An engine extension section variable wall thickness flat plate processing tool and process method

Abstract

The application discloses an engine extension section variable-wall-thickness flat plate processing tool and a processing method, which comprise a base, a positioning shaft vertically fixed at the center of the base and serving as an initial positioning reference, a pressing ring fixedly connected to the base and used for pressing the outer periphery of a product to be processed, a plurality of independent detachable pressing plates, at least comprising first, second, third and fourth pressing plates, each of the pressing plates being arranged in a radial direction from inside to outside on the base and being pressed across by a long pressing plate or a short pressing plate, a plurality of pressing covers, at least comprising first, second, third, fourth and fifth pressing covers, each of the pressing covers being sleeved on the positioning shaft through a shaft hole to realize radial positioning and being axially pressed by a fastener, the diameters of the pressing covers being sequentially increased, and the pressing covers being used for applying pressing force to different radial ranges of the product to be processed, wherein the first pressing cover is not removed during turning of the product to be processed, and the remaining pressing covers and the pressing plates are dynamically combined during the turning of the product to be processed, so that segmented and continuous processing of the product to be processed is realized.

Description

Technical Field

[0001] This invention relates to the field of rocket engine product machining, and in particular to a tooling and process for machining variable wall thickness flat plates for engine extension sections. Background Technology

[0002] The extension section of a rocket engine used for deep space exploration is generally a single-walled, curved generatrix component with variable wall thickness. This type of part is primarily manufactured using sheet metal spinning technology. Typically, the wall thickness gradually decreases from the smaller end to the larger end, and different semi-cone angles and wall thicknesses correspond to different initial material thicknesses. The larger the part's dimensions (usually 200mm~2000mm), the larger the original sheet metal (generally made of niobium-tungsten alloy), and the larger the blank's cutting area. Furthermore, the wall thickness tolerance requirements for this type of part are strict; the wall thickness tolerance and flatness of the flat raw material blank cannot meet the requirements, necessitating surface machining.

[0003] The current traditional flat platen method cannot fix the flat blank material and cannot meet the precision requirements of part cutting, which greatly reduces the subsequent production efficiency of the product. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a tooling and process method for machining variable wall thickness flat plates for engine extension sections. The initial blank is machined with variable wall thickness on a vertical lathe so that the original blank fully fits the tire tread. Then, through CNC machining, the precision of the variable wall thickness flat plate blank reaches the machining precision process requirements, shortening the product processing time and improving the product processing efficiency.

[0005] The technical solution of the present invention is as follows: Firstly, a tooling for machining a variable wall thickness flat plate for an engine extension section is provided, comprising: Base; The positioning shaft is vertically fixed to the center of the base and serves as the initial positioning reference. A pressure ring, fixedly connected to the base, is used to press the outer periphery of the product to be processed; Multiple pressure plates that can be independently installed and removed include at least: a first pressure plate, a second pressure plate, a third pressure plate, and a fourth pressure plate; each pressure plate is arranged radially from the inside to the outside on the base and is pressed across by a long pressure plate or a short pressure plate; Multiple pressure caps, including at least: a first pressure cap, a second pressure cap, a third pressure cap, a fourth pressure cap, and a fifth pressure cap; each pressure cap is fitted into the positioning shaft through a shaft hole to achieve radial positioning, and is axially pressed by fasteners, with the diameter increasing sequentially, used to apply pressing force to different radial ranges of the product to be processed; The first pressure cap is not removed during the cutting process of the product to be processed; the remaining pressure caps and pressure plates are dynamically combined during the cutting process of the product to be processed to achieve segmented continuous processing of the product to be processed.

[0006] Furthermore, the pressure ring is fixedly connected to the base by circumferentially distributed fasteners to press the product surface; the inner side of the pressure ring has an annular groove, the height of which is equal to or less than the product thickness, and the diameter of the annular groove is clearance-fitted with the diameter of the product to ensure that the pressure ring presses the product surface.

[0007] Furthermore, the surface roughness of the pressure ring and the contact area between each pressure plate and the product surface is adjustable according to product requirements; the contact area between each pressure cap and the product surface is rounded, and the surface roughness is adjustable according to product requirements.

[0008] Furthermore, the upper surfaces of the pressure ring, each pressure plate, and each pressure cover are provided with threaded holes and equipped with eye bolts for tooling lifting.

[0009] Furthermore, the long or short pressure plates are evenly distributed along the circumference.

[0010] Furthermore, the long pressure plate can simultaneously press the first pressure plate, the second pressure plate, the third pressure plate, and the fourth pressure plate; the short pressure plate can simultaneously press the third pressure plate and the fourth pressure plate.

