CN108489718B

CN108489718B - Ejection type excitation device with adjustable force amplitude

Info

Publication number: CN108489718B
Application number: CN201810202038.5A
Authority: CN
Inventors: 潘宏侠; 许昕; 潘铭志; 付志敏
Original assignee: North University of China
Current assignee: North University of China
Priority date: 2018-03-12
Filing date: 2018-03-12
Publication date: 2020-05-29
Anticipated expiration: 2038-03-12
Also published as: CN108489718A

Abstract

The invention discloses an ejection type excitation device with adjustable force amplitude, belonging to the field of excitation force testing devices; the technical problem to be solved is to provide an ejection type excitation device which is adjustable in force amplitude, is used for measuring the surface of a narrow and complex structure and ensures that the magnitude and the rule of excitation force are consistent; the technical scheme for solving the technical problem is as follows: an ejection type excitation device with adjustable force amplitude comprises an ejector, wherein a trigger handle device is arranged on one side of the ejector, a movable hammer head body is arranged in the ejector and can adjust the ejection amplitude, an ICP (inductively coupled plasma) force sensor is arranged on the movable hammer head body, a digital acquisition frequency response analysis device is arranged on the outer side of the ejector and is connected with the ICP force sensor, and the surface of a structure is measured through excitation with fixed amplitude; the invention can be widely applied to the field of excitation force testing devices.

Description

Ejection type excitation device with adjustable force amplitude

Technical Field

The invention discloses an ejection type excitation device with adjustable force amplitude, and belongs to the technical field of excitation force testing devices.

Background

In the process of obtaining inherent characteristics of a structure by using a test modal analysis technology, such as frequency, mode shape, loss factor, modal quality, modal stiffness and other modal parameters, a frequency domain method is a classical and high-precision method, usually excitation and corresponding characteristics are required to be known, time domain and frequency domain characteristics of good excitation force are required, a force hammer excitation method is generally used, and the force hammer excitation method is widely applied due to the fact that the force hammer excitation method is simple, fast and low in cost, but human factors have large influence on measurement precision, and the force is not good when the force hammer excitation method is used for weak early-onset fault feature extraction.

In order to better test the frequency response characteristic curve of a complex surface structure in a narrow space, excitation with a fixed amplitude value is required to be carried out on the complex surface structure in an operating state, pulse excitation cannot generate continuous impact, the frequency domain distribution of excitation force needs to be ensured to be approximately in straight spectrum distribution in a frequency band range of interest, the amplitude value of the excitation force changes in a smaller range, and the size of the excitation force is required not to change and fluctuate due to the force application state of a person.

Disclosure of Invention

The ejection type excitation device overcomes the defects in the prior art, and is adjustable in force amplitude, used for measuring the surface of a narrow and complex structure and capable of ensuring the consistency of the magnitude and the law of the excitation force.

In order to solve the technical problems, the invention adopts the technical scheme that: an ejection type excitation device with adjustable force amplitude comprises an ejector, wherein a trigger handle device is arranged on one side of the ejector, a movable hammer head body is arranged in the ejector, a hammer head is arranged at the front end of the movable hammer head body, an ICP force sensor is fixedly arranged behind the hammer head, a digital acquisition frequency response analysis device is arranged on the outer side of the ejector, and the digital acquisition frequency response analysis device is connected with the ICP force sensor;

the outer surface of the movable hammer head body is provided with a sawtooth-shaped annular groove, a sawtooth-shaped clamping jaw corresponding to the sawtooth-shaped annular groove of the movable hammer head body is arranged on the trigger handle device, and through the matching of the groove and the clamping jaw, various energy storage of the spring can be realized, and various determined hammering exciting forces are formed.

The ejector comprises an ejector shell, a sliding groove is formed in the ejector shell, a front end sealing cover is arranged at the front end of the ejector shell, a rear end sealing cover is arranged at the rear end of the ejector shell, an inner groove is formed in the rear end of the movable hammer head body, a spring is arranged behind the inner groove, and an adjusting rod assembly is arranged at the rear end of the spring.

