Bonding forming method and device for large-length-diameter-ratio long tail pipe of solid rocket engine

Abstract

The invention discloses a bonding forming method and equipment for a large-length-diameter-ratio long tail pipe of a solid rocket engine, and belongs to the technical field of solid rocket engines. The forming equipment comprises an overturning device for adjusting the included angle between the center axis of the spray pipe shell and the horizontal plane, a rotating device for controlling the spray pipe shell to rotate around the axis and an assembling and bonding tool. Different angle requirements of the spray pipe shell during assembly of the tail pipe liner are adjusted through the turnover device; when the center shaft of the spray pipe shell is adjusted to be located on the horizontal plane through the rotating device, the spray pipe shell can rotate around the shaft; and the tail pipe lining and the convergent section lining which are mounted in the spray pipe shell are pressed and positioned from the two ends in the axial direction through the assembling and bonding tool. According to the method, a corresponding one-time bonding forming process is established for bonding forming of the large-length-diameter-ratio long tail pipe of the solid rocket engine with the length as long as 2000 mm, and the purposes that the coaxiality of a spray pipe lining and a spray pipe shell is guaranteed, exhaust of a glue layer between the tail pipe lining and the spray pipe shell is smooth, and ultrasonic flaw detection is qualified are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of solid rocket engines, and in particular relates to a bonding molding method and equipment for a long tail tube with a large aspect ratio for a solid rocket engine. Background Art

[0002] The nozzle of a solid rocket engine is mainly composed of the nozzle shell and the nozzle liner (or tail pipe liner). There are two main ways of bonding and forming. One is the glue injection method, that is, after the shell and the liner are assembled vertically, a certain gap is reserved between the two. After the glue is injected from a small opening at the lower end, it is left to solidify and then formed. The other is the sleeve bonding method, which is to sandblast the nozzle shell and machine the tail pipe liner, apply glue to the bonding surface, and then rotate and press the tail pipe liner into the nozzle shell. The rotation and pressing of the liner is mainly to ensure a uniform glue layer and gas discharge. After the tooling is manually assembled, it is pressurized and solidified. The glue injection method was a common method used in the early days, that is, in the 1980s and 1990s. It has a complicated process and is suitable for small diameters ( The glue injection bonding of long tail pipes (or long tail nozzles) of small tactical engines with a length of less than 500mm and a length of less than 500mm has been applied in batch production.

[0003] At the beginning of this century, due to the continuous development of solid rocket engines, the nozzle diameter of solid rocket engines has continued to increase. For nozzle structures with a diameter greater than 200mm and a length of about 200mm to 600mm, the increase in the damping effect of the glue injection method causes an increase in the glue injection pressure, so that the glue injection process cannot be used to form the tail pipe lining and the nozzle shell. Therefore, the simple sleeve bonding method is mainly used. With the continuous expansion of solid rocket engine technology, the length of the solid rocket engine nozzle that provides power in a targeted manner continues to increase. For the bonding of the long tail nozzle and the nozzle shell of the engine with a length of up to 2000mm, due to the huge length, weight and volume of the nozzle, the traditional sleeve bonding method of manually rotating and pressing the nozzle liner and the manual handling method are no longer applicable. It is necessary to solve technical problems such as matching bonding devices and bonding processes to ensure uniform glue layer, smooth exhaust, coaxiality of the nozzle lining and the nozzle shell, and feasible bonding processes. Summary of the invention

[0004] Technical issues to be solved:

[0005] In order to avoid the shortcomings of the prior art, the present invention provides a method and equipment for bonding and forming a long tail pipe with a large aspect ratio of a solid rocket engine. Aiming at the bonding and forming of a long tail pipe with a large aspect ratio of a solid rocket engine with a length of up to 2000mm, a corresponding one-time bonding and forming process is established to ensure the coaxiality of the nozzle liner and the nozzle shell, and to ensure that the glue layer between the tail pipe liner and the nozzle shell is vented smoothly and the ultrasonic flaw detection is qualified. At the same time, in view of the huge length, weight and volume of the nozzle, the design and engineering application of the bonding implementation device required for rotation, flipping, lifting and moving encountered in the bonding, assembly, curing and flaw detection of the matching nozzle is solved.

[0006] The technical solution of the present invention is: a method for bonding and forming a long tail tube with a large aspect ratio of a solid rocket engine, and the specific steps are as follows:

[0007] Pre-treatment is performed on the nozzle shell, tail pipe lining and convergent section lining before assembly to ensure that each component meets the assembly requirements; the tail pipe lining is a three-section structure, and adjacent tail pipe linings are overlapped and installed by step surfaces;

[0008] Install the tail pipe liner and convergent section liner into the nozzle shell at the designated position, measure the installation position gap to determine whether it is suitable, and perform ultrasonic flaw detection on each component after it is qualified;

[0009] A plurality of streamlined asbestos sheets are arranged on the outer peripheral surface of the tail pipe liner to ensure the coaxiality of the tail pipe liner after it is installed into the nozzle shell;

[0010] The tail pipe liner is assembled into place in the nozzle housing by using an assembly bonding tool;

[0011] The convergent section liner is assembled into place in the nozzle shell by using an assembly bonding tool to obtain an assembled nozzle workpiece;

[0012] Post-process the nozzle workpiece to ensure that the glue coating of each component is evenly solidified;

[0013] Conduct flaw detection on the nozzle workpiece before curing;

[0014] The nozzle workpiece is cured and then subjected to flaw detection after curing.