[0011] Furthermore, all components of the tooling are made of carbon steel.

[0012] Furthermore, the heat treatment hardness values ​​of all components of the tooling are greater than HRC25.

[0013] Secondly, a process method for machining a variable wall thickness plate for an engine extension section using the aforementioned tooling is provided, comprising the following steps: S1. Install and fix the first pressure cap, tighten the pressure ring, and press the surface of the product to be processed; use a long pressure plate to press the first pressure plate, the second pressure plate, the third pressure plate, and the fourth pressure plate, and cut the first section of the product surface within the range of the first pressure plate and the first pressure cap; S2. After the first section is cut, adjust the long pressure plate to press the second, third and fourth pressure plates, remove the first pressure plate, install the second pressure cover and press it tight, and cut the second section of the product surface. S3. After the second section is cut, remove the long pressure plate, the second pressure plate, and the second pressure cover, replace them with the short pressure plate, press the third pressure plate and the fourth pressure plate, install the third pressure cover and press it tight, and cut the third section of the product surface. S4. After the third section is cut, adjust the short pressure plate to press the fourth pressure plate, remove the third pressure plate and the third pressure cover, install the fourth pressure cover and press it, and cut the fourth section of the product surface. S5. After the fourth section is cut, remove the short pressure plate, the fourth pressure plate, and the fourth pressure cover. Install the fifth pressure cover and tighten it. Cut the fifth section of the product surface. Remove all tooling parts. The machining is complete.

[0014] Thirdly, it relates to the application of the aforementioned engine extension section variable wall thickness plate processing fixture for processing engine extension section variable wall thickness plates with a diameter of 200mm to 2000mm.

[0015] The advantages of this invention compared to the prior art are: This invention innovatively proposes a machining fixture and process for large-size niobium-tungsten alloy variable wall thickness flat plates. Prior to this invention, existing technologies involved first leveling the flat plate using a flat plate leveling machine and then manually leveling it, followed by flatbed cutting using evenly distributed pressure plates. After this process, the local gaps in the blank flat plate remained at 0.40mm-0.50mm. Using the fixture of this invention, the original blank fully conforms to the fixture's surface, achieving a precision of 0-0.05mm for the variable wall thickness blank, thus improving the precision and production efficiency of machining large-size niobium-tungsten alloy variable wall thickness flat plates. This invention solves the problems of low precision and low yield rate in machining large-size niobium-tungsten alloy variable wall thickness flat plates, improving the production efficiency and precision of subsequent spinning processes. It also improves the production quality and product stability of liquid rocket engine nozzle parts and is adaptable to the precision machining of variable wall thickness flat plates for different engine models. Attached Figure Description

[0016] Figure 1 Assembly drawing of tooling for machining niobium-tungsten alloy variable wall thickness flat plates; Figure 2 A schematic diagram of the first section of the machining tooling for machining niobium-tungsten alloy variable wall thickness flat plates; Figure 3 Schematic diagram of the second section of the machining tooling for machining niobium-tungsten alloy variable wall thickness flat plate; Figure 4 Schematic diagram of the third section of the machining tooling for machining niobium-tungsten alloy variable wall thickness flat plates; Figure 5 Schematic diagram of the fourth section of the machining tooling for machining niobium-tungsten alloy variable wall thickness flat plates; Figure 6 Schematic diagram of the fifth section of the machining tooling for machining niobium-tungsten alloy variable wall thickness flat plates; Reference numerals in the attached diagram: Base-1, Pressure ring-2, Hexagonal shoulder bolt-3, First pressure cap-4, Positioning shaft-5, Hexagonal nut-6, First pressure plate-7, Second pressure plate-8, Third pressure plate-9, Fourth pressure plate-10, Hexagonal shoulder bolt-11, Eye bolt-12, Long pressure plate-13, Short pressure plate-14, Eye bolt-15, Second pressure cap-16, Third pressure cap-17, Fourth pressure cap-18, Fifth pressure cap-19, Hexagonal shoulder nut-20. Detailed Implementation

[0017] To better understand the technical solution of the present invention, the specific embodiments of the present invention are described below.

[0018] like Figure 1 As shown in the figure, the machining fixture for the variable wall thickness plate of the engine extension section provided in this embodiment includes a base 1, a pressure ring 2, a hexagonal shoulder bolt 3, a first pressure cover 4, a positioning shaft 5, a hexagonal nut 6, a first pressure plate 7, a second pressure plate 8, a third pressure plate 9, a fourth pressure plate 10, a hexagonal shoulder bolt 11, a lifting eye screw 12, a long pressure plate 13, a short pressure plate 14, a lifting eye screw 15, a second pressure cover 16, a third pressure cover 17, a fourth pressure cover 18, a fifth pressure cover 19, and a hexagonal shoulder nut 20.

