Bellows Design Method and Assembly Method Based on the Safe Operating Temperature of a Two-Floater Gyro

Abstract

The present invention relates to a design method for gyro components, specifically to a design and assembly method for bellows based on the safe operating temperature of the gyro, which solves the technical problem that the change in temperature causes the change in the volume of the floating liquid, damaging the gyro sealing structure and thus affecting the accuracy and stability of the gyro. The design method provided by the present invention includes the design of the bellows wave number, the design of the pre-compression amount of the bellows, and the positive verification of the bellows design. The design methods of the bellows wave number and the pre-compression amount are based on the model of the bellows itself and the temperature of the gyro bayonet, meeting the volume compensation requirements and ensuring the safe operation of the gyro; through positive verification, it further ensures that the designed bellows range meets the product requirements. The present invention also provides an assembly method for the bellows assembly, including the assembly of the bellows assembly and the setting of the pre-compression amount. Using a compression tooling, while not damaging the bellows assembly, it ensures uniform solder in the weld and the bonding quality; the pre-compression amount of the bellows is achieved through scribing, which is simple and highly practical.

Description

Technical Field

[0001] The present invention relates to a design method for gyro components, and particularly to a design method and an assembly method for a bellows based on the safe operating temperature of a two-degree-of-freedom gyro. Background Art

[0002] Due to its characteristics such as anti-vibration, shock resistance, high reliability, and long service life, the two-degree-of-freedom gyro is widely used in the navigation and attitude systems of spacecraft, satellites, space stations, and ships. As an attitude-sensitive element of a sensor, the two-degree-of-freedom gyro is used to measure the angular motion of a vehicle and is a very important inertial sensor. The long-term stability of the gyro will affect the accuracy of the navigation and attitude systems.

[0003] The interior of the two-degree-of-freedom gyro is filled with a floating liquid, which suspends the float at the operating temperature, reduces the positive pressure of the float's own weight on the support, decreases the support friction coefficient, and plays a certain role in viscous resistance. Since the temperature before the two-degree-of-freedom gyro is heated is different from that during normal operation, including the temperature rise of the motor during the operation of the two-degree-of-freedom gyro or the temperature control of a high-precision instrument that makes the two-degree-of-freedom gyro operate at a certain temperature, as well as the change in the external environmental temperature, all will cause the temperature of the two-degree-of-freedom gyro to change. When the temperature changes, the volume of the floating liquid will expand or contract with the rise and fall of the temperature. In order to ensure the measurement accuracy of the two-degree-of-freedom gyro, it is necessary to compensate for the changed volume. Therefore, a temperature compensator needs to be designed for the two-degree-of-freedom gyro. A bellows assembly can be used as the temperature compensator of the two-degree-of-freedom gyro. The sealing reliability of the bellows assembly directly affects the sealing reliability of the two-degree-of-freedom gyro, and its bonding technology is the key technology for the sealing of the two-degree-of-freedom gyro, which will directly affect the accuracy and stability of the two-degree-of-freedom gyro. As Figures 1 - 4 shown, the bellows assembly consists of a bellows cover 1, a bellows 2, and a bellows bottom plate 3, and the bellows assembly is installed at one end of the two-degree-of-freedom gyro housing.

[0004] The bellows is an elastic element. When the volume of the floating liquid expands, the bellows is compressed to compensate for the increased volume after the expansion of the floating liquid; when the volume of the floating liquid contracts, the bellows elongates to compensate for the reduced volume after the cold shrinkage of the floating liquid, so that there is no cavity inside the gyro, thus enabling the two-degree-of-freedom gyro to work safely and reliably. Therefore, it is required that the bellows must have sufficient compensation within a certain range. If the compensation is insufficient, the pressure inside the housing of the two-degree-of-freedom gyro will increase sharply at high temperatures, resulting in the destruction of the sealing of the two-degree-of-freedom gyro and thus causing oil leakage from the two-degree-of-freedom gyro; at low temperatures, cavities will appear and bubbles will form, generating random liquid convection torques.

[0005] Therefore, as the temperature compensator of the two-floater gyroscope, the key to the design of the bellows assembly lies in the design of the bellows. The bellows can be selected according to the structure and size characteristics of the gyroscope. Therefore, the number of waves is the core parameter of the bellows design and is also a necessary condition to determine whether the volume compensation can ensure the safe and reliable operation of the two-floater gyroscope. The pre-compression of the bellows realizes the volume compensation of the floating liquid and is a guarantee condition for realizing the allowable temperature change and temperature range of the two-floater gyroscope and the safe temperature range of the gyroscope. When the temperature of the two-floater gyroscope changes, the bellows drives the bellows cover to move relative to the bellows bottom plate, and the bellows assembly bears the pressure or torque brought by the volume change. Therefore, the sealing quality of the bellows assembly is also one of the factors affecting the accuracy and stability of the gyroscope.

[0006] However, in the related art regarding the performance of gyroscopes, only aspects such as the sealing structure, machining, and temperature compensation of gyroscopic instruments are usually involved, and no design and implementation methods for the safe temperature range of gyroscopes are seen. Summary of the Invention

[0007] The purpose of the present invention is to solve the technical problem that the volume change of the floating liquid caused by temperature change damages the gyroscope sealing structure, thereby affecting the accuracy and stability of the gyroscope, and to provide a design method and assembly method for a bellows assembly based on the safe temperature of a two-floater gyroscope.

[0008] The design idea of the present invention is as follows:

[0009] The floating liquid inside the two-floater gyroscope is affected by temperature and its volume changes. The compression or elongation of the bellows is used to compensate for the volume change of the floating liquid. Based on the standard of the bellows itself model, through the design of the number of waves and the pre-compression amount of the bellows, the design of the volume compensation amount and the compensation of the floating liquid volume are realized, thereby ensuring the operation of the two-floater gyroscope within the safe temperature range.

