CN1657876A - Light and small three-axis integrated fiber optic gyroscope - Google Patents

Abstract

This invention discloses a light small-scale optic fibre peg-top with three axle integratively, including light source discreteness, optic fibre discreteness, mechanical skeleton, control circuit board and outside interface used for getting in touch with external information, light source discreteness install in mechanical top of skeleton, X axle optic fibre discreteness, Y axle optic fibre discreteness and Z axle optic fibre discreteness install in mechanical X axle protruding body of the platform of skeleton respectively, Y axle install wall and Z axle localization to install wall on the piece, outside interface install on mechanical ring flange of skeleton, control circuit board install at mechanical skeleton firm urgent device of bottom and imbed in the mechanical skeleton heavy concave of bottom.

Description

Light and small three-axis integrated fiber optic gyroscope

technical field

The invention relates to a three-dimensional angular velocity measuring device, specifically a light and small digital closed-loop three-axis integrated optical fiber gyroscope based on the optical SAGNAC effect, which can share a light source, a common detection circuit, and an integrated structure design.

Background technique

The fiber optic gyroscope is based on the Sagnac effect. In the inertial space, the Sagnac effect can usually be described as: "In the same closed loop, two The rotation of a beam of light around an axis perpendicular to the loop will cause a change in the phase difference between the two beams, and the magnitude of the phase difference is proportional to the rotation rate of the light loop." The principle diagram of the Sagnac effect is shown in Figure 1. In the figure, the ring represents the fiber ring, the point S is the injection point of two beams of light traveling in opposite directions, and Ω is the clockwise rotational angular velocity. In the inertial space, when the fiber ring is stationary, the optical path experienced by the two beams of light returning to point S is the same, so there will be no phase difference; when the fiber ring rotates clockwise at an angular velocity Ω, the injection point S turns to S' At , the beam traveling in the clockwise direction will experience a longer optical path than the beam traveling in the counterclockwise direction, thus producing a phase difference. And this phase difference Δφ is proportional to the rotational angular velocity Ω of the optical fiber ring: $\mathrm{\Δ\φ}=\frac{2\mathrm{\πLD}}{\mathrm{\λc}}\mathrm{\Ω},$ In the formula, L is the length of the fiber, D is the diameter of the fiber ring, c is the propagation speed of light in vacuum, and λ is the wavelength of the incident light.

Fiber optic gyroscope is a new type of angular rate sensor. Compared with mechanical gyroscopes, it has the advantages of all solid state, insensitivity to gravity, and fast startup. Compared with ring laser gyroscopes, it has no high-voltage power supply and no mechanical jitter; It has the advantages of light weight, long life and low cost. It has broad application prospects in military fields such as aviation, aerospace, and navigation, as well as civil fields such as geology and oil exploration. The current typical structural form is: three independent single-axis fiber optic gyro subsystems are used to measure the angular velocity or position of the rotation axis of three orthogonal space coordinate systems. Each fiber optic gyro subsystem includes a light source, a photodetectors and a processing circuit. With the development of application fields, higher requirements are put forward for the size and weight of fiber optic gyroscopes. At the same time, three-dimensional measurement is involved in many application fields. Therefore, the research of light and small three-axis gyroscope has attracted extensive attention in the world.

Contents of the invention

The object of the present invention is to provide a light and small three-axis integrated fiber optic gyroscope. In order to reduce the size and weight of the fiber optic gyroscope system, the structure of the fiber optic gyroscope is optimized and the control circuit is optimized and combined. In the present invention, an integrated structure design is adopted, and a light source and a processing circuit are shared, which not only saves components, reduces volume, and reduces cost, but also helps to improve system reliability. The method of sharing the signal processing circuit is adopted to simplify the structure of the fiber optic gyro system, reduce the volume, reduce the cost and power consumption.

