Integrated sealed housing for lightweight inertial navigation module

Abstract

The application relates to a shell structure of an inertial navigation module, in particular to an integrated sealing shell of a lightweight inertial navigation module, which aims to solve the technical problem that the sealing design of the existing inertial navigation module shell has high requirements on the size and thickness of the shell, leading to a large weight of the inertial navigation module shell. The application comprises a base, a cover plate and a plurality of mounting screws, the base is provided with a slope on the outer side around the opening position of the cavity, the cover plate is provided with a matching slope for abutting and matching with the slope, the slope is provided with a first inner sealing groove and a first outer sealing groove, the matching slope is provided with a second inner sealing groove and a second outer sealing groove, an inner sealing strip is arranged in the mounting cavity surrounded by the first inner sealing groove and the second inner sealing groove, an outer sealing strip is arranged in the mounting cavity surrounded by the first outer sealing groove and the second outer sealing groove, and the plurality of mounting screws are fixedly connected to the base through a plurality of threaded blind holes arranged on the slope and a plurality of screw mounting holes arranged on the cover plate.

Description

Technical Field

[0001] This invention relates to the housing structure of an inertial navigation module, and more specifically to an integrated sealed housing for a lightweight inertial navigation module. Background Technology

[0002] As a key component of a navigation system, the inertial navigation module's core function is to ensure the normal operation of its internal instruments and meters. Maintaining the airtightness of the inertial navigation module's casing is crucial for ensuring the proper functioning of these core components, especially in environments with high humidity, salt spray, and varying air pressures.

[0003] Currently, the sealing design of inertial navigation module housings mainly uses sealant, gaskets, or single-weight sealing strips. While these designs provide a certain degree of sealing, they impose high requirements on housing thickness and offer little consideration for lightweight design, resulting in a significant weight for the inertial navigation module housing. Other sealing designs for inertial navigation module housings include... Figure 1 The structure shown has a first inner sealing groove and a first outer sealing groove on the end face of the base, and a second inner sealing groove and a second outer sealing groove on the cover plate. The second inner sealing groove has the same depth as the first inner sealing groove. An inner sealing strip is installed in the mounting cavity formed by the first inner sealing groove and the second inner sealing groove. The second outer sealing groove has the same depth as the first outer sealing groove. An outer sealing strip is installed in the mounting cavity formed by the first outer sealing groove and the second outer sealing groove. Compared with a single sealing strip, the double sealing strip structure formed by the inner and outer sealing strips has better sealing performance, but at the same time, it requires a thicker outer shell, resulting in a heavier inertial navigation module shell. Summary of the Invention

[0004] The purpose of this invention is to solve the technical problem that the sealing design of existing inertial navigation module housings has high requirements for the size and thickness of the housing, resulting in a large weight of the inertial navigation module housing, and to provide an integrated sealed housing for a lightweight inertial navigation module.

[0005] To achieve the above objectives, the technical solution provided by this invention is as follows:

[0006] An integrated sealed housing for a lightweight inertial navigation module, characterized by:

[0007] Includes a base, cover plate, inner sealing strip, outer sealing strip, and multiple mounting screws;

[0008] The base has an internal cavity, and the base has inclined surfaces around the opening of the cavity. The cover plate has a mating inclined surface that abuts against the inclined surface.

[0009] A first inner sealing groove and a first outer sealing groove are provided on the inclined surface, and a second inner sealing groove and a second outer sealing groove are provided on the inclined surface. The inner sealing strip is set in the mounting cavity formed by the first inner sealing groove and the second inner sealing groove, and the outer sealing strip is set in the mounting cavity formed by the first outer sealing groove and the second outer sealing groove.

[0010] The inclined surface is provided with multiple threaded blind holes that correspond one-to-one with multiple mounting screws. The cover plate is provided with multiple screw mounting holes that correspond one-to-one with multiple mounting screws. Multiple mounting screws fix the cover plate to the base through the corresponding screw mounting holes and threaded blind holes. Multiple mounting screws are arranged at intervals around the opening of the cavity and are all located outside the outer sealing strip.

[0011] Furthermore, the distance between any two adjacent mounting screws shall not exceed 25mm.

