application is described in further detail below with reference to figures 1-8.

Referring to fig. 1, the embodiment of the application discloses a system for testing the natural frequency of an engine blade, which comprises a bearing machine table 1, a clamping device 2, a knocking device 3, a control device 4, a sound detection device 5, a data acquisition device 6 and a signal processing device 7. The clamping device 2 is arranged on the bearing machine table 1 and used for clamping and fixing the blade 8 to be measured; the knocking device 3 is arranged on the bearing machine table 1 and adjacent to the clamping device 2 and is used for knocking the blade 8 to be tested to generate vibration; the control device 4 is used for controlling the knocking device 3 to knock the detected blade 8; the sound detection device 5 is used for detecting a vibration sound signal of the detected blade 8; the data acquisition device 6 is connected with the sound detection device 5 and is used for acquiring data according to the vibration sound signal detected by the sound detection device 5; and the signal processing device 7 is connected with the data acquisition device 6 and is used for processing the data acquired by the data acquisition device 6 to obtain the natural frequency of the blade 8 to be detected.

Referring to fig. 2, the clamping device 2 includes a base 21, a slide table 22, and a slider 23. The sliding table 22 is arranged on the base 21, a boss 24 is arranged on the upper surface of the sliding table 22, and the boss 24 and the sliding table 22 are integrally formed. The slide block 23 can slide on the upper surface of the slide table 22 along the length direction of the slide table 22, and a space capable of accommodating the installation end of the measured blade 8 is formed between the boss 24 and the slide block 23.

A screw 25 is arranged inside the sliding table 22, two ends of the screw 25 are rotatably connected with two ends of the sliding table 22, and the end part of the screw 25, which is far away from one end of the boss 24, penetrates out of the sliding table 22 to be matched with a wrench. Specifically, bearings may be sleeved at both ends of the screw 25, and the bearings are installed at both ends of the sliding table 22, so that the screw 25 can rotate under the support of the two bearings.

A transmission block (not shown in the figure) is fixedly arranged at the bottom of the sliding block 23, the transmission block is a square structure fixedly connected with the bottom of the sliding block 23, and the transmission block is provided with a threaded hole which penetrates through and is matched with the screw rod 25. When the screw 25 rotates, the slider 23 can move linearly along the upper surface of the slide table 22 toward or away from the boss 24.

In order to ensure the clamping effect of the tested blade 8 and avoid the damage to the mounting end of the tested blade 8 in the clamping process, a first clamping block 26 is arranged on the end surface of one side of the boss 24 facing the slider 23, a second clamping block 27 is arranged on the end surface of one side of the slider 23 facing the boss 24, a bottom clamping block 28 is arranged between the first clamping block 26 and the second clamping block 27, and the space formed among the first clamping block 26, the second clamping block 27 and the bottom clamping block 28 can be matched with the shape of the mounting end of the tested blade 8. The first clamping block 26 may be coupled to the corresponding surface of the boss 24 by a pin or a bolt, and the second clamping block 27 may be coupled to the corresponding surface of the slider 23 by a pin or a bolt. To facilitate positioning of the bottom clamping block 28, the bottom clamping block 28 and the first clamping block 26 may be pinned together. When different blades 8 to be tested need to be clamped, only the corresponding first clamping block 26, second clamping block 27 and bottom clamping block 28 need to be replaced.

Limiting blocks 29 are respectively arranged at two ends of the first clamping block 26 and the second clamping block 27, and the limiting blocks 29 are fixedly connected with the first clamping block 26 and the second clamping block 27 through bolts. The first clamping block 26 and the second clamping block 27 are further stabilized in the axial position by the provision of the stopper 29.

Referring to fig. 2, a first positioning groove 211 and a second positioning groove (not shown) are respectively formed at both sides of the base 21, and the first positioning groove 211 and the second positioning groove are symmetrically formed. The first positioning groove 211 and the second positioning groove penetrate through the base 21 in the thickness direction, and the base 21 can adjust the angle of the bearing machine table 1 relative to the knocking device 3 through the first positioning groove 211 and the second positioning groove.