A light and small three-axis integrated fiber optic gyroscope of the present invention includes a light source component, an optical fiber component, a control circuit board, a mechanical frame, and an external interface for generating information with the outside. The light source component is installed on the top of the mechanical frame, and the X-axis The optical fiber assembly, the Y-axis optical fiber assembly and the Z-axis optical fiber assembly are respectively installed on the positioning surfaces of the X-axis boss body, the Y-axis installation wall and the Z-axis installation wall of the mechanical skeleton, and the external interface is installed on the flange of the mechanical skeleton. The control circuit board is installed on the fastening device at the bottom of the mechanical frame and embedded in the large concave cavity at the bottom of the mechanical frame; the mechanical frame is an integrated structure conforming to the rules of the right-handed coordinate system, and the X-axis boss body is set on the flange. The first side of the X-axis boss body is vertically provided with a Y-axis installation wall, the second side of the X-axis boss body is vertically provided with a Z-axis installation wall, and the coplanarity of the Y-axis installation wall and the Z-axis installation wall is vertical; The center of the X-axis boss body of the mechanical skeleton is a cavity, and a positioning surface for fixing the X-axis optical fiber assembly is provided in the cavity, and a mounting platform is provided at the opposite corner of the X-axis boss body and the same plane; The center of the Y-axis installation wall of the mechanical skeleton is a cavity, the back of the Y-axis installation wall is provided with a concave cavity, and a raised positioning surface is provided in the concave cavity; the center of the Z-axis installation wall of the mechanical skeleton is a cavity, The back of the Z-axis mounting wall is provided with a cavity, and a raised positioning surface is provided in the cavity; the flange of the mechanical frame 11 is provided with through holes and a plurality of mounting holes for mounting parts, each mounting hole Evenly distributed at an angle of 120°, the back of the flange is provided with a fastening device and a large concave cavity for fastening the control circuit board, and the connecting plate on the back of the flange is provided with a mounting platform.

The light source assembly is composed of a light source, a first beam splitter, a second beam splitter, a light source drive and a light source base plate. A fan-shaped boss is arranged on the light source base plate, and a light source is installed on the fan-shaped boss. On two opposite corners of the light source base plate The first beam splitter and the second beam splitter are respectively provided, and the light source driver is installed on the mounting column of the light source base plate; the light source assembly is installed on the top of the Y-axis installation wall and the Z-axis installation wall on the upper part of the mechanical skeleton.

The Y-axis optical fiber assembly is composed of a ring skeleton, an optical fiber, a detector, a pre-amplifier circuit, a modulator, and a coupler. The ring skeleton is wound with an optical fiber, and the upper part of the ring skeleton is equipped with a modulator and a coupler. The detector is installed On the pre-amplifier circuit, the pre-amplifier circuit is installed on the threaded column on the ring frame; the Y-axis optical fiber assembly is installed on the positioning surface of the Y-axis installation wall of the mechanical frame.

The control circuit board includes at least an FPGA, a signal conversion circuit, and a modulator drive circuit. The FPGA receives the light intensity and voltage signals output by the detectors in the X-axis optical fiber assembly, the Y-axis optical fiber assembly, and the Z-axis optical fiber assembly through a three-axis preamplifier. The digital signal is amplified by the circuit and converted and output by the A/D converter. The FPGA outputs the phase compensation voltage signal to the D/A converter and the modulation drive circuit of the three-axis modulator after the timing control and processing of the received digital signal. After demodulation, the output voltage signal controls the three-axis modulator to perform phase modulation to keep the interference light intensity constant.

The light and small three-axis integrated fiber optic gyroscope is controlled in an all-digital closed-loop control mode.

The advantages of the present invention: (1) The integrated structural design of the three-axis gyroscope not only effectively utilizes the space, but also reduces the weight and mechanical components. In addition, because the design reduces the intermediate links of gyro installation, it is more conducive to ensuring the installation and positioning accuracy of the gyro; (2) sharing high-power light sources saves optical components and reduces costs. It is conducive to improving the consistency and reliability of products; (3) sharing a three-axis all-digital closed-loop signal processing circuit of FPGA; sharing the signal processing circuit effectively saves the area of the circuit board, which is beneficial to miniaturization and integration. At the same time, the all-digital closed-loop control circuit effectively improves the anti-interference ability and the dynamic range of the gyro test; (4) The standard external interface is beneficial to the user's practicality and convenience.

Description of drawings

Figure 1 is a schematic diagram of the Sagnac effect.

Fig. 2 is a schematic diagram of the overall structure of the fiber optic gyroscope of the present invention.

Fig. 3 is a side view of the fiber optic gyroscope of the present invention.

Fig. 4 is a schematic diagram of the structure of the mechanical skeleton of the present invention.

Fig. 5 is a side view of the mechanical skeleton of the present invention.

