Non-rigid casing and constraint machining method thereof

Abstract

The invention discloses a non-rigid casing and a constraint machining method thereof, belongs to the technical field of machining, and comprises technological processes and constraint conditions. The machining method is used for solving the problems that according to a machining method of a non-rigid case in the prior art, deformation is prone to being generated in the machining process, the coaxiality or position degree of parts is out of tolerance, the assembly precision is affected, and the assembly stress is increased. According to the method, the technical requirements of the constraint state and the free state are clearly distinguished, and the deformation control is enhanced. The flatness error of the reference surface in a free state is controlled to reduce the compression deformation of the casing; the roundness error of the reference circle in a free state is controlled to reduce the positioning deformation of the cartridge receiver; the technical requirement of controlling the free state is to strengthen the control of cutting parameters, namely cutting force; the shape error of the case in the machining state is limited by adopting reasonable constraint conditions, so that the machining state and the assembly state of the case are consistent, the assembly precision of the case on an engine is improved, and the assembly stress is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical processing, and in particular relates to a constraint processing method for a non-rigid casing. Background Art

[0002] Aircraft engines have very strict weight control. They use material stiffness and structural stiffness to ensure the overall stiffness of the engine. That is, under the premise of meeting the overall stiffness of the engine, the weight of the parts is controlled as much as possible. Therefore, a large number of thin-walled parts are used in aircraft engines. These parts are relatively weak in rigidity and are collectively referred to as non-rigid parts. During the manufacturing process, as the blank excess is continuously removed and the structural dimensions of the parts are gradually refined, the internal stress of the parts is constantly changing. The change in internal stress causes the parts to deform, affecting the manufacturing accuracy of the parts.

[0003] During the manufacturing process, the deformation of non-rigid parts makes it very difficult to inspect and accept parts. At present, the industry generally adopts the acceptance method of conducting limit inspection during the process and checking the process records during delivery and acceptance. This method avoids the impact of processing deformation on the inspection results, but covers up process design defects and quality control loopholes in the manufacturing process, often resulting in out-of-tolerance products being delivered as "qualified".

[0004] Some people have proposed to perform limit detection on non-rigid parts when finished parts are delivered for acceptance. However, after verification, it was found that limit detection can indeed improve the qualified rate of the tested elements, but the qualified rate is not high and is not stable. Further research found that the results of limit detection are not only related to the limit method and limit size, but also to the process control method and part deformation size during the manufacturing process. Only by implementing reasonable process methods and strictly controlling the deformation amount can the limit detection results be stable and meet the design requirements.

[0005] The compressor casing of a new aircraft engine is a typical non-rigid part. Figure 1 As shown in the figure, its structure is a split type with upper and lower halves. In order to ensure the coaxiality with the front and rear casings and the radial clearance between the rotating parts and the stator parts, strict circular runout, coaxiality or position requirements are stipulated between the front and rear positioning elements of the casing, such as Figures 2 to 4 As shown. Due to machining deformation, when the process design is inappropriate, it will cause the coaxiality or position of the parts to exceed the tolerance, affecting the assembly accuracy and increasing the assembly stress.

[0006] In summary, the processing method of the non-rigid casing in the prior art is prone to deformation during the processing, resulting in excessive coaxiality or position of parts, affecting assembly accuracy and increasing assembly stress. Summary of the invention

[0007] The purpose of the present invention is to provide a non-rigid casing and a constrained processing method thereof, including a process flow and constraint conditions. The method is used to solve the problem that the processing method of the non-rigid casing in the prior art is prone to deformation during the processing, causing the coaxiality or position of the parts to exceed the tolerance, affecting the assembly accuracy, and increasing the assembly stress. The method can reduce the processing deformation, and make the finishing state of the casing consistent with the assembly state, effectively improve the manufacturing accuracy of the casing, ensure the assembly accuracy of the casing, and reduce the assembly stress.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A constrained machining method for a non-rigid casing includes: during fine machining, axially pressing the part, and then fine turning the front end reference surface to provide a reference surface for the next process;

[0010] Using the front reference surface as the reference, axially press the parts; finish turning the rear reference surface and the rear reference hole;

[0011] Taking the rear end reference surface and the rear end reference hole as the reference, the fixture is used to support the rear end reference surface of the part, locate the rear end reference hole, and press the back side of the mounting edge; finish turning the front section of the casing, and finish machining without compression deformation and positioning deformation. By adjusting the cutting parameters, the deformation after machining can be controlled;

