A method for processing a complex profile rocket engine nozzle assembly

Abstract

The application discloses a processing method of a complex profile rocket engine nozzle assembly, which comprises the following steps: after processing a part one, re-measuring related dimensions, drawing an accurate profile graph in CAD, and then obtaining a matching profile of a part two through offsetting the gap value between each surface. In the actual processing process, the interference surface of the part one and the part two is converted into a fitting surface, and an indirect measurement method is provided to accurately measure the gap value of each surface, which is convenient for processing program adjustment and part two size inspection, so that the gap value of each surface is ensured, and finally the interference amount of the interference surface of the part is ensured through the pressing amount by press-fitting the part two. The method can accurately process the complex labyrinth profile gap value and accurately measure the gap value, and improves the processability and inspectability of the part.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of solid rocket engine for aerospace, and particularly relates to a processing method for a swing nozzle assembly. BACKGROUND

[0002] With the rapid development of aerospace industry, solid rocket engine has become the main power device of spacecraft due to its simple structure, low manufacturing cost, high reliability, fast response and many other advantages.

[0003] As an important part of the solid rocket engine thrust vector control system, the nozzle is an important energy conversion device. The nozzle converts the heat energy generated by the combustion of the propellant in the combustion chamber into the kinetic energy of high-speed jet flow, and the resulting counteracting force makes the engine obtain the preset thrust. The swing nozzle is mainly composed of a movable body, a fixed body and a flexible joint, and its working temperature is about 3200℃ and the gas velocity is 2500m / s. The working environment is very harsh, and the processing requirements for the matching surfaces of various components are extremely high. Due to the difference in the linear expansion coefficient of the materials of the components and the need for a certain buffer space provided by each part at the moment of engine ignition, a gap is required between the matching surfaces of each part during production and processing to provide a buffer for the thermal expansion and pressure displacement of each part. When the gap between the matching surfaces is too small, the extrusion force caused by the displacement and thermal expansion of the parts will cause the parts to be extruded and damaged, resulting in the failure of the nozzle to work; when the gap is too large, the high-temperature gas flow through the gap surface will exacerbate the ablation of the parts, and the nozzle will also appear to be on fire, which will also cause the engine to fail.

[0004] Therefore, it is particularly important to strictly ensure the matching gap between the parts of the nozzle. With the increase of the function and performance of the nozzle, the complexity of its structure is also increasing. The complex labyrinth surface matching surface of a certain type of swing nozzle component assembly has as many as 12 surfaces, including gap surfaces and interference surfaces. Because the matching surface contains interference surfaces, all the gap surfaces cannot be directly measured before the nozzle is pressed and formed, and the existing measuring equipment cannot measure the internal gap. Therefore, it is impossible to determine whether all the matching surfaces have been processed in place during the production process, which brings great difficulties to the actual production and processing. SUMMARY

[0005] In view of the problems in the background art, the purpose of the present application is to provide a processing method for a complex surface rocket engine nozzle assembly that can ensure the processing precision of the gap surfaces of the nozzle parts.

[0006] To achieve the above purpose, the processing method for a complex surface rocket engine nozzle assembly designed by the present application comprises the following steps:

[0007] S1, machining the part one according to the design size, re-measuring each size of the part one, taking one water platform surface as a reference surface to measure the height difference between the rest of the water platform surfaces and the reference surface, and the inner hole diameter;

[0008] S2, drawing the mating surface according to the measurement results in step S1, and obtaining the surface machining drawing of the part two by offsetting according to the requirement of each gap surface, and precisely machining each surface of the part two according to the surface machining drawing of the part two;

[0009] S3, measuring each size of the part two machined in step S2, the position of the above size measurement is the same as the reference in the re-measurement in step S1;

[0010] S4, naturally fitting the interference surfaces of the part one and the part two, measuring the gap value of the part one and the part two at the two side mating surfaces, and calculating the gap value of each hole position;

[0011] S5, raising the reference surface in step S1, measuring the gap value of the part one and the part two at the outer side mating surface, and calculating the gap value of the reference surface when the interference surfaces are naturally fitted;

[0012] S6, calculating the height difference value of each water platform surface of the part two according to the design index of each water platform surface and the calculation result in step S5;

[0013] S7, comparing the measurement value of each water platform surface height difference in step S2 with the calculation value of each water platform surface height difference in step S6, and taking the difference value as the repair allowance of each step surface of the part two.