[0010] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0011] A design method for a bellows assembly based on the safe operating temperature of a two-floater gyroscope, the bellows is coaxially installed at one end inside the housing of the two-floater gyroscope, and the special feature lies in including the following steps:

[0012] Step A1. Design of the number of waves of the bellows 2

[0013] Step A1.1 Calculate the volume compensation amount ΔV of the floating liquid in the two-floater gyroscope when the temperature changes;

[0014] ΔV = Vα(T2 - T1)

[0015] Wherein, V is the volume of the floating liquid; α is the volume expansion coefficient of the gyroscope floating liquid; T1 and T2 are respectively the lower limit and upper limit of the set safe operating temperature of the two-floater gyroscope, and T2 - T1 is the change amount of the set safe operating temperature of the two-floater gyroscope;

[0016] Step A1.2 Select the model of the bellows 2 according to the internal structure of the two-float gyroscope float, the volume of the floating liquid, and the volume compensation amount ΔV, and query the effective area S and the maximum displacement L of a single wave stretching of the selected bellows 2 + , and the maximum displacement L of a single wave contraction - ;

[0017] Step A1.3 Calculate the total displacement ΔL of the volume compensation amount;

[0018] ΔL = ΔV / S

[0019] Step A1.4 Calculate the range of the number of waves n of the bellows 2;

[0020] n ≥ ΔL / (L + -L - )

[0021] Step A2. Calculation of the pre-compression amount of the bellows 2 in the free state at the gyroscope bayonet temperature

[0022] Calculate the compression amount ΔL of the bellows 2 at the bayonet temperature; + ;

[0023] ΔL + = ΔL(T2 - T3) / (T2 - T1)

[0024] In the formula: T3 is the gyroscope bayonet temperature;

[0025] Calculate the pre-compression amount Δ of the bellows 2 in the free state at the gyroscope bayonet temperature;

[0026] Δ = ΔL + -ΔL×(|L - | / (L + +|L - |))

[0027] Furthermore, in the step A1.1:

[0028] T2 - T1 is 1.5 - 2.5 times the change in the safe operating temperature of the two-float gyroscope required by the product;

[0029] The lower limit T1 of the safe operating temperature of the two-float gyroscope is lower than the freezing point temperature T0 of the gyroscope floating liquid.

[0030] Furthermore, in the step A1.1, the expansion coefficient α of the floating liquid = 1.546×10 -3 .

[0031] Furthermore, it also includes step A3:

[0032] Step A3. Positive verification of the safe temperature range of the two-float gyroscope

[0033] Step A3.1 Determine the value of the wave number n of the bellows 2 within the range of the wave number n obtained in step A1.4, according to n = ΔL' / (L + -L - ), calculate the total displacement ΔL′ of the actual volume compensation;

[0034] Step A3.2: Calculate the actual volume compensation amount ΔV′ according to ΔL′=ΔV′ / S;

[0035] Step A3.3: Calculate the actual change T2′-T1′ of the safe working temperature of the two floating gyroscopes according to ΔV′=Vα(T2′-T1′);

[0036] Step A3.4: The total displacement ΔL′ of the actual volume compensation calculated in step A3.1 is calculated by ΔL + = ΔL′(T2-T3) / (T2′-T1′) Calculate the compression value ΔL of the bellows 2 at the gyro mount temperature + ″, then according to Δ2=ΔL + ″-ΔL′×(|L - | / (L + +|L - |)) Calculate the calculated value Δ2 of the pre-compression of the bellows 2 in the free state at the gyro mount temperature, and determine the actual pre-compression Δ′ of the bellows 2 in the free state at the gyro mount temperature from the calculated value Δ2, and it is required that Δ′ is greater than Δ2;

[0037] Step A3.5: The actual pre-compression amount Δ′ of the bellows 2 in the free state at the bayonet temperature determined in step A3.4 is given by Δ′=ΔL + ′-ΔL′×(|L - | / (L + +|L - |)) Calculate the actual compression ΔL of bellows 2 at the two-floating gyro bayonet temperature + '; According to the actual change of the safe working temperature of the two floating gyroscopes obtained in step A3.3, T2'-T1', by ΔL + '=ΔL'(T2'-T3) / (T2'-T1') calculates the upper limit T2' of the safe working temperature of the two-floating gyroscope, which is the actual upper limit of the safe working temperature of the two-floating gyroscope, and then determines the actual lower limit T1' of the safe working temperature of the two-floating gyroscope according to T2'-T1';

[0038] Step A3.6 determines whether the lower limit T1′ of the actual two-floating gyro safe working temperature is lower than the freezing point temperature T0 of the gyro suspension. If T1′<T0, the product requirements are met and step A3.7 is performed; if T1′≥T0, the lower limit and upper limit of the set two-floating gyro safe working temperature are adjusted and the process returns to step A1;

[0039] Step A3.7 Determine whether the upper limit T2' of the actual safe operating temperature of the two-floated gyroscope is higher than the product bonding and curing temperature T0'. If T2' > T0', it meets the product requirements, and proceed to Step A3.8; if T2' ≤ T0', adjust the set lower and upper limits of the safe operating temperature of the two-floated gyroscope, and return to Step A1;

[0040] Step A3.8 Determine whether the actual safe operating temperature range T1'~T2' of the two-floated gyroscope meets the required safe operating temperature range of the two-floated gyroscope of the product. If it does not meet the requirements, adjust the set lower and upper limits of the safe operating temperature of the two-floated gyroscope, and return to Step A1.

[0041] Further, in Step A3.1, the specific method for determining the value of the wave number n of the bellows 2 within the value range of the wave number n obtained in Step A1.4 is as follows: The actual wave number n of the bellows 2 takes the half-wave or integral wave closest to ΔL / (L + -L - ).

