A small inertial exciter

Abstract

This application discloses a small inertial exciter, which includes a movable part, a fixed connection part, and a support part. The fixed connection part is located above the movable part and is connected to it via the support part. The support part is equipped with a coil, the fixed connection part is equipped with a magnet, and the movable part is equipped with a spring. The coil moves under the action of current, causing the spring to move, and the displacement is transmitted to the outside through the inner and outer studs of the fixed connection part. This small inertial exciter can output a large inertial force at low and low-to-medium frequencies.

Description

Technical Field

[0001] This invention discloses a small inertial exciter, belonging to the field of mechanical vibration environment testing technology. Background Technology

[0002] Mechanical equipment is typically subjected to complex dynamic environments during transportation or use, which can affect its reliability and lifespan. Conducting mechanical environment tests is the most effective and direct method to verify structural reliability, simulating the complex forces actually experienced by the structure.

[0003] In mechanical environment testing, vibrators are typically used as the force source for small structures. Traditional electromagnetic vibrators usually require fixed installation; however, for locations on the structure where fixed installation is not feasible, additional hoisting is necessary. Furthermore, for certain excitation points in confined spaces, electromagnetic vibrators may not even be able to be installed to apply effective excitation. Small inertial vibrators, because they use the inertial force of movable parts as the excitation applied to the structure, can be directly mounted on the structural surface by adhesive or screwing, and their small size reduces the requirements for installation location. Summary of the Invention

[0004] To address the aforementioned technical problems, this application aims to provide a small inertial exciter that can output a large inertial force at low and low-to-medium frequencies.

[0005] This invention relates to a small inertial exciter, which includes a movable part, a fixed connection part, and a support part. The fixed connection part is located above the movable part and is connected to it through the support part. The support part is provided with a coil, the fixed connection part is provided with a magnet, and the movable part is provided with a spring. The coil moves under the action of current and drives the spring to move, which is transmitted to the outside through the inner and outer studs of the fixed connection part.

[0006] Furthermore, the movable part includes a base 1, a magnet 2, a magnetic gap inner ring 3, a lower pressure ring 4, and an upper pressure ring 5; the magnet 2 and the magnetic gap inner ring 3 are stacked one on top of the other and fixedly connected to the base through a central screw hole; the lower pressure ring 4 is connected to the screw hole on the base 1 by a screw, and the upper pressure ring 5 is connected to the screw hole on the lower pressure ring 4 by a screw passing through a through hole.

[0007] Furthermore, the supporting part includes a moving coil frame 6, a spring, and a double-ended stud 8, wherein the spring includes a first spring and a second spring; the moving coil frame is located above the magnetic gap inner ring 3, and the coil is wound on the moving coil frame 6, ensuring complete coverage of the magnetic gap inner ring 3 during its up-and-down movement; the double-ended stud 8 has no thread in the middle, but external threads at both ends, with the lower external thread passing through the central through hole of the first spring 7 and engaging with the central threaded hole of the moving coil frame 6; the double-ended stud 8 has no thread in the middle. The threaded portion is larger in diameter than the upper end face of the moving coil skeleton 6, and is used to press the first spring 7 against the upper end of the moving coil skeleton 6. The first spring 7 is pressed by the upper and lower pressure rings around its perimeter, and is passed through by the connecting screws of the upper and lower pressure rings to restrict its axial rotation and radial movement. The second spring 7' passes through the external threaded portion of the upper end of the double-ended stud 8 and is placed on the upper surface of the unthreaded portion in the middle of the double-ended stud 8. The second spring 7' is pressed by the upper pressure ring 5 and the pressure plate around its perimeter, and is passed through by the connecting screw to restrict its axial rotation and radial movement.

[0008] Furthermore, the fixed connection part includes a force ring support 9, a force sensor 10, inner and outer studs 11, and a top cover 12; wherein, the outer diameters of the two ends of the force ring support 9 are different, with the smaller diameter end facing down and the larger diameter end facing up, and there is a through hole for the upper end of the double-ended stud 8 to pass through and be placed on the upper surface of the second spring 7'; the force sensor 10 is placed on the larger diameter end of the force ring support 9; the internal thread of the inner and outer studs 11 engages with the external thread of the upper end of the double-ended stud 8 to achieve the purpose of pre-tightening the force sensor; the top cover 12 is screwed onto the external thread of the inner and outer studs 11. Beneficial effects

[0009] (1) The present invention significantly reduces the distance between the base and the inner ring of the magnetic gap at the end of the magnetic circuit, which can form a concentrated and uniform magnetic field at this point, improve the magnetic field strength, and help increase the output force of the inertial exciter.

