JP4993661B2 - Pneumatic vibration test equipment - Google Patents

Description

  The present invention relates to a pneumatic vibration test apparatus, and by simplifying the structure of the vibration test apparatus and reducing the size thereof, the present invention is not limited by the form and material of the test body, and can be added to the test body. The present invention relates to a pneumatic vibration device that can easily and quickly perform a precise vibration test that does not require mass.

  When obtaining the mechanical constants of various materials or checking the natural frequencies of designed and manufactured equipment or devices, it is necessary to perform a so-called vibration test. A vibration test apparatus comprising: a support unit to be installed; a vibration unit that applies vibration to the test body; a detection unit that detects a response of the test body; and an arithmetic processing unit that calculates a natural frequency based on the detection signal. Is used.

In addition, a non-contact type vibration device is often used for the vibration unit from the viewpoint that it does not affect the vibration characteristics of the specimen, and a discharge vibration device, a magnetic vibration device, a sound wave vibration device, Various vibration devices such as a device and an air vibration device have been developed.
Among them, the air vibration device can be applied relatively easily even when the test body is made of a non-magnetic material or the test body has a complicated form, and has high practicality. It has.

FIG. 5 shows an example of an object deformation characteristic measuring apparatus which is a kind of vibration test apparatus (Japanese Patent Laid-Open No. 2004-69668). The pressurized air from the compressor 41 is supplied to the regulator 42, the electromagnetic valve 43, and the tube. 23 and thereby ejected to the specimen 25 through the air nozzle 24, by continuously opening and closing the electromagnetic valve 43 at a predetermined period T _1, the pulsed air pressure applied to the test body 25 to vibrate the specimen 25. The vibration measurement sensor 26 detects at least one of acceleration, velocity or displacement generated in the test body as a result of the excitation by the pulsed air pressure, and the detection signal is sent to the computer 28 together with the detection signal of the pressure sensor 27. Entered.

In the computer 28, transmission between the excitation force applied to the test body 25 by the pulsed air ejected from the air nozzle 24 and any one of the acceleration, velocity or displacement detected by the vibration sensor 26. The characteristic and the deformation characteristic of the object using the same are calculated, and a control signal such as an operation period (pneumatic pulse period T ₁ ) of the electromagnetic valve 43 is sent to the control box 29, and the electromagnetic valve is transmitted via the control box 29. 43 operation control etc. are performed.

The air vibration device in the vibration test apparatus shown in FIG. A vibration pressure can be uniformly applied without being affected by the shape of the test body, and any shape of the test body can be easily subjected to a vibration test; It has a high practical utility such that the impact applied to the specimen is relatively small and does not cause damage.
However, since it is configured to generate a pulsed air flow by opening and closing the solenoid valve 43, it is basically difficult to obtain a high excitation frequency, and even if a high-speed solenoid valve is used, the upper limit is about 50 cycles. Furthermore, the use of a high-speed solenoid valve is restricted in terms of air pressure and air flow rate, and as a result, there is a problem that the selection range of vibration frequency and excitation force becomes extremely narrow.

On the other hand, at the fields of fatigue testing device of the material, by using an air non-contact vibration device having a structure as shown in FIG. 6, so as to obtain a 270～5300H _Z a high frequency of approximately pneumatic pulse stream Have been disclosed (Japanese Patent Laid-Open No. 2004-77163).

  That is, in FIG. 6, 30 is a specimen to be subjected to a fatigue test, 31 is a holding frame, 32 is a telescopic hollow tube, 33 is a pulse generator main body, 34 is a motor, 35 is a shaft, 36 is a pressure sensor, 37 is an air ejection nozzle body, 38 is a fixed side perforated disk, and 39 is a rotation side perforated disk.

