JPH08136406A - High speed rotation vibration testing device - Google Patents

Abstract

PURPOSE: To perform accurate validation test for specimen by providing an exciting means arranged in a space around the rotation range of a rotary shaft and a specimen arranged rotatively inside a vacuum vessel in which vibration is given by means of magnetic field. CONSTITUTION: A rotary shaft 5 is arranged inside a vacuum vessel 1 with the shaft being connected to a rotation drive source 4, the lower part thereof is engaged with a rotor vibration stop 6, and a flange-shaped support body on which a specimen A is to be mounted on the way is provided. A plurality of excitation means 11 is arranged at constant intervals in the rotation direction around the rotation range of the specimen A, and the specimen A is magnetized by means of a magnetic field formed between the specimen A or that support body, and vibration is generated. When the specimen A is magnetized with it rotated, vibration is given to the specimen A. The vibration status of the specimen A is detected by means of a distortion sensor, and acquisition of desired data is performed by a wing vibration measuring unit 14, an FFT analyzer 15, a data recorder 17, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-speed rotation vibration test apparatus, and particularly to a case where centrifugal acceleration and vibration due to fluid force act in superposition as in a turbine rotor blade used in a high-speed rotation field. It is related to the strength evaluation technology of.

[0002]

2. Description of the Related Art One of the methods for verifying the strength of a rotating body that rotates at high speed, such as aircraft engine parts, is the so-called spin test in which the rotating speed is increased by centrifugal force until the specimen is destroyed and the rotating strength is examined. Is performed.

As structural materials for aircraft engine parts,
Carbon fiber reinforced carbon composite materials, glass fiber reinforced plastics (FRP), composite materials thereof, ceramics and the like have been studied. When a turbine disk or the like is manufactured from these materials, the mechanical characteristics greatly differ depending on the material, the fibers used, the manufacturing method, etc. Therefore, it is important to verify the strength by a rotary fracture test. The breaking rotation speed of the test piece is considered to reach 25,000 to 60,000 rpm.

As a related technology for performing high-speed rotation up to the breaking rotation speed, for example, it is described in "The 4th Symposium on Advanced Material Technology Symposium" published by Japan Society for Advanced Materials Technology, and published on June 8, 1993. Lecture paper entitled "Rotary Fracture Test of ACC Turbine Disk <First Report>" presented at Yamagami Kaikan, University of Tokyo is there. In this lecture paper, the disk as the test piece was housed inside the vacuum container of the rotary destruction tester, and the circumference of the test piece was placed in a vacuum atmosphere to increase the number of rotations while preventing the occurrence of windage loss. The technology of collecting with a felt and tire is posted.

On the other hand, when the test piece is a gas turbine rotor blade, the internal stress due to the centrifugal acceleration is combined with the excitation force due to the vibration of the fluid force, so that the member such as the gas turbine rotor blade is used. Although it is appropriate to perform the strength test under the actual use condition for the strength evaluation of, the measurement in the actual machine is often impractical due to various restrictions.

[0006]

In the above-described spin test and rotary rupture test apparatus, the test piece is housed in a vacuum container and is operated under an environmental condition of zero aerodynamic friction resistance. Although the degree of internal stress can be evaluated (strength evaluation), it is difficult to apply it to a composite test assuming vibration in actual working conditions.

The present invention has been made in view of these problems and has the following objects. a) To improve the test accuracy by reproducing the actual operating environment conditions,
Make sure that it is proven. b) To be able to collect vibration test data in a vibration state or a resonance state. c) Make it easy to set vibration conditions and expand the range of applications. d) In addition to the test equivalent to the actual operating conditions, it should be possible to perform tests that exceed the operating conditions.

[0008]

As a device for performing a vibration test by rotating a test piece at a high speed inside a vacuum container, a rotary shaft rotatably arranged inside the vacuum container and rotationally driven by a rotary drive source, A structure is provided around the rotation range of the test piece, which is arranged at intervals in the rotation direction, and includes excitation means for applying vibration to the test piece by a magnetic field between the test piece or its support. A ferromagnetic foil film is attached to the sample or its support, if necessary. A direct current electromagnet is adopted as the excitation means, and a direct current is supplied to the direct current electromagnet, and an electromagnetic excitation controller that sets the magnitude of the current is connected to the electromagnetic excitation controller. Will be distributed. And for the specimen,
A strain sensor for detecting the vibration displacement is arranged, and a signal transmitting means is arranged in the strain sensor, and the signal transmitting means is arranged in the rotating shaft and connected to the strain sensor, and the slip ring is connected to the slip ring. And a signal transmission line for transmitting the detection signal of the strain sensor to the outside of the vacuum container. Outside the vacuum container, a blade vibration measuring device for processing vibration displacement data,
A vibration waveform analysis means, a Campbell analysis device, etc. are arranged.