[0010] (2) The present invention uses heat-treated beryllium bronze as the material of the spring, which has good elastic limit, fatigue limit and thermal conductivity, improves the stiffness and service life of the spring, and has good heat dissipation capacity.

[0011] (3) The reed of the present invention has been optimized in terms of configuration and thickness, and can output a large inertial force in the low frequency stage with small vibration displacement. Attached Figure Description

[0012] Figure 1 This is a front view of the structure of an embodiment of the present invention;

[0013] Figure 2 This is an embodiment of the present invention. Figure 1 A cross-sectional view along the AA direction;

[0014] Figure 3 This is a schematic diagram of the external structure of the reed in an embodiment of the present invention;

[0015] Figure 4 This is a schematic diagram of the magnetic induction intensity of the movable part in an embodiment of the present invention;

[0016] The components are: 1. base, 2. magnet, 3. magnetic gap inner ring, 4. lower pressure ring, 5. upper pressure ring, 6. moving coil frame, 7. first spring, 7', second spring, 8. double-ended stud, 9. force ring support, 10. force sensor, 11. inner and outer studs, 12. top cover. Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings. Example

[0018] This embodiment is a small inertial exciter, characterized in that the exciter includes a movable part, a fixed connection part, and a support part. The fixed connection part is located above the movable part and is connected to it through the support part. The support part is provided with a coil. The fixed connection part is provided with a magnet. The movable part is provided with a spring. The coil moves under the action of current and drives the spring to move, which is transmitted to the outside through the inner and outer studs of the fixed connection part.

[0019] like Figure 2 As shown, the movable part of this embodiment includes a base 1, a magnet 2, a magnetic gap inner ring 3, a lower pressure ring 4, and an upper pressure ring 5. The magnet 2 and the magnetic gap inner ring 3 are stacked one on top of the other and fixedly connected to the base through a central screw hole. The lower pressure ring 4 is connected to the screw hole on the base 1 by four screws passing through evenly distributed countersunk through holes. The upper pressure ring 5 is connected to the screw hole on the lower pressure ring 4 by four screws passing through through holes.

[0020] like Figure 2 , 3 As shown, the support portion of this embodiment includes a moving coil frame 6, springs 7 / 7', and a double-ended stud 8. The coil is wound around the lower end of the moving coil frame 6, ensuring complete coverage of the inner magnetic gap ring 3 during its up-and-down movement. The external threaded portion of the lower end of the double-ended stud 8 passes through the central through hole of the spring 7, engaging with the central threaded hole of the moving coil frame 6. The unthreaded portion in the middle of the double-ended stud 8 and the larger diameter of the upper end of the moving coil frame 6 allow the spring 7 to be pressed against the upper end of the moving coil frame 6. The spring 7 is pressed tightly around its perimeter by upper and lower pressure rings, and its connecting screws pass through the upper and lower pressure rings to restrict its axial rotation and radial movement. The spring 7' passes through the external threaded portion of the upper end of the double-ended stud 8 and rests on the upper surface of the unthreaded portion in the middle of the double-ended stud 8. Similar to the spring 7, the spring 7' is pressed tightly around its perimeter by the upper pressure ring 5 and a pressure plate, and its connecting screws pass through to restrict its axial rotation and radial movement.

[0021] like Figure 2 As shown, the fixed connection portion of this embodiment includes a force ring support 9, a force sensor 10, internal and external studs 11, and a top cover 12. The force ring support 9 has its small-diameter end facing down and its large-diameter end facing up, and is placed on the upper surface of the spring 7' via the external thread of the upper end of the double-ended stud 8. The force sensor 10 is placed on the large-diameter end of the force ring support 9. The internal thread portion of the internal and external studs 11 engages with the external thread of the upper end of the double-ended stud 8 to achieve the purpose of pre-tightening the force sensor. The top cover 12 is directly screwed onto the external thread portion of the internal and external studs 11.

