Solid rocket engine insulation film groove manufacturing equipment and method

Abstract

The present invention provides a device and method for making a bevel of an insulating film for a solid rocket engine. The device includes a lower template fixedly mounted on a fixed platform of a press and an upper template fixedly mounted on a movable platform of the press, and also includes a baffle for limiting the relative movement of the two. A square film to be processed is placed between the upper and lower templates. The upper and lower templates are tightly fitted on one side of the square film by means of a concave-convex fit. The ends of the processed square film are both provided with a vertical bevel blunt edge and an inclined bevel surface. The upper template includes a first contact surface that fits with the inclined bevel surface. The lower template includes a second contact surface that fits with the vertical bevel blunt edge. Compared with existing manual grinding, the method for making a bevel of the present invention does not generate large amounts of dust, thus reducing harm to personnel. Compared with existing blade cutting, it requires less skill from technicians.

Description

Technical Field

[0001] The invention belongs to the field of manufacturing thermal insulation structures of composite products, and in particular relates to equipment and a method for manufacturing thermal insulation film grooves of solid rocket engines. Background Art

[0002] China's commercial space industry has experienced rapid growth in recent years. Most commercial, especially civilian, companies use solid rocket engines, which offer relatively low technical complexity and production costs. Furthermore, with the rise of composite materials, these materials, with their higher specific strength and stiffness, are gradually replacing traditional steel, aluminum, and titanium alloys. This is evident in the use of filament-wound composite engine casings.

[0003] The insulation layer is a protective layer placed between the propellant and the engine casing. Its primary function is to protect the engine casing from the high-temperature gases of propellant combustion, allowing the engine to operate properly. Furthermore, it acts as a buffer for free-loading propellants, reducing collisions between the free-loading propellant and the casing and mitigating stress transfer. Unlike steel casings, filament-wound casings can be pressurized using methods such as airbags, with the casing itself serving as a formwork for the insulation layer. The primary process involves applying the insulation layer to the core formwork surface. The film is cut to specific dimensions and then overlapped one by one to cover the entire core formwork. Due to the significant overlap between the films and the straight edges of the cut films, direct stacking can create localized high spots, resulting in either film or fiber overhangs, which can affect the quality of the insulation layer itself.

[0004] The existing solution involves creating a bevel on the cut EPDM film, creating a gradual transition from thick to thin, with overlapping bevels. This requires specialized beveling of the film, and there are two traditional methods: cutting with a blade and grinding with a handheld grinder. The former requires high operator skill, is inefficient, and suffers from poor quality consistency. The latter, while also requiring a certain level of skill, generates significant dust, which can be harmful to the operator's health.

[0005] Therefore, it is necessary to provide a new device and method for making the thermal insulation film groove of the solid rocket engine to solve the above-mentioned problems of low efficiency, poor processing quality and generation of a large amount of dust. Summary of the Invention

[0006] The purpose of the present invention is to provide an apparatus and method for producing a thermal insulation film groove for a solid rocket engine. The apparatus and method not only have low requirements on the skill level of the technicians, but also have high processing efficiency and stable groove quality, and do not generate a large amount of dust.

[0007] To achieve the above-mentioned object, the present invention discloses a device for manufacturing a thermal insulation film groove of a solid rocket engine, the device comprising:

[0008] A lower template fixedly arranged on the fixed platform of the press and an upper template fixedly arranged on the movable platform of the press, and also comprising a baffle for limiting the relative movement between the two;

[0009] The square film to be processed is placed between the upper template and the lower template;

[0010] The upper template and the lower template are tightly fitted together on one side of the square film by means of concave-convex fitting;

[0011] The end of the processed square film is provided with a vertical bevel blunt edge and an inclined bevel surface;

[0012] The upper template includes a first contact surface that fits the inclined groove surface;

[0013] The lower template includes a second contact surface that fits with the blunt edge of the vertical groove, and a third contact surface that intersects with the second contact surface, and the third contact surface fits with the upper surface of the lower template.

[0014] Furthermore, the angle α between the inclined groove surface and the horizontal plane is 7 to 15°.

[0015] Furthermore, the height h of the blunt edge of the vertical groove is 0.2-0.7 mm.

[0016] Furthermore, the shape of the upper template is L-shaped, the shape of the lower template is square and matches the size of the upper template, there are at least two baffles, and the two baffles are respectively fixed on the side ends of the concave and convex fitting of the L-shaped upper template and the lower template.

[0017] Furthermore, the uppermost end of the baffle is lower than the upper surface of the upper template.