Referring to fig. 3, the supporting machine 1 may be provided with a first positioning hole 11, a second positioning hole 12 and a third positioning hole 13, and when the first positioning groove 211 corresponds to the first positioning hole 11, and the second positioning groove corresponds to the second positioning hole 12, the length direction of the clamping device 2 is parallel to the length direction of the supporting machine 1; when the first positioning slot 211 corresponds to the first positioning hole 11 and the second positioning slot corresponds to the third positioning hole 13, the length direction of the clamping device 2 and the length direction of the supporting machine 1 form an angle of 45 °.

After the position of the clamping device 2 on the bearing machine table 1 is set, the first positioning groove 211 and the first positioning hole 11 can be fastened through the first fastening element, and the second positioning groove and the second positioning hole 12 or the third positioning hole 13 can be fastened, so that the clamping device 2 is prevented from deviating in the process of knocking the tested blade 8. The first fastening element may be a bolt or a pin.

The number and the angle of the positioning holes for adjusting the angle of the clamping device 2 on the supporting machine 1 are limited to the aforementioned first positioning hole 11, second positioning hole 12 and third positioning hole 13, and those skilled in the art can set the positioning holes according to the needs.

Through setting up first constant head tank 211 and second constant head tank, can adjust clamping device 2 angle on bearing board 1 for it is in the optimum angle to be surveyed blade 8 and knocking device 3, guarantees to strike the effect.

The clamping force of the tested blade 8 on the clamping device 2 can be adjusted through a torque wrench, and the clamping force of a plurality of identical blades is the same so as to ensure the consistency of the natural frequency testing conditions of the plurality of blades.

Referring to fig. 4, the knocking device 3 includes a bottom plate 31, a bearing plate 32 and a top plate 33, a first guide post 34, a second guide post 35 and a third guide post 36 are arranged between the bottom plate 31 and the top plate 33 in a triangular arrangement, the first guide post 34, the second guide post 35 and the third guide post 36 are all arranged perpendicular to the top plate 33 and the bottom plate 31, the bearing plate 32 is located between the bottom plate 31 and the top plate 33, and the bearing plate 32 is sleeved on the first guide post 34, the second guide post 35 and the third guide post 36 and can slide in a vertical direction along the first guide post 34, the second guide post 35 and the third guide post 36. The top ends of the first, second and third guide posts 34, 35, 36 may be connected to the top plate 33 by screws, and the bottom ends of the first, second and third guide posts 34, 35, 36 may be connected to the bottom plate 31 by screws, whereby the rapping device 3 forms a stable supporting structure.

The matching parts of the bearing plate 32, the first guide post 34, the second guide post 35 and the third guide post 36 are provided with linear bearings 37. The linear bearing 37 has a flange to facilitate connection with the carrier plate 32. The loading plate 32 slides relative to the first guide post 34, the second guide post 35 and the third guide post 36 through the linear bearing 37, thereby making the sliding of the loading plate 32 smoother. In order to fix the loading plate 32 at a designated position in the vertical direction, the linear bearing 37 where the loading plate 32 is matched with the first guide post 34 is a linear bearing 371 with a clamping handle, and when the loading plate 32 is at the designated position, the position of the loading plate 32 can be defined by clamping the first guide post 34 by the clamping handle.

Referring to fig. 5, a pad 313 may be further sleeved on the lower end of the first guide pillar 34, the pad 313 is located between the bottom plate 31 and the bearing plate 32, and the pad 313 may be made of nylon. By arranging the cushion block 313, when the linear bearing 371 with the clamping handle is in an unclamped state, the bearing plate 32 can fall freely and is supported by the cushion block 313, so that damage caused by contact between corresponding parts on the bearing plate 32 and the bearing machine table 1 is avoided.

