A machining method for combined turning of gas turbine casing

Abstract

The present invention relates to the field of gas turbine machining technology, and in particular to a machining method for combined turning of a gas turbine casing, comprising the following steps S1: connecting a combination with a process ring to form a preliminary combination; S2, performing a first stage of turning to obtain a preliminary turning combination; S3, using a primary process ring as a positioning, assembling a fifth part with the primary process ring to form a secondary assembly; S4, performing a second stage of turning to obtain a turned finished part; S5, decomposing the turned finished part to obtain a secondary process ring and a turned fifth part, and assembling the turned fifth part with the combination to form a turned assembly. The present invention processes the combination of five casing parts together, and uses a process ring to realize the conversion of the machining datum, and divides the assembly into two parts for segmented machining, which not only ensures the design requirements of the combined machining, but also reduces the machining difficulty, solves the equipment limitation, and improves the machining efficiency and quality.

Description

Technical Field

[0001] The invention relates to the technical field of gas turbine machining, in particular to a machining method for combined turning of a gas turbine casing. Background Art

[0002] In the design requirements of modern gas turbines, there are requirements for combining multiple parts to ensure certain characteristics. The five parts of a certain type of gas turbine, including the front casing, outer ring, anti-surge casing, rotatable guide housing, and compressor casing, need to be combined and machined after assembly. The height of the assembled components exceeds the processing size of ordinary CNC lathes, and higher requirements are placed on the processing stroke and precision of CNC lathes. Such a high stroke requires special large-scale equipment for processing, which completely limits the universal processing of parts. In addition, since it is not easy to operate and observe during combined turning, parts are prone to vibration during processing, which affects the processing efficiency and quality. At the same time, combined processing can only be carried out when all related parts are complete and synchronous. Therefore, when the parts are not complete, each part cannot continue to be processed and can only wait for each other, which seriously affects the production progress of each part. The combined processing of different parts has always been a difficult point in mechanical processing. Summary of the invention

[0003] In view of the problem that it is difficult to process multiple casings in the prior art, the present invention provides a method for combined turning of gas turbine casings.

[0004] The present invention is achieved through the following technical solutions:

[0005] A gas turbine casing combined turning processing method comprises the following steps:

[0006] S1: Assemble the first part, the second part, the third part and the fourth part to form an assembly; then connect the assembly with the process ring to form a preliminary assembly;

[0007] S2, clamping the preliminary assembly on the turning equipment, performing the first alignment, and then performing the first turning process to obtain a preliminary turning assembly, which includes a primary process ring and an assembly;

[0008] S3, decomposing the preliminary turning assembly to obtain a primary process ring and an assembly; using the primary process ring as a positioning member, assembling the fifth part with the primary process ring to form a secondary assembly;

[0009] S4, clamping the secondary assembly on the turning equipment, performing a second alignment, and then performing a second turning process to obtain a turned finished part, the turned finished part including the secondary process ring and the turned fifth part;

[0010] S5, decomposing the finished turning part to obtain a secondary process ring and a fifth turning part, and assembling the fifth turning part and the assembly to form a turning assembly.

[0011] Preferably, the process ring includes a main body and a process bolt, the main body is provided with bolt holes corresponding to the end face of the casing, the A face and the B face of the process ring are respectively used for fitting with the end face of the casing; the B face, the C face and the N face of the process ring are respectively parallel to the A face, and the parallelism is 0.01mm; the outer circle of the process ring is provided with a groove, and the groove is used for tightening; the process bolt is used for fixing the main body and the casing.

[0012] Preferably, in S1, the process ring is connected to the fourth part with the A surface of the process ring facing downward, and the gap between the end surface of the process ring and the fourth part is less than 0.02 mm.

[0013] Preferably, in S2, the standard for aligning the assembly for the first time is: aligning the datum Q1 and the datum G7 of the first part, and the alignment requirement is less than or equal to 0.01 mm.