[0012] Furthermore, the axes of the screw mounting holes and the threaded blind holes are perpendicular to the inclined plane;

[0013] The thickness of the base not only meets the requirements for the thread engagement length of the mounting screws, but also ensures that for any threaded blind hole, the distance between the bottom of the threaded blind hole and the cavity wall is greater than 1.5mm.

[0014] Furthermore, if we define the depth of the first inner sealing groove as h1, the depth of the second inner sealing groove as h2, the depth of the first outer sealing groove as h3, and the depth of the second outer sealing groove as h4, then h1 < h3 and h2 > h4.

[0015] Furthermore, the inner sealing strip is bonded to the second inner sealing groove, and the outer sealing strip is bonded to the first outer sealing groove.

[0016] Furthermore, h1 and h2 also satisfy h1 / h2=2 / 3 or h1 / h2=3 / 7;

[0017] h3 and h4 also satisfy h3 / h4=3 / 2 or h3 / h4=7 / 3.

[0018] Furthermore, h1, h2, h3, and h4 also satisfy h1 + h2 = h3 + h4.

[0019] Furthermore, h1 > h3 and h2 < h4.

[0020] Furthermore, both the inner and outer sealing strips use closed sealing rings.

[0021] Furthermore, the dimensional tolerances of the mounting cavity are as follows:

[0022] The upper deviation of the depth dimension is 0 mm, and the lower deviation is -0.1 mm;

[0023] For inner and outer sealing strips with diameters less than 2.03mm or greater than 2.63mm, the upper deviation of the width dimension is +0.1mm and the lower deviation is 0mm.

[0024] For inner and outer sealing strips with a diameter greater than or equal to 2.03 mm and less than or equal to 2.63 mm, the upper deviation of the width dimension is +0.05 mm and the lower deviation is 0 mm.

[0025] Compared with the prior art, the present invention has the following beneficial technical effects:

[0026] 1. The integrated sealed shell of the lightweight inertial navigation module of the present invention adopts a double sealing strip structure with inner and outer sealing strips, which has better sealing performance than a single sealing strip. On this basis, by setting an inclined surface on the outer perimeter of the cavity opening of the base, and setting a mating inclined surface on the cover plate to abut against the inclined surface, and setting the first inner sealing groove, the first outer sealing groove and multiple threaded blind holes on the inclined surface, and setting the second inner sealing groove and the second outer sealing groove on the mating inclined surface, the wall thickness of the base is reduced. This can significantly reduce the overall weight and increase the internal size while ensuring good sealing performance at the connection between the base and the cover plate.

[0027] 2. The integrated sealed housing of the lightweight inertial navigation module of the present invention has a spacing of no more than 25mm between any two adjacent mounting screws, which can ensure that the cover plate uniformly and effectively presses the inner and outer sealing strips together, thereby achieving a better sealing effect.

[0028] 3. The integrated sealed shell of the lightweight inertial navigation module of the present invention has a base thickness that meets the requirements of the thread engagement length of the mounting screws, and also ensures that the distance between the bottom of any threaded blind hole and the cavity wall is greater than 1.5mm, thus guaranteeing the airtightness of the base structure itself.

[0029] 4. The integrated sealed housing of the lightweight inertial navigation module of the present invention, by setting h1 < h3 and h2 > h4, or h1 > h3 and h2 < h4, makes one of the inner sealing strip and the outer sealing strip more biased towards the base and the other more biased towards the cover plate. In terms of coping with high temperature / thermal cycling, a high-low misalignment effect is formed, which can effectively resist the deformation caused by thermal expansion and contraction. The stability of the integrated sealed housing of the lightweight inertial navigation module in compensating for thermal expansion gap is better than that of a symmetrical structure in which the second inner sealing groove and the first inner sealing groove have the same depth and the second outer sealing groove has the same depth; setting h1 < h3 and h2 > h4, or h1 > h3 and h2 < h4, makes one of the inner sealing strips more biased towards the base and the other more biased towards the cover plate. 4. This will result in different compression ratios between the inner and outer sealing strips. In dealing with high vibration / impact, the difference in compression ratio between the inner and outer sealing strips can resist dynamic displacement. The misalignment of the compression ratios and stress characteristics of the inner and outer sealing strips achieves complementary performance and can prevent leakage channels from appearing at both the inner and outer sealing strips simultaneously. In dealing with vacuum / high-pressure gas (greater than 10MPa), the misalignment of the inner and outer sealing strips can reduce the total pressure load of a single seal. In addition, among the inner and outer sealing strips, the sealing strip with a higher compression ratio undertakes the main sealing, while the sealing strip with a lower compression ratio ensures long-term resilience. The two form an effective mechanical complementarity, resulting in more comprehensive performance.

