Solid engine embedded wire pressure-bearing sealing structure

Abstract

The invention belongs to the technical field of solid engines, and particularly discloses a solid engine embedded wire pressure-bearing sealing structure which comprises a mounting hole, a wire baffle and a covering cap. The mounting hole is formed in the combustion chamber shell; the mounting hole is composed of a plurality of columnar holes which are sequentially arranged from inside to outside and have gradually increased diameters; a plurality of wire passing holes are formed in the wire blocking plate, the wire blocking plate is installed in the installation hole, and the inner end face of the wire blocking plate is attached to the first step face, counted from inside to outside, of the installation hole; the covering cap comprises a cover plate part and an inserting part which are coaxially arranged; the cover plate part is fixedly mounted at the opening of the mounting hole; a through hole is formed in the center of the inner end face of the inserting part, the inserting part is inserted into the mounting hole, and the inner end of the inserting part abuts against the outer end face of the wire blocking plate; and gaps among the cable, the mounting hole, the wire passing hole and the opening cover through hole are filled with epoxy resin glue for sealing. The structure and the assembly process are simple, and the cable is wrapped in the epoxy resin glue, so that the cable can be sealed in a high-temperature and high-pressure environment generated when the solid engine works.

Description

Technical Field

[0001] The invention belongs to the technical field of solid engines, and in particular relates to a pressure-bearing sealing structure for embedded wires in solid engines. Background Art

[0002] When a solid engine is in use, it may be necessary to provide power supply or communication cables for other parts installed in front and behind. The common practice in the industry is to install cables on the outer surface of the combustion chamber, but this will increase the maximum profile of the product. This problem can be solved by using a solid engine internal wire design. When a solid engine is working, the propellant will produce high-temperature combustion gas when it burns inside the combustion chamber, creating a high-temperature and high-pressure environment inside the combustion chamber. The position where the internal wire appears needs to withstand the pressure load and ensure that the gas does not flow out from the outlet.

[0003] The Chinese patent application with publication number CN217632713U: A solid rocket engine pressure measuring hole outlet sealing connection device discloses a pressure-bearing sealing structure, which is sealed by a sealing ring, a sealing gasket, a connecting thread, a connecting screw and a sealant. This structure includes a sealing ring and a sealing gasket, and a matching sealing groove needs to be designed. The surface quality and mechanical properties of the sealing ring and the sealing gasket need to be controlled during the processing, and there are many assembly processes. This structure is connected to the combustion chamber by a thread, which will cause the cable to twist and there is a risk of cable damage. This structure can only ensure that the cable can achieve the predetermined function (communication, transmission of electrical energy) before the solid rocket engine works. The cable has failed when the solid rocket engine is working, and it is impossible to achieve the predetermined function of the cable during and after the solid rocket engine works.

[0004] The Chinese patent application with publication number CN117578333A: A cable integrated cabin sealing device and installation method discloses a pressure-bearing sealing structure, which realizes water pressure and sealing through an outer watertight box, a glass sintered terminal block, a cup-shaped pipe joint, an inner watertight box and a connector. This structure is used in underwater environments. After the cable passes through the housing of the adapter product, it ensures sealing under the condition of bearing external water pressure. This structure adopts a glass sintering process, and the product needs to be placed in a high-temperature sintering furnace, which has high energy consumption and time costs. In addition, due to the limited size of the sintering furnace, when the installed product exceeds a certain volume or cannot withstand the sintering temperature, the sealing structure needs to be designed separately from the product and a set of connection and sealing structures are added. This structure is only suitable for sealing under conventional temperature and pressure environments (≤100℃, ≤0.3MPa), and cannot adapt to the sealing of the high temperature and high pressure environment (≥2000℃, ≥3MPa) inside the solid engine. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a solid engine internal wire pressure-bearing sealing structure which has a simple structure, low production cost, can achieve sealing under the high temperature and high pressure environment generated by the operation of the solid engine, and can ensure that the cable will not be damaged during the operation of the solid engine.

