CN115400932A

CN115400932A - Pneumatic miniature vibration exciter

Info

Publication number: CN115400932A
Application number: CN202211123370.5A
Authority: CN
Inventors: 张宴豪; 张继轩; 杨政杰; 温济铭; 赵富龙; 赵俊达
Original assignee: Harbin Engineering University
Current assignee: Harbin Engineering University
Priority date: 2022-09-15
Filing date: 2022-09-15
Publication date: 2022-11-29

Abstract

A pneumatic miniature vibration exciter relates to a miniature vibration exciter. The invention aims to solve the problems that the existing miniature vibration exciter has large measurement deviation, interference of electromagnetism on data transmission and large size. The pneumatic control device comprises a control center (1), an air pump (2), a hard air pipe (3) and an impact part (4), wherein the control center (1) is electrically connected with the air pump (2), and the air pump (2) is hermetically connected with the impact part (4) through the hard air pipe (3); the impact part (4) comprises an air cavity shell and a firing pin device, the upper part of the air cavity shell is hermetically connected with the hard air pipe (3), the firing pin device is horizontally and hermetically installed in the lower part of the air cavity shell in a sliding manner, impact is realized under the drive of the air pump (2), and the air cavity shell is a right-angle cylindrical shell. The invention can operate in a narrow space with extremely small mass and volume, and is suitable for frequency domain measurement of the microstructure. The invention relates to microstructure frequency domain measurement.

Description

Pneumatic miniature vibration exciter

Technical Field

The invention relates to a miniature vibration exciter, in particular to a pneumatic miniature vibration exciter, and relates to the field of frequency domain results of rod-shaped objects.

Background

A heat transfer tube bundle of a steam generator in a nuclear power plant can generate flow-induced vibration due to uneven cross flow scouring, the flow-induced vibration characteristic of a rod-shaped structure is a key factor influencing the integrity of a first radiation barrier and a second radiation barrier of a reactor, and the dry mode and the wet mode of the rod-shaped structure are basic data for researching the vibration response characteristic of the rod-shaped structure under the action of fluid. In the process of researching the structural mode of the rod bundle in the liquid-phase medium, a frequency domain result of rod body vibration needs to be obtained, and therefore step excitation needs to be given to the rod bundle to carry out frequency sweep processing on the rod body. However, since the inner diameter of the heat transfer pipe is too small, the size of a common miniature vibration exciter cannot be installed inside the heat transfer pipe for testing, and if the vibration exciter is installed outside for measurement, the flow field around the heat transfer pipe is affected, so that the accuracy of the modal frequency measurement result is affected. There is a need for an exciter that can be mounted inside a rod structure to impart step excitation.

The vibration exciter is used as a tool for realizing excitation, is used for satisfying modal experimental research of rod body and pipe body structures, and further provides support for researching flow-induced vibration behaviors of a reactor fuel element and a heat transfer pipe bundle. For micro rod body and tube body structures, the existing micro vibration exciter cannot be installed in the micro rod body and tube body structures to carry out modal experimental research, and a new vibration exciter structure needs to be redesigned to measure dry and wet dual modes of the rod body and the tube body.

The invention discloses a miniature moving magnet vibration exciter with a patent application publication number CN101741208B, which structurally comprises a linear motor assembly, a compressor assembly and a suspension assembly. The linear motor assembly comprises a concentric magnetic yoke pair, an excitation coil and a permanent magnet ring; the cylinder in the compressor assembly is fixed in the central ring of the magnetic yoke pair through the cylinder bracket, the piston is positioned in the cylinder, and the magnetic yoke pair is suspended and positioned on the cylinder bracket; the suspension assembly is a leaf spring. The miniature moving-magnet vibration exciter structurally adopts a moving-magnet type, utilizes a magnetic induction principle to convert electric energy into mechanical energy, and is added to certain mechanical equipment to generate exciting force, but the exciting frequency of the vibration exciter is difficult to change, and the exciting force is difficult to measure. And the electromagnetism can generate common frequency interference on the signals, influence data transmission and increase the deviation of the measurement result.