[0012] Taking the front reference surface as the reference, the fixture is used to support the front face of the part, locate the front reference hole, and press the back of the front mounting edge; the rear section of the casing is fine-turned, and the deformation after pressing and positioning is controlled. The deformation after processing is controlled by adjusting the cutting parameters;

[0013] Taking the rear end reference surface and the rear end reference hole as references, the clamp is used to support the rear end reference surface of the part, locate the rear end reference hole, and press the back of the rear mounting edge; at the same time, the front end reference hole is constrained to be rounded; drill and bore the holes on the front mounting edge; drill and bore the holes in the front end reference hole and the rear end reference hole in the rounded state to ensure the position requirements of the holes and control the distance difference between each precision hole drilled or bored and the wall of the reference hole;

[0014] The parts are constrained by fixtures, the front end faces of the parts are supported, the front end reference holes are located, the precision holes on the front mounting edge are located, and the back of the front mounting edge is pressed; at the same time, the rear end reference holes are constrained by support circles; the holes on the rear mounting edge are drilled and bored; the reference holes at both ends are simultaneously supported and bored to ensure the position of the holes and control the distance difference between each precision hole and the wall of the reference hole.

[0015] Preferably, before finishing the parts, the blank is subjected to roughing and semi-finishing to remove large excess; and heat treatment is performed to eliminate residual stress of the blank and residual stress of roughing.

[0016] Preferably, when precision turning the front end reference surface, align the front end inner hole, and the point runout should not exceed 0.2mm; use four claws to lightly lean against the outer circle of the rear mounting edge to prevent the parts from moving during processing; use a pressure plate to press the back of the rear mounting edge, and the clearance under the reference surface corresponding to the position of the front pressure plate should not be greater than 0.02mm, otherwise add a feeler gauge for adjustment.

[0017] Preferably, when precision turning the rear end reference surface and the rear end reference hole, align the rear end inner hole, and the point runout should not exceed 0.02mm; use four claws to lightly touch the outer circle of the front mounting edge to prevent the parts from moving during processing; use a pressure plate to press the back of the front mounting edge, and the clearance under the reference surface corresponding to the position of the front pressure plate should not be greater than 0.02mm, otherwise add a feeler gauge for adjustment.

[0018] Preferably, when finish turning the front section of the receiver, the total runout of the locating end face of the alignment fixture is no more than 0.01mm, and the runout of the locating outer circle of the alignment fixture is no more than 0.005mm; before clamping, use a feeler gauge to check the gap between the rear end face and the locating end face of the fixture to confirm that the receiver is clamped in place; after clamping, use a feeler gauge to check the reference surface gap, and the local gap is no more than 0.02mm.

[0019] Preferably, when finish turning the rear section of the receiver, the total runout of the locating end face of the alignment fixture is no more than 0.01mm, and the runout of the locating outer circle of the alignment fixture is no more than 0.005mm; before clamping, use a feeler gauge to check the gap between the front end face and the locating end face of the fixture to confirm that the receiver is clamped in place; after clamping, use a feeler gauge to check the reference surface gap, and the local gap is no more than 0.02mm.

[0020] Preferably, when drilling or boring the holes on the front mounting edge, the total runout of the positioning end face of the alignment fixture is no more than 0.01mm, and the runout of the positioning outer circle of the alignment fixture is no more than 0.005mm; before clamping, use a feeler gauge to check the gap between the rear end face of the receiver and the positioning end face of the fixture to confirm that the receiver is clamped in place; after clamping, use a feeler gauge to check the reference surface gap, and the local gap is no more than 0.02mm.

[0021] Preferably, when the side hole is installed after drilling and boring, the total runout of the positioning end face of the alignment fixture is no more than 0.01mm, and the runout of the positioning outer circle of the alignment fixture is no more than 0.005mm; before clamping, use a feeler gauge to check the gap between the front end face of the receiver and the positioning end face of the fixture to confirm that the receiver is clamped in place; after clamping, use a feeler gauge to check the reference surface gap, and the local gap is no more than 0.02mm.

[0022] Preferably, when drilling or boring the hole on the front mounting edge, the front reference hole is constrained to be rounded while positioning the rear reference hole; the holes are drilled or bored while the reference holes at both ends are simultaneously rounded to ensure the position requirements of the holes and control the distance difference between each precision hole drilled or bored and the wall surface of the reference hole;

[0023] When drilling or boring holes on the rear mounting edge, the front reference hole is positioned while the rear reference hole is constrained to be rounded; drilling or boring is performed while the reference holes at both ends are simultaneously rounded to ensure the position of the holes and control the distance difference between each precision hole drilled or bored and the wall of the reference hole.