The front end sealing cover comprises an end sealing cover body and a rubber pad, the end sealing cover body is tightly attached to the rubber pad, the inner diameter of the rubber pad is smaller than the outer diameter of the hammer head, the front end of the rubber pad is tightly attached to the surface of an excitation point when the semi-sinusoidal pulse hammer is used, elastic deformation is generated, elastic energy is released at the moment of impact between the hammer head and a member, secondary impact between the hammer head and the member is prevented, and an output force signal is kept to be ideal semi-sinusoidal pulse.

And a connecting wire between the ICP force sensor and the data acquisition frequency response analysis device is a low-noise shielding wire.

The adjusting rod assembly comprises an adjusting rod, a movable blocking piece and a blocking piece positioning nut are sequentially arranged on the front end face of the adjusting rod in the direction towards the spring, the movable blocking piece can incline at an angle consistent with the helical angle of the spring on the adjusting rod, the movable blocking piece can be moved freely along the axial direction of the spring, and the variable stiffness of the spring is achieved.

The trigger handle device comprises a lever trigger, a leaf spring is arranged behind the lever trigger, and a handle is arranged behind the leaf spring.

Compared with the prior art, the invention has the following beneficial effects.

1. Through the matching of the movable hammer head body and the adjusting rod assembly, the size of the exciting force can be adjusted at will within a certain exciting force range, and after the exciting force is determined, the excitation of each time can be ensured not to be changed due to human factors, so that the regularity of the made frequency response curves is ensured to be consistent.

2. The ICP force sensor is connected with the data acquisition frequency response analysis device through a low-noise shielding wire, time domain and frequency domain rules of exciting force are processed through analysis and diagnosis software built in the sensor, and then a cross-point frequency response function is formed by the time domain and frequency domain rules and response signals input to the data acquisition frequency response analysis device, so that weak early faults of complex structures can be analyzed.

3. The invention has simple structure and convenient use, the hammer head can be quickly separated from the tested piece after excitation is finished, secondary or even multiple excitation phenomena caused by oscillation can not be generated, the time domain and frequency domain excitation force rule of the measured structure at the excitation point can be accurately measured, and the hammer head can be conveniently replaced and has wide application.

Drawings

The invention is further described below with reference to the accompanying drawings.

FIG. 1 is a schematic structural diagram of the present invention.

In the figure, 1 is an ejector, 2 is a data acquisition frequency response analysis device, 3 is a trigger handle device, 4 is an ICP force sensor, 5 is a movable hammer head body, 6 is an adjusting rod assembly, 7 is a spring, 8 is an ejector shell body, 9 is a front end sealing cover, 10 is a rear end sealing cover, 11 is an end sealing cover body, 12 is a rubber pad, 13 is a movable baffle, 14 is a baffle positioning nut, 15 is a hammer head, 16 is a lever type trigger, 17 is a core shaft, 18 is a leaf spring and 19 is a handle.

Detailed Description

As shown in figure 1, the ejection type excitation device with adjustable force amplitude of the invention comprises an ejector 1, one side of the ejector 1 is provided with a trigger handle device 3, the ejector 1 is internally provided with a movable hammer head body 5, the front end of the movable hammer head body 5 is provided with a hammer head 15, an ICP force sensor 4 is fixedly arranged behind the hammer head 15, the outer side of the ejector 1 is provided with a plurality of acquisition frequency response analysis devices 2, the acquisition frequency response analysis devices 2 are connected with the ICP force sensor 4, the outer surface of the movable hammer head body 5 is provided with a sawtooth-shaped annular groove, the trigger handle device 3 is provided with a sawtooth-shaped clamping jaw corresponding to the sawtooth-shaped annular groove of the movable hammer head body, the ejector 1 comprises an ejector shell 8, the ejector shell 8 is internally provided with a sliding groove, the front end of the ejector shell 8 is provided with a front end sealing cover 9, the rear end is provided with a rear end sealing cover 10, the rear end of the movable, the rear end of the spring 7 is provided with an adjusting rod assembly 6, the front end sealing cover 9 comprises an end sealing cover body 11 and a rubber pad 12, the end sealing cover body 11 and the rubber pad 12 are tightly attached, the inner diameter of the rubber pad 12 is smaller than the outer diameter of a hammer 15, a connecting line between the ICP force sensor 4 and the data acquisition frequency response analysis device 2 is a low-noise shielding conducting wire, the adjusting rod assembly 6 comprises an adjusting rod, a movable blocking piece 13 and a blocking piece positioning nut 14 are sequentially arranged on the front end face of the adjusting rod in the direction towards the spring, the trigger handle device 3 comprises a lever type trigger 16, a leaf spring 18 is arranged behind the lever type trigger 16, and a handle 19 is arranged behind the leaf.