The utility model with publication number CN214347694U describes a miniature vibration exciter, which comprises a cylindrical outer casing; a circumferential hanging ring and a top hanging ring which are arranged on the periphery of the outer shell; a control board and a resonance generator in the outer shell. The utility model discloses a structure of vibration exciter has been optimized on the structure basis of traditional electromagnetic type vibration exciter, better solution traditional electromagnetic type excitation frequency be difficult to change, the difficult measuring problem of exciting force, nevertheless electromagnetism is not considered to data transfer's interference problem in its structure, and the utility model discloses a vibration exciter inner structure is abundant, and is bulky, does not have the breakthrough in size.

In summary, the existing miniature vibration exciter has the problems of large measurement deviation, interference of electromagnetism on data transmission and large size.

Disclosure of Invention

The invention aims to solve the problems that the existing miniature vibration exciter has large measurement deviation, interference of electromagnetism on data transmission and large size. Further provides a pneumatic miniature vibration exciter.

The technical scheme of the invention is as follows: a pneumatic miniature vibration exciter comprises a control center, an air pump, a hard air pipe and an impact part, wherein the control center is electrically connected with the air pump, and the air pump is hermetically connected with the impact part through the hard air pipe; the impact part comprises an air cavity shell and a firing pin device, the upper part of the air cavity shell is hermetically connected with the hard air pipe, the firing pin device is horizontally and hermetically installed in the lower part of the air cavity shell in a sliding manner, impact is realized under the drive of the air pump, and the air cavity shell is a right-angle cylindrical shell.

Further, the hard air pipe is a right-angle hard air pipe.

Further, the air cavity shell comprises a vertical cylinder and a horizontal cylinder, the upper end of the vertical cylinder is connected with the hard air pipe in a sealing mode, the horizontal cylinder is horizontally arranged at the lower end of the vertical cylinder, and the firing pin device is embedded in the horizontal cylinder.

Furthermore, the lower ends of the horizontal cylinder and the vertical cylinder are communicated and hermetically connected in a welding mode.

Further, the inner diameter of the vertical cylinder is smaller than the inner diameter of the horizontal cylinder.

Further, the wall thickness of the horizontal cylinder is greater than the wall thickness of the horizontal cylinder.

Furthermore, the firing pin device comprises a firing pin, a spring and a gasket, the firing pin is horizontally and slidably sealed in the horizontal cylinder, one end of the spring is positioned in the horizontal cylinder and connected with the firing pin, the other end of the spring is connected with the gasket, and the gasket is abutted against the side wall of the vertical section in the horizontal cylinder.

Furthermore, the firing pin comprises a connecting plate and a protrusion, the connecting plate is a circular connecting plate, the protrusion is arranged in the middle of the circular connecting plate on the outer side of the horizontal cylinder, and the connecting plate and the protrusion are integrally formed.

Further, the thickness of the spacer is smaller than the thickness of the connecting plate.

Further, the striker is sealed with the inner side wall of the horizontal cylinder by lubricating oil.

Compared with the prior art, the invention has the following effects:

1. the invention can operate in the space with minimum size not less than 15mm with extremely small mass and volume, and is suitable for frequency domain measurement of the microstructure. The invention mainly aims at measuring the vibration frequency domain of the heat transfer pipe of the steam generator in the nuclear power system, and is also suitable for the experimental field of frequency domain measurement of the vibration of other objects.

2. When the vibration exciter is started, the compression and the release of the spring are controlled by the air pumping of the air pump, and the spring releases to push the striker to complete the excitation action. This miniature vibration exciter of pneumatic type has abandoned the design of traditional vibration exciter integration, adopts the novel structure of independently designing, only installs in operational environment with the striking part and the design of part stereoplasm trachea of testee direct contact in the vibration exciter structure, and installs outside operational environment with the great air pump of volume and the higher control maincenter design of requirement for the environment, greatly reduces the volume of vibration exciter in operational environment to this is applicable to more narrow and small, in the more complicated operational environment of environment. And the number of the components is small, the structure is simple, and the matching is stable and reliable. Meanwhile, the method can adapt to the dry and wet mode measurement of the rod body structure, and stably and reliably give step excitation to the rod body.