[0019] The positioning shaft 5 is the initial positioning reference of the product. The machining accuracy and hardness requirements of the positioning shaft 5 must be guaranteed, and the accuracy of the positioning hole of the product must be kept within the product's required tolerance. The positioning shaft 5 is connected to the base 1 by threads. The first pressure cover 4, the second pressure cover 16, the third pressure cover 17, the fourth pressure cover 18, and the fifth pressure cover 19 are respectively positioned with the positioning shaft 5 through shaft hole positioning relationship to ensure radial positioning. They are tightened by hexagonal nuts 6 to ensure axial positioning.

[0020] The pressure ring 2 is connected to the base by a hexagonal shoulder bolt 3 to press the product surface. The inner side of the pressure ring 2 is machined with a ring groove. The height of the ring groove is equal to or less than the product thickness. The diameter of the ring groove is clearance-fitted with the diameter of the product to ensure that the pressure ring 2 presses the product surface.

[0021] The first pressure cap 4 is fixed by a hexagonal shoulder nut 20 to press the product, and it does not need to be removed or replaced during the cutting process; The surface roughness of the contact surfaces of pressure ring 2, first pressure plate 7, second pressure plate 8, third pressure plate 9, and fourth pressure plate 10 can be adjusted appropriately according to product requirements. All surfaces are threaded and equipped with eye bolts (12) for lifting. The contact surfaces of first pressure cap 4, second pressure cap 16, third pressure cap 17, fourth pressure cap 18, and fifth pressure cap 19 are all rounded, and the surface roughness can be adjusted appropriately according to product requirements to avoid damaging the product surface. The upper end face of the tooling is threaded and equipped with eye bolts (12) for lifting.

[0022] There are 8 long pressure plates 13, 8 short pressure plates 14, and 8 hexagonal shoulder bolts 3. There is only one pressure ring 2, one positioning shaft 5, one first pressure cap 4, one first pressure plate 7, one second pressure plate 8, one third pressure plate 9, one fourth pressure plate 10, one second pressure cap 16, one third pressure cap 17, one fourth pressure cap 18, and one fifth pressure cap 19. All the above components are made of carbon steel, and the heat treatment hardness value should be greater than HRC25 to ensure the strength of the tooling during machining.

[0023] The process for machining a variable wall thickness plate for an engine extension section using the tooling of this embodiment includes the following steps: Step 1, as follows Figure 2As shown, fix the first pressure cover 4, tighten the hexagonal shoulder bolt 3 to press the pressure ring 2; tighten the hexagonal shoulder bolt 11 so that the long pressure plate 13 presses the first pressure plate 7, the second pressure plate 8, the third pressure plate 9, and the fourth pressure plate 10, and cut the first section of product size within the range of the first pressure plate 7 and the first pressure cover 4.

[0024] Step 2, as follows Figure 3 As shown, after the first section is cut, adjust the long pressure plate 13 to press the second pressure plate 8, the third pressure plate 9, and the fourth pressure plate 10, remove the first pressure plate 7, use the hexagonal nut 6 to press the second pressure cover 16, and cut the second section of product surface dimensions.

[0025] Step 3, as follows Figure 4 As shown, after the second section of the product dimensions are cut, remove the long pressure plate 13, the second pressure plate 8, and the second pressure cover 16, replace the short pressure plate 14, tighten the hexagonal shoulder bolt 11 so that the short pressure plate 14 presses against the third pressure plate 9 and the fourth pressure plate 10, and use the hexagonal nut 6 to press against the third pressure cover 17, and cut the third section of the product surface dimensions.

[0026] Step 4, as follows Figure 5 As shown, after the third product segment is cut to size, adjust the short pressure plate 14 to press the fourth pressure plate 10, remove the third pressure plate 9 and the third pressure cover 17, use the hexagonal nut 6 to press the fourth pressure cover 18, and cut the fourth product segment to size.

[0027] Step 5, as follows Figure 6 As shown, after the fourth product segment is machined to the required dimensions, remove the short pressure plate 14, the fourth pressure plate 10, and the fourth pressure cover 18. Use hexagonal nuts 6 to tighten the fifth pressure cover 19, and machine the fifth product segment's profile dimensions. After all five product segments are machined, remove all tooling parts.