Referring to fig. 4, in order to facilitate the adjustment of the height of the position of the bearing plate 32, a graduation mark 341 is provided on the surface of the first guide pillar 34, so that the adjustment of the height of the bearing plate 32 is visualized.

Referring to fig. 5, in order to improve the efficiency of height adjustment of the bearing plate 32 when the blades 8 to be measured with different heights are knocked, a height pillar 314 may be further disposed between the bearing plate 32 and the bottom plate 31, and both ends of the height pillar 314 abut against the bottom plate 31 and the bearing plate 32, respectively. A mounting groove may be provided on the upper surface of the base plate 31 to be fitted with the height post 314. When the tested blades 8 with different heights need to be knocked, the distance between the bearing plate 32 and the bottom plate 31 can be adjusted by only installing the height column 314 with the corresponding height, so that the adjustment efficiency is improved.

Referring to fig. 4, a first mounting hole 311 is formed in a side of the upper surface of the bottom plate 31 of the knocking device 3, which is close to the clamping device 2, and a plurality of second mounting holes 312 are uniformly formed in an arc around the first mounting hole 311. The angle between the adjacent second mounting holes 312 can be set by those skilled in the art according to the requirement, and is not particularly limited herein.

Referring to fig. 3, the supporting machine 1 is provided with a fourth positioning hole 14 corresponding to the first mounting hole 311 and a fifth positioning hole 15 corresponding to the second mounting hole 312. Referring to fig. 4, after the first mounting hole 311 on the bottom plate 31 of the clamping device 2 corresponds to the fourth positioning hole 14 on the supporting platform 1, the angle of the knocking device 3 relative to the clamping device 2 can be adjusted by adjusting the second mounting hole 312 to correspond to the fifth positioning hole 15. After the position of the knocking device 3 is adjusted, the first mounting hole 311 and the fourth positioning hole 14, and the second mounting hole 312 and the fifth positioning hole 15 may be fastened by bolts, respectively.

Referring to fig. 4 and 6, the carrier plate 32 is provided with a striking assembly 38 facing the clamping device 2. The knocking assembly 38 comprises a driving mechanism 381 and a hammer head mechanism 382, wherein the driving mechanism 381 can drive the hammer head mechanism 382 to do linear motion to knock the blade 8 to be measured fixed on the clamping device 2.

Referring to fig. 6, the driving mechanism 381 includes a push-pull electromagnet 3811, a fixing plate 3812 is disposed on the upper surface of the supporting plate 32 near the edge of the clamping device 2, and the push-pull electromagnet 3811 is disposed on the supporting plate 32 through the fixing plate 3812. The push-pull electromagnet 3811 and the fixing plate 3812 may be fastened by bolts, and the fixing plate 3812 and the carrier plate 32 may be fastened by bolts. The push-pull electromagnet 3811 has a push-pull rod (not shown) extending toward the clamping device 2, and when the push-pull electromagnet 3811 is energized, the push-pull rod can extend toward the clamping device 2 and retract rapidly.

Referring to fig. 7, the hammer head mechanism 382 includes a coupling 3821, a positioning rod 3822, a locking cap 3823, and a striking rod 3824. The coupling 3821 is a cylindrical structure, and one end of the coupling 3821 is connected to the push-pull rod of the push-pull electromagnet 3811, and the other end is connected to the positioning rod 3822. One end of the coupler 3821, which is close to the push-pull rod of the push-pull electromagnet 3811, is provided with a first splitting groove 38211 along the axial direction of the coupler 3821, the depth of the first splitting groove 38211 is the same as the thickness of the side wall of the coupler 3821, the end of the first splitting groove 38211, which faces the positioning rod 3822 direction, is provided with a third splitting groove 38212 perpendicular to the first splitting groove 38211, two sides of the first splitting groove 38211 are provided with first threaded fastening holes 38213, and when the push-pull rod is inserted into the coupler 3821, a screw penetrates through the first threaded fastening hole 38213 to enable the coupler 3821 to clamp the push-pull rod.