[0022] The installation and main working process of the inertial exciter in this embodiment are described as follows:

[0023] The external threads of the inner and outer studs 11 can directly mate with the threaded holes of the excited structure to complete the installation in this embodiment. For example... Figure 4 As shown, the magnet 2 is magnetized in the up-down direction, forming a uniform magnetic field loop with the base 1 and the inner ring 3 of the magnetic gap, and forming a horizontal uniform magnetic field that diffuses from the inside out between the base 1 and the inner ring 3 of the magnetic gap.

[0024] When the inertial exciter of this embodiment is working, an external AC signal passes through the coil. Since the coil is in a horizontal, uniform magnetic field spreading from the inside out, according to the left-hand rule, the direction of the Ampere force is vertically up and down. This Ampere force reacts on the movable part of this embodiment, causing the movable part to move up and down. Due to the constraint of the reed 7 / 7', the movable part can produce a small displacement at the equilibrium position. The inertial force generated by the displacement of the movable part is transmitted to the excited structure through the reed 7 / 7' and the fixed connection part of this embodiment. During the transmission process, this inertial force passes through the force sensor 10, and the force sensor can accurately measure the magnitude of the force transmitted to the structure. The highest output frequency of the inertial exciter of this embodiment is greater than 1000Hz, the optimal excitation frequency band of the exciter is 5-1000Hz, the weight of the exciter is less than 0.8Kg, the maximum amplitude is 4mm, and the excitation force amplitude can reach 5Nrms.

Claims

1. A small inertial exciter, characterized in that, The vibrator includes a movable part, a fixed connection part, and a support part. The fixed connection part is located above the movable part and is connected to each other through the support part. The support part is provided with a coil, the fixed connection part is provided with a magnet, and the movable part is provided with a spring. The coil moves under the action of current and drives the spring to move, which is transmitted to the outside through the inner and outer studs of the fixed connection part. The supporting part includes a moving coil frame (6), a spring, and a double-ended stud (8). The spring includes a first spring and a second spring. The moving coil frame is located above the magnetic gap inner ring (3). The coil is wound on the moving coil frame (6). The coil always completely covers the magnetic gap inner ring (3) during its up-and-down movement. The double-ended stud (8) has no thread in the middle and external threads at both ends. The lower external threaded part passes through the central through hole of the first spring (7) and matches the central threaded hole of the moving coil frame (6). The double-ended stud (8) has no thread in the middle. The diameter of the upper end face of the moving coil frame (6) is larger than that of the moving coil frame (6), and is used to press the first spring (7) on the upper end of the moving coil frame (6); the first spring (7) is pressed by the upper and lower pressure rings around its perimeter, and is passed through by the connecting screws of the upper and lower pressure rings to restrict its axial rotation and radial movement; the second spring (7') passes through the external threaded part of the upper end of the double-ended stud (8), and is placed on the upper surface of the unthreaded part in the middle of the double-ended stud (8); the second spring (7') is pressed by the upper pressure ring (5) and the pressure plate around its perimeter, and is passed through by the connecting screws to restrict its axial rotation and radial movement; The fixed connection part includes a force ring support (9), a force sensor (10), inner and outer studs (11), and a top cover (12); wherein, the outer diameters of the two ends of the force ring support (9) are different, with the smaller diameter end facing down and the larger diameter end facing up, and there is a through hole for the upper part of the double-ended stud (8) to be placed on the upper surface of the second spring (7'); the force sensor (10) is placed on the larger diameter end of the force ring support (9); the inner thread of the inner and outer studs (11) is engaged with the outer thread of the upper end of the double-ended stud (8) to achieve the purpose of pre-tightening the force sensor; the top cover (12) is screwed onto the outer thread of the inner and outer studs (11).

2. A small inertial exciter according to claim 1, characterized in that, The movable part includes a base (1), a magnet (2), a magnetic gap inner ring (3), a lower pressure ring (4), and an upper pressure ring (5); the magnet (2) and the magnetic gap inner ring (3) are stacked on top of each other and fixedly connected to the base through a central screw hole; the lower pressure ring (4) is connected to the screw hole on the base (1) by a screw, and the upper pressure ring (5) is connected to the screw hole on the lower pressure ring (4) by a screw passing through a through hole.

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