3. According to the invention, the impact part and part of the hard air pipe can be arranged in the micro rod body, and the hard air pipe can guide air and can also realize the fixation of the vibration exciter. The impact part can give step excitation to the rod body, so that the aim of measuring the dry and wet modes of the rod body is fulfilled.

4. The miniature vibration exciter of the invention divides the traditional integrated vibration exciter into two parts, namely an impact part and a control part, which are mutually matched to finish the vibration exciting action. The impact part is responsible for giving the excitation to the rod body, and the control part is responsible for controlling the excitation frequency. The control part is composed of a control center and an air pump, and the purpose of controlling the frequency of the vibration exciter is achieved by adjusting the output signal of the control center to the air pump. The impact part consists of two parts, namely an air cavity shell and a firing pin device, wherein the firing pin device is further divided into three parts, namely a firing pin, a spring and a gasket, and the maximum excitation quantity of the vibration exciter can be changed by using the springs with different stiffness coefficients. The control part may be considered as the driving part of the device and the impact part may be considered as the driven part. The control part and the impact part are connected by a hard air pipe. When the vibration exciter starts to work, the air pump is controlled to start to exhaust after the frequency is determined by the control center, so that air in an air cavity of the impact part is reduced, the external atmospheric pressure works to compress the spring, the air pump stops exhausting and communicates with the atmosphere at the same time after a certain degree is reached, the spring is released, the striker is pushed to knock the object to be tested, the vibration excitation on the object is realized, and the electromagnetic interference is avoided.

5. The invention constructs a frame of the vibration exciter by two mutually perpendicular cylinders (a vertical cylinder 5 and a horizontal cylinder 6), which can assemble all parts of the vibration exciter and play a role of fixing the vibration exciter when the vibration exciter goes deep into a rod body to work.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention; FIG. 2 is a cross-sectional view of the impact portion; FIG. 3 is a schematic view of the striker assembly; fig. 4 is a schematic workflow diagram of the present invention.

Detailed Description

The first specific implementation way is as follows: the embodiment is described with reference to fig. 1 to 3, the pneumatic miniature vibration exciter of the embodiment comprises a control center 1, an air pump 2, a hard air pipe 3 and an impact part 4, wherein the control center 1 is electrically connected with the air pump 2, and the air pump 2 is hermetically connected with the impact part 4 through the hard air pipe 3; the impact part 4 comprises an air cavity shell and a firing pin device, the upper part of the air cavity shell is hermetically connected with the hard air pipe 3, the firing pin device is horizontally and hermetically installed in the lower part of the air cavity shell in a sliding manner, impact is realized under the drive of the air pump 2, and the air cavity shell is a right-angle cylindrical shell.

The control part of the embodiment is positioned outside the working environment and is not in direct contact with the measured object; the impact portion is in direct contact with the object to be measured.

The horizontal cylinder 6 of the vibration exciter of the present embodiment is coaxially connected to the striker device, and the striker device is detachable and replaceable from the horizontal cylinder 6.

According to the embodiment, the purpose of controlling the vibration exciting amount output by the vibration exciter can be realized more simply and reliably by matching the striker device and the vibration exciter air cavity. The air pump 2 achieves simple control and power output functions through the control center 1. On the premise of ensuring that the size meets the requirement, the vibration excitation action is stably and reliably completed.

The second embodiment is as follows: the present embodiment will be described with reference to fig. 1, and the rigid air tube 3 of the present embodiment is a right-angled rigid air tube. So arranged, the connection of the hard air tube 3 and the impact part 4 is facilitated. Other components and connections are the same as in the first embodiment.

The third concrete implementation mode: referring to fig. 1 and 2, the air chamber housing of the present embodiment includes a vertical cylinder 5 and a horizontal cylinder 6, the upper end of the vertical cylinder 5 is hermetically connected with the hard air tube 3, the horizontal cylinder 6 is horizontally installed at the lower end of the vertical cylinder 5, and the striker device is embedded in the horizontal cylinder 6.