[0009]

The specimen is housed inside the vacuum container while being integrally attached around the rotary shaft. When the test piece is not a ferromagnetic material, a ferromagnetic foil film is attached to the test piece or its support to give an exciting force. The inside of the vacuum container is placed in a vacuum state, and the rotary shaft is rotated by the operation of the rotary drive source, and a centrifugal force is applied to the sample to generate an internal stress based on the centrifugal force. When a direct-current magnetic field is generated in the electromagnet by the operation of the electromagnetic excitation controller in the excitation means, the rotating test piece is magnetized, so that the test piece is repeatedly magnetized by the number of electromagnets each time the rotating shaft makes one rotation, Vibration is applied to the test piece by this magnetization. The amplitude is set by the magnitude of the DC current supplied, and the acceleration and the vibration frequency are set by the product of the rotation speed of the rotating shaft and the number of electromagnets. The vibration displacement of the sample is detected by the strain sensor, and the detection signal of the strain sensor is transmitted from the rotating part to the non-rotating part by the slip ring and the signal transmission line of the signal transmitting means, and the blade vibration measuring device and the vibration waveform analysis are performed. Necessary processing is performed by the means, the Campbell analyzer, and the like.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the high speed rotary vibration test apparatus according to the present invention will be described below with reference to FIGS. In each drawing, reference numeral 1 is a vacuum container, 2 is a buffer block, 3A and 3B are support structures, 4 is a rotary drive source (air turbine), 5 is a rotary shaft, 6 is a rotor steady rest, and 7
Is a monitoring window, A is a specimen, 11 is an excitation means, 12 is a strain sensor, and 13 is a signal transmission means.

As shown in FIG. 1, the vacuum container 1 is a vacuum container that can seal between a body 1a and an upper lid 1b, and has a buffer block 2 and support structures 3A and 3B inside.
A rotating shaft 5, a rotor steady rest 6, and the like are arranged.

As shown in FIG. 1, the buffer block 2 is arranged inside the vacuum container 1 in a standing state so as to surround the outside of the rotating portion.

As shown in FIG. 1, one supporting structure 3A is a suspension rod 3a which is suspended inside the vacuum vessel 1 with respect to an upper lid 1b, and a suspension rod 3a which is connected to the suspension rod 3a and is in a horizontal state. A mounting frame 3b which is arranged to mount the rotor steady rest 6 and the like, and a fastener 3c such as a nut for integrating these
And have. The other support structure 3B is disposed between the one support structure 3A and the rotary shaft 5 and is hung under the upper lid 1b of the vacuum container 1 as shown in FIGS. 5 and 6. A suspension bracket 3d in a held state, an adjustment sleeve 3e attached to the suspension bracket 3d and having a sliding portion for adjusting the vertical dimension, and a fastener 3f such as a bolt or a nut for fixing these. Etc. apply.

The rotary drive source 4 is, as shown in FIG.
It is mounted on the upper lid 1b of the vacuum container 1 to generate a rotational force, and has a high rotational speed (25000 to 2500) as described above.
In order to obtain (60000 rpm) relatively easily, an air turbine or the like is applied.

The rotary shaft 5 is arranged inside the vacuum container 1 in a state of being connected to the rotary drive source 4, the lower part of which engages with the rotor steady rest 6 and a flange for mounting the sample A on the way. A support 5a having a shape of a circle is provided.

As shown in FIG. 1, the rotor steady rest 6 rotatably supports a rotating portion (rotor) at upper and lower positions and is rotatably supported. The upper bearing portion 6a attached to the upper lid 1b and a supporting structure. 3 has a lower bearing portion 6b which is attached to the mounting frame 3b of No. 3 and which holds the lower portion of the rotary shaft 5 in a non-contact state during normal rotation and prevents the swing of the rotary shaft 5 when the shake is large.

The monitoring window 7 is arranged in a part of the upper lid 1b of the vacuum container 1 to monitor the sample A inside, and the condition of the sample A is observed outside the monitoring window 7. A high-speed video camera for visualizing, an illuminator such as a halogen lamp for illuminating the inside of the vacuum container 1, and the like are installed as necessary.

A plurality of the excitation means 11 are arranged around the rotation range D of the sample A at equal intervals in the rotation direction,
The magnetic field formed between the sample A or its support 5a magnetizes the sample A to generate vibration.