Fig. 6 is a bottom view of the flange of the present invention.

Fig. 7 is an exploded view of the light source assembly of the present invention.

Fig. 8 is an exploded view of the optical fiber assembly of the present invention.

FIG. 9 is a schematic diagram of the processing circuit structure of the optical circuit of the present invention.

Fig. 10 is a circuit schematic diagram of the circuit control of the present invention.

In the figure: 11. Mechanical skeleton 1. X-axis boss body 101. Cavity 102. Positioning surface 103. Mounting table 104. First side 105. Second side 106. Coplanar 2. Y-axis installation wall 201. Cavity 202. Positioning surface 203. Concave 3. Z-axis installation wall 301. Cavity 4. Flange 401. Fastening device 402. Flat section 403. Mounting platform 404. Mounting hole 405. Through hole 406. Large concave cavity 40 7 .Connection plate 12.Y-axis fiber optic component 13.External interface 14.Light source component 15.Control circuit board 16.X-axis fiber optic component 17.Z-axis fiber optic component 501.Light source bottom plate 502.First beam splitter 503.Sector-shaped boss 504 .Light source driver 505. Light source 506. Second beam splitter 507. Threaded column 601. Controller 602. Ring frame 603. Optical fiber 604. Controller 605. Preamp circuit 606. Coupler 607. Threaded column

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings.

The light and small three-axis integrated fiber optic gyroscope in the present invention has an integrated design for its three axes, that is, the structure of the mechanical skeleton 11 (as shown in FIG. 4 ) is an integrated design. Because the design of the mechanical skeleton 11 has reduced the weight of the overall fiber optic gyroscope, it also makes the X-axis fiber optic assembly 16, the Y-axis fiber optic assembly 12, the Z-axis fiber optic assembly 17 and the light source assembly 14 share the same control circuit board 15, saving energy. Consumption of resources and power.

Please refer to Figures 2 to 8, the present invention is a light and small three-axis integrated fiber optic gyroscope, which consists of a light source assembly 14, an X-axis optical fiber assembly 16, a Y-axis optical fiber assembly 12, a Z-axis optical fiber assembly 17, a mechanical skeleton 11, The control circuit board 15 and the external interface 13 used to communicate with the outside to generate information, the mechanical skeleton 11 is used to install the source assembly 14, the X-axis optical fiber assembly 16, the Y-axis optical fiber assembly 12, the Z-axis optical fiber assembly 17 and the control circuit Plate 15. The light source assembly 14 is installed on the top of the mechanical skeleton 11, and the X-axis optical fiber assembly 16, the Y-axis optical fiber assembly 12 and the Z-axis optical fiber assembly 17 are respectively installed on the X-axis boss body 1, the Y-axis installation wall 2 and the Z axis of the mechanical skeleton 11. On the positioning surface of the shaft installation wall 3, the external interface 13 is installed on the flange plate 4 of the mechanical frame 11 (see Fig. 2 and Fig. 3), and the control circuit board 15 is installed on the fastening device 401 at the bottom of the mechanical frame 11 And embedded in the large cavity 406 at the bottom of the mechanical frame 11 (see FIG. 6).

In the present invention, the mechanical skeleton 11 is an integral structure conforming to the rules of the right-handed coordinate system, the X-axis boss body 1 is arranged on the flange 4, and the first side 104 of the X-axis boss body 1 is vertically provided with a Y-axis installation Wall 2, the second side 105 of the X-axis boss body 1 is vertically provided with a Z-axis installation wall 3, and the co-plane 106 of the Y-axis installation wall 2 and the Z-axis installation wall 3 is vertical; the X-axis convex of the mechanical skeleton 11 The center of the table body 1 is a cavity 101, the cavity 101 is provided with a positioning surface 102 for fixing the X-axis optical fiber assembly 16, and a mounting table 103 is provided at the opposite corner of the X-axis boss body 1 and the co-plane 106; The center of the Y-axis installation wall 2 of the mechanical skeleton 11 is a cavity 201, the back of the Y-axis installation wall 2 is provided with a concave cavity 203, and a raised positioning surface 202 is provided in the concave cavity 203; the Z-axis of the mechanical skeleton 11 The center of the mounting wall 3 is a cavity 301, the back of the Z-axis mounting wall 3 is provided with a cavity, and a raised positioning surface is provided in the cavity; the flange 4 of the mechanical frame 11 is provided with a through hole 405 and A plurality of mounting holes 404 for mounting components, each mounting hole 404 is evenly distributed according to an angle of 120°, the back of the flange 4 is provided with a fastening device 401 and a large concave cavity 406 for fastening the control circuit board 15, the method The connecting plate 407 on the back of the blue plate 4 is provided with a mounting platform 403 (see FIG. 4 , FIG. 5 , and FIG. 6 ).