[0042] Further, in Step A3.4, the specific method for determining the actual pre-compression amount Δ' of the bellows 2 in the free state at the gyroscope bayonet temperature from Δ2 is as follows: The actual pre-compression amount Δ' of the bellows 2 in the free state at the gyroscope bayonet temperature is greater than the calculated value Δ2, and there is a 40%-60% margin compared with the calculated value.

[0043] The present invention also provides a bellows assembly method based on the safe operating temperature of the two-floated gyroscope. The bellows is obtained based on the above-mentioned bellows design method for the safe operating temperature of the two-floated gyroscope, and is characterized in that it includes the following steps:

[0044] Step B1, Bellows assembly

[0045] The bellows assembly includes a bellows 2 and bellows caps 1 and bellows bottom plates 3 axially arranged at both ends of the bellows 2;

[0046] Solder the bellows cap 1 and the bellows 2 with tin-lead solder, and adhesively seal between the bellows 2 and the bellows bottom plate 3; use an auxiliary tooling to make the bellows cap 1, the bellows 2, and the bellows bottom plate 3 coaxial and subject to axial pressure, so that the solder or adhesive flows into the gaps between the bellows cap 1 and the bellows 2, and between the bellows 2 and the bellows bottom plate 3 respectively;

[0047] The auxiliary tooling includes a bellows compression tooling I 4 and a bellows compression tooling II 5. A stepped component installation groove 51 and an installation hole for the bellows compression tooling I 4 are provided in the center of the bellows compression tooling II 5. The bellows bottom plate 3 is installed in the component installation groove 51. The side of the bellows compression tooling I 4 is provided with threads and is threadedly connected to the bellows compression tooling II 5. One end is designed with a boss 41. The boss 41 passes through the inner cavities of the bellows 2 and the bellows bottom plate 3 and is threadedly connected to the bellows cover 1.

[0048] Step B2. Setting the pre-compression amount of the bellows 2 in the free state at the gyro bayonet temperature

[0049] Step B2.1 Calculate the angle θ that the bellows compression tooling II 5 rotates when it pushes the bellows bottom plate 3 to drive the bellows 2 to contract by Δ.

[0050] θ = 2πΔ / d

[0051] In the formula, d is the pitch of the thread on the bellows compression device II 5.

[0052] Step B2.2 Rotate the bellows compression tooling II 5 so that the bellows compression tooling II 5 fits with the bellows bottom plate 3 and the bellows 2 is in the initial state. Mark a scale line I 11 on the end face of the bellows compression tooling II 5. Along the direction of the scale line I 11, make a marking line 10 on the end face of the two-degree-of-freedom gyro housing.

[0053] Step B2.3 Rotate the scale line I 11 by an angle θ in the clockwise and counterclockwise directions respectively, and mark the scale line II 12 and the scale line III 13.

[0054] Step B2.4 Rotate the bellows compression tooling II 5 to push the bellows bottom plate 3 to drive the bellows 1 to move towards the inside of the gyro until the scale line II 12 or the scale line III 13 on the bellows compression tooling II 5 is first aligned with the marking line 10 on the gyro housing end face, so as to realize the setting of the pre-compression amount of the bellows 2 before gyro oil filling.

[0055] Further, step B1 is specifically as follows:

[0056] Step B1.1 Assemble the bellows assembly and the auxiliary tooling

[0057] Successively sleeved the bellows 2 and the bellows cover 1 on the bellows bottom plate 3, and put the sleeved bellows cover 1, bellows 2 and bellows bottom plate 3 into the component installation groove 51 of the bellows compression tooling II 5. The bellows compression tooling I 4 is installed in the installation hole in the center of the bellows compression tooling II 5. The boss 41 passes through the inner cavities of the bellows 2 and the bellows bottom plate 3 and is threadedly connected to the bellows cover 1.

[0058] Adjust the position of the corrugated pipe bottom plate 3 to make it at the center of the component installation groove 51 of the corrugated pipe compression tooling II 5. Rotate the corrugated pipe compression tooling II 5, and push the corrugated pipe 2 through the corrugated pipe bottom plate 3 to make the corrugated pipe 2 fit tightly with the corrugated pipe cover 1 and receive axial pressure;

[0059] Step B1.2 Weld the corrugated pipe cover 1 and the corrugated pipe 2

[0060] Pass the assembled corrugated pipe assembly and the auxiliary tooling through the rotatable three-jaw turntable, and fix the three movable jaws of the three-jaw turntable on the outer circle of the corrugated pipe compression tooling I 4. Rotate the three-jaw turntable to drive the corrugated pipe compression tooling I 4, the corrugated pipe compression tooling II 5 and the corrugated pipe assembly to rotate simultaneously. At this time, place the soldering iron at the welding part of the corrugated pipe cover 1 and the corrugated pipe 2, and gradually melt the tin-lead and let it flow into the gap between the two;

[0061] Step B1.3 Bond the corrugated pipe 2 and the corrugated pipe bottom plate 3

[0062] Disassemble the welding auxiliary tooling, clean the corrugated pipe assembly ultrasonically in gasoline and acetone, roughen the bonding part of the cleaned corrugated pipe bottom plate 3, and then start bonding; when bonding, make the adhesive liquid flush with the end face of the corrugated pipe 2;

[0063] Step B1.4 Cure the corrugated pipe assembly

[0064] Assemble the corrugated pipe assembly and the auxiliary tooling by the method of Step B1.1, rotate the corrugated pipe compression tooling II 5, apply axial pressure between the corrugated pipe 2 and the corrugated pipe cover 1, and then cure the corrugated pipe assembly at a temperature of 80°C ± 2°C for 4 h.