As shown in FIGS. 1 to 6, the excitation means 11 is arranged inside the adjustment sleeve 3e in the support structure 3B so as to face each specimen A in the radial direction.
As shown in FIG. 4, when the sample A is not a ferromagnetic material while having a plurality of small DC electromagnets 11a or large DC electromagnets 11b arranged as shown in FIG. 2 and FIG. The ferromagnetic foil film 11c is placed on the surface of the sample A or its support 5a in a stuck state. Further, as shown in FIG. 1, the DC electromagnets 11a and 11b are provided with an electromagnetic vibration controller 11d for supplying a DC current and setting the magnitude of the DC current, and the electromagnetic vibration controller 11d is also provided. The controller 11d is arranged outside the vacuum container 1 and is provided on the power supply line 11e and the upper lid 1b.
and f are connected to the DC electromagnets 11a and 11b. In FIG. 5, the composite magnetic field formed by the plurality of DC electromagnets 11b is made to intersect the sample A.

As shown in FIG. 4, the strain sensor 12 is arranged at a required position on the surface of the specimen A to detect a vibration displacement, and the detection signal of the strain sensor 12 is a signal. It is transmitted to the outside of the vacuum container 1 by the transmission means 13. The strain sensor 12 is added with a compensating circuit for canceling the induced electromotive force generated by crossing the magnetic field, and is set so as to detect strain condition data under a high S / N ratio.

The signal transmission means 13 is, as shown in FIGS. 1 and 4, a signal transmission line 13a which is pulled out to the outside of the vacuum container 1 in an airtight state via a central hole of the rotary shaft 5 or the like.
And a slip ring 13b arranged on the upper part of the rotating shaft 5 for connecting a rotating portion and a non-rotating portion of the signal transmission line 13a.

Further, a blade vibration measuring device 14, an FFT analyzer 15, an XY plotter 16, a data recorder 17, a Campbell analyzing device 18, etc. are connected to the slip ring 13b to record the detection data of the strain sensor 12. , Analysis, display, etc. are performed.

A lubricating / cooling oil supply source 19 for lubricating and cooling the rotating friction portion is connected to the rotating shaft 5.

In the high-speed rotary vibration test apparatus having the above-described structure, as shown in FIG. 1, the sample A is assembled inside the vacuum container 1 and a vacuum is drawn to obtain a desired degree of vacuum. Then, the test piece A is rotated by the operation of the rotary drive source 4 to perform a vibration test in a high-speed rotation state.

The inside of the vacuum container 1 is evacuated, and the rotary shaft 5 is rotated by the operation of the rotary drive source 4.
When the sample A is rotated at a high speed, aerodynamic friction does not occur and the air resistance is not substantially received. Therefore, only internal stress based on the centrifugal force occurs in the sample A. The internal stress in this case is set by the rotation speed and the diameter of the rotation range D.

With the specimen A being rotated, the electromagnetic excitation controller 11d in the excitation means 11 is operated to supply a DC current to one of the DC electromagnets 11a and 11b, so that all or a required number of them are supplied. When a DC magnetic field is generated to magnetize the sample A, the sample A is repeatedly magnetized by the number of excitations of the DC electromagnets 11a and 11b every time the rotating shaft 5 makes one rotation, and the magnetizing attraction during the magnetization occurs. Vibration is applied to the sample A based on the force.
The acceleration and the frequency in this case are set by the product of the number of rotations and the number of the selected DC electromagnets 11a and 11b, and the amplitude is the magnitude of the DC current and the DC electromagnets 11a and 11b.
It is set by selecting the type of. Then, the switching of the DC electromagnets 11a and 11b and the number to be used are set depending on what number of revolutions the resonance frequency of the specimen A in actual operation corresponds to, and how many revolutions they are to be reproduced. . Therefore, a desired vibration condition can be set according to the internal stress of the sample A.

The vibration state of the specimen A is detected by the strain sensor 12, and the signal transmission line 13 of the signal transmission means 13 is detected.
a, the slip ring 13b transmits from the rotating part to the non-rotating part, and the desired data is collected by the blade vibration measuring device 14, the FFT analyzer 15, the XY plotter 16, the data recorder 17, the Campbell analyzing device 18, etc. Done.

FIGS. 2 and 3 show an example of the arrangement of the DC electromagnets 11a and 11b in the excitation means 11. As described above, the support structure is provided in order to give (excite) a frequency that is a multiple of the rotation speed. In FIG. 2, 24 small DC electromagnets 11a are attached at equal intervals in the rotational direction inwardly with respect to the adjusting sleeve 3e in 3B, and in FIG. The electromagnets 11b are attached at equal intervals in the rotation direction. These DC electromagnets 11
By raising or lowering or replacing the adjusting sleeve 3e with a or 11b, it is possible to excite an integral multiple of the rotation speed.