  The fixed-side perforated disk 38 has a plurality of (4 to 8) small holes formed on the outer peripheral edge thereof at predetermined angular intervals on the same circumference, and is fixed to the inlet side of the nozzle body 37. Has been. The rotation side perforated disk 39 is fixed concentrically to the tip of the motor shaft 35, and the same number as the fixed side perforated disk 38 is provided on the outer peripheral edge of the rotation side perforated disk 39. Are formed at the same angular interval on the same circumference. Further, the fixed-side perforated disk 38 and the rotary-side perforated disk 39 are arranged so as to be slidable and rotatable in a state of being concentric with each other and maintaining airtightness. When the small holes of both disks 38 and 39 match, the air flows from the main body body 33 to the air ejection nozzle body 37 side through the small holes.

  The number of airflows per unit time (that is, the frequency of the pulsed airflow) flowing through the small holes of the disks 38 and 39 to the side of the air ejection nozzle body 37 is the outer peripheral portion of the disks 38 and 39. As described above, a high-frequency pulsed air flow of 270 to 5300 Hz can be obtained by controlling the number of rotations of the motor 34. Yes. Also, since the nozzle length is adjusted to resonate in order to obtain a large excitation force, the nozzle length is adjusted every time the frequency is changed, and furthermore, the resonance reduction of sound is used. Therefore, it corresponds to the excitation in the high frequency region of 270 to 5000 Hz.

  The air-type non-contact vibration exciter for the fatigue test apparatus shown in FIG. 6 is excellent in that it can easily obtain a high-frequency pulsed air flow exceeding 5000 Hz and can easily adjust the vibration frequency. It has a practical utility.

However, the fatigue test apparatus shown in FIG. 6 has a disadvantage that it is large and lacks in handling because the pneumatic non-contact vibration apparatus is for a fatigue test apparatus.
Further, it is necessary to rotate the rotating side perforated disk 39 at a high speed in a state where the fixed side perforated disk 38 having a plurality of small holes 38a and 39a and the rotating side perforated disk 39 are in airtight surface contact. Therefore, as shown in FIG. 7, it is necessary to have a structure in which not only the sliding surfaces of the two-holed disks 38 and 39 but also the entire surface 39b on the motor side of the rotary-side holey disk 39 is sealed. As a result, it is extremely difficult to maintain the airtightness between the two perforated disks 38 and 39 and to maintain the airtightness of the motor side surface 39b of the perforated disk 39 due to the fact that the rotating perforated disk 39 rotates at a high speed. Therefore, there is a problem that it takes time to check and repair the vibration device.

JP 2003-98031 A JP-A-10-253490 JP 2004-117323 A JP2004-69668 JP 2004-77163 A

  The present invention relates to the above-mentioned problems in the conventional pneumatic vibration test apparatus, namely, i. In the vibration exciter having a structure in which a pulsed pneumatic flow is obtained by opening and closing the solenoid valve, the upper limit of the frequency of the pulsed pneumatic flow that can be generated due to restrictions on the operating characteristics of the solenoid valve is about 50 to 100 Hz. The required vibration frequency cannot be obtained depending on the type of b. Generation of a pulsed pneumatic flow in a vibration device using a mechanism for generating a pulsed pneumatic flow consisting of a combination of a stationary disk and a rotating disk with a plurality of small holes used in a fatigue testing device It is difficult to maintain the airtightness of the parts, and a lot of work is required for inspection and repair. The pneumatic exciter for fatigue testing equipment is extremely large and lacks handleability, and it is difficult to apply it directly to an exciter for vibration testing of plastic structures. It can be applied regardless of the material and form of the test specimen, and can easily obtain the frequency in the frequency range required for the vibration test. The main object of the present invention is to provide a pneumatic vibration testing apparatus capable of reducing the frequency of repairs and inspections.

In order to solve the above-mentioned problems, the invention of claim 1 of the present application is such that compressed air is passed through a valve device that repeatedly opens and closes at high speed, and is intermittently blown onto a test body fixed to a surface plate to vibrate the test body. In the pneumatic vibration test apparatus for applying an excitation force, the valve device includes a rotating disk having a small hole formed in the outer peripheral edge, a motor for rotating the rotating disk, and an outer peripheral edge of the rotating disk. An inlet side cover and an ejection side cover, which are arranged in airtight and slidable manner on the both sides of the portion where the small hole is formed, and are formed on the inlet side by the rotation of the rotating disk. A pulsed airflow that has flowed into the ejection side cover through a small hole from the inside of the cover is ejected from the ejection nozzle.