[0065] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0066] 1. The design method of the corrugation number and the pre-compression amount provided in the method of the present invention, based on the requirements of the corrugated pipe itself model and the gyroscope bayonet temperature, can ensure the safe operation of the gyroscope, meet the volume compensation requirements, and enable the two-degree-of-freedom gyroscope to work safely when the temperature changes;

[0067] 2. The positive verification method of the safe temperature range of the two-degree-of-freedom gyroscope provided in the method of the present invention, through the verification of the designed corrugated pipe parameters, ensures that the allowable working range of the corrugated pipe meets the gyroscope working safety temperature range required by the product, and can further guarantee the accuracy, safety and stability of the two-degree-of-freedom gyroscope product designed by the method provided in the present invention;

[0068] 3. The bellows assembly method provided in the method of the present invention realizes axial pressurization, radial limit, and non-destructive clamping between bellows assemblies, avoids the adverse effects of the structural design of the bellows assembly on welding, ensures uniform welding, reduces the operation difficulty, and at the same time ensures the bonding quality, avoiding problems such as the decline of gyro accuracy and the loss of functions caused by gyro oil leakage.

[0069] 4. The bellows pre-compression amount setting method provided in the method of the present invention controls the rotation angle of the bellows compression tooling through scribed lines, thereby precisely controlling the bellows pre-compression amount, which is simple and easy to operate. Description of the Drawings

[0070] Figure 1 It is a three-dimensional structural sectional view of the bellows assembly of a two-floating gyro;

[0071] Figure 2 It is a sectional view of the bellows cover structure of a two-floating gyro;

[0072] Figure 3 It is a sectional view of the bellows structure of a two-floating gyro;

[0073] Figure 4 It is a sectional view of the bellows bottom plate structure of a two-floating gyro;

[0074] Figure 5 It is a schematic structural view of the bellows compression tooling I of the present invention;

[0075] Figure 6 It is a schematic structural view of the bellows compression tooling II of the present invention;

[0076] Figure 7 It is a schematic structural view of the bellows assembly and auxiliary tooling assembly of the embodiment of the present invention;

[0077] Figure 8 It is a front view of the initial position before the adjustment of the bellows pre-compression amount in the embodiment of the present invention;

[0078] Figure 9 It is a right view of the initial position before the adjustment of the bellows pre-compression amount in the embodiment of the present invention;

[0079] Figure 10 It is a front view of the bellows pre-compression amount after adjustment in the embodiment of the present invention;

[0080] Figure 11 It is a right view of the bellows pre-compression amount after adjustment in the embodiment of the present invention;

[0081] The descriptions of the reference numerals are as follows:

[0082] 1 - Bellows cover, 2 - Bellows, 3 - Bellows bottom plate, 4 - Bellows compression tooling Ⅰ, 5 - Bellows compression tooling Ⅱ, 41 - Boss, 51 - Component installation groove;

[0083] 10 - Marking line, 11 - Scoring line Ⅰ, 12 - Scoring line Ⅱ, 13 - Scoring line Ⅲ. Specific implementation mode

[0084] The following further elaborates in detail a bellows design and assembly method based on the gyro's safe operating temperature in combination with the attached drawings and specific embodiments. Those skilled in the art should understand that these implementation modes are only used to explain the technical principle of the present invention, and the purpose is not to limit the protection scope of the present invention.

[0085] A bellows design method based on the safe operating temperature of a two - floated gyro includes bellows wave number design, bellows pre - compression amount design, and positive verification of bellows design. In this embodiment, taking the gyro design for H - type hydrodynamic motor assembly as an example, the bellows component design method is described. The floating liquid volume V of the gyro for H - type hydrodynamic motor assembly is 12.521 cm 3 , and the generally required safe operating temperature of the gyro for the product is - 5°C to 50°C, and the gyro bayonet temperature is 23°C. The bellows design method based on the safe temperature of the two - floated gyro includes the following steps:

[0086] Step A1, Bellows 2 wave number design

[0087] Step A1.1 Calculate the volume compensation amount ΔV of the floating liquid of the two - floated gyro when the temperature changes;

[0088] The set change amount of the safe operating temperature of the two - floated gyro is about twice the change amount of the required safe operating temperature of the gyro for the product, and a certain margin is left for the upper and lower limits of the safe operating temperature of the gyro. Since the freezing point of the gyro suspension liquid is - 8°C, the limit range of the safe operating temperature of the two - floated gyro is set to - 20°C to 100°C; α is the expansion coefficient of the gyro floating liquid, α = 1.546×10 -3 , unit is 1 / °C;

[0089] Substitute V, α, T1, and T2 into the following formula to calculate that ΔV is 2.323 cm 3 ;

[0090] ΔV = Vα(T2 - T1)

[0091] Step A1.2 Select the NNX28×28×18 type bellows according to the internal structure of the two - floated gyro float, the volume of the floating liquid, and the volume compensation amount. Through standard query, the effective area S of the NNX28×28×18 type bellows is 4.15 cm 2 , and the maximum displacement L of a single wave in tension += 0.66 mm, the maximum displacement L of a single-wave contraction - = -1 mm;

[0092] Step A1.3 Substitute ΔV and S into the following formula to calculate the total displacement ΔL of the volume compensation amount to be 5.60 mm;

[0093] ΔL = ΔV / S

[0094] In the formula: ΔV is the volume compensation amount, with the unit of cm 3 ; S is the effective area of the bellows 2, with the unit of cm 2 ;

[0095] Step A1.4 Calculate the range of the number of waves n of the bellows 2, n ≥ 3.37;

[0096] n ≥ ΔL / (L + - L - )

[0097] Step A2. Calculation of the pre-compression amount of the bellows 2 in the free state at the gyro bayonet temperature

[0098] Step A2.1 Calculate the compression amount ΔL of the bellows at the gyro bayonet temperature + ;

[0099] As known from Step A1.1, T1 = -20 °C, T2 = 100 °C, and from Step A1.3, ΔL = 5.60 mm. Substitute T1, T2, T3, and ΔL into the following formula to calculate ΔL + to be 3.60 mm;

[0100] ΔL + = ΔL(T2 - T3) / (T2 - T1)

[0101] In the formula: ΔL + The unit is mm; T3 is the gyro bayonet temperature, which is the temperature at which the gyro operates normally, with the unit of °C, generally the room temperature of 23 °C;

[0102] Step A2.2 Calculate the pre-compression amount Δ of the bellows (2) in the free state at the gyro bayonet temperature;

[0103] Substitute ΔL + , ΔL, L + and L - into the following formula to calculate Δ to be 0.23 mm;

[0104] Δ = ΔL + - ΔL × (|L - | / (L + + |L - |))

[0105] In the formula: The unit of Δ is mm.

