CN110596424A - A vibration fastening device for an accelerometer - Google Patents

Abstract

The present disclosure relates to a vibration fastening device for an accelerometer, comprising: a bottom plate and a pressure plate, M groups of fastening units are placed on the bottom plate, each group of fastening units includes N accelerometers arranged in a certain shape, and each A protective cover is installed on the accelerometer, and the number of the pressure plates is M, corresponding to each group of fastening units, and placed on the protective cover for fixing. The advantages of the present invention are: simple structure, greatly improved installation efficiency, increased structural strength of the fastening device and contact area with the vibrating table surface, ensured that the magnitude of the accelerometer does not amplify during the vibration process, and effectively solved the problem of accelerometer vibration. The problem of magnitude magnification.

Description

A vibration fastening device for an accelerometer

technical field

The invention relates to a vibration fastening device for an accelerometer.

Background technique

Process vibration is a way for the accelerometer to remove stress, including fixed-frequency vibration, random vibration, etc. The installation and fastening method of the accelerometer during the vibration process is to use four M2×6 screws to install the mounting holes of the flange plate in sequence. Fixed, after the vibration is over, you need to unscrew the 4 screws and replace the new accelerometer to vibrate. During the operation, the screwdriver is easy to slip and damage the accelerometer shell, affecting its appearance quality, and the installation efficiency is extremely low. With the increase of accelerometer output, this way of vibrating installation has seriously restricted the output cycle of accelerometer. At the same time, the structural form of the original vibrating fixture leads to magnitude amplification when the accelerometer vibrates.

Contents of the invention

The technical problem to be solved by the present invention is to provide a vibration fastening device for the accelerometer, which can effectively reduce the installation space of the steering gear and greatly improve the measurement reliability.

In order to solve the above-mentioned technical problems, the technical solution adopted in the present invention is: a vibration fastening device for an accelerometer, which is characterized in that it includes: a bottom plate and a pressure plate, and M groups of fastening units are placed on the bottom plate, and each group of fastening units The unit includes N accelerometers arranged in a certain shape, a protective cover is installed on each of the accelerometers, the number of the pressure plates is M, corresponding to each group of fastening units, and placed on the protective cover to fix.

Compared with the prior art, the present invention has the following beneficial technical effects:

The structure is simple, including: a bottom plate and a pressure plate, M groups of fastening units are placed on the bottom plate, each group of fastening units includes N accelerometers arranged in a certain shape, and a protective cover is installed on each of the accelerometers , the number of the pressing plates is M, corresponding to each group of fastening units, and placed on the protective cover for fixing, which greatly improves the installation efficiency, increases the structural strength of the fastening device and the contact area with the vibrating table surface, and ensures The magnitude of the accelerometer has no amplification during the vibration process, which effectively solves the problem of the magnitude amplification of the accelerometer during vibration.

Description of drawings

Fig. 1 is the structural representation of the vibration fastening device of accelerometer of the present invention;

Fig. 2 is the structural sectional view figure of the fastening unit of the vibration fastening device of accelerometer of the present invention;

Fig. 3 is a vibration magnitude diagram of the present invention;

Fig. 4 is a schematic diagram of test implementation;

Figure 5 is the second schematic diagram of the test implementation.

Reference signs indicate

11——bottom plate, 12——accelerometer, 13——protective cover, 14——pressure plate

Detailed ways

The present invention will be described in further detail below through specific embodiments, but these examples of implementation are only intended to illustrate, and do not limit the scope of the present invention.

Please refer to Fig. 1 to Fig. 2, the vibration fastening device of a kind of accelerometer of the present invention comprises: base plate 11 and pressure plate 14, place M groups of fastening units on described bottom plate 11, each group of fastening units comprises N Accelerometers 12 arranged in a certain shape, a protective cover 13 is installed on each of the accelerometers 12, the number of the pressure plates 14 is M, corresponding to each group of fastening units, and placed on the protective cover 13 fixed on.

In one embodiment, said M is equal to 5.

In one embodiment, said N is equal to three.

In one embodiment, the certain shape is an equilateral triangle.

In one embodiment, the adjacent fastening units are arranged in an inverted manner.

In one embodiment, the distance between the centers of the adjacent fastening units is 31 mm.

In one embodiment, the pressure plate is annular with a cutout 17, and a rectangular groove 15 is provided at the position of the cutout.

In one embodiment, the distance from the cutout to the center of the platen is 20mm.

In one embodiment, the width of the rectangular groove is 8.4mm.