[0014] Preferably, in S2, the specific steps of the first turning process are as follows: first, turning the N surface of the process ring, the turning standard of the N surface is: all exposed to light, and the runout requirements of the N surface relative to the datum Q1 and the datum G7 of the first part are both less than or equal to 0.01 mm;

[0015] Then turn the outer circle of the process ring. The turning standard of the outer circle is: all visible to light, and the runout requirements of the outer circle relative to the datum Q1 and datum G7 of the first part are both less than or equal to 0.01mm, and a process ring is obtained.

[0016] Preferably, machining allowances are left on the outer circle and N surface of the primary process ring.

[0017] Preferably, in S3, during assembly, with the N surface of the primary process ring facing downward, the end face and the outer circle as the reference, the outer circle is aligned to be less than or equal to 0.01mm, and the end face runout range is less than or equal to 0.01mm; the A surface of the primary process ring is matched with the end face of the fifth part, and the gap between the process ring and the end face of the fifth part is less than 0.02mm.

[0018] Preferably, in S4, during the second alignment, the N surface of the primary process ring is used as the positioning surface to align the outer circle reference of the primary process ring, and the alignment requirement is less than or equal to 0.01 mm.

[0019] Preferably, in S4, the specific steps of the second turning process are: first check whether the alignment runout and the runout value of the inner hole flow channel of the fifth part meet the requirements; and process the fifth part after the requirements are met.

[0020] Preferably, in S5, the turning assembly is subjected to assembly inspection, and the inspection standard is: the runout requirement of the casing channel and the mounting edge of the fifth part to the datum Q1 and the datum G7 of the first part is within 0.01 mm.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The invention discloses a method for combined turning of a gas turbine casing. A combined component of five casing parts is processed together. The combination is processed in two sections by using a process ring to realize the conversion of the processing datum. This not only ensures the design requirements of the combined processing, but also reduces the processing difficulty, solves the equipment limitation, and improves the processing efficiency and quality.

[0023] After the conversion of the datum, the datum misalignment error includes longitudinal (i.e., component height direction) and radial aspects. The longitudinal datum misalignment error is the parallelism error of the bottom surface flatness of the process ring after processing relative to the first part datum. The radial datum misalignment error is the coaxiality error between the outer circle of the process ring after processing and the first part datum. Because these two machined surfaces are repaired before each processing, the error is within 0.01mm. For the installation datum misalignment error of the secondary clamping, considering the different deformation of the clamping force and the different contact clearance of the positioning surface, it can be ignored by comparing and aligning the end face runout of the process ring with the previous state and its consistency.

[0024] The present invention uses a process ring to assemble and process the relevant characteristics of the fifth part casing in sections, indirectly ensuring the runout requirements of the casing channel and the mounting edge of the fifth part relative to the datum Q1 and the datum G7 of the first part. The above method first divides the assembly into two parts, reduces the total height of the parts during machining, greatly increases the number of selectable equipment, and solves the bottleneck of having to use special equipment for machining; by assembling and using the process ring and machining the process ring, the conversion of the machining datum is achieved, and the relevant technical requirements of the design drawing are met. This method effectively avoids the vibration of the tool that often occurs due to the excessive height of the parts, greatly improves the size qualification rate and machining efficiency, and reduces the difficulty of machining. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the combination of the first part, the second part, the third part, the fourth part and the fifth part in a specific embodiment of the present invention;

[0026] Figure 2 is a cross-sectional view of a process ring in a specific embodiment of the present invention;

[0027] Figure 3 is a top view of a process ring in a specific embodiment of the present invention;

[0028] Figure 4 It is a schematic diagram of a process bolt in a specific embodiment of the present invention;

[0029] Figure 5 It is a schematic diagram of the assembly of the assembly during the first turning process in a specific embodiment of the present invention;

[0030] Figure 6 In the specific embodiment of the present invention Figure 5 A partial enlarged view of

[0031] Figure 7 It is a schematic diagram of assembling the secondary assembly during the second turning process in a specific embodiment of the present invention;

[0032] Figure 8 for Figure 7 A partial enlarged view of .