[0106] Step A3, Positive Verification of the Safe Temperature Range of the Gyro

[0107] Step A3.1 Take n as a half-wave or full-wave greater than 3.37 and closest to 3.37, so n is taken as 3.5; According to n = ΔL′ / (L + -L - ), calculate the total displacement of the actual volume compensation amount ΔL′, and ΔL′ is 5.81 mm;

[0108] Step A3.2 Calculate the actual volume compensation amount ΔV′ according to ΔL′ = ΔV′ / S, and ΔV′ is 2.41115 cm 3 ;

[0109] Step A3.3 Calculate the actual change amount T2′ - T1′ of the safe operating temperature of the two-float gyro according to ΔV′ = Vα(T2′ - T1′), and T2′ - T1′ is 124.5 °C;

[0110] Step A3.4 According to the total displacement of the actual volume compensation amount ΔL′ determined in Step A3.1, calculate the calculated value of the compression amount ΔL + ″ of the bellows 2 at the gyro bayonet temperature by ΔL + ″ = ΔL′(T2 - T3) / (T2′ - T1′). The calculated value of ΔL + ″ is about 3.60 mm. Then, according to Δ2 = ΔL - ″ - ΔL′×(|L + | / (L - +|L + |)), calculate the calculated value of the pre-compression amount Δ2 of the free state of the bellows 2 at the gyro bayonet temperature as 0.23 mm. For the convenience of implementation and calculation, and a margin of more than 50% needs to be designed for the bellows, so the actual pre-compression amount Δ′ of the free state of the bellows at the gyro bayonet temperature of 23 °C is taken as 0.4 mm.

[0111] Step A3.5 According to the actual pre-compression amount Δ′ of the free state of the bellows 2 at the gyro bayonet temperature determined in Step A3.4, calculate the compression amount ΔL of the bellows 2 at the actual bayonet temperature by Δ′ = ΔL - ′ - ΔL′×(|L + | / (L - +|L + |)). The calculated value of ΔL +′ = ΔL′(T2′ - T3) / (T2′ - T1′). The upper limit T2′ of the safe operating temperature of the two-floated gyroscope is calculated to be 106.5 °C, which is the actual upper limit of the safe operating temperature of the two-floated gyroscope. Then, according to T2′ - T1′, the lower limit T1′ of the safe operating temperature of the two-floated gyroscope for the bellows 2 is determined, and T1′ = -18 °C;

[0112] Step A3.6 Determine whether the lower limit T1′ of the actual safe operating temperature of the two-floated gyroscope is lower than the freezing point temperature T0 of the gyroscope suspension liquid. T0 = -8 °C, and T1′ < T0, meeting the product requirements;

[0113] Step A3.7 Determine whether the upper limit T2′ of the actual safe operating temperature of the two-floated gyroscope is higher than the product bonding and curing temperature T0′. T0′ = 80 °C, and T2′ > T0′, meeting the product requirements;

[0114] Step A3.8 The actual safe operating temperature range of the two-floated gyroscope is -18 °C to 106.5 °C, while the required gyroscope safe operating temperature range of the product is -5 °C to 50 °C, meeting the product requirements.

[0115] This embodiment also provides a method for assembling a bellows assembly based on the safe operating temperature of a two-floated gyroscope. The bellows is implemented using the above-mentioned bellows design method, including the assembly of the bellows assembly and the setting of the pre-compression amount of the bellows, which specifically includes the following steps:

[0116] Step B1. Assembly of the bellows assembly

[0117] Step B1.1 Assemble the bellows assembly and the auxiliary tooling

[0118] As Figure 1 , it is the structure diagram of the bellows. The bellows assembly includes the bellows 2 and the bellows covers 1 and the bellows bottom plate 3 arranged axially at both ends of the bellows 2; the structure diagrams of the bellows cover 1, the bellows 2, and the bellows bottom plate 3 are respectively as Figure 2 , Figure 3 , Figure 4 . The auxiliary tooling is the bellows compression tooling I 4 and the bellows compression tooling II 5, as Figure 5 and Figure 6 ; as Figure 5 shown, the side of the bellows compression tooling I 4 is provided with threads and is connected to the bellows compression tooling II 5 through threads. One end is designed with a boss 41, and the boss 41 passes through the inner cavities of the bellows 2 and the bellows bottom plate 3; as Figure 6 , a stepped component installation groove 51 and an installation hole for the bellows compression tooling I 4 are provided in the center of the bellows compression tooling II 5, and the bellows bottom plate 3 is installed in the component installation groove 51;

[0119] The corrugated pipe 2 and the corrugated pipe cover 1 are successively sleeved on the corrugated pipe bottom plate 3, and the sleeved corrugated pipe cover 1, corrugated pipe 2 and corrugated pipe bottom plate 3 are placed into the component installation groove 51 of the corrugated pipe compression tooling II 5; the corrugated pipe compression tooling I 4 is installed in the installation hole at the center of the corrugated pipe compression tooling II 5, and the convex platform 41 passes through the inner cavities of the corrugated pipe 2 and the corrugated pipe bottom plate 3 and is threadedly connected to the corrugated pipe cover 1;