[0014] Preferably, in step S2, a part machining allowance is reserved in the X-axis direction of the machine tool when precisely machining each surface of the part two.

[0015] As a preferred solution, the following steps are further included after step S7:

[0016] S8, after resetting the part one and the part two, raising the inclined surface adjacent to the outer side mating surface again, and measuring the gap value of the part one and the part two at the outer side mating surface;

[0017] S9, if the gap value of all surfaces is greater than the requirement, adjusting the machining value of the interference surface in the Z direction to move the surface as a whole downward, otherwise adjusting the machining parameters of each surface separately;

[0018] S10, after all the gap values of the surfaces meet the requirements, removing the machining allowance reserved in the X-axis direction.

[0019] Preferably, the interference amount of the interference surface ranges from 0.02mm to 0.04mm.

[0020] Preferably, between step S3 and step S4, there is also included the requirement that the gap between the faces be converted when the natural fit of the interference faces is achieved:

[0021] Twelfth face gap: X1+△HsinZ1~X2+△HsinZ1;

[0022] Eleventh face gap: X3~X4mm;

[0023] Tenth face gap: X5+△H~X6+△H;

[0024] Ninth face gap: X7~X8mm;

[0025] Eighth face gap: X9+△H~X10+△H;

[0026] Sixth face gap: X11+△H~X12+△H;

[0027] Fifth face gap: X13~X14mm;

[0028] Fourth face gap: X15+△H~X16+△H;

[0029] Third face gap: X17~X18mm;

[0030] Second face gap: X19+△HsinZ3~X20+△HsinZ3;

[0031] First face gap: X21+△HsinZ4~X22+△HsinZ4;

[0032] △H=H' / sinZ2, H' is the interference amount of the interference face, and the included angle between the seventh face and the axis is an acute angle Z2;

[0033] Wherein, the matching surface of the rocket engine nozzle assembly is sequentially connected from outside to inside, and sequentially is the first surface to the twelfth surface; the gap requirement of the first surface is X21~X22 mm; the gap requirement of the second surface is X19~X20 mm; the gap requirement of the third surface is X17~X18 mm; the gap requirement of the fourth surface is X15~X16 mm; the gap requirement of the fifth surface is X13~X14 mm; the gap requirement of the sixth surface is X11~X12 mm; the seventh surface is an interference surface; the gap requirement of the eighth surface is X9~X10 mm; the gap requirement of the ninth surface is X7~X8 mm; the gap requirement of the tenth surface is X5~X6 mm; the gap requirement of the eleventh surface is X3~X4 mm; the gap requirement of the twelfth surface is X1~X2 mm; the angle between the first surface and the vertical plane one is an acute angle Z4, and the vertical plane one is the surface at the junction of the first surface and the second surface; the angle between the extension line of the second surface and the vertical plane two is an acute angle Z3, and the vertical plane two is the surface at the junction of the second surface and the third surface; the angle between the twelfth surface and the vertical plane three is an acute angle Z1, and the vertical plane three is the surface at the junction of the eleventh surface and the twelfth surface.

[0034] Further preferably, in step S4, the gap values of the outermost matching surface, the first surface, and the innermost matching surface, the twelfth surface, are measured, and the gap value of each hole is half of the difference between the inner hole measurement value in step S1 and the inner hole measurement value in step S3.