[0030] 5. The integrated sealed housing of the lightweight inertial navigation module of the present invention uses closed sealing rings for both the inner and outer sealing strips, which can increase airtightness compared to sealing rings formed by bonding the ends with adhesive.

[0031] 6. The integrated sealed housing of the lightweight inertial navigation module of the present invention can effectively improve sealing performance by specifying the dimensional tolerance of the mounting cavity and strictly controlling the tolerance of the sealing groove. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a sealing design structure for an existing inertial navigation module housing (the cover plate is not shown in the figure).

[0033] Figure 2 This is a three-dimensional structural diagram of an embodiment of an integrated sealed housing for a lightweight inertial navigation module according to the present invention (the cover plate and mounting screws are not shown in the figure).

[0034] Figure 3 This is a partial cross-sectional view of an embodiment of an integrated sealed housing for a lightweight inertial navigation module according to the present invention (the inner and outer sealing strips are not shown in the figure).

[0035] The annotations in the attached figures are explained as follows:

[0036] 1-Base, 11-Bevel, 12-First inner sealing groove, 13-First outer sealing groove, 14-Threaded blind hole, 15-Cavity, 2-Cover plate, 21-Matching bevel, 22-Second inner sealing groove, 23-Second outer sealing groove, 24-Screw mounting hole, 3-Inner sealing strip, 4-Outer sealing strip, 5-Mounting screw. Detailed Implementation

[0037] To make the objectives, advantages, and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0038] In the description of this invention, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0039] like Figure 2 and Figure 3 As shown in the figure, an integrated sealed housing for a lightweight inertial navigation module provided in this application embodiment includes a base 1, a cover plate 2, an inner sealing strip 3, an outer sealing strip 4, and multiple mounting screws 5.

[0040] The base 1 has a cavity 15 inside, and the base 1 has a slope 11 on the outer side of the opening of the cavity 15. The cover plate 2 has a mating slope 21 that abuts against the slope 11.

[0041] A first inner sealing groove 12 is provided on the inclined surface 11, and a second inner sealing groove 22 is provided on the inclined surface 21. An inner sealing strip 3 is disposed within the mounting cavity formed by the first inner sealing groove 12 and the second inner sealing groove 22. A first outer sealing groove 13 is also provided on the inclined surface 11, and a second outer sealing groove 23 is also provided on the inclined surface 21. An outer sealing strip 4 is disposed within the mounting cavity formed by the first outer sealing groove 13 and the second outer sealing groove 23. The outer sealing strip 4 is located outside the inner sealing strip 3. The depths of the first inner sealing groove 12 are defined as h1, the depth of the second inner sealing groove 22 as h2, the depth of the first outer sealing groove 13 as h3, and the depth of the second outer sealing groove 23 as h4. In this embodiment, h1 < h3 and h2 > h4. In other embodiments, h1 > h3 and h2 < h4 can also be set. In this embodiment, h1 + h2 = h3 + h4. In other embodiments, h1+h2>h3+h4 or h1+h2<h3+h4 can also be set.

[0042] In traditional designs where the depths of the second inner sealing groove and the first inner sealing groove are the same, and the depths of the second outer sealing groove and the first outer sealing groove are also the same, the stress and failure modes of the inner and outer sealing strips are highly consistent, potentially leading to simultaneous failure during thermal expansion and contraction. In the integrated sealing shell of this lightweight inertial navigation module, by setting h1 < h3 and h2 > h4, or h1 > h3 and h2 < h4, the inner sealing strip 3 and the outer sealing strip 4 are misaligned. This ensures that the inner sealing strip 3 and the outer sealing strip 4 maintain effective contact even under deformation. Even if one fails, the other remains a reliable backup, thus providing structural redundancy and higher reliability to the integrated sealing shell of this lightweight inertial navigation module.

