CN-120134015-B - Rocket engine injector thin-wall milling self-positioning clamp and assembly method

CN120134015BCN 120134015 BCN120134015 BCN 120134015BCN-120134015-B

Abstract

The invention relates to a thin-wall milling self-positioning clamp for a rocket engine injector and an assembly method thereof, mainly comprising an upper positioning carcass assembly, a conical expansion ring, a tire unloading bottom plate, a compression cover plate, a tire unloading lifting ring, a compression bolt, an expansion screw, a lower positioning chassis assembly, a locking bolt and a long fixing bolt, wherein the lower positioning bottom plate assembly is fixed on a machine tool workbench for a long time through the locking bolt and is not detached all the time. The product milling process is preceded by positioning, clamping and supporting the injector thin wall and the positioning carcass assembly through the conical surface expanding ring, the tire unloading bottom plate, the compression cover plate, the compression bolt and the expansion screw, limiting the radial and axial movement of the injector thin wall, moving the injector thin wall and the upper positioning carcass assembly into a machine tool through the hanging ring after the assembly of the injector thin wall and the upper positioning carcass assembly is completed, rapidly assembling and positioning the upper positioning carcass assembly and the lower positioning chassis assembly fixed on a machine tool workbench, and milling, wherein the self-centering rapid-changing combined clamp is provided with a plurality of upper positioning carcass assemblies for assembling a plurality of injector thin wall products for rapid production changing.

Inventors

ZHANG TAO
Duan Ruihu
LIANG XIANGPENG
SHANG QI
HUANG JUNXIN
BAO LIN
YAO BO

Assignees

西安航天发动机有限公司

Dates

Publication Date: 20260508
Application Date: 20250331

Claims (8)