[0018] The present invention also discloses a method for manufacturing a thermal insulation film groove of a solid rocket engine, comprising the following steps:

[0019] Clean the upper and lower templates: fix the upper template on the movable platform of the press, set the lower template on the fixed platform of the press, and clean the surfaces of the upper and lower templates;

[0020] Making film: Making square film in an open mill;

[0021] First mold closing: Place the square film on the lower template, align two adjacent sides of the square film with the second contact surface of the lower template, operate the press to align the upper template with the lower template, perform the first mold closing, then pressurize the press to a specified pressure and immediately release the pressure, and raise the upper template;

[0022] Second mold closing: remove the square film, turn it horizontally 180 degrees, align the other two sides with the second contact surface of the lower template, operate the press to align the upper template with the lower template, and perform the second mold closing. Then, press the press to the specified pressure and immediately release the pressure, lift the upper template, and remove the square film;

[0023] Final cleaning: cleaning the burrs produced by the square film.

[0024] Furthermore, cleaning the surfaces of the upper template and the lower template includes:

[0025] Use industrial wiping paper to wipe off the oil stains on the surfaces of the upper template and the lower template, and use polytetrafluoroethylene glass fiber tape with adhesive backing to wrap their surfaces.

[0026] Furthermore, the film making includes:

[0027] The heat-insulating layer material made of EPDM or nitrile rubber is placed in an open mill, and the gap between the rollers of the open mill is adjusted to make the rubber into a film with a thickness of 1 to 3 mm; the film is cut into square films of a specific size according to the use requirements, and the square films are placed for 3 to 5 hours.

[0028] Furthermore, the specified pressure of the press is 6 to 9 tons, the mold closing rate is 200 to 1000 mm / min, and the mold gap after mold closing is 0.1 to 0.3 mm.

[0029] Furthermore, the final cleaning also includes cleaning the EPDM or NBR overflowing into the gap between the upper and lower templates.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. The upper and lower templates of the solid rocket engine insulation film groove manufacturing equipment of the present invention are simple to process. The upper and lower templates are made of 45 steel, which can withstand the high pressure of the press and can be used repeatedly;

[0032] 2. Compared with the existing manual grinding, the method for manufacturing the bevel of the thermal insulation film of the solid rocket engine of the present invention does not generate large dust and reduces the harm to the operator's body;

[0033] 3. Compared with the existing blade cutting, the method for making the bevel of the thermal insulation film of the solid rocket engine of the present invention has lower requirements on the skill level of the technicians. It only requires the two sides of the bevel to be aligned with the second contact surface of the lower template at the beginning, and then the direction of the film is adjusted once in the middle. It is highly efficient and the quality of the bevel is stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the upper template structure in the device of the present invention;

[0035] Figure 2 Schematic diagram of the lower template structure in the device of the present invention;

[0036] Figure 3 A schematic diagram of the square film structure processed by the device of the present invention;

[0037] Figure 4 A cross-sectional view of the upper and lower templates and the square film in the device of the present invention;

[0038] Figure 5 for Figure 4 Enlarged view of point A in the middle.

[0039] In the figure: upper template 1, upper template upper surface 11, first contact surface 12, square film 2, vertical groove blunt edge 21, inclined groove surface 22, lower template 3, second contact surface 31, third contact surface 32, baffle 4. DETAILED DESCRIPTION

[0040] In order to better explain the present invention, the main contents of the present invention are further illustrated below in conjunction with specific examples, but the contents of the present invention are not limited to the following examples.

[0041] like Figures 1 to 5 As shown, this embodiment discloses an apparatus for producing a beveled edge for a thermal insulation film for a solid rocket engine. The apparatus comprises a lower template 3 fixedly mounted on a fixed platform of a press, an upper template 1 fixedly mounted on a movable platform of the press, and a baffle 4 for limiting relative movement between the lower template 1 and the upper template 3. A square film 2 to be processed is placed between the upper template 1 and the lower template 3. The upper surface 1 of the upper template contacts the movable platform of the press. The upper template 1 and the movable platform are fixedly connected using screws, and when the press is raised or lowered, the upper template 1 is moved up and down.

[0042] In this embodiment, Figure 4 As shown, the upper template 1 and the lower template 3 achieve concave-convex fit through stepped steps. This arrangement allows for a tight fit and improves the quality of the groove.

[0043] In this embodiment, the upper and lower templates are both made of 45# steel, which has good pressure resistance and can meet the pressure requirements of the press.