[0043] Furthermore, the staggered arrangement of the inner sealing strip 3 and the outer sealing strip 4 results in different compression ratios for the two strips. The more tightly compressed strip provides the primary seal, while the looser strip ensures long-term resilience. This creates effective mechanical complementarity between the inner and outer sealing strips 3 and 4, making the integrated sealing shell of this lightweight inertial navigation module more comprehensive and capable of handling various operating conditions. It is recommended that the depth ratio of the two sealing grooves forming the same mounting cavity be 3 / 2 or 7 / 3, although other ratios can be used depending on actual needs.

[0044] The inner sealing strip 3 is bonded to the second inner sealing groove 22, and the outer sealing strip 4 is bonded to the first outer sealing groove 13, which facilitates installation.

[0045] To increase airtightness, both the inner sealing strip 3 and the outer sealing strip 4 are closed sealing rings, rather than sealing rings formed by bonding the ends with adhesive.

[0046] The dimensional tolerances for the mounting cavity are as follows: The upper deviation for depth is 0 mm, and the lower deviation is -0.1 mm; for inner sealing strips 3 and outer sealing strips 4 with diameters less than 2.03 mm or greater than 2.63 mm, the upper deviation for width is +0.1 mm, and the lower deviation is 0 mm; for inner sealing strips 3 and outer sealing strips 4 with diameters greater than or equal to 2.03 mm and less than or equal to 2.63 mm, the upper deviation for width is +0.05 mm, and the lower deviation is 0 mm. By specifying the dimensional tolerances for the mounting cavity and strictly controlling the tolerances of the sealing groove, sealing performance can be effectively improved. The table below provides recommended mounting cavity dimensions for sealing rings with diameters of 1.02 mm, 1.57 mm, 2.03 mm, 2.36 mm, 2.63 mm, and 3.18 mm.

[0047]

[0048] The integrated sealed housing of this lightweight inertial navigation module is mechanically connected to the cover plate 2 and the base 1 by multiple mounting screws 5, achieving an integrated design. Specifically, the inclined surface 11 is provided with multiple threaded blind holes 14 that correspond one-to-one with the multiple mounting screws 5, and the cover plate 2 is provided with multiple screw mounting holes 24 that correspond one-to-one with the multiple mounting screws 5. The axes of the screw mounting holes 24 and the threaded blind holes 14 are perpendicular to the inclined surface 11. The multiple mounting screws 5 are fixedly connected to the cover plate 2 and the base 1 through the corresponding screw mounting holes 24 and threaded blind holes 14. The multiple mounting screws 5 are arranged at intervals around the opening of the cavity 15 and are all located outside the outer sealing strip 4.

[0049] The spacing between any two adjacent mounting screws 5 is no more than 25mm. This ensures that the mechanical connection between the cover plate 2 and the base 1 is achieved through the mounting screws 5 at a specific distance, which can ensure that the cover plate 2 can evenly and effectively press the inner sealing strip 3 and the outer sealing strip 4 tightly.

[0050] In addition, the thickness of the base 1 not only meets the thread engagement length requirement of the mounting screw 5, but also ensures that for any threaded blind hole 14, the distance between the bottom of the threaded blind hole 14 and the cavity wall of the cavity 15 is greater than 1.5mm, thus ensuring the airtightness of the base 1 structure itself.

[0051] Both the base 1 and the cover plate 2 are made of aluminum alloy, which reduces the weight of the base 1 and the cover plate 2 while meeting the requirements of strength and rigidity.

[0052] During assembly of the integrated sealed housing of the aforementioned lightweight inertial navigation module, the inner sealing strip 3 and the outer sealing strip 4 are first bonded to the second inner sealing groove 22 and the first outer sealing groove 13, respectively. Then, the cover plate 2 is rigidly connected to the base 1 by multiple mounting screws 5. Finally, all mounting screws 5 are tightened with the mounting torque corresponding to the screw specifications to complete the assembly of the integrated sealed housing of the lightweight inertial navigation module.