[0033] In the figure, 1, main body 1; 2, process bolt; 3, first part; 4, second part; 5, third part; 6, fourth part; 7, fifth part. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0035] The invention discloses a combined turning method for a gas turbine casing, comprising the following steps:

[0036] S1: Reference Figure 1 , mark the "zero degree" position on the outer circle of the mounting edge of each stage of the first part 3, the second part 4, the third part 5, and the fourth part 6 with a marker, assemble them in sequence using process connecting bolts and process pins, check the inner circle runout and end face runout for each stage of installation, and finally form an assembly; then connect the assembly to the process ring, that is, with the A side of the fourth part 6 facing downward, connect the process ring to the end face of the fourth part 6 with process bolts 2 to form a preliminary assembly; check the gap between the mounting edges of each stage, and meet the gap of less than 0.00mm when tightened, that is, the 0.02mm feeler gauge does not pass.

[0037] Reference Figure 2 , 3 and 4, the process ring includes a main body and a process bolt 2, the main body is provided with bolt holes corresponding to the end face of the casing, the A face and the B face of the process ring are respectively used for fitting with the end face of the casing; the B face, the C face and the N face of the process ring are respectively parallel to the A face, and the parallelism is 0.01mm; a groove is provided on the outer circle of the process ring, and the groove is used for tightening; the process bolt 2 is used for fixing the main body and the casing.

[0038] S2, reference Figure 5 , 6, clamp the preliminary assembly on the turning equipment, perform the first alignment (align the datum Q1 and datum G7 of the first part 3, the alignment requirement is less than or equal to 0.01mm), and then perform the first turning process to obtain the preliminary turning assembly, which includes a primary process ring and an assembly; the specific steps are as follows: first, turn the N surface of the process ring, and the turning standard of the N surface is: all exposed to light, and the runout requirements of the N surface relative to the datum Q1 and datum G7 of the first part 3 are less than or equal to 0.01mm;

[0039] Then turn the outer circle of the process ring. The turning standard of the outer circle is: all visible to light, and the runout requirements of the outer circle relative to the datum Q1 and the datum G7 of the first part 3 are both less than or equal to 0.01mm, and a process ring is obtained.

[0040] Machining allowances are left on the outer circle and N surface of the primary process ring to achieve the reuse of the process ring and help reduce costs.

[0041] S3, decompose the preliminary turning assembly to obtain a primary process ring and an assembly, use the primary process ring as a positioning, assemble the fifth part with the primary process ring to form a secondary assembly, refer to Figure 7 , 8 During assembly, with the N surface of the primary process ring facing downward, the end face and outer circle as the reference, the outer circle should be aligned to be less than or equal to 0.01mm, and the end face runout should be less than or equal to 0.01mm;

[0042] Align with the outer circle as the reference, match the A surface of the primary process ring with the end surface of the fifth part 7, and the gap between the process ring and the end surface of the fifth part 7 is less than 0.02m.

[0043] S4, clamp the secondary assembly on the turning equipment, perform the second alignment (use the N surface of the primary process ring as the positioning surface, align the outer circle reference of the primary process ring, and the alignment requirement is less than or equal to 0.01mm), and then perform the second turning process to obtain the turned finished part. The turned finished part includes the secondary process ring and the turned fifth part.

[0044] The specific steps are: first check whether the alignment runout and the runout value of the inner hole flow channel of the fifth part 7 meet the requirements; if the requirements are met, process the fifth part 7 with the converted size.

[0045] S5, decomposing the finished turning part to obtain a secondary process ring and a turned fifth part 7, and assembling the turned fifth part 7 and the assembly to form a turned assembly.

[0046] The turning assembly is subjected to assembly inspection, and the inspection standard is: the runout requirement of the casing channel and the mounting edge of the fifth part 7 to the datum Q1 and the datum G7 of the first part 3 is within 0.01 mm.