The invention according to claim 2 is a pneumatic vibration test apparatus that applies a vibrational excitation force to a test body by allowing compressed air to pass through a valve device that repeatedly opens and closes at high speed and intermittently sprays it onto the test body fixed to a surface plate. In the present invention, the valve device includes a rotating disk having a plurality of small holes formed at an outer peripheral edge at a predetermined constant angle pitch or a random angle pitch, a motor for rotating the rotating disk, and the motor of the rotating disk; An inlet-side cover disposed on the opposite side surface so as to be airtight and slidable with the side surface; and an ejection-side cover disposed on the other side surface of the rotating disk so as to be airtight and slidable with the side surface. , And a pulsed pneumatic flow that flows into the ejection side cover through a plurality of small holes from the entrance side cover by the rotation of the rotating disk is ejected from the ejection nozzle.

According to a third aspect of the present invention, a pneumatic vibration test apparatus for applying a vibration excitation force to a test body by allowing compressed air to pass through a valve device that repeatedly opens and closes at high speed and intermittently blows the test air to a test body fixed to a surface plate. The valve device includes a belt-like metal film in which a plurality of small holes having different shapes are formed at a desired pitch, a roller that rotatably supports the metal film in an endless manner, and the metal film is rotated. A motor to be moved, an inlet-side cover disposed on one side surface of the rotating metal film so as to be airtight and slidable with the side surface, and the other side surface of the metal film being airtightly slid with the side surface. A pulsating air flow that flows from the inlet side cover through the small hole into the ejection side cover by the rotation of the metal film and is ejected from the ejection nozzle. It is intended.

The invention according to claim 4 is a pneumatic vibration test apparatus for applying a vibration excitation force to a test body by allowing compressed air to pass through a valve device that repeatedly opens and closes at high speed and intermittently sprays the test body fixed to a surface plate. The valve device includes a rotating drum body having a plurality of small holes having different forms formed in the body wall at a desired pitch, a motor for rotating the rotating drum body, and the inner wall surface on the inner surface side of the rotating drum body. And an inlet side cover disposed in an airtight and slidable manner, and an ejection side cover disposed in an airtight and slidable manner on the outer wall surface of the rotating drum body, A pulsed pneumatic flow that flows into the ejection side cover through a small hole from the entrance side cover by the rotation of the rotating drum body is ejected from the ejection nozzle.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention, the compressed air filled in the high-pressure vessel is used as the compressed air.

In the pneumatic vibration testing device of the present invention, the compressed air flow is passed through a valve device that repeatedly opens and closes at high speed, and is intermittently sprayed onto the test body. In addition, it is possible to easily apply an excitation force having a necessary number of vibrations.
In the pneumatic vibration testing apparatus of the present invention, since the pneumatic vibration apparatus is reduced in size and weight, the handling is easy, and the vibration of the test object can be easily changed by changing the injection direction with respect to the test object. The direction can be changed.
Further, when the valve device is formed of a rotating disk having one small hole, the structure of the valve device can be greatly simplified, and troubles such as airtight leakage can be greatly reduced.
Furthermore, by using a rotating disk provided with a plurality of small holes, a high-frequency vibration excitation force can be easily obtained, and a pneumatic exciter having a structure in which two conventional rotating disks are used in combination is used. In comparison, trouble related to airtightness can be greatly reduced.
In addition, by using a metal film or drum body in which a plurality of small holes are drilled in a rotating disk at a random angular pitch or a plurality of small holes having different forms are formed at a desired pitch, pseudo-randomness is achieved. A test using waves or the like can be easily performed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a system diagram showing a configuration of a pneumatic vibration test apparatus according to the present invention, and FIG. 2 is a needle surface view showing an embodiment of a vibration test using the pneumatic vibration test apparatus. FIG. 3 is a schematic sectional view showing the main part of the valve device.