[0015] A further technical solution of the present invention is: the pre-assembly pretreatment steps are as follows:

[0016] Sandblast the bonding surface of the nozzle shell and complete bonding within 4 hours after sandblasting or within 24 hours after storage in a sealed dry oven;

[0017] Clean and dry the tail pipe lining and convergent section lining;

[0018] Prepare epoxy adhesive for later use.

[0019] A further technical solution of the present invention is: the method for assembling the tail pipe liner in place in the nozzle housing is:

[0020] Apply glue evenly on the bonding surface of the streamlined asbestos sheet, the bonding surface of the tail pipe lining, and the bonding surface of the nozzle shell, without any accumulation or missing glue;

[0021] Place the nozzle shell vertically with the large diameter end facing upwards by using a flipping device, install the three-section tail pipe liner into the nozzle shell in sequence, and fill the remaining bonding surface of the nozzle shell with glue after each section of the tail pipe liner is assembled in place;

[0022] The uncoated convergent section liner is installed into the nozzle housing, and the components assembled in the nozzle housing are pressed into place by assembling and bonding tooling;

[0023] Remove the assembly bonding tooling and take out the lining of the convergent section;

[0024] If the distance between the upper end face of the tail pipe liner and the end face of the large diameter end of the nozzle shell meets the design requirements, it is determined that the tail pipe liner is bonded in place.

[0025] A further technical solution of the present invention is: the method for assembling the convergent section liner in place in the nozzle housing is:

[0026] Apply glue evenly on the bonding surface of the convergent section lining and the bonding surface of the nozzle shell, without any accumulation or missing glue;

[0027] Press the glue-coated convergent section lining into the nozzle shell, pressurize it into place and maintain the pressure for 5 minutes, and clean the squeezed excess glue;

[0028] The components assembled in the nozzle shell are pressed into place by assembling the bonding tool, and the distance between the upper end face of the tail pipe liner and the end face of the large diameter end of the nozzle shell is measured. If it meets the design requirements, it is judged that the tail pipe liner is bonded in place;

[0029] Apply a proper amount of silicone grease on the threads of the nozzle housing and the overflow area, and apply a proper amount of silicone grease on the contact area between the assembly bonding tooling and the nozzle workpiece.

[0030] A further technical solution of the present invention is: the method for post-processing the nozzle workpiece is: placing the nozzle workpiece with the assembly and bonding tooling horizontally on a rotating device, rotating it at room temperature for 4 hours, with a rotation speed of 35r / min±5r / min; after 4 hours, the nozzle workpiece with the assembly and bonding tooling is placed vertically through a flipping device, and left standing at room temperature for 24 hours.

[0031] A bonding and molding device for a long tail pipe with a large aspect ratio of a solid rocket engine, comprising a turning device for adjusting the angle between the central axis of a nozzle shell and a horizontal plane, a rotating device for controlling the rotation of the nozzle shell around the axis, and an assembly bonding tool;

[0032] The nozzle shell is adjusted to different angles during tail pipe liner assembly by means of a flipping device;

[0033] When the central axis of the nozzle housing is adjusted to be in a horizontal plane by a rotating device, it can rotate around the axis;

[0034] The tail pipe liner and the convergent section liner installed in the nozzle shell are pressed and positioned from both ends along the axial direction by assembling the bonding tool.

[0035] A further technical solution of the present invention is: the flipping device includes a base and a flipping table hinged thereon, one end of the flipping table is hinged to the base, and the other end is a free end, the free end is connected to the base through a hydraulic cylinder, and the hydraulic cylinder is used to control the rotation angle of the flipping table relative to the base; the upper surface of the flipping table is provided with a nozzle shell positioning assembly and a strap, which can fix the nozzle shell on the flipping table.

[0036] A further technical solution of the present invention is: the rotating device comprises a vehicle body and an active supporting wheel group and a passive supporting wheel group installed thereon, the central axes of the active supporting wheel group and the passive supporting wheel group are arranged in parallel, the nozzle housing is placed on the two, and the active supporting wheel group is driven to rotate, so as to drive the nozzle housing to rotate around the axis, and the passive supporting wheel group follows;

[0037] The active support wheel group includes two coaxially arranged active support wheels, and the passive support wheel group includes two coaxially arranged passive support wheels; by synchronously adjusting the axial distance between the two active support wheels and the axial distance between the two passive support wheels, it is suitable for the assembly of nozzle shells of different lengths; by adjusting the distance between the central axis of the active support wheel group and the central axis of the passive support wheel group, it is suitable for the assembly of nozzle shells of different diameters.

[0038] A further technical solution of the present invention is: the assembly and bonding tooling includes an upper cover plate and a lower cover plate encapsulated at both ends of the nozzle shell, and a core shaft passing through the center holes of the upper cover plate and the lower cover plate, and both ends of the core shaft are provided with external threads, and the tail pipe lining and the convergent section lining are pressed and positioned by two nuts respectively screwed on the outer ends of the upper cover plate and the lower cover plate.

[0039] A further technical solution of the present invention is: it also includes a vertical liftable device, which includes a base and a lifting platform installed thereon by a screw; the lifting platform is a U-shaped operating platform, and its U-shaped notch position is used to place the nozzle shell in a vertical state, so as to facilitate the operator to install the tail pipe lining and the convergent section lining.