[0053] The integrated sealed housing of the aforementioned lightweight inertial navigation module, while fully considering the requirements of manufacturability, reliability, and ease of maintenance in the processing and assembly of the inertial navigation module, achieves a lightweight integrated sealed design for the housing of the inertial navigation module. The overall weight is reduced by about 33%, while the internal volume is increased by about 12%. This significantly reduces the overall weight and increases the internal dimensions. Moreover, the manufacturing and assembly process is simple and can be widely used.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. An integrated sealed housing for a lightweight inertial navigation module, characterized in that: Includes a base (1), a cover plate (2), an inner sealing strip (3), an outer sealing strip (4), and multiple mounting screws (5); The base (1) has a cavity (15) inside, and the base (1) has an inclined surface (11) on the outer side of the opening of the cavity (15). The cover plate (2) has a mating inclined surface (21) that abuts against the inclined surface (11). The inclined surface (11) is provided with a first inner sealing groove (12) and a first outer sealing groove (13), the mating inclined surface (21) is provided with a second inner sealing groove (22) and a second outer sealing groove (23), the inner sealing strip (3) is provided in the mounting cavity formed by the first inner sealing groove (12) and the second inner sealing groove (22), and the outer sealing strip (4) is provided in the mounting cavity formed by the first outer sealing groove (13) and the second outer sealing groove (23). The inclined surface (11) is provided with a plurality of threaded blind holes (14) that correspond one-to-one with a plurality of mounting screws (5). The cover plate (2) is provided with a plurality of screw mounting holes (24) that correspond one-to-one with a plurality of mounting screws (5). The plurality of mounting screws (5) fix the cover plate (2) to the base (1) through the corresponding screw mounting holes (24) and threaded blind holes (14). The plurality of mounting screws (5) are arranged at intervals around the opening of the cavity (15) and are all located outside the outer sealing strip (4).

2. The integrated sealed housing of the lightweight inertial navigation module according to claim 1, characterized in that: The distance between any two adjacent mounting screws (5) shall not exceed 25mm.

3. The integrated sealed housing of the lightweight inertial navigation module according to claim 1, characterized in that: The axes of the screw mounting hole (24) and the threaded blind hole (14) are perpendicular to the inclined plane (11). The thickness of the base (1) not only meets the thread engagement length requirement of the mounting screw (5), but also satisfies that: for any one of the thread blind holes (14), the distance between the bottom of the thread blind hole (14) and the cavity wall of the cavity (15) is greater than 1.5mm.

4. The integrated sealed housing of the lightweight inertial navigation module according to claim 1, characterized in that: Define the depth of the first inner sealing groove (12) as h1, the depth of the second inner sealing groove (22) as h2, the depth of the first outer sealing groove (13) as h3, and the depth of the second outer sealing groove (23) as h4, then h1 < h3 and h2 > h4.

5. The integrated sealed housing of the lightweight inertial navigation module according to claim 4, characterized in that: The inner sealing strip (3) is bonded to the second inner sealing groove (22), and the outer sealing strip (4) is bonded to the first outer sealing groove (13).

6. The integrated sealed housing of the lightweight inertial navigation module according to claim 4, characterized in that: h1 and h2 also satisfy h1 / h2=2 / 3 or h1 / h2=3 / 7; h3 and h4 also satisfy h3 / h4=3 / 2 or h3 / h4=7 / 3.

7. The integrated sealed housing of the lightweight inertial navigation module according to claim 6, characterized in that: h1, h2, h3, and h4 also satisfy h1 + h2 = h3 + h4.

8. The integrated sealed housing of the lightweight inertial navigation module according to claim 1, characterized in that: h1 > h3 and h2 < h4.

9. The integrated sealed housing of the lightweight inertial navigation module according to any one of claims 1-8, characterized in that: Both the inner sealing strip (3) and the outer sealing strip (4) are closed sealing rings.

10. The integrated sealed housing of the lightweight inertial navigation module according to claim 9, characterized in that, The dimensional tolerances of the mounting cavity are as follows: The upper deviation of the depth dimension is 0 mm, and the lower deviation is -0.1 mm; For the inner sealing strip (3) and the outer sealing strip (4) with diameters less than 2.03 mm or greater than 2.63 mm, the upper deviation of the width dimension is +0.1 mm and the lower deviation is 0 mm; For the inner sealing strip (3) and the outer sealing strip (4) with a diameter greater than or equal to 2.03 mm and less than or equal to 2.63 mm, the upper deviation of the width dimension is +0.05 mm and the lower deviation is 0 mm.

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