[0044] like Figures 3-5As shown, in this embodiment, the film is made of insulating rubber and is rectangular in shape, although a square shape is also possible. The ends of the square film 2 are each provided with a vertical bevel edge 21 and an inclined bevel surface 22. The angle α between the inclined bevel surface 22 and the horizontal plane is 7 to 15°. The height h of the vertical bevel edge 21 is 0.2 to 0.7 mm.

[0045] like Figure 1 and 2 As shown, in this embodiment, the upper template 1 is L-shaped, the lower template 3 is square in shape to match the size of the upper template 1, and there are two baffles 4, each of which is fixedly arranged at the side ends of the two free edges of the L-shaped upper template to prevent the upper and lower templates from moving relative to each other during the operation of the press, which would affect the quality of the final square crack.

[0046] In this embodiment, the uppermost end of the baffle 4 is lower than the upper surface of the upper mold plate 1. This arrangement prevents interference with the upper and lower mold plates during operation of the press. The upper mold plate 1 includes a first contact surface 12 that mates with the inclined groove surface 22; the lower mold plate 3 includes a second contact surface 31 that mates with the blunt edge 21 of the vertical groove, and a third contact surface 32 that intersects with the second contact surface 31 and mates with the upper surface of the lower mold plate 3. In this embodiment, the first, second, and third contact surfaces are all rectangular in shape.

[0047] The method for manufacturing the thermal insulation film groove of the solid rocket engine comprises the following steps:

[0048] Clean the upper and lower templates: Fix the upper template 1 on the movable platform of the press, set the lower template 3 on the fixed platform of the press, use industrial wipes to wipe off the oil stains on the surface of the upper template 1 and the lower template 3, and wrap their surfaces with adhesive-backed polytetrafluoroethylene glass fiber tape.

[0049] Making the film: first clean the open mill, then place the insulation layer material such as EPDM or nitrile rubber in the open mill, adjust the rollers, and make the rubber into a film with a thickness of 1 to 3 mm; then cut the film into square films 2 of specific sizes according to the requirements of use, and place the square films 2 at room temperature for 3 to 5 hours to allow them to be better formed.

[0050] In this embodiment, cleaning the mill includes using an organic solvent such as ethyl acetate or anhydrous ethanol to clean the rollers and the receiving tray of the mill. Clean scrap rubber can also be used to pass the rollers 3 to 4 times to ensure that the surfaces of the rollers and the receiving tray are clean and free of debris.

[0051] Adjusting the rollers includes adjusting the roller distance between the two rollers to 1-3mm, controlling the roller temperature to ≤70℃, and the frequency conversion speed to 30-60Hz. After the rubber material passes through the mixing mill 3-4 times, the corresponding roller distance is adjusted according to the required film thickness, so that the film wraps around the rollers and comes out as a sheet, and then the produced film is cut into the required size.

[0052] First mold closing: Place the square film 2 on the lower template 3, align the adjacent sides of the square film 2 with the second contact surface 31 of the lower template 3, operate the press to align the upper template 1 with the lower template 3, perform the first mold closing, then pressurize the press to the specified pressure and immediately release the pressure, and lift the upper template 1.

[0053] In this embodiment, during the mold closing process, since the shear force on the square film 2 is limited, it will not slip during the molding process, and there is no need to fix the other two sides of the square film 2 separately.

[0054] In this embodiment, the specified pressure of the press is 6-9 tons, the mold closing speed is 200-1000 mm / min, and the gap between the upper and lower mold plates after mold closing is 0.1-0.3 mm. That is, the final tight fit gap between the concave and convex parts of the upper and lower molds is 0.1-0.3 mm.

[0055] Second mold closing: Remove the square film 2, rotate it horizontally 180° so that the other two sides are aligned with the second contact surface 31 of the lower template 3, operate the press to align the upper template 1 with the lower template 3, and perform the second mold closing. Then, pressurize the press to the specified pressure and immediately release the pressure, lift the upper template 1, and remove the square film 2.

[0056] During the second mold closing process in this embodiment, the press pressure is specified to be 6-9 tons, the mold closing rate is 200-1000 mm / min, and the gap between the upper and lower mold plates after mold closing is 0.1-0.3 mm. A press pressure of 6-9 tons is sufficient to press a 1-3 mm square film 2. The required molding pressure increases linearly with its thickness.

[0057] Final cleaning: The flash produced by the square film 2 is cleaned, and the square film is further cleaned with ethyl acetate. Of course, ethyl acetate can also be replaced with an organic solvent such as anhydrous ethanol or n-butyl acetate. Compared with the manual polishing method in the prior art, the square film of the present invention is cleaner, and the mold pressing and flash cleaning personnel are separated, which improves overall work efficiency.