[0040] Beneficial Effects

[0041] The beneficial effects of the present invention are as follows: the bonding and forming process of the long tail pipe with a large aspect ratio of the present invention adopts special equipment and tooling, which can perform corresponding operations according to the huge length, weight and volume of the nozzle. With the cooperation of the special equipment and tooling, the coaxiality and precise positioning during the installation process can be guaranteed, avoiding the problems of installation error or poor bonding quality caused by positioning or inadequate fixing between processes. The specific advantages are as follows:

[0042] (1) The rotating device in the present invention can be used for gluing, ultrasonic flaw detection, and curing. It is highly universal, safe, and reliable, and provides convenience for the bonding operation of large products. The flipping device in the present invention has a simple structure, high reliability, small space occupation, and high universality. The vertical lifting device in the present invention is quick and convenient to lift and has good versatility.

[0043] (2) The use of the streamlined asbestos sheet positioning piece on the outer surface of the tail pipe liner in the present invention ensures the coaxiality between the nozzle shell and the tail pipe liner, simplifies the cumbersome axial positioning tooling, reduces costs, and improves production efficiency and product quality.

[0044] (3) The present invention adopts a process design method of cumulative step sleeve connection of several sections of linings. Compared with the use of a single nozzle integral lining, the molding difficulty and cost of the tail pipe lining itself are reduced, the bonding operability of the tail pipe lining and the nozzle shell is strong, the exhaust channel is increased, and the bonding quality is improved.

[0045] (4) The wave number obtained by the empty matching of the tail pipe liner and the nozzle shell used in the present invention is used as the debonding standard for ultrasonic flaw detection, which reforms the traditional flat plate bonding flaw detection standard test plate method, reduces the error of the flat plate bonding flaw detection standard test plate and the cylindrical bonding workpiece flaw detection, and is practical, effective and easy to use.

[0046] (5) In the present invention, the tail pipe liner and the shell are bonded together, and the pull rod type liner and nozzle shell positioning bonding tooling is adopted, and the milling design of the cover plate ensures that the final liner and the nozzle shell are bonded in place with the axial dimensions, which is simple and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 Schematic diagram of the distance between the tail pipe liner and the nozzle shell reference plane and the test-matching measured value L in the present invention;

[0048] Figure 2 This is a schematic diagram of a rotating device in an embodiment of the present invention;

[0049] Figure 3 This is a schematic diagram of a flipping device in an embodiment of the present invention;

[0050] Figure 4 It is a schematic diagram of a vertical liftable device in an embodiment of the present invention;

[0051] Figure 5 This is a schematic diagram of a streamlined asbestos sheet positioning sheet in an embodiment of the present invention;

[0052] Figure 6 A schematic diagram of circumferential positioning during bonding in an embodiment of the present invention;

[0053] Figure 7 This is a schematic diagram of axial positioning during the bonding process in an embodiment of the present invention;

[0054] Figure 8 It is a schematic diagram of the step-connection of several sections of nozzle liners in an embodiment of the present invention.

[0055] Explanation of the accompanying drawings: 1. third tail pipe lining, 2. nozzle housing, 3. active support wheel, 4. driven support wheel, 5. axial guide rail, 6. transverse screw, 7. car body, 8. transverse hand wheel, 9. axial screw, 10. axial hand wheel, 11. roller, 12. control box, 13. binding seat, 14. roller, 15. turning table, 16. hydraulic cylinder, 17. base, 18. ladder, 19. hand wheel, 20. guardrail, 21. lifting platform, 22. reducer, 23. transmission shaft, 24. screw, 25. base, 26. roller, 27. streamlined asbestos sheet positioning plate, 28. first tail pipe lining, 29. upper cover plate, 30. lower cover plate, 31. core shaft, 32. convergent section lining, 33. second tail pipe lining. DETAILED DESCRIPTION

[0056] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0057] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0058] Based on the problems of design and engineering application of bonding implementation devices required for rotation, flipping, lifting and moving in the bonding, assembly, curing and flaw detection of matching nozzles in the prior art, the present invention provides a bonding molding method for a long tail tube with a large aspect ratio of a solid rocket engine, and the specific steps are as follows:

[0059] Step 1: Pre-treatment of the nozzle shell, tail pipe lining, and convergent section lining before assembly to ensure that each component meets assembly requirements; the tail pipe lining is a three-section structure, and adjacent tail pipe linings are overlapped and installed by step surfaces;

[0060] The pre-assembly pre-treatment steps are as follows:

[0061] Step 1.1: Sandblast the bonding surface of the nozzle shell, and bond it within 4 hours after sandblasting or store it in a sealed and dry oven for 24 hours;

[0062] Step 1.2: Clean and dry the tail pipe lining and the convergent section lining;

[0063] Step 1.3: Prepare epoxy adhesive for later use.

[0064] Step 2: Install the tail pipe liner and the convergent section liner into the nozzle shell at the specified position, measure the installation position gap to determine whether it is suitable, and perform ultrasonic flaw detection on each component after it is qualified;

[0065] Step 3: Arrange a plurality of streamlined asbestos sheets on the outer peripheral surface of the tail pipe liner to ensure the coaxiality of the tail pipe liner after it is installed into the nozzle shell;

[0066] Step 4: Use the assembly and bonding tool to assemble the tail pipe liner into place in the nozzle shell; the specific steps are as follows:

[0067] Step 4.1: Apply glue evenly on the bonding surface of the streamlined asbestos sheet, the bonding surface of the tail pipe lining, and the bonding surface of the nozzle shell, without any accumulation or missing glue;

[0068] Step 4.2: Place the nozzle shell vertically with the large diameter end facing upwards by using a flipping device, and install the three-section tail pipe liner into the nozzle shell in sequence. After each section of the tail pipe liner is assembled in place, glue the remaining bonding surface of the nozzle shell;

[0069] Step 4.3: Install the uncoated convergent section liner into the nozzle housing, and press the components assembled in the nozzle housing into place by assembling the bonding tool;

[0070] Step 4.4: Remove the assembly bonding tooling and take out the lining of the convergent section;

[0071] Step 4.5: If the distance between the upper end face of the tail pipe liner and the end face of the large diameter end of the nozzle shell meets the design requirements, it is determined that the tail pipe liner is bonded in place.