[0006] The technical solution adopted by the present invention is: a solid engine internal buried wire pressure-bearing sealing structure, comprising a mounting hole, a wire blocking plate and a cover; the mounting hole is arranged on the combustion chamber shell, and the mounting hole is a through hole; the mounting hole is composed of a plurality of columnar holes arranged in sequence from the inside to the outside and with increasing cross-sectional areas, and the plurality of columnar holes are coaxial; a plurality of wire passing holes are arranged on the wire blocking plate, and the wire blocking plate is installed in the mounting hole, and the inner end surface of the wire blocking plate is in contact with the first step surface of the mounting hole from the inside to the outside; The mouth cover includes a coaxially arranged cover plate portion and an insertion portion, the cover plate portion is fixedly installed at the opening of the mounting hole; a through hole is provided at the center of the inner end surface of the insertion portion, and the through hole is arranged along the axis of the mouth cover; the insertion portion is inserted into the mounting hole, and the insertion portion is matched with a partial gap between the wire baffle plate of the mounting hole and the opening, the gap between the insertion portion and the mounting hole is filled with epoxy resin glue for sealing, and the inner end of the insertion portion supports the outer end surface of the wire baffle plate; the cable passes through the through hole of the mouth cover and the wire passing hole of the wire baffle plate to enter the combustion chamber; the gap between the cable and the mounting hole, the gap between the cable and the wire passing hole, and the gap between the cable and the through hole of the mouth cover are filled with epoxy resin glue for sealing.

[0007] Furthermore, the end surface of the cover plate portion of the mouth cover is rectangular.

[0008] Furthermore, a protective sleeve fixing portion is provided on the outer end surface of the cover plate portion, and the protective sleeve fixing portion is connected to one end of the protective sleeve; the through hole on the mouth cover passes through the protective sleeve fixing portion, the tube hole of the protective sleeve is connected to the through hole of the mouth cover, and the protective sleeve is located on the outside of the cable.

[0009] Furthermore, the cover plate portion of the port cover is connected to the combustion chamber housing by bonding, welding, riveting or screwing.

[0010] Furthermore, a wire passing hole is provided on the wire blocking plate.

[0011] Furthermore, the epoxy resin glue used is SG-200 room temperature curing high temperature resistant glue.

[0012] Furthermore, the number of the columnar holes is 2, 3, 4 or 5.

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. The structure and assembly process of the present invention are simple, and have no special requirements on equipment and personnel, and can improve the reliability of sealing during mass production.

[0014] 2. The present invention will not cause the cable to rotate during installation, thus preventing the cable from being damaged due to twisting or friction. There is no need to rework the cable due to damage, thus reducing the cost of rework and repair.

[0015] 3. The cable of the present invention is wrapped in epoxy resin glue and will not come into contact with high-temperature combustion gas during operation, so that the present invention can achieve sealing in the high-temperature and high-pressure environment generated by the operation of the solid engine, and can ensure that the cable will not be damaged during the operation of the solid engine.

[0016] 4. The present invention does not require glass sintering, which reduces energy consumption and shortens time; thereby reducing production costs and ensuring that the combustion chamber of the present invention is not limited by the size of the sintering furnace.

[0017] 5. The wire baffle and the mouth cover of the present invention can be processed separately from the product, which can shorten the processing time and thus reduce the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural diagram of Example 1 of the present invention.

[0019] Figure 2 yes Figure 1 Middle AA section view.

[0020] Figure 3 It is a front view of a mouth cover of the present invention.

[0021] Figure 4 yes Figure 3 Middle BB section view.

[0022] Figure 5 It is a rear view of the mouth cover of the present invention.

[0023] Figure 6 It is a structural diagram of Example 2 of the present invention.

[0024] Figure 7 yes Figure 6 Middle CC section view. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the embodiments and drawings.

[0026] Example 1 like Figure 1-5As shown, the present invention includes a mounting hole 8, a wire blocking plate 4 and a cover 5; the mounting hole 8 is arranged on the combustion chamber housing 2, and the mounting hole 8 is a through hole. The mounting hole 8 is composed of two cylindrical holes with waist-shaped cross-sections (the number of cylindrical holes is not limited to two, can be more than two, and generally does not exceed 5) arranged in sequence from the inside to the outside and with increasing cross-sectional areas, and the two cylindrical holes are coaxial. The length of the first cylindrical hole from the inside to the outside is 15 mm, the width is 3 mm, and the minimum depth is 20 mm. The length of the second cylindrical hole is 31 mm, the width is 7 mm, and the depth is 25 mm. A wire passing hole is provided on the wire blocking plate 4 (the number of wire passing holes can be multiple, and the number is the same as the number of cables), and the wire passing hole is a waist-shaped hole. The length of the wire blocking plate 4 is 30 mm, the width is 6.5 mm, and the thickness is 6 mm. The length of the wire passing hole is 13.5 mm and the width is 1.5 mm. The wire blocking plate 4 is installed in the mounting hole 8 , and the inner end surface of the wire blocking plate 4 is in contact with the first step surface of the mounting hole 8 from the inside to the outside.