[0120] Adjust the position of the corrugated pipe bottom plate 3 to make it at the center of the component installation groove 51 of the corrugated pipe compression tooling II 5. Rotate the corrugated pipe compression tooling II 5, and push the corrugated pipe 2 through the corrugated pipe bottom plate 3 to make the corrugated pipe 2 fit tightly with the corrugated pipe cover 1 and be subjected to axial pressure; the assembly structure of the corrugated pipe assembly and the auxiliary tooling is as Figure 7 ;

[0121] Step B1.2 Weld the corrugated pipe cover 1 and the corrugated pipe 2

[0122] Pass the assembled corrugated pipe assembly and the auxiliary tooling through the rotatable three-jaw turntable, and fix the three movable jaws of the three-jaw turntable on the outer circle of the corrugated pipe compression tooling I 4. Rotate the three-jaw turntable to drive the corrugated pipe compression tooling I 4, the corrugated pipe compression tooling II 5 and the corrugated pipe assembly to rotate simultaneously. At this time, place the soldering iron at the welding part of the corrugated pipe cover 1 and the corrugated pipe 2, and gradually melt the solder and let it flow into the gap between the two;

[0123] Step B1.3 Bond the corrugated pipe 2 and the corrugated pipe bottom plate 3

[0124] Clean the corrugated pipe 2 and the corrugated pipe bottom plate 3 with ultrasonic waves in gasoline and acetone, roughen the bonding part of the cleaned corrugated pipe bottom plate 3, and then start bonding; when bonding, make the adhesive liquid flush with the end face of the corrugated pipe 2;

[0125] Step B1.4 Cure the corrugated pipe assembly

[0126] Assemble the corrugated pipe assembly and the auxiliary tooling by the method of Step B1.1. Rotate the corrugated pipe compression tooling II 5 to apply axial pressure between the corrugated pipe 2 and the corrugated pipe cover 1, and then cure the corrugated pipe assembly at a temperature of 80°C ± 2°C for 4 h.

[0127] Axial pressurization, radial limitation and non-destructive clamping of the corrugated pipe cover 1, corrugated pipe 2 and corrugated pipe bottom plate 3 are realized through the corrugated pipe compression tooling I 4 and the corrugated pipe compression tooling II 5. During welding, ensure that the corrugated pipe cover 1 and the corrugated pipe 2 are coaxial, the corrugated pipe bottom plate 3 is at the center of the component installation groove 51 of the corrugated pipe compression tooling II 5, use the three-jaw turntable to clamp the corrugated pipe compression tooling I without damaging the corrugated pipe assembly, and at the same time ensure that the solder of the weld seam is uniform.

[0128] During bonding, cleaning ensures the cleanliness of the bonding surface. Roughening the bonding part on the corrugated pipe bottom plate 3 in the morning can enhance the connection strength between the adhesive and the matrix. Controlling the amount of adhesive flush with the end face of the corrugated pipe 2 ensures sufficient connection area between the adhesive and the matrix. By rotating the corrugated pipe compression tooling II 5, a certain axial pressure is applied between the corrugated pipe 2 and the corrugated pipe cover 1, and at the same time, the relative positions of the corrugated pipe 2 and the corrugated pipe bottom plate 3 are radially restricted, and then curing is carried out. It can avoid problems such as non-coaxiality, inconsistent bonding gaps, and unreliable bonding caused by the displacement of the corrugated pipe assembly during the curing process, and ensure the bonding quality.

[0129] Step B2. Setting the pre-compression amount of the corrugated pipe 2 in the free state at the gyroscope bayonet temperature

[0130] Step B2.1 Calculate the angle θ that the corrugated pipe compression tooling II 5 rotates when it pushes the corrugated pipe bottom plate 3 to drive the corrugated pipe 2 to shrink by Δ;

[0131] θ = 2πΔ / d

[0132] In the formula, d is the pitch of the thread on the corrugated pipe compression tooling II 5;

[0133] One pitch of the thread on the corrugated pipe compression device II 5 represents the displacement of the corrugated pipe compression device II 5 rotating one week. The corrugated pipe compression device II 5 pushes the corrugated pipe bottom plate 3 to drive the corrugated pipe 2 to shrink. The pre-compression amount Δ of the corrugated pipe can be achieved by rotating the angle θ of the corrugated pipe compression device II;

[0134] Step B2.2 Rotate the corrugated pipe compression tooling II 5 so that the corrugated pipe compression tooling II 5 fits with the corrugated pipe bottom plate 3, and the corrugated pipe 2 is in the initial state. Mark the scale line I 11 on the end face of the corrugated pipe compression tooling II 5. Along the direction of the scale line I 11, make a marking line 10 on the end face of the gyro housing; as Figure 8 、 Figure 9 , which are the front view and right view of the initial position before the adjustment of the pre-compression amount of the corrugated pipe respectively;

[0135] Step B2.3 Rotate the scale line I 11 clockwise and counterclockwise by the angle θ respectively, and mark the scale line II 12 and the scale line III 13;

[0136] Step B2.4 Rotate the corrugated pipe compression tooling II 5 to push the corrugated pipe bottom plate 3 to drive the corrugated pipe 1 to move towards the inside of the gyro until the scale line II 12 or the scale line III 13 on the corrugated pipe compression tooling II 5 aligns with the marking line 10 on the end face of the gyro housing, so as to achieve the setting of the pre-compression amount of the corrugated pipe 2 before gyro oil filling, as Figure 10 、 Figure 11 , which are the front view and right view after the adjustment of the pre-compression amount of the corrugated pipe respectively.

[0137] Verified through 5-year mass production verification of products and flight tests (verification of SJ20 satellite, TZ-2 to TZ-4, SZ-12 to TZ-14, core module of the space station, and supporting system for high-precision gyroscopes). During the mass production tests, no decrease in gyroscope accuracy or functional failures caused by gyroscope oil leakage were found.