The light source assembly 14 in the present invention is composed of a light source 505, a first beam splitter 502, a second beam splitter 506, a light source driver 504, and a light source base plate 501. The light source base plate 501 is provided with a fan-shaped boss 503. A light source 505 is installed, a first beam splitter 502 and a second beam splitter 506 are respectively provided on two opposite corners of the light source base plate 501, and a light source drive 504 is installed on the mounting column of the light source base plate 501; the light source assembly 14 is installed on the upper part of the mechanical frame 11 The top ends of the Y-axis installation wall 2 and the Z-axis installation wall 3 (see Figure 7). In this example, the first beam splitter 502 and the second beam splitter 506 are one-two beam splitters, so the two beam splitters are installed oppositely on the light source base plate 501 of the light source assembly 14 . In the present invention, when the optical power output by the light source 505 is divided into three, only one optical splitter (i.e., one-to-three optical splitter) can be used, but in consideration of expanding the power of light and reducing the cost of the entire fiber optic gyro, so Use the solution of installing two beam splitters. For the light source 505, either an SLD light source or an SFS erbium-doped fiber light source can be used.

In the present invention, because it is a three-axis co-body, there are three optical fiber assemblies, namely the X-axis optical fiber assembly 16, the Y-axis optical fiber assembly 12 and the Z-axis optical fiber assembly 17. The structures of these three optical fiber assemblies are the same. The structure of the optical fiber assembly 12 is described in detail. The three optical fiber assemblies are respectively installed in the three shaft systems of the mechanical skeleton 11 (the X-axis boss body 1, the Y-axis installation wall 2 and the Z-axis installation wall 3). The Y-axis fiber optic assembly 12 is composed of a ring skeleton 602, an optical fiber 603, a detector 601, a preamp circuit 605, a modulator 604, and a coupler 606. The ring skeleton 602 is wound with an optical fiber 603, and the upper part of the ring skeleton 602 is equipped with a modulator 604. And the coupler 605, the detector 601 is installed on the pre-amplification circuit 605, and the pre-amplification circuit 605 is installed on the threaded column 607 on the ring frame 602; the Y-axis optical fiber assembly 12 is installed on the positioning of the Y-axis mounting wall 2 of the mechanical frame 11 surface 202 (see FIG. 8). In this example, the modulator is an integrated optical modulator, which has better stability, and the phase compensation of the entire fiber optic gyroscope is beneficial to the improvement of test accuracy.