The positioning rod 3822 has a hollow cavity, and the tapping rod 3824 may be inserted into the hollow cavity of the positioning rod 3822. One end of the positioning rod 3822 near the coupler 3821 can be inserted into the coupler 3821 and tightly connected to the coupler 3821. The retaining rods 3822 may be threaded or snap-fit to the couplers 3821. The outer surface of one end, away from shaft coupling 3821, of locating lever 3822 is the circular conical surface, and the one end that the shaft coupling 3821 was kept away from to locating lever 3822 evenly is provided with a plurality of along the second segmentation groove 38221 of locating lever 3822 length direction extension in the circumferencial direction, and the degree of depth of second segmentation groove 38221 equals with locating lever 3822's lateral wall thickness, and second segmentation groove 38221 is divided into a plurality of parts with locating lever 3822 keep away from the one end of shaft coupling 3821 on average.

The top end of the locking cap 3823 is provided with a first through hole through which the knocking rod 3824 can pass, and the locking cap 3823 can be mounted at one end of the positioning rod 3822 far away from the coupler 3821 to lock the knocking rod 3824 inserted into the positioning rod 3822. Specifically, the locking cap 3823 is connected through screw-thread fit with the one end of locating lever 3822 far away from shaft coupling 3821, and after knocking pole 3824 inserted the cavity of connecting rod in, with locking cap 3823 lid fit locating lever 3822 and screw, because the existence of second segmentation groove 38221 for thereby the oral area of locating lever 3822 reduces and presss from both sides tightly knocking pole 3824.

Due to the fact that the sizes of the measured blades 8 are different, the knocking rods 3824 with proper lengths can be selected according to the sizes of the measured blades 8, and therefore the knocking rods 3824 can be guaranteed to be in full contact with the measured blades 8 to perform knocking. Also, to ensure that high frequency signals can be knocked out, the material of the knocking rod 3824 is preferably a hard metal material, such as steel.

Referring to fig. 4 and 8, the side of the carrier plate 32 facing the clamping device 2 is provided with a clamping assembly 39, and the clamping assembly 39 is used for fixing the sound detection device 5.

Referring to fig. 8, the clamping assembly 39 includes a first supporting rod 391 disposed on a side of the carrier plate 32 facing the clamping device 2, the first supporting rod 391 being perpendicular to the side of the carrier plate 32 facing the clamping device 2. The fixing clamp 392 is sleeved on the first supporting rod 391, an adjusting knob 393 is arranged at one end of the fixing clamp 392, and the clamping degree of the fixing clamp 392 on the first supporting rod 391 can be adjusted by rotating the adjusting knob 393. A second support bar 394 is provided at the other end of the fixing clip 392, and the second support bar 394 is disposed in parallel with the first support bar 391. The other end of the fixing clip 392 is provided with a second through hole which is matched with the second support rod 394, and the second support rod 394 can be inserted into the second through hole. When the adjustment knob 393 is unscrewed, the position of the fixing clip 392 on the first support rod 391 may be adjusted, thereby adjusting the protruding length of the clip assembly 39.

One end of the second support rod 394, which is far away from the bearing plate 32, is provided with a fixing seat 395 for installing the sound detection device 5. The fixing seat 395 is provided with a third through hole allowing the sound detection device 5 to pass through, the fixing seat 395 is further provided with a fourth split groove 3951, the fourth split groove 3951 is coplanar with the axis of the third through hole, and second threaded fastening holes 3952 perpendicular to the fourth split groove 3951 are arranged on two sides of the fourth split groove 3951. After the sound check device 5 is inserted into the third through hole, the sound check device 5 may be clamped by fastening the second threaded fastening holes 3952 at both sides of the fourth split slit 3951 with screws. The fixing seat 395 may be fastened to an end of the second support bar 394 by a bolt.