Claims

1. A design method for a bellows based on the safe operating temperature of a two-degree-of-freedom gyroscope, the bellows being coaxially installed at one end inside the housing of the two-degree-of-freedom gyroscope, characterized in that, It includes the following steps: Step A1, Design of the wave number of the bellows (2) Step A1.1 Calculate the volume compensation amount ΔV of the floating liquid of the two-degree-of-freedom gyroscope when the temperature changes; ΔV = Vα(T2 - T1) Wherein, V is the volume of the floating liquid; α is the volume expansion coefficient of the gyroscope floating liquid; T1 and T2 are respectively the lower limit and the upper limit of the set safe operating temperature of the two-degree-of-freedom gyroscope, and T2 - T1 is the change amount of the set safe operating temperature of the two-degree-of-freedom gyroscope; Step A1.2 selects the model of the bellows (2) according to the internal structure of the float of the two-degree-of-freedom gyroscope, the volume of the floating liquid and the volume compensation amount ΔV, and queries the effective area S and the maximum displacement L of a single wave in tension of the selected bellows (2) + , the maximum displacement L of a single wave in compression - ; Step A1.3 Calculate the total displacement ΔL of the volume compensation amount; ΔL = ΔV / S Step A1.4 Calculate the range of the wave number n of the bellows (2); n≥ΔL / (L + -L - ) Step A2, Calculation of the pre-compression amount of the bellows (2) in the free state at the gyroscope bayonet temperature Calculate the compression amount ΔL of the bellows (2) at the gyro bayonet temperature + ; ΔL + = ΔL(T2 - T3) / (T2 - T1) In the formula: T3 is the gyroscope bayonet temperature; Calculate the pre-compression amount Δ of the bellows (2) in the free state at the gyroscope bayonet temperature; Δ = ΔL + -ΔL × (|L - | / (L + + |L - |))。 2. The bellows design method based on the safe operating temperature of a two-floating gyroscope according to claim 1, characterized in that, In the said step A1.1: T2 - T1 is 1.5 - 2.5 times the change amount of the safe operating temperature of the two-degree-of-freedom gyroscope required by the product; The lower limit T1 of the set safe operating temperature of the two-degree-of-freedom gyroscope is lower than the freezing point temperature T0 of the gyroscope floating liquid.

3. The design method of the bellows based on the safe operating temperature of the two-float gyroscope according to claim 2, characterized in that, In step A1.1, the volume expansion coefficient α of the gyroscopic floating liquid is 1.546×10 -3 .

4. The bellows design method based on the safe operating temperature of a two-floating gyroscope according to any one of claims 1 to 3, characterized in that, It also includes step A3: Step A3, Positive verification of the safe temperature range of the two-degree-of-freedom gyroscope Step A3.1 determines the value range of the wave number n of the bellows (2) within the value range of the wave number n obtained in Step A1.

4. According to n = ΔL′ / (L + -L - ), calculate the total displacement ΔL′ of the actual volume compensation amount; Step A3.2 Calculate the actual volume compensation amount ΔV′ according to ΔL′ = ΔV′ / S; Step A3.3 Calculate the actual change amount T2′ - T1′ of the safe operating temperature of the two-degree-of-freedom gyroscope according to ΔV′ = Vα(T2′ - T1′); Step A3.4 Based on the total displacement of the actual volume compensation amount ΔL′ calculated in Step A3.1, calculate the calculated compression amount ΔL + ″ of the bellows (2) at the gyroscope bayonet temperature by ΔL + ″ = ΔL′(T2 - T3) / (T2′ - T1′), and then according to Δ2 = ΔL + ″ - ΔL′×(|L - | / (L + +|L - |)), calculate the calculated pre-compression amount Δ2 of the free state of the bellows (2) at the gyroscope bayonet temperature, and determine the actual pre-compression amount Δ′ of the free state of the bellows (2) at the gyroscope bayonet temperature from the calculated value Δ2, requiring that Δ′ is greater than Δ2; Step A3.5 Based on the actual pre-compression amount Δ′ of the bellows (2) in the free state at the gyro bayonet temperature determined in Step A3.4, calculate the compression amount ΔL + ′ of the bellows (2) at the actual gyro bayonet temperature from Δ′ = ΔL - ′ - ΔL′×(|L + | / (L - +|L + |)); Based on the actual change amount T2′ - T1′ of the safe operating temperature of the two-degree-of-freedom gyro obtained in Step A3.3, calculate the upper limit T2′ of the safe operating temperature of the two-degree-of-freedom gyro from ΔL + ′ = ΔL′(T2′ - T3) / (T2′ - T1′), which is the actual upper limit of the safe operating temperature of the two-degree-of-freedom gyro. Then determine the lower limit T1′ of the actual safe operating temperature of the two-degree-of-freedom gyro based on T2′ - T1′; Step A3.6 Judge whether the lower limit T1′ of the actual safe operating temperature of the two-degree-of-freedom gyroscope is lower than the freezing point temperature T0 of the gyroscope floating liquid. If T1′ < T0, it meets the product requirements, and proceed to step A3.7; if T1′ ≥ T0, adjust the lower limit and the upper limit of the set safe operating temperature of the two-degree-of-freedom gyroscope, and return to step A1; Step A3.7 Judge whether the upper limit T2′ of the actual safe operating temperature of the two-degree-of-freedom gyroscope is higher than the product bonding and curing temperature T0′. If T2′ > T0′, it meets the product requirements, and proceed to step A3.8; if T2′ ≤ T0′, adjust the lower limit and the upper limit of the set safe operating temperature of the two-degree-of-freedom gyroscope, and return to step A1; Step A3.8 Judge whether the actual safe temperature range T1′~T2′ of the two-degree-of-freedom gyroscope meets the working safe temperature range of the two-degree-of-freedom gyroscope required by the product. If it does not meet the requirements, adjust the lower limit and the upper limit of the set safe operating temperature of the two-degree-of-freedom gyroscope, and return to step A1.