[0072] Step 5: Use the assembly and bonding tool to assemble the convergent section liner into the nozzle shell to obtain the assembled nozzle workpiece; the specific steps are as follows:

[0073] Step 5.1: Apply glue evenly on the bonding surface of the convergent section lining and the bonding surface of the nozzle shell, without any accumulation or missing glue;

[0074] Step 5.2: Press the glue-coated convergent section lining into the nozzle shell, pressurize it into place and maintain the pressure for 5 minutes, and clean the remaining glue squeezed out;

[0075] Step 5.3: Press and fit the components assembled in the nozzle shell into place by assembling the bonding tool, and measure the distance between the upper end surface of the tail pipe liner and the end surface of the large diameter end of the nozzle shell. If it meets the design requirements, it is determined that the tail pipe liner is bonded in place;

[0076] Step 5.4: Apply a proper amount of silicone grease to the threads of the nozzle housing and the overflow area, and apply a proper amount of silicone grease to the contact area between the assembly bonding tool and the nozzle workpiece.

[0077] Step 6: Post-process the nozzle workpiece to make the glue of each component solidify evenly; the post-processing method is to place the nozzle workpiece with the assembly and bonding tooling horizontally on a rotating device, rotate it at room temperature for 4 hours, and the speed is 35r / min±5r / min; after 4 hours, the nozzle workpiece with the assembly and bonding tooling is placed vertically through a flip device and left to stand at room temperature for 24 hours.

[0078] Step 7: Perform flaw detection on the nozzle workpiece before curing;

[0079] Step 8: Cure the nozzle workpiece and then perform flaw detection after curing.

[0080] The present invention discloses a bonding and molding device for a long tail pipe of a solid rocket engine with a large aspect ratio, comprising a flipping device for adjusting the angle between the central axis of a nozzle shell and a horizontal plane, a rotating device for controlling the rotation of the nozzle shell around the axis, and an assembly bonding tool; the flipping device is used to adjust different angle requirements of the nozzle shell during tail pipe liner assembly; the rotating device is used to adjust the central axis of the nozzle shell to be located in a horizontal plane so that the nozzle shell can rotate around the axis; and the tail pipe liner and the convergent section liner installed in the nozzle shell are pressed and positioned from both ends along the axial direction by the assembly bonding tool.

[0081] Specifically, the flipping device includes a base and a flipping table hinged thereon, one end of the flipping table is hinged to the base, and the other end is a free end, the free end is connected to the base through a hydraulic cylinder, and the hydraulic cylinder is used to control the rotation angle of the flipping table relative to the base; the upper surface of the flipping table is provided with a nozzle housing positioning assembly and a strap, which can fix the nozzle housing on the flipping table.

[0082] Specifically, the rotating device includes a vehicle body and an active supporting wheel group and a passive supporting wheel group installed thereon, wherein the central axes of the active supporting wheel group and the passive supporting wheel group are arranged in parallel, and the nozzle housing is placed on the two, and the active supporting wheel group is driven to rotate, so as to drive the nozzle housing to rotate around the axis, and the passive supporting wheel group follows;

[0083] The active support wheel group includes two coaxially arranged active support wheels, and the passive support wheel group includes two coaxially arranged passive support wheels; by synchronously adjusting the axial distance between the two active support wheels and the axial distance between the two passive support wheels, it is suitable for the assembly of nozzle shells of different lengths; by adjusting the distance between the central axis of the active support wheel group and the central axis of the passive support wheel group, it is suitable for the assembly of nozzle shells of different diameters.

[0084] Specifically, the assembly and bonding tooling includes an upper cover plate and a lower cover plate encapsulated at both ends of the nozzle shell, and a core shaft passing through the center holes of the upper cover plate and the lower cover plate. Both ends of the core shaft are provided with external threads, and the tail pipe lining and the convergent section lining are pressed and positioned by two nuts respectively screwed on the outer ends of the upper cover plate and the lower cover plate.

[0085] Specifically, it also includes a vertical liftable device, which includes a base and a lifting platform installed thereon by a screw; the lifting platform is a U-shaped operating platform, and its U-shaped notch position is used to place the nozzle shell in a vertical state, so as to facilitate the operator to install the tail pipe lining and the convergent section lining.

[0086] The above technical solution is further described below in conjunction with the accompanying drawings:

[0087] Reference Figure 1 As shown, this embodiment is suitable for the bonding and molding of engine tail nozzles with a large aspect ratio (length up to 2000mm), and the bonding and molding of the tail nozzle includes the one-time bonding and molding of the convergent section lining, the long tail nozzle lining (referred to as the tail pipe lining or nozzle lining) and the nozzle shell.

[0088] Reference Figure 2 , 3 As shown in , 4 , the engine tail nozzle bonding and molding equipment of this example includes a horizontal movable rotating device (referred to as the rotating device), a turning device, and a vertical lifting platform device.