[0058] In this embodiment, the final cleaning also includes cleaning the EPDM or NBR overflowing into the gap between the upper and lower templates after the entire batch of square films 2 is processed, to ensure the overall cleanliness and prevent interference with the next processing.

[0059] In this embodiment, the groove making method of the present invention has lower requirements on the skill level of technicians compared to the existing blade cutting. It only requires the two sides of the groove to be aligned with the second contact surface 31 of the lower template 3 at the beginning, and then the direction of the square film 2 is adjusted once in the middle. It is highly efficient and the quality of the groove is stable.

Claims

1. A device for manufacturing a thermal insulation film groove of a solid rocket engine, characterized in that: The device includes: A lower template (3) fixedly arranged on a fixed platform of a press machine and an upper template (1) fixedly arranged on a movable platform of the press machine also include a baffle (4) for limiting relative movement between the two; The square film (2) to be processed is placed between the upper template (1) and the lower template (3); The upper template (1) and the lower template (3) are tightly fitted on a side adjacent to the square film (2) by means of concave-convex fitting; The end of the processed square film (2) is provided with a vertical groove blunt edge (21) and an inclined groove surface (22); The upper template (1) comprises a first contact surface (12) that is in contact with the inclined groove surface (22); The lower template (3) comprises a second contact surface (31) that fits with the blunt edge (21) of the vertical groove, and a third contact surface (32) that intersects with the second contact surface (31), wherein the third contact surface (32) fits with the upper surface of the lower template (3); The included angle α between the inclined groove surface (22) and the horizontal plane is 7-15°.

2. The device for manufacturing the thermal insulation film groove of a solid rocket engine according to claim 1, characterized in that: The height h of the blunt edge (21) of the vertical groove is 0.2-0.7 mm.

3. The device for manufacturing the thermal insulation film groove of a solid rocket engine according to claim 1, characterized in that: The upper template (1) is L-shaped, the lower template (3) is square in shape and matches the size of the upper template (1), and there are at least two baffles (4), which are respectively fixed on the side ends of the concave and convex fitting parts of the L-shaped upper template (1) and the lower template (3).

4. The device for manufacturing the thermal insulation film groove of a solid rocket engine according to claim 3, characterized in that: The uppermost end of the baffle (4) is lower than the upper surface of the upper template (1).

5. A method for manufacturing an insulation film groove of a solid rocket engine using the device according to any one of claims 1 to 4, characterized in that: The following steps are involved: Cleaning the upper and lower templates: fixing the upper template (1) on the movable platform of the press, placing the lower template (3) on the fixed platform of the press, and cleaning the surfaces of the upper template (1) and the lower template (3); Making film: Making square film in an open mill (2); First mold closing: placing the square film (2) on the lower template (3), aligning two adjacent sides of the square film (2) with the second contact surface (31) of the lower template (3), operating the press to align the upper template (1) with the lower template (3), performing the first mold closing, then immediately releasing the pressure after applying pressure to a specified value, and raising the upper template (1); Second mold closing: remove the square film (2), turn it horizontally 180 degrees, align the other two sides with the second contact surface (31) of the lower template (3), operate the press to align the upper template (1) with the lower template (3), and perform the second mold closing. Then, press the press to a specified pressure and immediately release the pressure, and lift the upper template (1) to remove the square film (2); Final cleaning: cleaning the burrs produced by the square film (2).

6. The method for manufacturing the thermal insulation film groove of the solid rocket engine according to claim 5, characterized in that: Cleaning the surfaces of the upper template (1) and the lower template (3) includes: Oil stains on the surfaces of the upper template (1) and the lower template (3) are wiped off with industrial wiping paper, and their surfaces are wrapped with polytetrafluoroethylene glass fiber tape with adhesive backing.

7. The method for manufacturing the thermal insulation film groove of the solid rocket engine according to claim 5, characterized in that: The film making comprises: The heat insulation layer material made of EPDM or nitrile rubber is placed in an open mill, and the gap between the rollers of the open mill is adjusted to make the rubber into a film with a thickness of 1 to 3 mm; the film is then cut into square films (2) of a specific size according to usage requirements, and the square films (2) are placed for 3 to 5 hours.

8. The method for manufacturing a thermal insulation film groove of a solid rocket engine according to claim 5, characterized in that: The specified pressure of the press is 6-9t, the mold closing rate is 200-1000mm / min, and the mold gap after mold closing is 0.1-0.3mm.

9. The method for manufacturing the thermal insulation film groove of the solid rocket engine according to claim 5, characterized in that: The final cleaning also includes: cleaning the EPDM or NBR that overflows into the gap between the upper and lower templates.

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