In one embodiment, the accelerometer includes a gauge head and a servo circuit, the gauge head and the servo circuit are connected by an adhesive, and the gauge head is composed of a pendulum plate torquer coil assembly, an upper yoke assembly, a lower yoke component, connecting ring, isolation ring and base, the coil assembly of the swing plate torquer, the upper yoke assembly, the lower yoke assembly, and the connection ring are connected by laser welding, and the isolation ring and the base are connected by Adhesive connection.

As a specific embodiment, the present invention replaces the traditional screw fastening method with a pressing plate, and one pressing plate can fasten 3 accelerometers at the same time, and a set of devices can fasten 15 accelerometers, which greatly improves the installation efficiency .

As a specific embodiment, the present invention increases the structural strength of the fastening device and the contact area with the vibrating table surface to ensure that the accelerometer has no magnitude amplification during the vibration process. The vibration spectrum of the present invention is shown in Figure 3. The magnitude is 7.29g, which is basically consistent with the required value, which effectively solves the problem of magnitude amplification when the accelerometer vibrates.

test

Please refer to Figure 4. In the vibration test of the laser gyro, the parameters of the vibration direction can meet the product design requirements, but the parameters of the vertical direction of the vibration are out of tolerance. The structure of the laser gyro. , where the square is the structural frame, and the circle is the glass fiber-wound disk. After the winding is completed, it is installed on the direction frame by screws. The positions of the four black dots are the screw installation positions, and the direction of the arrow is the vibration direction.

In the original structure, the positions of the four black dots are the four columns, and the contact surface between the disk and the box is only four cylinders, please refer to Figure 5, and the force of the four cylinders mainly depends on the four fastening screws , during the vibration process, the force on the front disc is the tensile force of the screws, that is, the disc and the frame are fastened by the tension of the four screws, while the side disc is tightened by the pressure of the four screws. The friction force generated on the cylindrical surface moves with the force of the vibration test. During the vibration test, the frame is installed in the metal shell, and the metal shell is crimped on the body of the vibrating table, so that during the vibration process, the excitation of the vibrating table is transmitted to the shell through the pressure plate, and then transmitted to the frame through the shell, and finally Pass it on to the disc.

The ideal connection mode in vibration is rigid connection, and the vibration magnitude of all parts on the product is consistent with the excitation of the vibration table. However, in the actual vibration process, due to the elastic deformation of the product and the size of the screw connection force, the vibration magnitude of the product is gradually amplified. The magnitude of the square frame is slightly larger than that of the shell, and finally the magnitude of the disc is larger than that of the square frame in different directions. In this way, in the actual vibration process, the vibration magnitude of the disk may be much greater than the requirements of the test conditions. During this test, the reason why the vibration direction meets the test requirements but the vertical plane does not meet the test requirements is that the amplification of each part of the product is different during the connection process, especially the magnitude on the final disc. The different ways of connecting the disk and the box in different directions lead to different levels of amplification on the final product. The following is a detailed analysis of the connection mode of the disc part.

The connection between the disk in the vibration direction (that is, the disk perpendicular to the vibration direction) and the box is screw connection, and the excitation is transmitted by the tensile force of the four screws and the box during the vibration process. If the elasticity of the metal itself is ignored, the magnitude of the tensile force is the excitation of the disk, that is, F pull = F excitation. As for the disk on the side, that is, the disk parallel to the vibration direction, although the connection between the disk and the frame is still threaded, the excitation on the disk is no longer the tensile force of the screw, but the tension of the disk. The frictional force produced by the four cylinders and the box under the action of the tensile force, that is, F excitation = kF pull, and the size of the friction coefficient k is related to the size of the tensile force and the size of the contact surface. In the case of a certain tensile force, the size of the contact surface will determine the size of all excitations on the disk. On the two surfaces, the stress of the screw is different. The force on the connecting screw on the vertical disk is tensile force, and the force on the screw on the parallel disk is shear force. Combining the above situations, the excitation finally transmitted to the disk, under the condition of ignoring the metal elastic deformation amplification factor, the excitation amplification of the vertical disk is much smaller than the excitation of the parallel disk, that is, the parallel disk The magnitude of vibration is amplified more, causing the magnitude of vibration to exceed the test requirements.

For this test, the vibration direction can meet the design requirements, but the parameters of the vertical vibration direction are out of tolerance, so the only way to reduce the lateral amplification is by changing the structure. Since the glass fiber needs to be wound on the disk, the fixed plan of making the disk and the frame into one body cannot be used because the glass fiber cannot be wound, and it can only be considered from the connection method of the disk and the frame. In the original plan, the connection mode between the disk and the frame is four cylinders as supporting points, which are connected by screws, so that the friction force between the disk and the frame on the parallel plane is small. Solution: under certain pressure, increase the contact area, and the method for increasing the contact area is to change the four cylinders on the ground into a plane as large as the whole disk.