Referring to fig. 1, the control device 4 may include a controller, the controller is connected to the push-pull electromagnet 3811 included in the knocking device 3, and the push-pull electromagnet 3811 may be controlled by the controller to operate, so that the push-pull electromagnet 3811 drives the knocking rod 3824 of the knocking device 3 to knock the blade 8 to be tested.

Referring to fig. 1, the sound detection device 5 may be a sound pressure sensor or a microphone, the sound pressure sensor is fixed by a clamping component 39 on the knocking device 3, a head of the sound pressure sensor is arranged near a surface of the blade 8 to be detected, and when the blade 8 to be detected is knocked to generate vibration, the sound detection device 5 detects a sound signal and transmits the sound signal to the data acquisition device 6.

Referring to fig. 1, the data acquisition device 6 may be a data acquisition card that performs dynamic data acquisition on the signal detected by the sound detection device 5. The data acquisition card may be a data acquisition card known in the related art, and is not particularly limited herein.

Referring to fig. 1, the signal processing device 7 is connected to the data acquisition device 6, and is configured to process the data acquired by the data acquisition device 6 to obtain the natural frequency of the blade 8 under test. The signal processing device 7 can comprise an industrial personal computer, a signal processing module built based on LabVIEW is arranged in the industrial personal computer, and the signal processing module sequentially carries out data interception, filtering, fast Fourier transform and natural frequency extraction on the data acquired by the data acquisition device 6, so that the natural frequency of the measured blade 8 is obtained.

The industrial personal computer can also be provided with a dispersion degree calculation module, the dispersion degree calculation module can calculate the natural frequency dispersion degree of the same group of the same tested blades 8, and when the natural frequency dispersion degree of the group of the tested blades 8 exceeds a limited range, an operator can replace the blade with the maximum natural frequency or the blade with the minimum natural frequency in the group of the tested blades 8. The smaller the natural frequency dispersion degree is, the better the natural frequency dispersion degree is, when the natural frequency dispersion degree of one group of blades is in a reasonable range, the blades of the engine can quickly pass through a resonant rotating speed range in the rotating process, and the stable operation of the engine is ensured.

The working principle of the engine blade natural frequency testing system disclosed by the application is as follows:

firstly, the blade 8 to be measured is clamped on the clamping device 2, and the angle of the clamping device 2 and the knocking device 3 is adjusted. Then, an appropriate tapping rod 3824 is selected according to the size of the blade 8 to be tested and assembled to the tapping unit 3, and then the corresponding height post 314 is provided between the base plate 31 of the tapping unit 3 and the carrier plate 32 to support the carrier plate 32, and the linear bearing 371 with the clamping handle is locked with the first guide post 34, at which time the carrier plate 32 is fixed in position in the vertical direction.

The controller is used for controlling the push-pull electromagnet 3811 to drive the knocking rod 3824 of the hammer mechanism 382 to knock the blade 8 to be tested. The blade 8 to be detected vibrates under the knocking action, the sound detection device 5 detects a vibration sound signal, and the data acquisition device 6 acquires data and transmits the data to the signal processing device 7.

And a signal processing module of the signal processing device 7 processes the acquired data to obtain the natural frequency information of the blade 8 to be measured. The dispersion degree calculation module calculates the dispersion degree from the measured natural frequencies of the plurality of measured blades 8.

The natural frequency testing system of the engine blade disclosed by the application tests the natural frequency of the blade 8 to be tested according to the vibration sound signal, and improves the testing efficiency. The angle of the knocking device 3 and the angle of the clamping device 2 on the bearing machine table 1 are adjustable, so that the knocking force of the knocking rod 3824 on the surface of the measured blade 8 is guaranteed, a high-frequency signal can be excited, and the accuracy of natural frequency testing is guaranteed. If the included angle between the knocking rod 3824 and the surface of the measured blade 8 is too small, the component force of the knocking force in the direction perpendicular to the measured blade 8 is too small, and a high-frequency signal cannot be excited.