5. The design method of the bellows based on the safe operating temperature of the two-floating gyroscope according to claim 4, characterized in that, In step A3.1, the specific value of the wave number n of the corrugated pipe (2) determined within the value range of the wave number n obtained in step A1.4 is as follows: the wave number n of the actual corrugated pipe (2) takes the half-wave or integral wave closest to ΔL / (L + -L - ).

6. The bellows design method based on the safe operating temperature of a two-floating gyroscope according to claim 5, wherein: In step A3.4, the specific method for determining the actual pre-compression amount Δ′ of the bellows (2) in the free state at the bayonet temperature by Δ2 is: the actual pre-compression amount Δ′ of the bellows (2) in the free state at the gyroscope bayonet temperature is greater than the calculated value Δ2, and there is a margin of more than 50% compared with the calculated value.

7. A bellows assembly method based on the safe operating temperature of a two-floated gyroscope, wherein the bellows is obtained by using the bellows design method based on the safe operating temperature of a two-floated gyroscope according to any one of claims 1-6, and is characterized in that, It includes the following steps: Step B1, Assembly of the bellows assembly The bellows assembly includes a bellows (2) and bellows covers (1) and bellows bottom plates (3) arranged axially at both ends of the bellows (2); The bellows cover (1) and the bellows (2) are soldered with tin-lead, and the bellows (2) and the bellows bottom plate (3) are adhesively sealed; an auxiliary tooling is used to make the bellows cover (1), the bellows (2) and the bellows bottom plate (3) coaxial and subject to axial pressure, so that the solder and the adhesive flow into the gaps between the bellows cover (1) and the bellows (2), and between the bellows (2) and the bellows bottom plate (3) respectively. The auxiliary tooling includes a bellows compression tooling I (4) and a bellows compression tooling II (5). A stepped component installation groove (51) and an installation hole for the bellows compression tooling I (4) are provided in the center of the bellows compression tooling II (5). The bellows bottom plate (3) is installed in the component installation groove (51); the side of the bellows compression tooling I (4) is provided with threads and is threadedly connected to the bellows compression tooling II (5). One end is designed with a boss (41), and the boss (41) passes through the inner cavities of the bellows (2) and the bellows bottom plate (3) and is threadedly connected to the bellows cover (1). Step B2: Setting the pre-compression amount of the bellows (2) in the free state at the gyro bayonet temperature Step B2.1 Calculate the angle θ that the bellows compression tooling II (5) turns when it pushes the bellows bottom plate (3) to drive the bellows (2) to contract by Δ. θ = 2πΔ / d In the formula, d is the pitch of the thread on the bellows compression device II (5). Step B2.2 Rotate the bellows compression tooling II (5) so that the bellows compression tooling II (5) fits with the bellows bottom plate (3), and the bellows (2) is in the initial state. Mark a line I (11) on the end face of the bellows compression tooling II (5). Along the radial direction of the line I (11), make a marking line (10) on the end face of the two-float gyro housing. Step B2.3 Mark a line II (12) and a line III (13) at the positions where the line I (11) rotates by an angle θ along the clockwise and counterclockwise directions respectively. Step B2.4 Rotate the bellows compression tooling II (5) to push the bellows bottom plate (3) to drive the bellows (1) to move towards the inside of the gyro until the line II (12) or the line III (13) on the bellows compression tooling II (5) is first aligned with the marking line (10) on the gyro housing end face, so as to realize the setting of the pre-compression amount of the bellows (2) before gyro oil filling.

8. The bellows assembly method based on the safe operating temperature of the two-floating gyro according to claim 7, characterized in that, Step B1 is specifically as follows: Step B1.1 Assemble the bellows assembly and the auxiliary tooling Sequentially sleeve the bellows (2) and the bellows cover (1) on the bellows bottom plate (3), and place the sleeved bellows cover (1), bellows (2) and bellows bottom plate (3) into the component installation groove (51) of the bellows compression tooling II (5); the bellows compression tooling I (4) is installed in the installation hole in the center of the bellows compression tooling II (5), and the boss (41) passes through the inner cavities of the bellows (2) and the bellows bottom plate (3) and is threadedly connected to the bellows cover (1). Adjust the position of the corrugated pipe bottom plate (3) so that it is at the center of the component installation groove (51) of the corrugated pipe compression tooling II (5). Rotate the corrugated pipe compression tooling II (5), and push the corrugated pipe (2) through the corrugated pipe bottom plate (3) to make the corrugated pipe (2) fit tightly with the corrugated pipe cover (1) and receive axial pressure. Step B1.2 Weld the corrugated pipe cover (1) and the corrugated pipe (2) Pass the assembled corrugated pipe assembly and the auxiliary tooling through the rotatable three-jaw turntable, and fix the three movable jaws of the three-jaw turntable on the outer circle of the corrugated pipe compression tooling I (4). Rotate the three-jaw turntable to drive the corrugated pipe compression tooling I (4), the corrugated pipe compression tooling II (5) and the corrugated pipe assembly to rotate simultaneously. At this time, place the soldering iron at the welding part of the corrugated pipe cover (1) and the corrugated pipe (2), and gradually melt the tin-lead and let it flow into the gap between the two. Step B1.3 Bond the corrugated pipe (2) and the corrugated pipe bottom plate (3) Disassemble the welding auxiliary tooling, clean the corrugated pipe assembly ultrasonically in gasoline and acetone, roughen the bonding part of the cleaned corrugated pipe bottom plate (3), and then start bonding; when bonding, make the glue flush with the end face of the corrugated pipe (2). Step B1.4 Cure the corrugated pipe assembly Assemble the corrugated pipe assembly and the auxiliary tooling in the method of Step B1.1, rotate the corrugated pipe compression tooling II (5), apply axial pressure between the corrugated pipe (2) and the corrugated pipe cover (1), and then cure the corrugated pipe assembly at a temperature of 80°C ± 2°C for 4 hours.

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