[0024] A non-rigid casing is manufactured by using any one of the above-mentioned constraint processing methods for a non-rigid casing.

[0025] Compared with the prior art, the present invention has the following beneficial technical effects:

[0026] The present invention provides a constrained processing method for a non-rigid casing, which clearly distinguishes the technical requirements of the constrained state and the free state, and strengthens the control of the deformation amount. Controlling the flatness error of the reference surface in the free state reduces the compression deformation of the casing; controlling the roundness error of the reference circle in the free state reduces the positioning deformation of the casing; controlling the technical requirements of the free state strengthens the control of the cutting parameters, that is, the cutting force; using reasonable constraint conditions to limit the shape error of the casing processing state, so that the processing state of the casing is consistent with the assembly state, improving the assembly accuracy of the casing on the engine, and reducing the assembly stress. The present invention can be extended to the processing of other non-rigid parts, and can also be extended to other manufacturing fields such as aerospace and gas turbines, which can improve the manufacturing accuracy of parts and better meet assembly requirements.

[0027] Furthermore, the present invention controls the flatness of the front reference end face and the rear reference end face in a free state, reduces compression deformation, and improves manufacturing accuracy.

[0028] Furthermore, the present invention controls the roundness of the front reference hole and the rear reference hole in a free state, reduces positioning deformation, and improves manufacturing accuracy.

[0029] Furthermore, the present invention drills and bores the holes on the mounting edge under the reference hole support circle constraint state, limits the roundness error of the reference hole, thereby controlling the distance error between the precision hole on the mounting edge and the adjacent reference hole wall, improving assembly accuracy and reducing assembly stress.

[0030] Furthermore, the present invention simulates the assembly state of the casing on the engine, positions the front end reference hole and the precision hole on the front mounting edge at the same time, and constrains the rear end reference hole to be round. In this state, the precision holes on the rear mounting edge are drilled and bored, which effectively ensures the overall position accuracy of the precision holes on the rear mounting edge to the precision holes on the front mounting edge, thereby improving the assembly accuracy of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a split compressor casing of a certain type of aircraft engine;

[0032] Figure 2This is the front view of the compressor casing;

[0033] Figure 3 for Figure 2 A-direction view of the main view;

[0034] Figure 4 for Figure 2 B-direction view of the main view;

[0035] Figure 5 Sketch for process 1;

[0036] Figure 6 Sketch for process 2;

[0037] Figure 7 Sketch for process 3;

[0038] Figure 8 Sketch for process 4;

[0039] Fig. 9 Sketch for process 5;

[0040] Fig.10 This is a sketch for process 6. DETAILED DESCRIPTION

[0041] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0042] 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", "axial", "radial", "circumferential" 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, and do not indicate or imply 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.

[0043] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0044] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0046] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0047] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0048] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0049] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0050] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0051] Example 1

[0052] The invention discloses a constrained processing method for a compressor casing, including a process flow and constraint conditions. The method can reduce processing deformation, make the casing finish processing state consistent with the assembly state, effectively improve the casing manufacturing accuracy, ensure the casing assembly accuracy, and reduce assembly stress. The specific contents are as follows:

[0053] 1) Process flow

[0054] 0: Rough machining + stress relief + semi-finishing (completed before finishing) → 1: Finish turning the front reference surface → 2: Finish turning the rear reference surface and reference hole → 3: Finish turning the front section of the casing → 4: Finish turning the rear section of the casing → 5: Drill and bore the holes on the front mounting side → 6: Drill and bore the holes on the rear mounting side;

[0055] 2) Constraints and main technical requirements

[0056] Process 0:

[0057] (1) Process purpose: remove large excess; heat treatment to eliminate residual stress in the blank and residual stress in rough machining; semi-finishing.

[0058] Process 1:

[0059] (1) Process purpose: to provide a reference surface close to the theoretical plane for the next process and to control the compaction deformation.

[0060] (2) Constraint conditions: Axial compression, try to keep the parts free.

[0061] (3) Main technical requirements: Flatness of the front end surface in the free state, such as Figure 5 shown.