[0035] Further preferably, in step S5, the gap value J1 of the reference surface is t1-(O2-O1) / sinZ4, wherein t1 is the height of the reference surface pad, O1 is the gap value of the outermost matching surface measured in step S4, and O2 is the gap value of the outermost matching surface measured after the reference surface pad.

[0036] The beneficial effects of the present application are:

[0037] The present application re-measures the relevant dimensions after machining the part one, draws the accurate surface graph in CAD, and then obtains the matching surface of the part two by offsetting the gap values between the surfaces. In the actual machining process, the interference surfaces of the part one and the part two are converted into the fitting surfaces, and an indirect measurement method is provided to accurately measure the gap value of each surface, facilitate the machining program adjustment and the inspection of the dimensions of the part two, thereby ensuring the gap value of each surface, and finally ensuring the interference amount of the interference surface of the part through the pressing amount by pressing the part two. The method can accurately machine the complex labyrinth surface gap value and accurately measure the gap value, and improves the machinability and inspectability of the part. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 It is the gap requirement of each matching surface of the nozzle part and the part two of the present application.

[0039] Figure 2 is a size requirement of the second part of the present application;

[0040] Figure 3 is a size requirement of the second part of the present application. DETAILED DESCRIPTION

[0041] The technical solutions of the present application (including the preferred technical solution) will be further described in detail below by means of the accompanying drawings and by listing some optional embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0042] As shown in Figure 1 , the rocket engine nozzle assembly to which the present application is directed has a mating profile with first to twelfth surfaces in turn connected from the outside to the inside, wherein: the first surface O is an inclined surface, the included angle between the first surface O and the vertical surface one is an acute angle Z4, the vertical surface one is located at the junction of the first surface O and the second surface N; the second surface N is an inclined surface, the second surface N is divided into two sides at the vertical surface one with the first surface O, the included angle between the extension line of the second surface N and the vertical surface two is an acute angle Z3, the vertical surface two is located at the junction of the second surface N and the third surface L; the third surface L is a vertical surface; the fourth surface J is a horizontal surface; the fifth surface I is a vertical surface, the sixth surface G is a horizontal surface, the fifth surface I is connected to the sixth surface G through an arc surface; the seventh surface F is an inclined surface, the included angle between the seventh surface F and the axis is an acute angle Z2; the sixth surface G is connected to the seventh surface F through an arc surface; the eighth surface E is a horizontal surface; the ninth surface D is a vertical surface, the eighth surface E is connected to the ninth surface D through a round corner; the tenth surface C is a horizontal surface; the eleventh surface B is a vertical surface; the twelfth surface A is an inclined surface, the included angle between the twelfth surface A and the vertical surface three is an acute angle Z1, the vertical surface three is located at the junction of the eleventh surface B and the twelfth surface A.

[0043] The gap requirement of the first surface O is X21~X22 mm; the gap requirement of the second surface N is X19~X20 mm; the gap requirement of the third surface L is X17~X18 mm; the gap requirement of the fourth surface J is X15~X16 mm; the gap requirement of the fifth surface I is X13~X14 mm; the gap requirement of the sixth surface G is X11~X12 mm; the seventh surface F is an interference surface; the gap requirement of the eighth surface E is X9~X10 mm; the gap requirement of the ninth surface D is X7~X8 mm; the gap requirement of the tenth surface C is X5~X6 mm; the gap requirement of the eleventh surface B is X3~X4 mm; the gap requirement of the twelfth surface A is X1~X2 mm.

[0044] As shown in Figures 1 to 3 , the processing method of the complex profile rocket engine nozzle assembly designed by the present application comprises the following steps:

[0045] S1, the part one 1 is processed to the position according to the design size requirement.