[0089] Reference Figure 2As shown, in this embodiment, the rotating device has two active support wheels 3, two driven support wheels 4, axial guide rails 5, transverse screw 6, car body 7, transverse hand wheel 8, axial screw 9, axial hand wheel 10, roller 11, etc. The axial screw 9 is driven to rotate by the axial hand wheel 10, and then the distance between the two active support wheels 3 and the distance between the two driven support wheels 4 are adjusted to adapt to the dynamic fixation of engine tail nozzles of different lengths during bonding. Similarly, the transverse screw 6 is driven to rotate by the transverse hand wheel 8, and then the distance between the active support wheel 3 and the driven support wheel 4 is adjusted to adapt to the dynamic fixation of engine tail nozzles of different diameters. The rotating device has an explosion-proof function and can achieve continuous work for at least 8 hours under the curing condition of 80°C in the drying oven. It is also equipped with an alarm system and automatic start and stop to prevent the workpiece from slipping during curing in the drying oven. The explosion-proof motor has a power of 1.5kW and a rotation speed of 0 to 50r / min. The rotating device can rotate clockwise and counterclockwise to ensure uniformity of the adhesive layer during curing. The rotating device can facilitate gluing and ultrasonic flaw detection on the inner surface of the nozzle shell.

[0090] Reference Figure 3 As shown, the flipping device in this embodiment is mainly composed of a control box, a binding seat, rollers, a flipping table, a base, a hydraulic cylinder, etc. The tilting angle of the workpiece placed in this device is adjustable from 0° to 90°; its motor power is 1.5kW; and it has a 6T×600L hydraulic system. Using this flipping device, when vertically bonding the tail pipe liner and the nozzle shell, it is only necessary to place the nozzle shell horizontally on the platform and fix it with a binding belt, and then use a hydraulic device to achieve the tilting of the placed workpiece. The angle is adjustable from 0° to 90°, which is convenient for replenishing adhesives during bonding and for the solvent to flow out when cleaning the nozzle shell. When the tilting angle of the device is 90 degrees, it can be horizontally aligned with the U-shaped groove entering the vertical lifting device operating platform to facilitate the assembly of the tail pipe liner into the nozzle shell.

[0091] Reference Figure 4 As shown, the vertical liftable device in this embodiment is mainly a U-shaped operating platform, 2m long, 0.6m high, and 1.2m in total height. The height of the U-shaped platform of this device is adjustable to accommodate engine tail nozzles of different lengths and personnel of different heights for vertical assembly of the tail pipe liner and the nozzle shell. The vertical assembly, to a certain extent, ensures that the tail pipe liner and the nozzle shell are roughly coaxial, offsetting the horizontal assembly, and the problem of misalignment of the annular gap between the nozzle shell and the nozzle liner, which is smaller at the bottom and larger at the bottom due to the weight of the liner itself. The vertical liftable device and the flip device with a tilt angle of 90 degrees cooperate to complete the assembly of the nozzle liner section by section into the nozzle shell. During the loading process, a special thrust device is required to cooperate to press the nozzle liner in.

[0092] Reference Figure 5As shown, in this embodiment, there are approximately rhombus-shaped streamlined asbestos sheet spacers (short axis 2-2.5mm long axis 4-5mm, thickness about 0-0.1mm smaller than the designed gap between the nozzle shell and the tail liner) at intervals of 90 degrees on the outer circumferential surface of each section of the tail pipe liner, with a total of two rows, and the long axis direction of the streamlined spacers is the axial direction of the nozzle shell. The bonding of the streamlined asbestos sheet spacers ensures the uniformity of the gap between the nozzle shell and the nozzle liner.

[0093] Reference Figure 6 and Figure 8 As shown, in this embodiment, the tail pipe liner and the tail pipe liner adopt a process design of step sleeve connection. The overall straightness and roundness of the tail pipe liner are guaranteed. At the same time, the gap of the step sleeve connection is conducive to the discharge of gas in the adhesive during bonding, avoiding the problem that the exhaust path is too long when the length of an integral tail pipe liner is too long, causing the gas formed in the adhesive during bonding to be discharged only from the two sections of the nozzle shell bonding seam, resulting in residual gas on the bonding surface, unqualified ultrasonic flaw detection, and substandard interface bonding strength.

[0094] Before bonding, the nozzle shell and tail pipe liner are matched together and then ultrasonic testing is carried out. The obtained wave number is used as the criterion for judging whether the bonding is debonded or not. That is, the actual object to be tested is used as the standard test piece for flaw detection, avoiding the influence of the nozzle shell thickness and the curvature of the nozzle shell on the flaw detection results.

[0095] Reference Figure 7 As shown, in this embodiment, the tail pipe liner and the nozzle shell are bonded and axially positioned using a special bonding tool. The convergent section liner and the nozzle shell are tightened using a cover plate and a core shaft, and the cover plate is milled on the plane and vertical surfaces every 90 degrees in the radial direction to facilitate the exposure of the end face of the convergent section liner after the tooling nut is tightened on the core shaft, and the distance between the end face and the large end reference surface of the metal shell is measured to determine whether the bonding is in place.