[0027] The mouth cover 5 includes a coaxially arranged cover plate portion 12, a protective sleeve fixing portion 13 and an inserting portion 11. The end face of the cover plate portion 12 is rectangular. The inserting portion 11 is arranged on the inner end face of the cover plate portion 12, and the protective sleeve fixing portion 13 is arranged on the outer end face of the cover plate portion 12. The cover plate portion 12 of the mouth cover 5 is fixedly installed at the opening of the mounting hole 8 by screws (it can also be installed by bonding, welding, or riveting), and the cover plate portion 12 blocks the opening of the mounting hole 8. A through hole 10 is provided at the center of the inner end face of the inserting portion of the mouth cover 5, and the through hole 10 is arranged along the axis of the mouth cover. The inserting portion 11 is inserted into the mounting hole 8, and the gap between the inserting portion 11 and the mounting hole 8 is filled with epoxy resin glue 3 for sealing, and the inner end of the inserting portion 11 presses against the outer end face of the wire blocking plate 4. The cable 1 passes through the through hole 10 of the cover and the wire hole of the baffle plate 4 to enter the combustion chamber; the gap between the cable 1 and the mounting hole 8, the gap between the cable 1 and the wire hole, and the gap between the cable 1 and the through hole 10 of the cover are filled with epoxy resin glue 3 for sealing. The epoxy resin glue 3 is SG-200 room temperature curing high temperature resistant glue (Q31 / 0106000059C006-2016).

[0028] The basic dimensions of the outer contour of the cross section of the insertion part 11 are the same as the basic dimensions of the mounting hole 8 outside the baffle plate 4, and the tolerance is used to ensure that the insertion part 11 is matched with the partial clearance between the baffle plate 4 and the hole of the mounting hole 8. The wall thickness of the insertion part 11 is 2 mm, and the through hole 10 is a round hole with a diameter of 8 mm.

[0029] The protective sleeve fixing part 13 is connected to one end of the protective sleeve 7; the through hole 10 on the mouth cover 5 penetrates the protective sleeve fixing part, the tube hole of the protective sleeve 7 is connected to the through hole 10 of the mouth cover 5, the protective sleeve 7 is located outside the cable 1, and the protective sleeve 7 can protect the cable 1. The wall thickness of the protective sleeve fixing part 13 is 0.5 mm. According to the water pressure test, the present invention maintains pressure for 35 seconds at an internal pressure of 15.5 to 16.5 MPa without rupture or water leakage.

[0030] Example 2

[0031] like Figure 6 , 7 As shown, the structure of this embodiment is similar to that of Embodiment 1, the only difference being that the mounting hole 8 is composed of three cylindrical holes with circular cross sections that are arranged in sequence from the inside to the outside and whose cross-sectional areas increase gradually.