[0046] S2, the type surface of the part one 1 is measured again, and three coordinate measuring instruments are required to accurately measure the step height values H1, H2 and H3 of each type surface of the part one 1, and the inner hole diameters φm1, φm2, φm3 and φm4, wherein H1 is the height difference between the second type surface and the first type surface in the axial direction, that is, the height difference between the sixth surface and the fourth surface of the part one 1; H2 is the height difference between the third type surface and the first type surface in the axial direction, that is, the height difference between the eighth surface and the fourth surface of the part one 1; H3 is the height difference between the fourth type surface and the first type surface in the axial direction, that is, the height difference between the tenth surface and the fourth surface of the part one 1; φm1 is the inner hole diameter at the first type surface, that is, the diameter at the third surface of the part one 1; φm2 is the inner hole diameter at the second type surface, that is, the diameter at the fifth surface of the part one 1; φm3 is the inner hole diameter at the third type surface, that is, the diameter at the ninth surface of the part one 1; and φm4 is the inner hole diameter at the fourth type surface, that is, the diameter at the eleventh surface of the part one 1.

[0047] S3, according to the re-measured dimensions of the part one 1 in step S2, the mating type surface of the part one 1 is redrawn using CAD software.

[0048] S4, according to the requirements of each gap surface, the type surface of the part one 1 is offset by the corresponding gap median and interference median in CAD, so as to obtain the type surface machining drawing of the part two 2.

[0049] S5, according to the type surface machining drawing of the part two 2, each type surface of the part two 2 is accurately machined, and a part machining allowance is reserved in the X-axis direction of the machine tool.

[0050] S6, after the type surface machining of the part two 2 is completed, the step heights H4a, H5a and H6a thereof are measured, which have very little allowance and need to be matched and repaired subsequently; and the outer circle diameters φm5, φm6, φm7 and φm8 are measured, wherein H4a is the height difference between the sixth type surface and the fifth type surface in the axial direction, that is, the height difference between the sixth surface and the fourth surface of the part two 2; H5a is the height difference between the seventh type surface and the fifth type surface in the axial direction, that is, the height difference between the eighth surface and the fourth surface of the part two 2; H6a is the height difference between the eighth type surface and the fifth type surface in the axial direction, that is, the height difference between the tenth surface and the fourth surface of the part two 2; φm5 is the inner hole diameter at the fifth type surface, that is, the diameter at the third surface of the part two 2; φm6 is the inner hole diameter at the sixth type surface, that is, the diameter at the fifth surface of the part two 2; φm7 is the inner hole diameter at the seventh type surface, that is, the diameter at the ninth surface of the part two 2; and φm8 is the inner hole diameter at the eighth type surface, that is, the diameter at the eleventh surface of the part two 2.

[0051] S7, the seventh face F is an interference face, the angle Z2, generally the interference amount is 0.02-0.04mm, the interference amount in the embodiment is the median 0.03mm, the interference state of the F face of the part two 2 is converted into the natural fitting state of the F face, all the end face gaps will be raised △H, △H=0.03 / sinZ2.

[0052] S8, when the F face of the part 2 is naturally fitted, each face gap is required to be converted as follows:

[0053] The twelfth face A face gap: X1+△HsinZ1-X2+△HsinZ1;

[0054] The eleventh face B face gap: X3-X4mm;

[0055] The tenth face C face gap: X5+△H-X6+△H;

[0056] The ninth face D face gap: X7-X8mm;

[0057] The eighth face E face gap: X9+△H-X10+△H;

[0058] The sixth face G face gap: X11+△H-X12+△H;

[0059] The fifth face I face gap: X13-X14mm;

[0060] The fourth face J face gap: X15+△H-X16+△H;

[0061] The third face L face gap: X17-X18mm;

[0062] The second face N face gap: X19+△HsinZ3-X20+△HsinZ3;

[0063] The first face O face gap: X21+△HsinZ4-X22+△HsinZ4.