1. The thin-wall milling self-positioning clamp for the rocket engine injector is characterized by comprising an expansion self-centering combined clamp, wherein the expansion self-centering combined clamp comprises a main positioning carcass (108), a conical expansion ring (2), a tire unloading bottom plate (3), a compression cover plate (4), a tire unloading lifting ring (5), a compression bolt (6), an expansion screw (7), a locking bolt (9), an upper positioning carcass assembly (1) and a lower positioning chassis assembly (8), and the expansion self-centering combined clamp comprises the following components: The outer surface of the main positioning carcass (108) and the inner surface of the conical expansion ring (2) are of conical structures with the same taper, The conical surface expander (2) is sleeved outside a main positioning carcass (108), the outer conical surface of the main positioning carcass (108) and the inner conical surface of the conical surface expander (2) are mutually attached, dozens of long grooves are formed in the inner surface and the outer surface of the conical surface expander (2), the conical surface expander (2) is uniformly elastically deformed due to radial stress by the long groove structure, the conical surface structure of the main positioning carcass (108) is used for generating radial force to promote the conical surface expander (2) to radially deform, an expansion screw (7) penetrates through a through hole at the lower end of the main positioning carcass (108) and is connected with a threaded hole at the bottom end surface of the conical surface expander (2) which is arranged on the main positioning carcass (108), a groove is formed in the upper surface of the main positioning carcass (108), a tire unloading bottom plate (3) is arranged in the groove, the conical surface of the injector is sleeved on the expander (2) along the axial direction of the main positioning carcass (108), the inner surface of the thin wall of the injector and the outer surface of the conical surface expander (2) are uniformly deformed, a pressing cover plate (4) is arranged on the upper surface of the injector, the pressing plate (6) penetrates through a pressing bolt (4) from the upper surface to the lower surface of the injector to the main positioning carcass (108), and the pressing screw is tightly screwed into the threaded hole (108) through the axial direction of the main positioning carcass (108), and the pressing screw is tightly pressed by the pressing bolt (4) and the pressing screw and the pressing bolt; The groove on the upper surface of the main positioning carcass (108) is provided with a semicircular bulge along the radial direction, the tire unloading bottom plate (3) is provided with a concave edge, the bulge and the concave edge are matched with each other and are used for positioning the circumferential position of the tire unloading bottom plate (3) and limiting the circumferential rotation of the tire unloading bottom plate (3); The upper positioning carcass assembly (1) comprises a circumferential positioning block (102), a conical positioning pin (103), a central guiding conical hole (104), a locking gasket (105), a fixing bolt (106) and a positioning supporting plate (107); the fixing bolt (106) and the anti-loose gasket (105) are used for carrying out locking connection on the positioning main positioning carcass (108) and the positioning supporting plate (107); The lower positioning chassis assembly (8) comprises a taper hole positioning block (801), a center guide taper column (802), a circumferential pre-positioning column (803) and a positioning chassis (804); Circumferential pre-positioning blocks (102) and circumferential pre-positioning columns (803) are matched with each other through shaft holes to perform circumferential pre-positioning when the upper positioning carcass assembly (1) and the lower positioning chassis assembly (8) are assembled, central positioning is achieved through conical surface matching of a central guide conical hole (104) and a central guide conical column (802), circumferential positioning is achieved through conical surface matching of a conical surface positioning pin (103) and a conical hole positioning block (801), and axial positioning is achieved through long fixing bolts (10) on the upper positioning carcass assembly (1) and the lower positioning chassis assembly (8).
2. A rocket engine injector thin-wall milling self-positioning fixture according to claim 1, wherein the height dimension of the circumferential pre-positioning block (102) is 10% greater than the conical surface positioning pin (103).
3. The self-positioning fixture for thin-wall milling of a rocket engine injector according to claim 1, wherein the bottom profile of the conical surface positioning pin (103) is a high-precision conical surface, the conical surface angle is 1.5 degrees, the conical surface roughness is Ra0.8, and the dimensional precision error of the conical surface is less than 0.005mm.
4. The self-positioning fixture for thin-wall milling of a rocket engine injector according to claim 1, wherein the inner hole of the taper hole positioning block (801) is a high-precision taper surface, the angle of the taper surface is 1.5 degrees, the roughness of the taper surface is Ra0.8, and the dimensional precision error of the taper surface is less than 0.005mm.
5. The self-positioning fixture for thin-wall milling of a rocket engine injector according to claim 1, wherein the outer surface of the main positioning carcass (108) and the inner surface of the conical expansion ring (2) are conical surfaces with an angle of 3.5 degrees, and the roughness of the conical surfaces is Ra1.6.
6. A rocket engine injector thin-wall milling assembly method based on the rocket engine injector thin-wall milling self-positioning clamp as claimed in claim 1, which is characterized by comprising the following steps: s1, combining and assembling a thin wall, an expanding self-centering combined clamp and an upper positioning carcass assembly (1) of an injector to form a whole; S2, assembling the lower positioning chassis assembly (8) in a combined way to form a whole; s3, integrally fixing the lower positioning chassis assembly (8) on a machine tool workbench; s4, moving the upper positioning carcass assembly (1) into the machine tool from an operation table outside the machine tool, assembling the upper positioning carcass assembly (1) and the lower positioning chassis assembly (8), ensuring that the circumferential pre-positioning block (102) and the circumferential pre-positioning column (803) are matched with each other to perform circumferential pre-positioning in the assembling process, realizing central positioning by conical surface matching of the central guide taper hole (104) and the central guide taper column (802), realizing circumferential positioning by conical surface matching of the conical surface positioning pin (103) and the taper hole positioning block (801), and finally fixing the upper positioning carcass assembly (1) and the lower positioning chassis assembly (8) through the long fixing bolt (10), thereby completing assembly of the thin-wall and expansion self-centering combined clamp, and facilitating thin-wall milling of the injector on the machine tool.
7. A rocket engine injector thin-wall milling assembly method according to claim 6, wherein the steps of assembling the injector thin-wall, expanding self-centering combined clamp and upper positioning carcass assembly (1) are as follows: Firstly, loading the conical surface expander (2) into a main positioning carcass (108), ensuring that the outer conical surface of the main positioning carcass (108) and the inner conical surface of the conical surface expander (2) are mutually attached, and measuring an attaching gap by using a clearance gauge to ensure that the gap value is between 0.1mm and 0.2 mm; Secondly, penetrating the expansion screw (7) through a through hole at the lower end of the main positioning carcass (108) and connecting the expansion screw with a threaded hole at the bottom end face of the conical expansion ring (2) arranged on the main positioning carcass (108); Thirdly, placing the tire unloading bottom plate (3) in a groove on the upper surface of the main positioning tire body (108); Fourthly, mounting the thin wall of the injector on a conical expansion ring (2) on the main positioning carcass (108) along the axial direction of the main positioning carcass (108), and ensuring that the inner surface of the thin wall of the injector is attached to the outer surface of the conical expansion ring (2), wherein the attaching gap is between 0.05 and 0.08 mm; fifthly, placing the compression cover plate (4) on the upper surface of the thin wall of the injector, connecting the compression bolts (6) with threaded holes uniformly distributed on the main positioning matrix (108) through the compression cover plate (4), and tightly fixing the compression cover plate (4), the thin wall of the injector and the main positioning matrix (108) through axial compression force generated by threaded fastening; And sixthly, rotating and screwing the expansion screw (7), wherein in the process, the expansion screw (7) generates an axial downward pulling force on the conical expansion ring (2), the conical expansion ring (2) axially moves downwards along the main positioning carcass (108), the conical expansion ring (2) deforms by the radial force of the conical surface to cause the diameter of the outer surface of the conical expansion ring to be enlarged, and the conical expansion ring (2) and the inner surface of the thin wall of the injector are mutually attached to generate a radial supporting force, so that the thin wall assembly of the injector is completed.
8. The rocket engine injector thin-wall milling assembly method according to claim 7, wherein after the fourth step is performed, the fit clearance between the inner surface of the injector thin-wall and the outer surface of the conical surface expander (2) is 0.05-0.08 mm.