The above is a preferred embodiment of the present application, and the scope of protection of the present application is not limited by the above, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. An engine blade natural frequency testing system, comprising:

a bearing machine table (1);

the clamping device (2) is arranged on the bearing machine table (1) and is used for clamping and fixing the blade (8) to be measured;

the knocking device (3) is arranged on the bearing machine table (1), is adjacent to the clamping device (2) and is used for knocking the blade (8) to be detected to generate vibration;

the control device (4) is connected with the knocking device (3) and is used for controlling the knocking device (3) to knock the blade (8) to be detected;

the sound detection device (5) is arranged close to the detected blade (8) and is used for detecting a vibration sound signal of the detected blade (8);

the data acquisition device (6) is connected with the sound detection device (5) and is used for acquiring data according to the vibration sound signal detected by the sound detection device (5);

and the signal processing device (7) is connected with the data acquisition device (6) and is used for processing the data acquired by the data acquisition device (6) to obtain the natural frequency of the blade (8) to be detected.

2. The engine blade natural frequency testing system according to claim 1, characterized in that the clamping device (2) comprises a base (21), a sliding table (22) and a sliding block (23), wherein the sliding table (22) is arranged on the base (21), a boss (24) is fixedly arranged on the upper surface of one end of the sliding table (22), the sliding block (23) can slide along the upper surface of the sliding table (22), and a space capable of accommodating the installation end of the tested blade (8) is formed between the boss (24) and the sliding block (23);

the end face of one side, facing the sliding block (23), of the boss (24) is provided with a first clamping block (26), the end face of one side, facing the boss (24), of the sliding block (23) is provided with a second clamping block (27), a bottom clamping block (28) is arranged between the first clamping block (26) and the second clamping block (27), and the first clamping block (26), the second clamping block (27) and the bottom clamping block (28) can clamp the mounting end of the blade (8) to be tested.

3. The engine blade natural frequency testing system of claim 2, wherein a first positioning groove (211) and a second positioning groove are respectively arranged on two sides of the base (21), and the first positioning groove (211) and the second positioning groove penetrate through the base (21) in the thickness direction;

the bearing machine table (1) is provided with a first positioning hole (11) corresponding to the position of the first positioning groove (211), a second positioning hole (12) and a third positioning hole (13) corresponding to the position of the second positioning groove, the first positioning groove (211) corresponds to the first positioning hole (11), the second positioning groove corresponds to the second positioning hole (12) or the third positioning hole (13), and the angle of the clamping device (2) relative to the knocking device (3) can be adjusted.

4. The engine blade natural frequency testing system of claim 1, characterized in that the knocking device (3) comprises a bottom plate (31), a bearing plate (32) and a top plate (33), wherein a first guide post (34), a second guide post (35) and a third guide post (36) which are arranged in a triangular manner are arranged between the bottom plate (31) and the top plate (33);

the bearing plate (32) is positioned between the bottom plate (31) and the top plate (33), and the bearing plate (32) is sleeved on the first guide post (34), the second guide post (35) and the third guide post (36) and can slide in the vertical direction;

the bearing plate (32) is provided with a knocking assembly (38) facing the clamping device (2), the knocking assembly (38) comprises a driving mechanism (381) and a hammer head mechanism (382), and the driving mechanism (381) can drive the hammer head mechanism (382) to do linear motion to knock a blade (8) to be detected fixed on the clamping device (2);

the side face, facing the clamping device (2), of the bearing plate (32) is provided with a clamping assembly (39), and the clamping assembly (39) is used for fixing the sound detection device (5).

5. The engine blade natural frequency testing system according to claim 4, characterized in that a first mounting hole (311) is formed in one side, close to the clamping device (2), of the upper surface of the bottom plate (31), and a plurality of second mounting holes (312) are uniformly formed in an arc with the first mounting hole (311) as a circle center;

a fourth positioning hole (14) corresponding to the first mounting hole (311) and a fifth positioning hole (15) corresponding to the second mounting hole (312) are formed in the bearing machine table (1), and the angle of the knocking device (3) relative to the clamping device (2) can be adjusted by corresponding the first mounting hole (311) to the fourth positioning hole (14) and corresponding the second mounting hole (312) to the fifth positioning hole (15).