[0062] Process 2:

[0063] (1) Process purpose: to provide a reference surface close to the theoretical plane for the next process to control the compaction deformation; to provide a positioning circle close to the theoretical shape for the next process to control the elastic deformation caused by positioning.

[0064] (2) Constraint conditions: Axial compression, try to keep the parts free.

[0065] (3) Main technical requirements: Flatness of the rear end surface in the free state; Roundness of the rear end reference hole in the free state, such as Figure 6 shown.

[0066] Process 3:

[0067] (1) Process purpose: To perform fine machining without compression deformation and positioning deformation, and to control the amount of deformation after machining; at the same time, to reduce the cutting force through cutting parameters and control the machining deformation of this process.

[0068] (2) Constraint conditions: Use fixture constraints, support the rear end face of the part, locate the rear end reference hole (constrained by the maximum physical size of the locating hole), and install the back side after pressing.

[0069] (3) Main technical requirements: Flatness of the front end surface in the free state; Roundness of the front end reference hole in the free state, such as Figure 7 shown.

[0070] Process 4:

[0071] (1) Process purpose: To perform fine machining under the conditions of controlling the compression deformation and positioning deformation, and to reduce the deformation after machining; at the same time, to reduce the cutting force through cutting parameters and control the machining deformation of this process.

[0072] (2) Constraint conditions: Use fixture constraints, support the front end face of the part, locate the front reference hole (constrained by the maximum physical size of the locating hole), and press the back of the front installation edge.

[0073] (3) Main technical requirements: parallelism of the rear end surface to the front end surface under constraint; circular runout of the rear end reference hole to the front end reference hole under constraint; flatness of the rear end surface under free state; roundness of the rear end reference hole under free state, such as Figure 8 shown.

[0074] Step 5:

[0075] (1) Process purpose: Drill and bore holes with the front and rear end reference holes in a rounded state to ensure the position requirements of the holes. The deeper purpose is to control the distance difference between each precision hole drilled or bored and the wall of the reference hole.

[0076] (2) Constraint conditions: Use a fixture to constrain, the rear end face is supported, the rear end reference hole is positioned (constrained by the maximum physical size of the positioning hole), and the back side of the installation edge is pressed; at the same time, the front end reference hole is constrained to support the circle (constrained by the maximum physical size of the supported circular hole).

[0077] (3) Main technical requirements: Position accuracy of the precision hole on the front mounting edge under the constraint state, such as Fig. 9 shown.

[0078] Step 6:

[0079] (1) Purpose of the process: Drilling and boring holes with both ends of the reference holes in a circular state to ensure the position of the holes. The deeper purpose is to control the distance difference between each precision hole drilled or bored and the wall of the reference hole.

[0080] (2) Constraints: Use fixture constraints, front end face support, front end reference hole positioning (constrained by the maximum physical size of the positioning hole), and at the same time, the 18 precision holes on the front mounting edge are positioned (constrained by the maximum physical size of the precision hole minus the hole position value), and the back of the front mounting edge is pressed; at the same time, the rear end reference hole is constrained to support the circle (constrained by the maximum physical size of the supported circular hole).

[0081] (3) Main technical requirements: Position accuracy of the precision hole on the rear mounting side to its adjacent reference hole under the constraint state; Position accuracy of the entire group of precision holes on the rear mounting side to the precision holes on the front mounting side under the constraint state, such as Fig.10 shown.

[0082] The present invention applies GB / T 16892-1997 Method for Marking Shape and Position Tolerances of Non-rigid Parts to the marking of process drawings, clearly distinguishes the inspection requirements of the constrained state and the free state, breaks the habit of completely inspecting the upper limit of the fixture for process technical requirements, and strengthens the control requirements for the deformation of the process.

[0083] The invention controls the flatness of the front and rear reference end faces in a free state, reduces compression deformation and improves manufacturing accuracy.

[0084] The invention controls the roundness of the front and rear reference holes in a free state, reduces positioning deformation and improves manufacturing accuracy.

[0085] The present invention drills and bores the hole on the mounting edge under the reference hole support circle constraint state, limits the roundness error of the reference hole, thereby controlling the distance error between the precision hole on the mounting edge and the wall surface of the adjacent reference hole, improves the assembly accuracy and reduces the assembly stress.

[0086] The present invention simulates the assembly state of the casing on the engine, positions the front end reference hole and the precision hole on the front mounting edge at the same time, and constrains the rear end reference hole to be round. In this state, the precision holes on the rear mounting edge are drilled and bored, which effectively ensures the overall position accuracy of the precision holes on the rear mounting edge to the precision holes on the front mounting edge, thereby improving the assembly accuracy of the engine.