  1 and 2, 1 is a test body, 2 is a valve device, 3 is an air compressor, 4 is a flow control device, 5 is a displacement meter, 6 is a computer (calculation / control device), and 7 is a pulsed pneumatic flow. Injection nozzle, 8 is a servo motor, 9 is a motor controller, 10 is a rotating disk, 11 is a shaft, 12 and 13 are sliding covers, 14 is a pipe, 15 is a surface plate, 16 is a valve device support, and 17 is a nozzle. Support.

  As shown in FIG. 1, the pneumatic vibration testing apparatus according to the present invention includes a valve device 2, an air compressor 3, a flow rate control device 4, a servo motor 8, a motor control device 9, and the like. An air flow A set to a desired pressure and flow rate by the flow rate adjusting device 4 is supplied into the sliding cover 12 of the valve device 2 through the pipe 14, and in the valve device 2, a pulsed pneumatic flow having a predetermined frequency is obtained. After the conversion, the excitation force having a predetermined sliding frequency is applied to the test body 1 by being sprayed from the pulsed pneumatic flow spray nozzle 7 onto the outer surface of the test body 1.

The vibration displacement or the like generated in the test body 1 by the application of the excitation force is detected by the laser displacement meter 5 or the like, and the natural vibration frequency or the like of the test body 1 is calculated by the computer 6.
Further, the frequency of the pulsed pneumatic flow is controlled to a desired frequency by changing the number of revolutions of the servo motor 8 via the motor control device 9 as will be described later, and also depends on the pulsed pneumatic flow applied to the test body 1. The excitation force is controlled by adjusting the flow rate and / or pressure of the air flow by the flow rate control device 4.

  The specimen 1 may be of any material and shape (form). In this embodiment, as will be described later, the specimen 1 is an acrylic cylindrical tank having a diameter of 300 mm, a height of 400 mm, and a thickness of 1 mm. The specimen 1 was filled with water up to a depth of 380 mm.

  Further, as shown in FIG. 3, the valve device 2 is fixed to the tip of the rotating shaft (shaft 11) of the motor 8, and has a rotating disk 10 having a small hole 18 formed in the outer peripheral edge portion; The inlet side sliding cover 13 and the ejection side sliding cover 12 provided on both sides of the outer peripheral edge of the rotating disk 10, the injection nozzle 7 provided on the outlet side of the ejection side cover 12, and both sliding covers 12, 13. And the seal ring 20 interposed between the sliding covers 12 and 13 and the flanges 12 a and 13 a and the rotating disk 10.

The air flow flowing into the inlet side sliding cover 13 through the pipe 14 flows into the ejection side sliding cover 12 through the small hole 18 every time the rotating disk 10 makes one rotation, and is so-called pulsed from the ejection nozzle 7. A pneumatic flow is injected, and the frequency of the pulsating pneumatic flow to be ejected, that is, the vibration frequency is controlled by controlling the rotational speed of the rotating disk 10.
Of course, the supply source of the compressed air flow A may be, for example, compressed air filled in a high pressure vessel other than the compressor or vaporized air from liquid air.

  In the present embodiment, since one small hole 18 formed in the rotating disk 10 is used and the sealing surface of the rotating disk 10 and the sliding covers 12 and 13 is made as small as possible, so-called so-called Troubles such as air leakage from the sliding surface are effectively prevented. However, since the frequency of the pneumatic flow is limited by the rotational speed of the rotating disk 10, the excitation frequency is limited to 200 Hz (rotating disk rotational speed 12,000 rpm).

Therefore, a plurality of small holes 18 (for example, 2 to 10) are provided in the rotating disk 10 at a predetermined angular pitch, and the number of small holes 18 is increased to increase the excitation frequency at a lower rotational speed of the motor 8. May be obtained.
Of course, the rotational speed of the rotating disk 10 is increased by changing the speed ratio of the speed change mechanism of the motor 8. Further, in the valve device 2 of FIG. 2, the small holes 18 are formed in the rotary disk 10 on the same circumference at a predetermined angular pitch. It is also possible to perform a vibration test using waves.