6. The engine blade natural frequency testing system of claim 4, characterized in that the driving mechanism (381) comprises a push-pull electromagnet (3811), the push-pull electromagnet (3811) having a push-pull rod protruding towards the clamping device (2);

the hammer mechanism (382) comprises a coupler (3821), a positioning rod (3822), a locking cap (3823) and a knocking rod (3824), one end of the coupler (3821) is connected with a push-pull rod of the push-pull electromagnet (3811), and the other end of the coupler (3821) is connected with the positioning rod (3822);

the positioning rod (3822) is provided with a hollow cavity, the outer surface of one end, away from the coupler (3821), of the positioning rod (3822) is a conical surface, a plurality of second cutting grooves (38221) extending along the length direction of the positioning rod (3822) are uniformly arranged at one end, away from the coupler (3821), of the positioning rod (3822) in the circumferential direction, the second cutting grooves (38221) divide one end, away from the coupler (3821), of the positioning rod (3822) into a plurality of parts on average, and the knocking rod (3824) can be inserted into the hollow cavity of the positioning rod (3822);

the locking cap (3823) is provided with a first through hole through which the knocking rod (3824) can pass, and the locking cap (3823) can be mounted at one end, far away from the coupler (3821), of the positioning rod (3822) to lock the knocking rod (3824) inserted into the positioning rod (3822).

7. The engine blade natural frequency testing system of claim 4, characterized in that the matching positions of the bearing plate (32) and the first guide post (34), the second guide post (35) and the third guide post (36) are provided with linear bearings (37), and the bearing plate (32) slides relative to the first guide post (34), the second guide post (35) and the third guide post (36) through the linear bearings (37);

the linear bearing (37) at the matching part of the bearing plate (32) and the first guide pillar (34) is a linear bearing (371) with a clamping handle, and is used for clamping the first guide pillar (34) to limit the position of the bearing plate (32) in the vertical direction.

8. The engine blade natural frequency testing system of claim 4, characterized in that the lower end of the first guide post (34) is sleeved with a cushion block (313);

a height column (314) is arranged between the bottom plate (31) and the bearing plate (32), and two ends of the height column (314) are respectively abutted against the bottom plate (31) and the bearing plate (32);

the first guide post (34) is provided with scale marks (341).

9. The engine blade natural frequency testing system of claim 4, characterized in that the clamping assembly (39) comprises a first support rod (391) arranged on the side of the carrier plate (32) facing the clamping device (2), the first support rod (391) being perpendicular to the side of the carrier plate (32) facing the clamping device (2);

the fixing clamp (392) is sleeved on the first supporting rod (391), one end of the fixing clamp (392) is provided with an adjusting knob (393), and the clamping degree of the fixing clamp (392) to the first supporting rod (391) can be adjusted by rotating the adjusting knob (393);

the other end of the fixing clamp (392) is provided with a second supporting rod (394), the second supporting rod (394) and the first supporting rod (391) are arranged in parallel, and one end, away from the bearing plate (32), of the second supporting rod (394) is provided with a fixing seat (395) for installing the sound detection device (5).

10. The engine blade natural frequency testing system according to any one of claims 1 to 9, characterized in that the sound detecting means (5) is a sound pressure sensor;

the signal processing device (7) comprises an industrial personal computer, a signal processing module and a dispersion degree calculating module which are built based on LabVIEW are arranged in the industrial personal computer, the signal processing module is used for processing data collected by the data collecting device (6) to obtain the natural frequency of the blade to be measured (8), and the dispersion degree calculating module is used for calculating the dispersion degree of the natural frequency of a plurality of same blades to be measured (8).