In this way, with the increase of the contact area, the frictional force will increase a lot, the excitation of the parallel disk will increase, and the magnitude of the disk amplification will be greatly reduced.

The existing installation fixtures have the following disadvantages:

1) The fixture uses four M2×6 screws to respectively fix the mounting holes of the accelerometer flange in sequence, which has poor operability and results in extremely low installation efficiency;

2) The structure of the fixture leads to magnitude amplification when the accelerometer vibrates.

a. Use the pressing plate to replace the traditional screw fastening method, and one pressing plate can fasten 3 accelerometers at the same time, and a set of devices can fasten 15 accelerometers, which greatly improves the installation efficiency;

b. Increase the structural strength of the fastening device and the contact area with the vibration table to ensure that the magnitude of the accelerometer does not amplify during the vibration process. The vibration spectrum of the new device is shown in Figure 5. The vibration magnitude is 7.29g, basically It is consistent with the required value, and effectively solves the problem of magnitude amplification when the accelerometer vibrates.

The present invention has 5 groups in total, and each group can install 3 products. The bottom plate is arranged in an upside-down manner, mainly considering the factors of installation and balance. , then it will cause 10 products to be installed on one side, and only 5 products to be installed on the other side. The distance between the 10 products on one side is very narrow (less than 10mm), which is not easy to operate. In addition, the supporting strength of the device will also be affected. , one side will be much weaker. Therefore, the present invention has the advantages of convenient operation and improved support strength.

The present invention has realized following beneficial technical effect:

The structure is simple, including: a bottom plate and a pressure plate, M groups of fastening units are placed on the bottom plate, each group of fastening units includes N accelerometers arranged in a certain shape, and a protective cover is installed on each of the accelerometers , the number of the pressing plates is M, corresponding to each group of fastening units, and placed on the protective cover for fixing, which greatly improves the installation efficiency, increases the structural strength of the fastening device and the contact area with the vibrating table surface, and ensures The magnitude of the accelerometer has no amplification during the vibration process, which effectively solves the problem of the magnitude amplification of the accelerometer during vibration.

Although the preferred embodiments of the present invention have been selected and disclosed as above, they are not intended to limit the present invention. Obviously, it is not necessary and impossible to exhaustively enumerate all implementation methods here. Any researcher in the field can use the design method and content in the above-mentioned disclosed embodiments to change and modify the research plan of the present invention without departing from the spirit and scope of the present invention. Any simple modifications, parameter changes and modifications made to the above-mentioned embodiments according to the research essence of the present invention all belong to the protection scope of the scheme of the present invention.

Claims (10)

1. a vibration fastening device of an accelerometer, it is characterized in that, comprises: base plate and pressure plate, place M group of fastening units on said base plate, every group of fastening units comprises N accelerometers arranged in a certain shape, A protective cover is installed on each of the accelerometers, and the number of the pressure plates is M, corresponding to each group of fastening units, and placed on the protective cover for fixing. 2 . The vibration fastening device for an accelerometer according to claim 1 , wherein said M is equal to 5. 3 . 3 . The vibration fastening device for an accelerometer according to claim 2 , wherein said N is equal to 3. 4 . 4. The vibration fastening device for an accelerometer according to claim 3, wherein the certain shape is an equilateral triangle. 5 . The vibration fastening device for an accelerometer according to claim 3 , wherein the adjacent fastening units are arranged in an inverted manner. 6 . The vibration fastening device for an accelerometer according to claim 5 , wherein the distance between the centers of the adjacent fastening units is 31 mm. 7 . 7 . The vibration fastening device for an accelerometer according to claim 4 , wherein the pressure plate is ring-shaped with a cutout, and a rectangular groove is provided at the position of the cutout. 8 . 8 . The vibration fastening device for an accelerometer according to claim 7 , wherein the distance from the cutout to the center of the pressure plate is 20 mm. 9 . The vibration fastening device for an accelerometer according to claim 8 , wherein the width of the rectangular groove is 8.4 mm. 10. the vibration fastening device of accelerometer described in claim 1, it is characterized in that, described accelerometer comprises meter head and servo circuit, is connected by adhesive between described meter head and servo circuit, and described meter head is made of pendulum The torque device coil assembly, the upper yoke assembly, the lower yoke assembly, the connecting ring, the spacer ring and the base are composed of the coil assembly, the upper yoke assembly, the lower yoke assembly and the connecting ring. It is connected by laser welding, and the spacer ring and the base are connected by adhesive.