When the invention is used, a rubber pad 12 is tightly attached to an excitation point, a lever type trigger 16 is used for loosening a movable hammer head body 5, a component is impacted by a hammer head 15 at the front end, the rubber pad 12 releases elastic energy at the impact moment to prevent the hammer head from impacting the component for the second time, an output signal is ensured to be ideal half sine pulse, an ICP force sensor 4 is used for transmitting the acquired signal to a data acquisition frequency response analysis device 2, the outer surface of the movable hammer head body 5 is provided with three saw-tooth-shaped annular grooves which are matched with corresponding saw-tooth-shaped clamping claws arranged on a trigger handle device 3, the energy storage of a spring at the rear part of the movable hammer head body can be realized, various hammering excitation forces are formed, a movable baffle 13 is arranged at the front end of a rear adjusting rod assembly 6, the movable baffle 13 can incline at an angle consistent with the helical angle of the spring on the adjusting rod, and the movable baffle 13 can be ensured, achieving a variable stiffness using a spring.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention.

Claims

1. An ejection type excitation device with adjustable force amplitude is characterized in that: the device comprises an ejector (1), wherein a trigger handle device (3) is arranged on one side of the ejector (1), a movable hammer head body (5) is arranged in the ejector (1), a hammer head (15) is arranged at the front end of the movable hammer head body (5), an ICP force sensor (4) is fixedly arranged behind the hammer head (15), a data acquisition frequency response analysis device (2) is arranged on the outer side of the ejector (1), and the data acquisition frequency response analysis device (2) is connected with the ICP force sensor (4);

the outer surface of the movable hammer head body (5) is provided with a sawtooth-shaped annular groove, and the trigger handle device (3) is provided with a sawtooth-shaped clamping jaw corresponding to the sawtooth-shaped annular groove of the movable hammer head body;

the catapult (1) comprises a catapult shell (8), a sliding chute is arranged in the catapult shell (8), a front end sealing cover (9) is arranged at the front end of the catapult shell (8), a rear end sealing cover (10) is arranged at the rear end of the catapult shell, the front end sealing cover (9) comprises an end sealing cover body (11) and a rubber pad (12), the end sealing cover body (11) is tightly attached to the rubber pad (12), and the inner diameter of the rubber pad (12) is smaller than the outer diameter of a hammer head (15);

an inner groove is formed in the rear end of the movable hammer head body (5), a spring (7) is arranged behind the inner groove, and an adjusting rod assembly (6) is arranged at the rear end of the spring (7); the adjusting rod assembly (6) comprises an adjusting rod, and a movable baffle (13) and a baffle positioning nut (14) are sequentially arranged on the front end face of the adjusting rod in the direction towards the spring.

2. The adjustable force amplitude catapult actuator of claim 1, wherein: and a connecting line between the ICP force sensor (4) and the data acquisition frequency response analysis device (2) is a low-noise shielding wire.

3. The adjustable force amplitude catapult actuator of claim 1, wherein: the trigger handle device (3) comprises a lever type trigger (16), a leaf spring (18) is arranged behind the lever type trigger (16), and a handle (19) is arranged behind the leaf spring (18).

4. The adjustable force amplitude catapult actuator of claim 1, wherein: the movable blocking piece (13) is inclined on the adjusting rod by an angle consistent with the helical angle of the spring (7), so that the movable blocking piece (13) can be moved randomly along the axial direction of the spring.