[0064] S9, the A face gap value A1 is directly measured by a feeler gauge;

[0065] The B face gap value B1=(φm4-φm8) / 2;

[0066] The D face gap value D1=(φm3-φm7) / 2;

[0067] The I face gap value I1=(φm2-φm6) / 2;

[0068] The L face gap value L1=(φm1-φm5) / 2;

[0069] The O face gap value O1 is directly measured by a feeler gauge;

[0070] S10, after taking out the part two 2, on the fourth surface J surface of the part one 1, that is, the reference surface of measuring height difference, four point pads 4 block gauges (standard measuring tools) of equal thickness t1 mm are symmetrically placed on the pads, and then the part two 2 is reassembled.

[0071] S11, the O surface gap value is measured by using the feeler gauge, and is recorded as O2.

[0072] S12, the F surface of the part two 2 is naturally fitted, and the J surface gap value J1=t1-(O2-O1) / sinZ4, so that the end surface gap value of the theoretical fitting surface can be calculated.

[0073] The G surface gap value G1=H1+J1-H4b.

[0074] The E surface gap value E1=H2+J1-H5b.

[0075] The C surface gap value C1=H3+J1-H6b.

[0076] The gap values G1, E1 and C1 are the design index values, and are known items; H1, H2 and H3 are reference values, and the calculated H4b, H5b and H6b are compared with H4a, H5a and H6a, and the differences are the allowances required for the end surface of the part two 2 to be repaired. Thus, the gap values of each end surface can be accurately controlled.

[0077] S13, after taking out the part two 2, the block gauges on the fourth surface J surface of the part one 1 are removed, and four block gauges (standard measuring tools) of equal thickness t2 mm are symmetrically placed on the four point inclined surfaces of the second surface N surface of the part one 1.

[0078] S14, the O surface gap value is measured by using the feeler gauge, and is recorded as O3.

[0079] S15, the N1=t2-(O3-O1)(sinZ3) / sinZ4.

[0080] S16, the gap values of each surface are checked, if the gap values of all surfaces are greater than the converted gap value requirements, the seventh surface F surface Z direction processing value of the part two 2 is adjusted, so that the overall surface is moved downward. If only individual surface gap values are small and large, the corresponding surface program can be individually adjusted for control.

[0081] S17, when all the surface gap values meet the converted gap value requirements, the X direction reserved fitting allowance is removed, and the surface of the part two 2 is completely machined.

[0082] S18, in the process of pressing and bonding of the late part one 1 and part two 2, the gap between O surface and A surface is measured by using a plug gauge, when the O surface gap = O1-△HsinZ4, and the A surface gap = A1-△HZ1 at the same time, the pressing is stopped, at this time, the F surface interference amount is 0.03mm, that is, the two parts are bonded and assembled in place, and the gap between each matching surface meets the design requirements.

[0083] Those skilled in the art will easily understand that the above is only a preferred embodiment of the present application, and is not intended to limit the present application, and any modification, combination, replacement, improvement, etc. made under the spirit and principle of the present application is included in the protection scope of the present application.

Claims

1. A method for processing a complex-shaped rocket engine nozzle assembly, characterized in that, Includes the following steps: S1. Process part one according to the design dimensions. Remeasure each dimension of part one. Take one horizontal platform surface as the reference surface and measure the height difference between the other horizontal step surfaces and the reference surface, as well as the inner hole diameter. S2, Draw the mating surface according to the measurement results in step S1, and offset it according to the requirements of each gap surface to obtain the surface machining drawing of part two, and perform fine machining on each surface of part two according to the surface machining drawing of part two; S3, Measure all dimensions of part two processed in step S2. The positions for measuring the above dimensions are the same as the reference for re-measurement in step S1. S4, make the interference surfaces of part one and part two fit together naturally, measure the clearance values ​​of the mating surfaces of part one and part two on both sides, and calculate the clearance values ​​of each hole position. S5, raise the reference surface from step S1, measure the gap value of the outer mating surfaces of part one and part two, and calculate the gap value of the reference surface when the interference surfaces are naturally in contact. S6, Calculate the height difference of each horizontal step surface of part two based on the design parameters of each horizontal step surface and the calculation results in step S5. S7. Compare the measured values ​​of the height differences of each horizontal step surface in step S2 with the calculated values ​​of the height differences of each horizontal step surface in step S6 to obtain the difference value. Use the above difference value as the rework allowance for each step surface of part two.