[0087] Example 2

[0088] Process 0:

[0089] The contents of rough machining, stress relief, semi-finishing, etc. before finishing do not involve the technical key points of the present invention and will not be elaborated here.

[0090] Process 1: Finish turning the front reference surface

[0091] 1) Equipment requirements: CNC vertical lathe or ordinary vertical lathe.

[0092] 2) Fixture alignment requirements: No fixture is used.

[0093] 3) Parts alignment requirements: Align the inner hole at the front end, with the point runout no greater than 0.2mm; use four claws to lightly lean against the outer circle of the rear mounting edge to prevent the parts from moving during processing.

[0094] 4) Parts clamping requirements: Use 6 pressure plates to press the back of the rear installation edge. The clearance under the reference surface corresponding to the position of the pressure plate before clamping shall not be greater than 0.02mm. If necessary, add copper pads or feeler gauges.

[0095] 5) Key points of processing and inspection: Control cutting force to ensure the flatness of the front end face in a free state.

[0096] Process 2: Finishing the rear end reference surface and reference hole

[0097] 1) Equipment requirements: CNC vertical lathe or ordinary vertical lathe.

[0098] 2) Fixture alignment requirements: No fixture is used.

[0099] 3) Parts alignment requirements: Align the inner hole at the rear end, with the point runout no greater than 0.02mm; use four claws to lightly lean against the outer circle of the rear mounting edge to prevent the parts from moving during processing.

[0100] 4) Parts clamping requirements: Use 6 pressure plates to press the back of the rear installation edge. The clearance under the reference surface corresponding to the position of the pressure plate before clamping shall not be greater than 0.02mm. Add a feeler gauge if necessary.

[0101] 5) Key points of processing and inspection: Control cutting force, ensure the flatness of the rear end face in the free state, and ensure the roundness of the rear end reference hole in the free state.

[0102] Process 3: Finishing the front section of the casing

[0103] 1) Equipment requirements: CNC vertical lathe or CNC horizontal lathe.

[0104] 2) Requirements for fixture alignment: The total runout of the alignment fixture positioning end face shall not exceed 0.01mm, and the runout of the alignment fixture positioning outer circle shall not exceed 0.005mm.

[0105] 3) Parts alignment requirements: No parts alignment is required.

[0106] 4) Part clamping requirements: Before clamping, use a feeler gauge to check the gap between the front end face and the positioning end face of the fixture to confirm that the receiver is clamped in place; after clamping, use a feeler gauge to check the reference surface gap, and the local gap should not exceed 0.02mm.

[0107] 5) Key points for processing and inspection: Strictly control cutting parameters to control cutting force and processing deformation. In the state of fixture limit, check the diameter size of the front reference hole, check the total runout of the front reference surface, and check the circular runout of the front reference hole. Remove the casing and check the flatness of the front face in a free state; check the roundness of the front reference hole.

[0108] Process 4: Finishing the rear section of the casing

[0109] 1) Equipment requirements: CNC vertical lathe or CNC horizontal lathe.

[0110] 2) Requirements for fixture alignment: The total runout of the alignment fixture positioning end face shall not exceed 0.01mm, and the runout of the alignment fixture positioning outer circle shall not exceed 0.005mm.

[0111] 3) Parts alignment requirements: No parts alignment is required.

[0112] 4) Part clamping requirements: Before clamping, use a feeler gauge to check the gap between the rear end face and the positioning end face of the fixture to confirm that the receiver is clamped in place; after clamping, use a feeler gauge to check the reference surface gap, and the local gap should not exceed 0.02mm.

[0113] 5) Key points for processing and inspection: Strictly control cutting parameters to control cutting force and processing deformation. In the clamp limit state, check the diameter size of the rear end reference hole, check the parallelism of the rear end reference surface; check the circular runout of the rear end reference hole. Remove the casing and check the flatness of the front end surface and the roundness of the front end reference hole in a free state.

[0114] Step 5: Drill and bore holes on the front mounting side

[0115] 1) Equipment requirements: Vertical CNC jig boring machine.

[0116] 2) Requirements for fixture alignment: The total runout of the alignment fixture positioning end face shall not exceed 0.01mm, and the runout of the alignment fixture positioning outer circle shall not exceed 0.005mm.