The control circuit board 15 in the present invention includes at least FPGA, signal conversion circuit, modulator drive circuit (see Fig. 9 shows), FPGA receives via X-axis optical fiber assembly 16, Y-axis optical fiber assembly 12 and Z-axis optical fiber assembly 17 The light intensity voltage signal output by the detector is amplified by the three-axis pre-amplification circuit, and the output digital signal is converted by the A/D converter. The FPGA outputs the phase compensation voltage signal to the D/A conversion after the received digital signal is processed by timing control. The modulator and the modulation drive circuit of the three-axis modulator, after demodulation by the modulation drive circuit, the output voltage signal controls the three-axis modulator to perform phase modulation to keep the interference light intensity constant. This design shares the light source and FPGA, and adopts the closed-loop detection control method. The overall signal flow of the fiber optic gyroscope can be divided into two parts: the optical path and the circuit. Among them, the detectors of each axis (X-axis detector, Y-axis detector, Z-axis detector) and the modulators of each axis (X-axis modulator, Y-axis modulator, Z-axis modulator) to complete photoelectric and electro-optical signal conversion respectively. The light source driving circuit 504 provides high stable constant current drive for the light source 505 and completes the constant temperature control inside the light source 505, so that the optical power and spectrum emitted by the light source 505 are stable. The light emitted by the light source 505 completes a power distribution of 1:2 through the first optical splitter 502, that is, the optical power reaching the second optical splitter 506 is one-third of the power of the light source, and the optical power reaching the X-axis coupler is one-third of the power of the light source. two thirds. It can be seen that the light source 505 divides the optical power into three equal parts through the first optical splitter 502, the second optical splitter 506 and the X-axis coupler, so that the X-axis optical fiber assembly 16, the Y-axis optical fiber assembly 12, and the Z-axis optical fiber assembly 17 are equal to each other. have the same light source. The following takes the Y axis as an example to illustrate the signal flow direction of the optical path (see Figure 9). The light source 505 distributed by the first beam splitter 502 then distributes one-third of the light through the second beam splitter 506 through the Y axis. From the coupler 606 to the Y-axis modulator 604, the light passes through the Y-axis modulator 604 to complete polarization, light splitting and loading control signals, and then enters the optical fiber 603 of the Y-axis in opposite directions. The control signal is loaded through the Y-axis modulator 604 , interfered (light-combined) and polarized and filtered, and then enters the Y-axis detector 601 through the Y-axis coupler 606 . The light starts from the second optical splitter 506, and the optical path part runs two paths of optical signals that flow in opposite directions, one is the signal from the light source 505 that does not carry the carrier angular motion information before entering the optical fiber 603, and the other is the carrier that returns from the optical fiber 603 Angular motion information is returned to the detector 601 signal. The optical signal completes the photoelectric conversion in the detector 601, completes the analog amplification and filtering through the pre-amplification circuit 605, and then converts the digital signal through the A/D converter, and outputs two signals after demodulation, filtering and integration of the signal by the FPGA. One of the signals is sent to the lower computer of the carrier to complete the guidance calculation; the other is converted by the D/A converter and output to the modulation drive for the Y-axis modulator to obtain a constant value of interference light intensity, thus realizing the control part Fully digital closed-loop control. Closed-loop control artificially introduces a phase difference equal to and opposite to the Sagnac phase shift between the two beams of light propagating in opposite directions to offset the Sagnac phase shift, so that the system always works in the zero phase state, thereby expanding the dynamic range of the system . Phase modulation technology refers to the technology of artificially introducing non-reciprocal phase in the optical path, thereby changing the phase of light. It is one of the main technologies in fiber optic gyro. Phase modulation is realized by phase modulator. The present invention chooses integrated optical Modulator. The integrated optical modulator is a multifunctional device. When the optical phase shift generated by the light source passes through a loop, it is modulated by the signal collected in real time by the FPGA to keep the modulator at a relatively stable interference light intensity value.

Due to the angular velocity, the phases of the two beams of light transmitted in opposite directions in the optical fiber 603 are biased, and the interference light intensity signal output by the modulator after the bias changes accordingly, and the interference light intensity signal is converted into a voltage signal by the detector, and the voltage signal After being amplified by the pre-amplifier circuit, it is output to the A/D converter and converted into a digital signal for the FPGA. After processing the received digital signal, the FPGA outputs an inverted voltage signal to the D/A converter. The analog signal is output to the modulation drive circuit, and the modulation drive circuit outputs a voltage signal to control the modulator to perform phase modulation, so that the interference light intensity remains constant. The schematic diagram of its control circuit is shown in Figure 10. In the figure, XC2V50 chip is selected for FPGA, AD7854 chip is selected for A/D converter, and AD569 chip is selected for D/A converter. FPGA is respectively connected with three A/D converters and D/A converters to realize timing control of input and output information.

Claims (7)

1, a kind of light small triaxial integral fibre-optical gyrometer, comprise light source assembly, optical fiber component, control circuit board and and be used for external interface with the contact of outside generation information, it is characterized in that: also comprise being used to install light source assembly, the machinery frame of optical fiber component and control circuit board (11), light source assembly (14) is installed in the top of machinery frame (11), X-axis optical fiber component (16), Y-axis optical fiber component (12) and Z axle optical fiber component (17) are installed in the X-axis boss body (1) of machinery frame (11) respectively, on the locating surface of Y-axis assembly wall (2) and Z axle assembly wall (3), external interface (13) is installed on the ring flange (4) of machinery frame (11), and control circuit board (15) is installed in the device for fastening (401) of machinery frame (11) bottom and goes up and embed in the big cavity (406) of machinery frame (11) bottom;