[0032] The pressure generated by the operation of the solid engine is transmitted to the outer wall of the combustion chamber shell 2 through two paths. The first path is the baffle plate 4, the cover 5, and the outer wall of the combustion chamber shell 2. The second path is the epoxy resin glue 3, the bonding interface between the epoxy resin glue 3 and the mounting hole 8, the bonding interface between the epoxy resin glue 3 and the baffle plate 4, the bonding interface between the epoxy resin glue 3 and the cover 5, and the outer wall of the combustion chamber shell 2. When the solid engine is working, the potential path for the flow of fuel gas is the space filled with the epoxy resin glue 3, which is sealed by the epoxy resin glue 3. Therefore, when designing the present invention, it is necessary to meet the following requirements: the shear force that the bonding gap can withstand + the separation force between the cover and the load-bearing tube ≥ the safety factor × the maximum working pressure of the solid engine × the cross-sectional area of ​​the first columnar hole, and the expression is as follows: ; A 1 ——The total area of ​​the inner surface of the mounting hole 8, in square millimeters; ——The shear strength of the bonding surface between the epoxy resin adhesive 3 and the pressure-bearing structure after curing, in MPa; A 2 ——Surface area of ​​the wire baffle 4, in square millimeters; A 3 ——The total area of ​​the inner and outer end surfaces of the wire baffle 4, in square millimeters; ——The shear strength of the bonding surface between the epoxy resin glue 3 and the wire baffle 4 after curing, in MPa; A 4 - the total area of ​​the through holes 10 of the cover 5, in square millimeters; A 5 ——The total area of ​​the outer side wall of the insertion portion 11, in square millimeters; - shear strength of the bonding surface between the epoxy resin glue 3 and the mouth cover 5 after curing, in MPa; F 1 ——Separation force between the cover 5 and the mounting hole 8, in Newton; n——safety factor, greater than or equal to 3; P max ——The maximum operating pressure of the solid rocket motor, in MPa; A 6 ——The cross-sectional area of ​​the first columnar hole in the mounting hole 8 from the inside to the outside, in square millimeters.

[0033] The separation force between the mouth cover 5 and the mounting hole 8 refers to the minimum force required to separate the two along the vertical direction of the connection surface after the cover plate part 12 of the mouth cover 5 is connected to the side wall of the combustion chamber shell 2 by bonding, welding, riveting or screwing. The connection surface refers to the fitting surface between the cover plate part 12 of the mouth cover 5 and the side wall of the combustion chamber shell 2.

Claims

1. A pressure-bearing sealing structure for buried wires in a solid engine, comprising a mounting hole, a wire blocking plate and a cover; the mounting hole is arranged on the combustion chamber casing, and the mounting hole is a through hole; the characteristics are: The mounting hole is composed of a plurality of columnar holes arranged in sequence from the inside to the outside and with increasing cross-sectional areas, and the plurality of columnar holes are coaxial; a plurality of wire passing holes are provided on the wire blocking plate, the wire blocking plate is installed in the mounting hole, and the inner end surface of the wire blocking plate is in contact with the first step surface of the mounting hole from the inside to the outside; The mouth cover includes a coaxially arranged cover plate portion and an insertion portion, the cover plate portion is fixedly installed at the opening of the mounting hole; a through hole is provided at the center of the inner end surface of the insertion portion, and the through hole is arranged along the axis of the mouth cover; the insertion portion is inserted into the mounting hole, and the insertion portion is matched with a partial gap between the wire baffle plate of the mounting hole and the opening, the gap between the insertion portion and the mounting hole is filled with epoxy resin glue for sealing, and the inner end of the insertion portion supports the outer end surface of the wire baffle plate; the cable passes through the through hole of the mouth cover and the wire passing hole of the wire baffle plate to enter the combustion chamber; the gap between the cable and the mounting hole, the gap between the cable and the wire passing hole, and the gap between the cable and the through hole of the mouth cover are filled with epoxy resin glue for sealing.

2. The solid rocket engine internal wire pressure-bearing sealing structure according to claim 1 is characterized by: The end surface of the cover plate portion of the flap is rectangular.

3. The solid rocket engine internal wire pressure-bearing sealing structure according to claim 1 is characterized by: A protective sleeve fixing part is provided on the outer end surface of the cover plate part, and the protective sleeve fixing part is connected to one end of the protective sleeve; the through hole on the port cover passes through the protective sleeve fixing part, the tube hole of the protective sleeve is connected to the through hole of the port cover, and the protective sleeve is located on the outside of the cable.

4. The solid rocket engine internal wire pressure-bearing sealing structure according to claim 1 is characterized by: The cover plate portion of the port cover is connected to the combustion chamber housing by bonding, welding, riveting or screwing.

5. The solid rocket engine internal wire pressure-bearing sealing structure according to claim 1 is characterized by: A wire passing hole is provided on the wire blocking plate.

6. The solid rocket engine internal wire pressure-bearing sealing structure according to claim 1, characterized in that: The epoxy resin glue used is SG-200 room temperature curing high temperature resistant glue.

7. The solid rocket engine internal wire pressure-bearing sealing structure according to claim 1 is characterized by: The number of columnar holes is 2, 3, 4 or 5.

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