[0117] 3) Parts alignment requirements: No parts alignment is required.

[0118] 4) Part clamping requirements: Before clamping, use a feeler gauge to check the gap between the rear end face and the positioning end face of the fixture to confirm that the receiver is clamped in place; after clamping, use a feeler gauge to check the reference surface gap, and the local gap should not exceed 0.02mm.

[0119] 5) Requirements for front support ring clamping and alignment: Install the front support ring and use a feeler gauge to check the gap between the lower reference surface of the front support ring and the front end surface of the receiver. The 0.02 feeler gauge must not pass. The inner hole runout of the front support ring should not exceed 0.005mm.

[0120] 6) Key points of processing and inspection: Use a special position measuring tool to check the position of the precision holes on the front installation edge.

[0121] Step 6: Drill and bore holes on the rear mounting side

[0122] 1) Equipment requirements: Vertical CNC jig boring machine.

[0123] 2) Requirements for fixture alignment: The total runout of the alignment fixture positioning end face shall not exceed 0.01mm, and the runout of the alignment fixture positioning outer circle shall not exceed 0.005mm.

[0124] 3) Parts alignment requirements: No parts alignment is required.

[0125] 4) Part clamping requirements: Before clamping, use a feeler gauge to check the gap between the front end face of the receiver and the positioning end face of the fixture to confirm that the receiver is clamped in place; after clamping, use a feeler gauge to check the reference surface gap, and the local gap should not exceed 0.02mm.

[0126] 5) Requirements for clamping and checking the rear support ring: Install the rear support ring and use a feeler gauge to check the clearance between the lower reference surface of the rear support ring and the rear end surface of the receiver. The 0.02 feeler gauge must not pass. Check that the circular runout of the inner hole of the rear support ring is not greater than 0.03mm. Pay special attention to this: this is only an inspection and the inner hole of the rear support ring must not be aligned.

[0127] 6) Key points of processing and inspection: Use a special position measuring tool to check the position of the precision holes on the rear mounting edge, including the position of the entire set of precision holes on the front mounting edge.

[0128] The processing is completed.

[0129] The present invention applies "GB / T 16892-1997 Shape and Position Tolerance Non-rigid Parts Marking Method" to the marking of process drawings, clearly distinguishes the technical requirements of the constrained state and the free state, and strengthens the control of the deformation. The flatness error of the control reference surface in the free state reduces the compression deformation of the casing; the roundness error of the control reference circle in the free state reduces the positioning deformation of the casing; the technical requirements of controlling the free state strengthen the control of the cutting parameters, that is, the cutting force; the shape error of the casing processing state is limited by reasonable constraint conditions, so that the processing state of the casing is consistent with the assembly state, the assembly accuracy of the casing on the engine is improved, and the assembly stress is reduced.

[0130] The present invention can be extended and applied to the processing of other non-rigid parts, and can also be extended and applied to other manufacturing fields such as aerospace and gas turbines, and can improve the manufacturing accuracy of parts and better meet assembly requirements.

[0131] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0132] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A constrained processing method for a non-rigid casing, characterized in that: include: When finishing, the part is axially pressed, and then the front reference surface is precision-turned to provide a reference surface for the next process; Using the front reference surface as the reference, axially press the parts; finish turning the rear reference surface and the rear reference hole; Taking the rear end reference surface and the rear end reference hole as the reference, the fixture is used to support the rear end reference surface of the part, locate the rear end reference hole, and press the back side of the mounting edge; finish turning the front section of the casing, and finish machining without compression deformation and positioning deformation. By adjusting the cutting parameters, the deformation after machining can be controlled; Taking the front reference surface as the reference, the fixture is used to support the front face of the part, locate the front reference hole, and press the back of the front mounting edge; the rear section of the casing is fine-turned, and the deformation after pressing and positioning is controlled. The deformation after processing is controlled by adjusting the cutting parameters; Taking the rear end reference surface and the rear end reference hole as references, the clamp is used to support the rear end reference surface of the part, locate the rear end reference hole, and press the back of the rear mounting edge; at the same time, the front end reference hole is constrained to be rounded; drill and bore the holes on the front mounting edge; drill and bore the holes in the front end reference hole and the rear end reference hole in the rounded state to ensure the position requirements of the holes and control the distance difference between each precision hole drilled or bored and the wall of the reference hole; The parts are constrained by fixtures, the front end faces of the parts are supported, the front end reference holes are located, the precision holes on the front mounting edge are located, and the back of the front mounting edge is pressed; at the same time, the rear end reference holes are constrained by support circles; the holes on the rear mounting edge are drilled and bored; the reference holes at both ends are simultaneously supported and bored to ensure the position of the holes and control the distance difference between each precision hole and the wall of the reference hole.