Description

Rocket engine injector thin-wall milling self-positioning clamp and assembly method Technical Field The invention belongs to the technical field of rocket engine mechanical manufacturing, and relates to a rocket engine injector thin-wall milling self-positioning clamp and an assembly method. Background The liquid rocket engine has the characteristics of high reliability, low cost and repeated use, so that the liquid rocket engine is used as the development focus of various heavy-duty rocket power for a long time, the thrust chamber is an important core combustion component, the injector positioned in the thrust chamber is the most core complex structural component in the thrust chamber, and the main functions of the liquid rocket engine are to atomize and mix the oxidant and the fuel in the propellant according to the required injection pressure and flow, and then to inject the atomized oxidant and the fuel into the combustion component for combustion so as to generate high-temperature and high-pressure propellant gas. Because the injector works in the severe working conditions of high temperature, high pressure and high heat flux density for a long time, the injector is designed to be composed of two parts of the thin wall of the injector and the outer shell, hundreds of high-precision spiral deep narrow grooves are uniformly distributed on the outer surface of the thin wall of the injector, and hundreds of mutually-closed spiral inner cavities are formed after brazing with the outer shell and used as a regenerative cooling structure for cooling and heat exchange. In order to ensure the heat dispersion of the thin wall of the injector, the thin wall of the injector adopts an injector thin wall milling structure with the total wall thickness of copper alloy materials being smaller than 3mm, the requirements on the dimensional accuracy and consistency of the groove depth and the groove width are high, the residual wall thickness of the thin wall of the injector is only 1mm after milling, the product is extremely easy to generate larger plastic deformation in the process of processing, the brazing clearance requirement between the thin wall of the injector and the outer wall and the consistency of the groove depth dimension are ensured, the plastic deformation quantity generated by workpieces is required to be strictly controlled in the process of processing the thin wall of the injector, so that the jump quantity of the excircle and the top plane of the thin wall of the injector after milling is not more than 0.02mm, and the special self-centering clamp for milling is designed to realize the clamping positioning and the plastic deformation control of the milling process of the thin wall of the copper injector, and finally the high-accuracy requirement of the product processing is ensured. Disclosure of Invention The invention solves the technical problems of overcoming the defects of the prior art, designing a self-positioning clamp and an assembly method for thin-wall milling of a rocket engine injector, solving the problems of easy deformation and difficult positioning and clamping in the thin-wall processing process of the injector and ensuring the processing precision requirement of products, and aiming at inhibiting the problems of uneven cutting quantity, difficult disassembly and assembly of the workpiece and the like caused by uneven milling quantity and no surface support due to easy deformation of the thin-wall workpiece of the copper alloy injector in the processing process of the thin-wall workpiece of the injector. The invention solves the technical problems by adopting a thin-wall milling self-positioning clamp for a rocket engine injector, which comprises an expansion self-centering combined clamp, wherein the expansion self-centering combined clamp comprises a main positioning carcass, a conical surface expansion, a tire unloading bottom plate, a compression cover plate, a tire unloading lifting ring, a compression bolt, an expansion screw, a lower positioning chassis component and a locking bolt; wherein: The outer surface of the main positioning carcass and the inner surface of the conical expansion ring are of conical structures with the same taper, the conical expansion ring is sleeved outside the main positioning carcass, the outer conical surface of the main positioning carcass and the inner conical surface of the conical expansion ring are mutually attached, the inner surface and the outer surface of the conical expansion ring are respectively provided with dozens of long grooves, the conical expansion ring is subjected to radial stress, the long grooves enable the conical expansion ring to generate uniform elastic deformation, the conical structure of the main positioning carcass is used for generating radial force to enable the conical expansion ring to generate radial deformation, an expansion screw penetrates through a through hole at the lower end of the main positioning carcass a