  FIG. 4 is a perspective view showing a main part of another example of the valve device 2 used in the present invention. In the valve device 2 of FIG. 4, a band-shaped metal film 21 is used instead of the rotating disk 10, and small holes 18 having different sizes and shapes are formed in the metal film 21 at a desired pitch. Yes.

The metal film 21 is rotated endlessly in the arrow direction at a desired speed by rotating the roller 22 by the motor 8, and air passes through the small hole 18 from the inlet side sliding cover 12. Then, it is ejected into the outlet side sliding cover 13.
In FIG. 4, 7 is an injection nozzle, 8 is a motor, 12 and 13 are sliding covers, and 22 is a roller.

In the valve device 2 shown in FIG. 4, by appropriately selecting the size, form, pitch, and the like of the small holes 18, an arbitrary excitation waveform, excitation force, and excitation frequency can be obtained. It can be used for vibration tests such as vibration.
In the valve device 2 shown in FIG. 4, the metal film 21 is rotated endlessly via the roller 21, but a rotating drum body (not shown) is used in place of the metal film 21, and this rotation is performed. A structure in which small holes 18 are formed at a predetermined pitch in the drum body wall, and both sliding covers 12 and 13 are slidably disposed on both inner and outer wall surfaces of the drum body. It is also good.

The valve device 2 is preferably placed as close to the injection nozzle 7 as possible in order to effectively generate a vibrational excitation force. For the same reason, the flow control device 4 is preferably placed upstream of the valve device 2.
In order to effectively generate the vibrational excitation force, it is preferable that the injection nozzle 7 has a relatively large diameter so that the injected pulsed pneumatic flow does not become a so-called jet flow.

Referring to FIG. 2, an acrylic cylindrical tank having a diameter of 300 mm, a height of 400 mm, and a thickness of 1 mm is formed on the upper surface of a platen 15 having a width of 1000 ^mm (width) × 700 ^mm (depth) × 500 ^mm (height). A test body 1 filled with water up to a height of 380 mm is installed inside, and a pulse of 0 to 200 Hz is directed from the injection nozzle 7 fixed to the nozzle support 17 toward the side wall surface 50 mm below the upper end of the test body 1. A pneumatic pressure flow was injected.

In this embodiment, the small hole 18 has an inner diameter of 30 mm, the diameter of the injection nozzle 7 is 20 mm, the air pressure of the air compressor is 0.95 MPa, the frequency of the pulsed air flow is 50 Hz (motor rotation speed 750 rpm), Several 4 are set to an average air velocity of 10 m / sec.
The average amplitude at a position 50 mm below the upper end of the test body 1 detected by the displacement meter 5 at 50 Hz vibration was about 0.02 mm.

From the test results according to the above examples, the vibration frequency of the pneumatic vibration test apparatus according to the present invention can be from 0 Hz to 200 Hz, and the vibration force depends on the capacity of the air compressor, but to a considerable level. It turned out to be possible.
In addition, since the specimen 1 is a thin wall made of acrylic, the vibration characteristics of the specimen will change when an excitation device such as an electromagnet that needs to be attached with an iron piece or the like is used. It was found that accurate vibration characteristics can be easily obtained with a pneumatic vibration test apparatus.
Furthermore, a constant frequency test can be performed by controlling the rotation speed of the servo motor to be constant, and a frequency insertion test can be performed by controlling the rotation speed to gradually increase.
In addition, it is also possible to perform a pseudo random wave test by making a plurality of holes in the rotating disk and randomizing the mutual intervals.

  The pneumatic vibration test apparatus of the present invention can be applied to a material fatigue test and the like in addition to the vibration test.

1 is a system diagram showing a basic configuration of a pneumatic vibration testing apparatus according to the present invention. It is a perspective view which shows the implementation state of the vibration test using a pneumatic vibration testing apparatus. It is a fragmentary sectional schematic diagram which shows the principal part of the valve apparatus of the pneumatic vibration testing apparatus which concerns on this invention. It is a perspective view which shows the principal part of the other example of a valve apparatus. It is a systematic diagram which shows the structure of the air vibration apparatus used for the deformation characteristic measuring apparatus of the former object. It is a cross-sectional schematic diagram of the air-type non-contact vibration apparatus used for the conventional fatigue test apparatus. FIG. 7 is a partial cross-sectional schematic view showing a main part of a pulse wave generating part of the pneumatic non-contact vibration exciter in the fatigue test apparatus of FIG. 6.