Described machinery frame (11) is for meeting the integrative-structure of right-handed coordinate system rule, X-axis boss body (1) is located on the ring flange (4), vertically be provided with Y-axis assembly wall (2) on first side (104) of X-axis boss body (1), vertically be provided with Z axle assembly wall (3) on second side (105) of X-axis boss body (1), the coplane (106) of Y-axis assembly wall (2) and Z axle assembly wall (3) is vertical; The center of the X-axis boss body (1) of described machinery frame (11) is a cavity (101), is provided with in the cavity (101) to supply the fixedly locating surface of usefulness (102) of X-axis optical fiber component (16), and X-axis boss body (1) is provided with erecting bed (103) with the place, diagonal angle of coplane (106); The center of the Y-axis assembly wall (2) of described machinery frame (11) is a cavity (201), and the back of Y-axis assembly wall (2) is provided with cavity (203), is provided with the locating surface (202) of projection in the cavity (203); The center of the Z axle assembly wall (3) of described machinery frame (11) is a cavity (301), and the back of Z axle assembly wall (3) is provided with cavity, is provided with the locating surface of projection in the cavity; The ring flange (4) of described machinery frame (11) is provided with through hole (405) and is used for a plurality of mounting holes (404) of installing component, each mounting hole (404) evenly distributes according to hexagonal angle, the back of ring flange (4) is provided with device for fastening (401) and the big cavity (406) that tightens up usefulness for control circuit board (15), and the terminal pad (407) at ring flange (4) back is provided with erecting bed (403);

Described light source assembly (14), form by light source (505), first optical splitter (502), second optical splitter (506), light source driving (504) and light source base plate (501), light source base plate (501) is provided with fan-shaped boss (503), light source (505) is installed on the fan-shaped boss (503), be respectively equipped with first optical splitter (502) and second optical splitter (506) on two diagonal angles of light source base plate (501), light source be installed on the erection column of light source base plate (501) drive (504); Light source assembly (14) is installed in the Y-axis assembly wall (2) and Z axle assembly wall (3) top on machinery frame (11) top;

Described Y-axis optical fiber component (12), form by ring skeleton (602), optical fiber (603), detector (601), preceding discharge road (605), modulator (604), coupling mechanism (606), be wound with optical fiber (603) on the ring skeleton (602), the top of ring skeleton (602) is equipped with modulator (604) and coupling mechanism (605), on the discharge road (605), preceding discharge road (605) was installed on the threaded post of encircling on the skeleton (602) (607) before detector (601) was installed in; Y-axis optical fiber component (12) is installed on the locating surface (202) of Y-axis assembly wall (2) of machinery frame (11);

Described control circuit board (15) comprises FPGA at least, signaling conversion circuit, modulator driver circuit, FPGA receives via X-axis optical fiber component (16), the optical intensity voltage signal of detector output is amplified through three preceding discharge road in Y-axis optical fiber component (12) and the Z axle optical fiber component (17), digital signal through A/D converter conversion output, FPGA gives D/A converter to the digital signal output phase compensation voltage signal after sequential control is handled that receives, the modulation drive circuit of three modulators, the modulator of three of output voltage signal controls carries out phase modulation (PM) and keeps interference light intensity constant after the modulation drive circuit demodulation.

2, light small triaxial integral fibre-optical gyrometer according to claim 1 is characterized in that: light source (505) can be SLD light source or SFS Er-Doped superfluorescent fiber source.

3, light small triaxial integral fibre-optical gyrometer according to claim 1 is characterized in that: first optical splitter (502) and second optical splitter (506) can be one minute three optical splitter or one-to-two optical splitter.

4, light small triaxial integral fibre-optical gyrometer according to claim 1 is characterized in that: modulator is an integrated optical modulator.

5, light small triaxial integral fibre-optical gyrometer according to claim 1 is characterized in that: complete-digital closed-loop control is adopted in optical fibre gyro control.

6, light small triaxial integral fibre-optical gyrometer according to claim 1 is characterized in that: FPGA chooses the XC2V50 chip, and A/D converter is chosen the AD7854 chip, and D/A converter is chosen the AD569 chip.

7, light small triaxial integral fibre-optical gyrometer according to claim 1 is characterized in that: ring flange (4) is the circular discs structure that a plane section (402) is arranged.

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