[0047] The present invention connects process loops so that different matching casings can be aligned with a unified datum. After any part is processed, the part can be replaced with another part in a combined turning process, which not only meets the requirement of uniformly aligning the processing datum for different casings, but also can act as an assembly part in this process and be assembled with another part in an original fixed position, thereby ensuring good continuity of the processing datum. At the same time, the time difference that the parts need to wait for each other is completely eliminated, so that different casings do not affect each other. Each part can be processed separately and stored separately, thereby achieving the purpose of on-time delivery. This process can be widely used in the combined processing of multiple casings of various models.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to impose any limitation on the technical solution of the present invention. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can also be subjected to several simple modifications and substitutions, and these modifications and substitutions are also within the scope of protection covered by the claims.

Claims

1. A method for combined turning of a gas turbine casing, characterized in that: The following steps are involved: S1: Assemble the first part, the second part, the third part and the fourth part to form an assembly; then connect the assembly with a process ring to form a preliminary assembly; wherein the process ring comprises a main body and a process bolt, the main body is provided with a bolt hole corresponding to the end face of the casing, and the A surface and the B surface of the process ring are respectively used for fitting with the end face of the casing; the B surface, the C surface and the N surface of the process ring are respectively parallel to the A surface, and the parallelism is 0.01mm; a groove is provided on the outer circle of the process ring, and the groove is used for pressing; the process bolt is used to fix the main body and the casing; the process ring is connected with the fourth part, with the A surface of the process ring facing downward, and the gap between the process ring and the end face of the fourth part is less than 0.02mm; S2, clamping the preliminary assembly on the turning equipment, performing the first alignment, and then performing the first turning process to obtain a preliminary turning assembly, which includes a primary process ring and an assembly; The standard for the first alignment of the assembly is: align the datum Q1 and datum G7 of the first part, and the alignment requirement is less than or equal to 0.01mm; The specific steps of the first turning process are as follows: First, turn the N surface of the process ring. The turning standard of the N surface is: all exposed to light, and the runout requirements of the N surface relative to the datum Q1 and datum G7 of the first part are less than or equal to 0.01mm; Then turn the outer circle of the process ring. The turning standard of the outer circle is: all visible to light, and the runout requirements of the outer circle relative to the datum Q1 and datum G7 of the first part are less than or equal to 0.01mm, and obtain a process ring; S3, decomposing the preliminary turning assembly to obtain a primary process ring and an assembly; using the primary process ring as a positioning member, assembling the fifth part with the primary process ring to form a secondary assembly; During assembly, with the N surface of the primary process ring facing downward, the end face and the outer circle as the reference, the outer circle is aligned to be less than or equal to 0.01mm, and the end face runout is less than or equal to 0.01mm; the A surface of the primary process ring is matched with the end face of the fifth part, and the gap between the process ring and the end face of the fifth part is less than 0.02mm; S4, clamping the secondary assembly on the turning equipment, performing a second alignment, and then performing a second turning process to obtain a turned finished part, the turned finished part including the secondary process ring and the turned fifth part; During the second alignment, the N surface of the primary process ring is used as the positioning surface to align the outer circle reference of the primary process ring. The alignment requirement is less than or equal to 0.01mm. The specific steps of the second turning process are: first check whether the alignment runout and the runout value of the inner hole flow channel of the fifth part meet the requirements; after meeting the requirements, process the fifth part; S5, decomposing the finished turning part to obtain a secondary process ring and a fifth turning part, and assembling the fifth turning part and the assembly to form a turning assembly.

2. The gas turbine casing combined turning processing method according to claim 1, characterized in that: The outer circle and N surface of the primary process ring are both left with machining allowances.

3. The gas turbine casing combined turning processing method according to claim 1, characterized in that: In S5, the turning assembly is inspected for assembly, and the inspection standard is: the runout of the casing channel and the mounting edge of the fifth part to the datum Q1 and the datum G7 of the first part is required to be within 0.01 mm.

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