[0028] It is understood that this invention has been described through embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this invention. Furthermore, under the teachings of this invention, these features and embodiments can be modified to adapt to specific circumstances without departing from the spirit and scope of this invention. Therefore, this invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are protected by this invention.

[0029] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A machining fixture for a variable wall thickness plate in an engine extension section, characterized in that, include: Base (1); The positioning shaft (5) is vertically fixed to the center of the base (1) as the initial positioning reference; The pressure ring (2) is fixedly connected to the base (1) and is used to press the outer periphery of the product to be processed. The pressure ring (2) is fixedly connected to the base (1) by fasteners evenly distributed around the circumference to press the product surface. The inner side of the pressure ring (2) has an annular groove, the height of which is equal to or less than the product thickness. The diameter of the annular groove is clearance-fitted with the diameter of the product to ensure that the pressure ring (2) presses the product surface. Multiple pressure plates that can be installed and removed independently include at least: a first pressure plate (7), a second pressure plate (8), a third pressure plate (9), and a fourth pressure plate (10); each pressure plate is arranged radially from the inside to the outside on the base and is pressed across by a long pressure plate (13) or a short pressure plate (14); Multiple pressure caps, including at least: a first pressure cap (4), a second pressure cap (16), a third pressure cap (17), a fourth pressure cap (18), and a fifth pressure cap (19); each pressure cap is fitted into the positioning shaft (5) through a shaft hole to achieve radial positioning, and is axially pressed by fasteners, with the diameter increasing sequentially, to apply pressing force to different radial ranges of the product to be processed; Among them, the first pressure cover (4) is not removed during the cutting process of the product to be processed; the remaining pressure covers and pressure plates are dynamically combined during the cutting process of the product to be processed to realize the segmented continuous processing of the product to be processed.

2. The machining fixture for the variable wall thickness plate of the engine extension section according to claim 1, characterized in that: The surface roughness of the pressure ring (2) and the contact parts of each pressure plate with the product surface can be adjusted according to product requirements; the contact parts of each pressure cap with the product surface are all rounded, and the surface roughness can be adjusted according to product requirements.

3. The machining fixture for the variable wall thickness plate of the engine extension section according to claim 1, characterized in that: The pressure ring (2), each pressure plate and each pressure cover are provided with threaded holes on their upper surfaces and are equipped with eye bolts for tooling lifting.

4. The machining fixture for the variable wall thickness plate of the engine extension section according to claim 1, characterized in that: The long pressure plate (13) or short pressure plate (14) is evenly distributed along the circumference.

5. The machining fixture for the variable wall thickness plate of the engine extension section according to claim 1, characterized in that: The long pressure plate (13) can simultaneously press the first pressure plate (7), the second pressure plate (8), the third pressure plate (9), and the fourth pressure plate (10); the short pressure plate (14) can simultaneously press the third pressure plate (9) and the fourth pressure plate (10).

6. The machining fixture for the variable wall thickness plate of the engine extension section according to claim 1, characterized in that: All components of the tooling are made of carbon steel.

7. The machining fixture for the variable wall thickness plate of the engine extension section according to claim 6, characterized in that: All components of the tooling have a heat treatment hardness value greater than HRC25.

8. A process method for machining a variable wall thickness plate for an engine extension section using the tooling as described in claim 1, characterized in that, Includes the following steps: S1. Install and fix the first pressure cap (4), tighten the pressure ring (2), and press the surface of the product to be processed; use the long pressure plate (13) to press the first pressure plate (7), the second pressure plate (8), the third pressure plate (9), and the fourth pressure plate (10), and cut the first section of the product surface within the range of the first pressure plate (7) and the first pressure cap (4); S2. After the first section is cut, adjust the long pressure plate (13) to press the second pressure plate (8), the third pressure plate (9), and the fourth pressure plate (10), remove the first pressure plate (7), install the second pressure cover (16) and press it, and cut the second section of the product surface. S3. After the second section is cut, remove the long pressure plate (13), the second pressure plate (8), and the second pressure cover (16), replace them with the short pressure plate (14), press the third pressure plate (9) and the fourth pressure plate (10), install the third pressure cover (17) and press it, and cut the third section of the product surface. S4. After the third section is cut, adjust the short pressure plate (14) to press the fourth pressure plate (10), remove the third pressure plate (9) and the third pressure cover (17), install the fourth pressure cover (18) and press it, and cut the fourth section of the product surface. S5. After the fourth section is cut, remove the short pressure plate (14), the fourth pressure plate (10), and the fourth pressure cover (18), install the fifth pressure cover (19) and tighten it, and cut the fifth section of the product surface; remove all tooling parts and the processing is completed.

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