[0096] The main process of the bonding process of a long tail pipe with a large aspect ratio for a solid rocket engine in this embodiment is as follows: first, the nozzle shell is sandblasted for surface treatment before the nozzle is bonded, and then the tail pipe liner and the metal nozzle shell are trial-fitted, and ultrasonic testing is performed to obtain the testing wave number of the empty nozzle, which is used as a criterion for whether the product is bonded or debonded. The nozzle shell is flipped over by a flipping device to clean it, and the tail pipe liner is installed into the nozzle shell to measure the distance between the liner and the reference plane of the large end face of the nozzle shell to determine whether the basic bonding conditions are met; after passing the test, glue is dispensed, the tail pipe liner is glued with a streamlined positioning sheet and glue is applied, and then the nozzle shell is automatically rotated and placed vertically, and then the tail pipe liner and the nozzle shell are assembled one by one after glue application using a vertical lifting device. During the process, the flipping device is used to apply and replenish the nozzle shell adhesive, and finally an indirect measurement is performed, i.e., the tail pipe liner and the nozzle shell are measured. The distance between the end face of the large end of the tube shell and the reference surface is used to determine whether the tail pipe lining is bonded in place, check whether there is glue flow on the bonding surface, clean up excess glue, assemble the bonding tooling, and measure the distance between the end face of the convergent section lining and the large end reference surface of the metal shell to determine whether the nozzle lining, the convergent section lining and the shell are bonded in place at one time. Before curing, the nozzle workpiece is inspected using a rotating device, placed vertically and left to stand, and placed horizontally using a moving device to enter the drying oven for rotation and curing. After curing, it is inspected again. After passing the inspection, the product is delivered to the next process. The specific steps are as follows:

[0097] Sandblasting: Sandblast the nozzle shell bonding surface. Before bonding, check the nozzle shell 2, convergent section liner 32, first tail pipe liner 28, second tail pipe liner 33 and third tail pipe liner 1. No bruises or obvious pieces are allowed to fall off. Use dry compressed air to blow away the sand and impurities on the nozzle shell 2. Before bonding, check the shell sandblasting quality. No rust spots and missed spraying are allowed. It is best to bond within 4 hours after sandblasting. If bonding cannot be done within the specified time, the nozzle shell 2 should be stored in a sealed and dry oven and can be used within 24 hours.

[0098] Cleaning and glue preparation: Use a long-handled brush dipped in acetone and utilize a flipping device (composed of a control box 12, a binding seat 13, a roller 14, a flipping table 15, a hydraulic cylinder 16, and a base 17) to clean the bonding surfaces of the first tail pipe lining 28, the second tail pipe lining 33, the third tail pipe lining 1, the convergent section lining 32, and the nozzle shell 2, and let them stand for 10 to 15 minutes for use. Meanwhile, prepare the epoxy adhesive.

[0099] Trial fitting: Place the nozzle shell 2 horizontally on a special frame, and then, without applying adhesive, push the first tail pipe liner 28, the second tail pipe liner 33, the third tail pipe liner 1 and the convergent section 32 liner into the nozzle shell in sequence using a special bonding tool. When the third tail pipe liner 1 is 78.5mm away from the large end of the nozzle shell, and the gap between the convergent section liner 32 and the large end of the nozzle shell 2 is 0.1mm to 0.9mm, it is a trial fit. At the same time, place the tail pipe liner and the metal nozzle shell on a rotating device for ultrasonic flaw detection without adhesive. The flaw detection wave number of the nozzle empty fitting is 8, which is used as the criterion for bonding debonding, that is, the flaw detection wave number is greater than or equal to 8 for bonding debonding. Weigh and record the weight of the first tail pipe liner 28, the second tail pipe liner 33, the third tail pipe liner 1 and the convergent section liner 32.

[0100] Bonding of tail pipe lining, bonding of tail pipe lining and asbestos sheet: Apply special adhesive to the streamlined asbestos sheet 27, and stick it on the outer wall of the first tail pipe lining 28, the second tail pipe lining 33 and the third tail pipe lining 1 in turn. After it is completely cured and passes the size inspection, it will be ready for use; then, use a glue spreading tool to evenly spread glue on the bonding surfaces of the streamlined asbestos sheet 27, the first tail pipe lining 28, the second tail pipe lining 33 and the third tail pipe lining 1, and all the bonding surfaces of the nozzle shell 2 placed horizontally on the special frame, without any accumulation or missing of glue. Then, the nozzle shell 2 is placed vertically and translated to the U-shaped groove of the vertical lifting device by using the turning device (composed of a control box 12, a binding seat 13, rollers 14, a turning platform 15, a hydraulic cylinder 16, and a base 17). After it is stabilized, with the cooperation of the vertical lifting device (composed of a ladder 18, a hand wheel 19, a guardrail 20, a lifting platform 21, a reducer 22, a transmission shaft 23, a screw 24, a base 25, and rollers 26), the first tail pipe liner 28, the second tail pipe liner 33, and the third tail pipe liner 1 are sequentially pushed into the vertically placed nozzle shell 2 using a special thrust device. During the process of inserting the first tail pipe liner 28, the second tail pipe liner 33 and the third tail pipe liner 1, the nozzle shell is adjusted in angle by using a flipping device (composed of a control box 12, a binding seat 13, rollers 14, a flipping table 15, a hydraulic cylinder 16 and a base 17). When each section of the tail pipe liner is pressed into the nozzle shell, the glue on the upper part of the nozzle shell is scraped off. The nozzle shell is adjusted to an axial level by the flipping device, the scraped glue in the nozzle shell is manually replenished, and then it is adjusted to a vertical position to continue to press-fit the remaining tail pipe liners. After the nozzle shell 2 is loaded with the first tail pipe liner 28, the second tail pipe liner 33 and the third tail pipe liner 1, the uncoated convergent section liner is loaded, and the tipping device (composed of a control box 12, a binding seat 13, rollers 14, a tipping table 15, a hydraulic cylinder 16, and a base 17) is used to lay it flat and transfer it to a special frame, and the bonding tooling (composed of an upper cover plate 29, a lower cover plate 30, and a core shaft 31) is assembled, and the nut is tightened to apply pressure; when the third tail pipe liner 1 is 77.7 mm away from the large end of the nozzle shell, it is bonded in place.