By the arrangement, the horizontal cylinder 6 is convenient for installing the striker device to realize vibration excitation, and the length of the vertical cylinder 5 is convenient for selecting a proper position to perform vibration excitation. Other compositions and connections are the same as in the first or second embodiments.

The fourth concrete implementation mode: referring to fig. 2, the horizontal cylinder 6 and the vertical cylinder 5 of the present embodiment are connected to each other by welding and sealing. Due to the arrangement, the use strength of the horizontal cylinder 6 can be ensured under the condition of shock excitation of the firing pin device, and the open welding and the cylinder body deformation caused by the shock excitation can be avoided. Other compositions and connection relationships are the same as in the first, second or third embodiment.

The fifth concrete implementation mode: the present embodiment is described with reference to fig. 1 and 2, and the vertical cylinder 5 of the present embodiment has an inner diameter smaller than that of the horizontal cylinder 6. So set up, the structure size is smaller and more exquisite, is convenient for reduce the quality of whole structure. Other compositions and connection relationships are the same as those in the first, second, third or fourth embodiment.

The sixth specific implementation mode: the present embodiment will be described with reference to fig. 1 and 2, and the horizontal cylinder 6 of the present embodiment has a larger wall thickness than the horizontal cylinder 6. So set up, be convenient for reduce the quality of whole structure. Other compositions and connection relationships are the same as in the first, second, third, fourth or fifth embodiment.

The seventh embodiment: the striker device according to the present embodiment is described with reference to fig. 2 and 3, and includes a striker 7, a spring 8, and a washer 9, the striker 7 being horizontally slidably sealed in the horizontal cylinder 6, one end of the spring 8 being located in the horizontal cylinder 6 and connected to the striker 7, the other end of the spring 8 being connected to the washer 9, and the washer 9 being abutted against a side wall of a vertical section in the horizontal cylinder 6. So arranged, the striker assembly can be formed into multiple sets of assemblies from springs 8 of different stiffness coefficients. Other compositions and connection relationships are the same as in the first, second, third, fourth, fifth or sixth embodiment.

The specific implementation mode eight: referring to fig. 2 and 3, the striker 7 of the present embodiment includes a link plate 7-1 and a boss 7-2, the link plate 7-1 is a circular link plate, the boss 7-2 is installed at the middle of the circular link plate outside the horizontal cylinder 6, and the link plate 7-1 and the boss 7-2 are integrally formed. So set up, be convenient for guarantee the strength of excitation. Other compositions and connection relationships are the same as those of embodiment one, two, three, four, five, six or seven.

The specific implementation method nine: the present embodiment is described with reference to fig. 2 and 3, and the thickness of the spacer 9 of the present embodiment is smaller than the thickness of the connection plate 7-1. So set up, prevent that gasket 9 is too thick to the impact of horizontal cylinder 6 inside wall, can also reduce the quality simultaneously. Other constitutions and connection relationships are the same as those of any one of the first to eighth embodiments.

The detailed implementation mode is ten: the present embodiment will be described with reference to fig. 2 and 3, and the striker 7 of the present embodiment is sealed with lubricating oil against the inner wall of the horizontal cylinder 6. The arrangement is convenient for keeping good air tightness of the contact part of the two. Other components and connection relationships are the same as those in any one of the first to ninth embodiments.

The working principle of the invention is explained in connection with fig. 1-4:

the control center 1 and the air pump 2 are connected by a data line from left to right and from top to bottom for transmitting control signals, the air pump 2 and the impact part 4 are connected by a hard air pipe 3, and the air tightness of the connection part is qualified.

As shown in figure 2, for the impact part, the air cavity housing is divided into a vertical cylinder 5 and a horizontal cylinder 6, and the vertical cylinder 5 can play a positioning role to realize the control of the depth and the excitation position of the impact part in the rod body. The horizontal cylinder 6 is internally provided with a firing pin device which comprises a firing pin 7, a spring 8 and a gasket 9, the firing pin 7, the spring 8 and the gasket 9 are welded into a whole, but the gasket 9 is not welded with the horizontal cylinder 6. The contact portion of the striker 7 and the horizontal cylinder 6 can be lubricated with a lubricating grease while maintaining good airtightness at the contact portion.