Next, an example of the Campbell diagram will be described with reference to FIG. The Campbell diagram referred to here is a diagram that shows what kind of vibration behavior the sample exhibits as the number of revolutions increases. That is, as the number of rotations of the test piece increases, the test piece shows a resonance state at an integral multiple of the number of electromagnets, so that the resonance frequency and vibration response amount of the test piece can be grasped. When an external force due to an exciting force is applied to the rotationally driven test piece, resonance occurs in the test piece when the excitation frequency and the natural frequency of the test piece match. When the rotation speed further increases, the excitation frequency also increases, and when this coincides with the resonance frequency that is an integral multiple of the natural frequency of the specimen, further resonance occurs. The strain signal detected by the strain sensor 12 is output as a frequency spectrum and a Campbell diagram by the FFT analyzer 15, the XY plotter 16, the data recorder 17, and the Campbell analyzer 18 through the blade vibration measuring device 14.

[0030]

According to the high-speed rotary vibration test apparatus of the present invention, the following effects can be obtained. (1) Since the test piece is attached to the rotary shaft that is rotationally driven inside the vacuum container, and the excitation means is arranged around it, in addition to generating internal stress in the test piece by centrifugal force, a magnetic field is also generated. By forming the vibration, vibration is applied to the test piece, and the environmental conditions of use of the test piece in the actual machine are equivalently reproduced, the high-speed rotation test accuracy is enhanced, and reliable verification can be performed. (2) By exciting with a DC electromagnet,
This makes it easy to set vibration conditions such as the magnitude of acceleration and amplitude, and expands the range of application. (3) As a signal transmission means of the strain sensor, a slip ring and a signal transmission line are arranged to transmit a signal to the outside of the vacuum container, thereby improving the collectability of vibration test data in a vibration state or a resonance state. it can. (4) By attaching a ferromagnetic foil film to the test piece or its support for excitation, even if the test piece is not a ferromagnetic material, use the actual test piece to make it simple and reliable. It is possible to carry out a high-speed rotation vibration test. (5) The centrifugal acceleration is set according to the rotation speed,
By setting the excitation condition by excitation, in addition to the test equivalent to the use condition, it is possible to perform a wide range of tests beyond the range of the use condition such as high rotation frequency at low rotation speed. .

[Brief description of drawings]

FIG. 1 is a front sectional view with a block diagram showing an embodiment of a high-speed rotation vibration test apparatus according to the present invention.

FIG. 2 is a plan view showing an example of a small DC electromagnet in FIG.

FIG. 3 is a plan view showing an example of a large DC electromagnet in FIG.

FIG. 4 is an enlarged front sectional view showing an example of attachment of the sample and the strain sensor in FIG.

5 is a front sectional view showing an arrangement example of a DC electromagnet in the excitation means of FIG.

6 is a front cross-sectional view showing another arrangement example of the DC electromagnet in the excitation means of FIG.

FIG. 7 is a model diagram of a Campbell diagram obtained by the high-speed rotation vibration test device according to the present invention.

[Explanation of symbols]

 A sample D rotation range 1 vacuum container 2 buffer block 3A, 3B support structure 3d suspension bracket 3e adjustment sleeve 3f fastener 4 rotary drive source (air turbine) 5 rotary shaft 5a support 6 rotor steady 11 excitation means 11a , 11b DC electromagnet 11c Ferromagnetic foil film 11d Electromagnetic excitation controller 11e Feed line 11f Connection plug 12 Strain sensor 13 Signal transmission means 13a Signal transmission line 13b Slip ring

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihisa Goshima 229 Togaya, Mizuho-cho, Nishitama-gun, Tokyo Ishi Kawashima Harima Heavy Industries Co., Ltd. Mizuho Plant (72) Inventor Eichi Taguchi 253 Kashiwa-shi Orenji, Chiba Maruwa Denki Co., Ltd.

Claims (4)

[Claims] 1. A device for performing a vibration test by rotating a sample (A) at a high speed inside a vacuum container (1), which is rotatably arranged inside the vacuum container and rotated by a rotary drive source (4). The magnetic field between the driven rotating shaft (5) and the test piece or its support (5a), which is arranged around the rotation range (D) of the test piece at intervals in the rotation direction, causes vibration to the test piece. A high-speed rotational vibration test apparatus comprising: an exciting means (11) for applying. 2. The excitation means (11) is a direct current electromagnet (11).
a, 11b), the high-speed rotary vibration test apparatus according to claim 1. 3. A specimen (A) is provided with a strain sensor (12) for detecting vibration displacement, and a signal transmission means (13) is arranged on the strain sensor, and the signal transmission means is a rotating shaft. A slip ring (13b) arranged in (5) and connected to the strain sensor, and a signal transmission line (13a) arranged in connection with the slip ring and transmitting the detection signal of the strain sensor to the outside of the vacuum container (1). The high-speed rotational vibration test apparatus according to claim 2, further comprising: 4. Specimen (A) or its support (5a)
The high-speed rotational vibration test device according to claim 2 or 3, wherein a ferromagnetic foil film (11c) is attached to the.