[0101] Bonding of the convergent section lining, assembly of the lining and the nozzle shell: Use a glue-spreading tool to evenly apply glue to the bonding surface of the convergent section lining 32 and the nozzle shell 2, without accumulation or missing glue. Then use a special tool to screw the convergent section lining 32 into the nozzle shell 2, pressurize it into place and maintain the pressure for 5 minutes, and clean up the excess glue squeezed out; the gap between the convergent section lining 32 and the nozzle shell 2 is (0.65mm), and when the third tail pipe lining 1 is (77.7mm) away from the large end of the nozzle shell 2, it is considered to be bonded in place; apply a proper amount of silicone grease to the threads and overflow of the nozzle shell 2, apply a proper amount of silicone grease to the contact between the tooling (composed of the upper cover plate 29, the lower cover plate 30, and the core shaft 31) and the workpiece, and assemble the tooling (composed of the upper cover plate 29, the lower cover plate 30, and the core shaft 31).

[0102] Static placement of the nozzle workpiece: Place the nozzle workpiece with tooling horizontally on the rotating device (composed of active support wheel 3, driven support wheel 4, axial guide rail 5, transverse screw 6, car body 7, transverse hand wheel 8, transverse screw 9, axial hand wheel 10, roller 11), and rotate it at room temperature for 4 hours; after 4 hours, place the nozzle workpiece with tooling vertically on the flipping device (composed of control box 12, binding seat 13, roller 14, flipping table 15, hydraulic cylinder 16, base 17), so that the nozzle shell is set vertically at 90 degrees. Static at room temperature for 24 hours, with 360-degree flipping every 12 hours.

[0103] NDT inspection of the nozzle workpiece before curing: Place the nozzle workpiece with tooling horizontally on a rotating device (consisting of an active support wheel 3, a driven support wheel 4, an axial guide rail 5, a transverse screw 6, a car body 7, a transverse hand wheel 8, a transverse screw 9, an axial hand wheel 10, and a roller 11) for NDT inspection. If the number of waves is less than 8, the NDT is qualified; the workpiece is transferred to the next curing process.

[0104] Curing of the nozzle workpiece: Place the nozzle workpiece after the flaw detection on the rotating device (consisting of the active support wheel 3, the driven support wheel 4, the axial guide rail 5, the transverse screw 6, the car body 7, the transverse hand wheel 8, the transverse screw 9, the axial hand wheel 10, and the roller 11), and move it into the drying oven, and heat it from room temperature to 80°C at a rate of 1°C / min, and cure it at 80°C±2°C for 8h, then close the drying oven and cool it naturally to room temperature; after curing, push the nozzle workpiece together with the rotating device (consisting of the active support wheel 3, the driven support wheel 4, the axial guide rail 5, the transverse screw 6, the car body 7, the transverse hand wheel 8, the transverse screw 9, the axial hand wheel 10, and the roller 11) out of the drying oven, and remove the tooling (consisting of the upper cover plate 29, the lower cover plate 30, and the core shaft 31), check the bonding quality, and clean the silicone grease and debris on the workpiece. Weigh and record the weight of the nozzle assembly; check the bonding quality and clean the silicone grease and debris on the workpiece; check that the nozzle shell 2, the convergent section liner 32, the first tail pipe liner 28, the second tail pipe liner 33 and the third tail pipe liner 1 have no bruises or obvious pieces falling off; check that the non-bonding surfaces of the nozzle shell 2, the convergent section liner 32, the first tail pipe liner 28, the second tail pipe liner 33 and the third tail pipe liner 1 are free of excess adhesive and debris.

[0105] Post-curing flaw detection inspection: Place the nozzle horizontally on a rotating device (composed of active support wheel 3, driven support wheel 4, axial guide rail 5, transverse screw 6, body 7, transverse hand wheel 8, transverse screw 9, axial hand wheel 10, roller 11) for post-curing flaw detection inspection with a flaw detection wave number of 3 to 6. If the inspection is qualified, it will be transferred to the next process. The results of CT non-destructive testing and actual dissection of the wreckage of two solid rocket engines after ignition prove that the flaw detection wave number of the nozzle empty assembly is 8, which is correct as a criterion for bonding and debonding.

[0106] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A method for bonding and molding a long tail tube of a solid rocket engine with a large aspect ratio, characterized in that The specific steps are as follows: Pre-treatment is performed on the nozzle shell, tail pipe lining and convergent section lining before assembly to ensure that each component meets the assembly requirements; the tail pipe lining is a three-section structure, and adjacent tail pipe linings are overlapped and installed by step surfaces; Install the tail pipe liner and convergent section liner into the nozzle shell at the designated position, measure the installation position gap to determine whether it is suitable, and perform ultrasonic flaw detection on each component after it is qualified; A plurality of streamlined asbestos sheets are arranged on the outer peripheral surface of the tail pipe liner to ensure the coaxiality of the tail pipe liner after it is installed into the nozzle shell; The tail pipe liner is assembled into place in the nozzle housing by using an assembly bonding tool; The convergent section liner is assembled into place in the nozzle shell by using an assembly bonding tool to obtain an assembled nozzle workpiece; Post-process the nozzle workpiece to ensure that the glue coating of each component is evenly solidified; Conduct flaw detection on nozzle workpieces before curing; The nozzle workpiece is cured and then subjected to flaw detection after curing.

2. According to claim 1, a method for bonding and molding a long tail tube of a solid rocket engine with a large aspect ratio, characterized in that: The pre-assembly pre-treatment steps are as follows: Sandblast the bonding surface of the nozzle shell and complete bonding within 4 hours after sandblasting or within 24 hours after storage in a sealed dry oven; Clean and dry the tail pipe lining and convergent section lining; Prepare epoxy adhesive for later use.