As shown in fig. 3, the striker assembly is a whole of the striker 7, the spring 8 and the washer 9. When springs with different stiffness coefficients are used, one set of pneumatic miniature vibration exciter can be provided with a plurality of striker devices, and the excitation quantity of the vibration exciter can be controlled by selecting a proper striker device according to working requirements.

With reference to the flowchart of fig. 4, when the vibration exciter starts to work, the control center first determines the pumping frequency and the pumping amount of the air pump, and determines which matching striker device is selected, so as to determine the working frequency and the vibration exciting amount of the vibration exciter. After the determination, the air pump is powered on and starts working according to the presetting of the control center. In a period, the air pump exhausts air to compress the spring, the air pump exhausts air after the spring is compressed to a preset degree, the spring releases to drive the firing pin to move towards the measured object and impact the measured object to complete one-time vibration excitation, then the air pump and the spring recover to an initial state, and after a preset time interval of the control center, the air exhaust action is repeated to perform the next vibration excitation.

Although the invention has been described with respect to a preferred embodiment, it will be understood by those skilled in the art that the foregoing and other changes, omissions and deviations in the form and detail thereof may be made without departing from the scope of this invention.

Claims

1. A pneumatic miniature vibration exciter is characterized in that: the device comprises a control center (1), an air pump (2), a hard air pipe (3) and an impact part (4), wherein the control center (1) is electrically connected with the air pump (2), and the air pump (2) is hermetically connected with the impact part (4) through the hard air pipe (3); the impact part (4) comprises an air cavity shell and a firing pin device, the upper part of the air cavity shell is hermetically connected with the hard air pipe (3), the firing pin device is horizontally and hermetically installed in the lower part of the air cavity shell in a sliding manner, impact is realized under the drive of the air pump (2), and the air cavity shell is a right-angle cylindrical shell.

2. A pneumatic miniature vibration exciter according to claim 1, wherein: the hard air pipe (3) is a right-angle hard air pipe.

3. A pneumatic miniature vibration exciter according to claim 1 or claim 2, wherein: the air cavity shell comprises a vertical cylinder (5) and a horizontal cylinder (6), the upper end of the vertical cylinder (5) is hermetically connected with the hard air pipe (3), the horizontal cylinder (6) is horizontally arranged at the lower end of the vertical cylinder (5), and the firing pin device is embedded in the horizontal cylinder (6).

4. A pneumatic miniature vibration exciter according to claim 3, wherein: the lower ends of the horizontal cylinder (6) and the vertical cylinder (5) are communicated and hermetically connected in a welding mode.

5. A pneumatic miniature vibration exciter according to claim 4, wherein: the inner diameter of the vertical cylinder (5) is smaller than that of the horizontal cylinder (6).

6. A pneumatic miniature vibration exciter according to claim 5, wherein: the wall thickness of the horizontal cylinder (6) is greater than the wall thickness of the horizontal cylinder (6).

7. A pneumatic miniature vibration exciter according to claim 1 or 6, wherein: the firing pin device comprises a firing pin (7), a spring (8) and a gasket (9), wherein the firing pin (7) is horizontally and slidably sealed in a horizontal cylinder (6), one end of the spring (8) is positioned in the horizontal cylinder (6) and connected with the firing pin (7), the other end of the spring (8) is connected with the gasket (9), and the gasket (9) is abutted against the side wall of a vertical section in the horizontal cylinder (6).

8. A pneumatic miniature vibration exciter according to claim 7, wherein: the firing pin (7) comprises a connecting plate (7-1) and a protrusion (7-2), the connecting plate (7-1) is a circular connecting plate, the protrusion (7-2) is arranged in the middle of the circular connecting plate on the outer side of the horizontal cylinder (6), and the connecting plate (7-1) and the protrusion (7-2) are integrated.

9. A pneumatic miniature vibration exciter according to claim 8, wherein: the thickness of the gasket (9) is smaller than that of the connecting plate (7-1).

10. A pneumatic miniature vibration exciter according to claim 9, wherein: the striker (7) is sealed with the inner side wall of the horizontal cylinder (6) through lubricating oil.