Explanation of symbols

1 is a test body 2 is a valve device 3 is an air compressor 4 is a flow control device 5 is a displacement meter 6 is a computer 7 is a pulsed pneumatic flow injection nozzle 8 is a motor 9 is a motor control device 10 is a rotating disk 11 is a shaft 12 , 13 is a sliding cover 14, a pipe 15, a surface plate 16, a valve device support 17, a nozzle support 18, a small hole 19, a pressing spring 20, a seal ring 21, a metal film.

Claims (5)

In a pneumatic vibration test apparatus for passing a compressed air through a valve apparatus that repeatedly opens and closes at high speed and intermittently blowing the compressed air to a test body fixed to a surface plate to give a vibrational excitation force to the test body, the valve device includes: A rotating disk having one small hole formed in the outer peripheral edge, a motor for rotating the rotating disk, and the rotating disk on both sides of the outer peripheral edge of the rotating disk where the small hole is formed. A pulsed air pressure formed from an inlet-side cover and a jet-side cover that is airtightly and slidably disposed on the side surface, and flows into the jet-side cover through a small hole from the inlet-side cover by the rotation of the rotating disk. Pneumatic vibration test device configured to inject a flow from an ejection nozzle. In a pneumatic vibration test apparatus for passing a compressed air through a valve apparatus that repeatedly opens and closes at high speed and intermittently blowing the compressed air to a test body fixed to a surface plate to give a vibrational excitation force to the test body, the valve device includes: A rotating disk in which a plurality of small holes are formed in the outer peripheral edge portion at a predetermined constant angle pitch or a random angle pitch, a motor that rotates the rotating disk, and a side surface of the rotating disk that faces the motor. An inlet-side cover that is air-tightly and slidably disposed on the side surface, and an ejection-side cover that is air-tightly and slidably disposed on the other side surface of the rotating disk. A pneumatic vibration test apparatus configured to eject from the ejection nozzle a pulsed pneumatic flow that has flowed into the ejection side cover through a plurality of small holes from the inside of the entrance side cover. In a pneumatic vibration test apparatus for passing a compressed air through a valve apparatus that repeatedly opens and closes at high speed and intermittently blowing the compressed air to a test body fixed to a surface plate to give a vibrational excitation force to the test body, the valve device includes: A belt-shaped metal film in which a plurality of small holes having different forms are formed at a desired pitch, a roller that rotatably supports the metal film in an endless manner, and a motor that rotates the metal film rotate. An inlet-side cover disposed on one side surface of the metal film so as to be airtight and slidable with the side surface, and a jet disposed on the other side surface of the metal film so as to be airtight and slidable with the side surface. A pneumatic vibration test in which a pulse-like pneumatic flow that is formed from the side cover and flows into the ejection side cover through a small hole from the entrance side cover by the rotation of the metal film is ejected from the ejection nozzle. Location. In a pneumatic vibration test apparatus for passing a compressed air through a valve apparatus that repeatedly opens and closes at high speed and intermittently blowing the compressed air to a test body fixed to a surface plate to give a vibrational excitation force to the test body, the valve device includes: A rotating drum body in which a plurality of small holes having different forms are formed in the body wall at a desired pitch, a motor that rotates the rotating drum body, and an inner surface of the rotating drum body that slides in an airtight manner on the inner wall surface An inlet-side cover arranged in a slidable manner, and an ejection-side cover arranged on the outer wall surface side of the rotating drum body so as to be airtight and slidable. A pneumatic vibration testing apparatus configured to eject a pulsed pneumatic flow flowing into the ejection side cover from the side cover through a small hole from the ejection nozzle. The pneumatic vibration testing apparatus according to any one of claims 1 to 4, wherein compressed air filled in a high-pressure vessel is used as the compressed air.

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