3. The bonding molding method of a solid rocket engine long tail tube with a large aspect ratio according to claim 1, characterized in that: The method for assembling the tail pipe liner in place in the nozzle housing is as follows: Apply glue evenly on the bonding surface of the streamlined asbestos sheet, the bonding surface of the tail pipe lining, and the bonding surface of the nozzle shell, without any accumulation or missing glue; Place the nozzle shell vertically with the large diameter end facing upwards by using a flipping device, install the three-section tail pipe liner into the nozzle shell in sequence, and fill the remaining bonding surface of the nozzle shell with glue after each section of the tail pipe liner is assembled in place; The uncoated convergent section liner is installed into the nozzle housing, and the components assembled in the nozzle housing are pressed into place by assembling and bonding tooling; Remove the assembly bonding tooling and take out the lining of the convergent section; If the distance between the upper end face of the tail pipe liner and the end face of the large diameter end of the nozzle shell meets the design requirements, it is determined that the tail pipe liner is bonded in place.

4. The method for bonding and molding a long tail tube of a solid rocket engine with a large aspect ratio according to claim 1, characterized in that: The method for assembling the convergent section liner in place in the nozzle housing is as follows: Apply glue evenly on the bonding surface of the convergent section lining and the bonding surface of the nozzle shell, without any accumulation or missing glue; Press the glue-coated convergent section lining into the nozzle shell, pressurize it into place and maintain the pressure for 5 minutes, and clean the squeezed excess glue; The components assembled in the nozzle shell are pressed into place by assembling the bonding tool, and the distance between the upper end face of the tail pipe liner and the end face of the large diameter end of the nozzle shell is measured. If it meets the design requirements, it is judged that the tail pipe liner is bonded in place; Apply a proper amount of silicone grease on the threads of the nozzle housing and the overflow area, and apply a proper amount of silicone grease on the contact area between the assembly bonding tooling and the nozzle workpiece.

5. The method for bonding and molding a long tail tube of a solid rocket engine with a large aspect ratio according to claim 1, characterized in that: The method for post-processing the nozzle workpiece is as follows: placing the nozzle workpiece with the assembly and bonding tooling horizontally on a rotating device, rotating it at room temperature for 4 hours at a speed of 35r / min±5r / min; after 4 hours, placing the nozzle workpiece with the assembly and bonding tooling vertically through a turning device, and leaving it at room temperature for 24 hours.

6. A solid rocket engine long tail tube bonding and molding equipment, used for implementing the solid rocket engine long tail tube bonding and molding method of any one of claims 1 to 5; characterized in that: It includes a turning device for adjusting the angle between the central axis of the nozzle shell and the horizontal plane, a rotating device for controlling the rotation of the nozzle shell around the axis, and an assembly and bonding tool; The nozzle shell is adjusted to different angles during tail pipe liner assembly by means of a flipping device; When the central axis of the nozzle housing is adjusted to be in a horizontal plane by a rotating device, it can rotate around the axis; The tail pipe liner and the convergent section liner installed in the nozzle shell are pressed and positioned from both ends along the axial direction by assembling the bonding tool.

7. The bonding and molding equipment for a long tail tube of a solid rocket engine with a large aspect ratio according to claim 6, characterized in that: The flipping device includes a base and a flipping platform hinged thereon, one end of the flipping platform is hinged to the base, and the other end is a free end, the free end is connected to the base through a hydraulic cylinder, and the hydraulic cylinder is used to control the rotation angle of the flipping platform relative to the base; the upper surface of the flipping platform is provided with a nozzle housing positioning assembly and a strap, which can fix the nozzle housing on the flipping platform.

8. The bonding and molding equipment for a long tail tube of a solid rocket engine with a large aspect ratio according to claim 6, characterized in that: The rotating device comprises a vehicle body and an active supporting wheel group and a passive supporting wheel group installed thereon, wherein the central axes of the active supporting wheel group and the passive supporting wheel group are arranged in parallel, and the nozzle housing is placed on the two, and the active supporting wheel group is driven to rotate, so as to drive the nozzle housing to rotate around the axis, and the passive supporting wheel group follows; The active support wheel set includes two active support wheels arranged coaxially, and the passive support wheel set includes two passive support wheels arranged coaxially; By synchronously adjusting the axial distance between the two active support wheels and the axial distance between the two passive support wheels, it is suitable for the assembly of nozzle shells of different lengths; by adjusting the distance between the central axis of the active support wheel group and the central axis of the passive support wheel group, it is suitable for the assembly of nozzle shells of different diameters.

9. The bonding and molding equipment for a long tail tube of a solid rocket engine with a large aspect ratio according to claim 6, characterized in that: The assembly and bonding tooling includes an upper cover plate and a lower cover plate encapsulated at both ends of the nozzle shell, and a core shaft penetrating the center holes of the upper cover plate and the lower cover plate. Both ends of the core shaft are provided with external threads. The tail pipe lining and the convergent section lining are pressed and positioned by two nuts respectively screwed on the outer ends of the upper cover plate and the lower cover plate.

10. The bonding and molding equipment for a long tail tube of a solid rocket engine with a large aspect ratio according to claim 6, characterized in that: It also includes a vertical liftable device, which includes a base and a lifting platform installed thereon by a screw; the lifting platform is a U-shaped operating platform, and its U-shaped notch position is used to place the nozzle shell in a vertical state, so as to facilitate the operator to install the tail pipe lining and the convergent section lining.

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