2. A method for constraining a non-rigid casing according to claim 1, characterized in that: Before finishing the parts, the blank is rough-machined and semi-finished to remove large excesses; and heat treatment is performed to eliminate residual stress in the blank and residual stress in roughing.

3. The constrained processing method of a non-rigid casing according to claim 1, characterized in that: When precision turning the front end reference surface, align the front end inner hole, and the point runout should not exceed 0.2mm; use four claws to lightly touch the outer circle of the rear installation edge to prevent the parts from moving during processing; use a pressure plate to press the back of the rear installation edge, and the clearance under the reference surface corresponding to the position of the pressure plate before pressing should not be greater than 0.02mm, otherwise add a feeler gauge for adjustment.

4. The constrained processing method of a non-rigid casing according to claim 1 is characterized in that: When precision turning the rear end reference surface and the rear end reference hole, align the rear end inner hole, and the point runout should not exceed 0.02mm; use four claws to lightly touch the outer circle of the front mounting edge to prevent the parts from moving during processing; use a pressure plate to press the back of the front mounting edge, and the clearance under the reference surface corresponding to the position of the pressure plate before pressing should not be greater than 0.02mm, otherwise add a feeler gauge for adjustment.

5. The constrained processing method of a non-rigid casing according to claim 1, characterized in that: When finishing the front section of the receiver, the total runout of the locating end face of the alignment fixture shall not exceed 0.01mm, and the runout of the outer circle of the locating fixture shall not exceed 0.005mm; before clamping, use a feeler gauge to check the gap between the rear end face and the locating end face of the fixture to confirm that the receiver is clamped in place; after clamping, use a feeler gauge to check the reference surface gap, and the local gap shall not exceed 0.02mm.

6. The constrained processing method of a non-rigid casing according to claim 1, characterized in that: When finishing the rear section of the receiver, the total runout of the locating end face of the alignment fixture shall not exceed 0.01mm, and the runout of the outer circle of the locating fixture shall not exceed 0.005mm; before clamping, use a feeler gauge to check the gap between the front end face and the locating end face of the fixture to confirm that the receiver is clamped in place; after clamping, use a feeler gauge to check the reference surface gap, and the local gap shall not exceed 0.02mm.

7. The constrained processing method of a non-rigid casing according to claim 1 is characterized in that: When drilling or boring the holes on the front installation side, the total runout of the alignment fixture positioning end face shall not exceed 0.01mm, and the outer circle runout of the alignment fixture positioning shall not exceed 0.005mm; before clamping, use a feeler gauge to check the gap between the rear end face of the receiver and the positioning end face of the fixture to confirm that the receiver is clamped in place; after clamping, use a feeler gauge to check the reference surface gap, and the local gap shall not exceed 0.02mm; When installing the side holes after drilling and boring, the total runout of the locating end face of the alignment fixture shall not exceed 0.01mm, and the runout of the locating outer circle of the alignment fixture shall not exceed 0.005mm; before tightening, use a feeler gauge to check the gap between the front end face of the receiver and the locating end face of the fixture to confirm that the receiver is clamped in place; after tightening, use a feeler gauge to check the reference surface gap, and the local gap shall not exceed 0.02mm.

8. The constrained processing method of a non-rigid casing according to claim 1, characterized in that: When drilling or boring holes on the front mounting edge, the front reference hole is constrained to be rounded while positioning the rear reference hole; drill or bore holes while the reference holes at both ends are simultaneously rounded to ensure the position requirements of the holes and control the distance difference between each precision hole drilled or bored and the wall of the reference hole.

9. The constrained processing method of a non-rigid casing according to claim 1, characterized in that: When drilling or boring holes on the rear mounting edge, the front reference hole is positioned while the rear reference hole is constrained to be rounded; drilling or boring is performed while the reference holes at both ends are simultaneously rounded to ensure the position of the holes and control the distance difference between each precision hole drilled or bored and the wall of the reference hole.

10. A non-rigid casing, characterized in that: It is manufactured by using the constraint processing method of a non-rigid casing as described in any one of claims 1 to 9.

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