2. The processing method for the complex-shaped rocket engine nozzle assembly according to claim 1, characterized in that: In step S2, when precisely machining each surface of part two, a machining allowance is reserved in the X-axis direction of the machine tool.

3. The processing method for the complex-shaped rocket engine nozzle assembly according to claim 2, characterized in that: The following steps are included after step S7: S8. After resetting parts one and two, raise the inclined surface adjacent to the outer mating surface and measure the gap value of parts one and two on the outer mating surface. S9, if the clearance values ​​of all surfaces are greater than required, adjust the machining value of the interference surface in the Z direction to move the entire surface downward; otherwise, adjust the machining parameters of each surface individually. S10, after the clearance values ​​of all surfaces meet the requirements, remove the machining allowance reserved in the X-axis direction.

4. The processing method for the complex-shaped rocket engine nozzle assembly according to claim 3, characterized in that: The interference range of the interference surface is 0.02 to 0.04 mm.

5. The processing method for the complex-shaped rocket engine nozzle assembly according to claim 4, characterized in that: Between steps S3 and S4, there is also a requirement to convert the gap between the surfaces during the natural fit of the interference surfaces: The gap on the twelfth face: X1+△HsinZ1~X2+△HsinZ1; Eleventh surface gap: X3~X4mm; The gap on the tenth side is: X5+△H to X6+△H; Ninth surface gap: X7~X8mm; The gap on the eighth surface is: X9+△H~X10+△H; The gap on the sixth surface is: X11+△H~X12+△H; Fifth surface clearance: X13~X14mm; The gap on the fourth surface is: X15+△H to X16+△H; Third-side clearance: X17~X18mm; Second surface gap: X19+△HsinZ3~X20+△HsinZ3; First surface gap: X21+△HsinZ4~X22+△HsinZ4; △H=H' / sinZ2, where H' is the interference of the interference surface, and the angle between the seventh surface and the axis is acute angle Z2; The mating surfaces of the rocket engine nozzle assembly are sequentially connected from the outside to the inside, numbered from the first to the twelfth surface. The clearance requirements for the first surface are X21–X22 mm; for the second surface, X19–X20 mm; for the third surface, X17–X18 mm; for the fourth surface, X15–X16 mm; for the fifth surface, X13–X14 mm; for the sixth surface, X11–X12 mm; the seventh surface is an interference fit; the eighth surface has a clearance of X9–X10 mm; the ninth surface has a clearance of X7–X8 mm; the tenth surface has a clearance of X5–X6 mm; the eleventh surface has a clearance of X3–X4 mm; and the twelfth surface has a clearance of X1–X2 mm. mm; the angle between the first face and the first perpendicular face is acute angle Z4, and the first perpendicular face is the face located at the junction of the first face and the second face; the angle between the extension of the second face and the second perpendicular face is acute angle Z3, and the second perpendicular face is the face located at the junction of the second face and the third face; the angle between the twelfth face and the third perpendicular face is acute angle Z1, and the third perpendicular face is the face located at the junction of the eleventh face and the twelfth face.

6. The processing method for the complex-shaped rocket engine nozzle assembly according to claim 5, characterized in that: In step S4, the clearance values ​​of the outermost mating surface—the first surface and the innermost mating surface—the twelfth surface are measured. The clearance value of each hole is half the difference between the inner hole measurement value in step S1 and the inner hole measurement value in step S3.

7. The method for processing complex-shaped rocket engine nozzle assemblies according to claim 5, characterized in that: In step S5, the gap value J1 of the reference surface is t1-(O2-O1) / sinZ4, where t1 is the height of the reference surface being raised, O1 is the gap value of the outermost mating surface measured in step S4, and O2 is the gap value of the outermost mating surface measured after the reference surface is raised.

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