A method for constructing a dovetail side rounding model of a turbine disc

Abstract

The application provides a turbine disc mortise and tenon groove side rounding model construction method, which comprises the following steps: constructing a part mortise and tenon groove structure model; completing the model establishment of the mortise and tenon groove structure according to design requirements; constructing the rounding of the mortise and tenon groove according to the middle difference; establishing the rounding of the mortise and tenon groove on a computer and constructing according to the middle difference; extracting the rounding surface in the form of a slice to form a plurality of slices; extracting the rounding center virtual line of the linear segment along the groove type in sequence; constructing the rounding linear of the linear segment and other related lines; forming the pruned rounding surface; constructing the envelope swept surface and the curve pruning between adjacent linear segments; using the stitching function to stitch the newly constructed swept surface to form a complete transition envelope surface; stitching the middle difference rounding slice; stitching the rounding surface along the groove type once to form a new rounding surface; program generation; and completing the numerical control machining of the part. The application has the advantages that the processing risk of overcutting and undercutting in processing can be solved from the source, the high surface integrity of the mortise and tenon groove side rounding is improved, 100% of the mortise and tenon groove side rounding is qualified, and higher value is created.

Description

Technical Field

[0001] This invention relates to the field of aero-engine manufacturing technology, and in particular to a method for constructing a model with rounded sides of a turbine disk tenon groove. Background Technology

[0002] As a key component of the rotor, the turbine disk operates in harsh environments and is the part of the engine with the highest thermal and mechanical load. In particular, the tenon and groove rounding structure is the main site for crack initiation and malfunction failure. However, machining using conventional methods is prone to undercutting and overcutting, and the shape control is extremely difficult. Achieving high surface integrity control and avoiding malfunction failure of the tenon and groove rounding has become a technical bottleneck and challenge that urgently needs to be solved. Summary of the Invention

[0003] The purpose of this invention is to address the bottleneck problem in the machining of turbine disk tenon groove side rounding, which is prone to overcutting and undercutting, resulting in part scrap. This invention provides a method for constructing a turbine disk tenon groove side rounding model, which solves the machining risk of overcutting and undercutting from the source, improves the high surface integrity and 100% qualification of the tenon groove side rounding, extends the service life of the parts, and accurately grasps the core machining technology capabilities of this type of structure.

[0004] This invention provides a method for constructing a turbine disk tenon groove side rounding model, comprising the following steps:

[0005] Step 1: Construct the mortise and tenon structure model of the part; complete the model of the mortise and tenon structure according to the design requirements;

[0006] Step 2: Construct the tenon groove rounding according to the center difference; create the tenon groove rounding on the computer, constructing it according to the center difference;

[0007] Step 3: Extract rounded surfaces in a sheet-like manner to form multiple sheets;

[0008] Step 4: Extract the virtual center lines of the rounded corners of the straight segments sequentially along the groove shape;

[0009] Step 5: Construct the rounded straight line segment and other related lines; according to the rounded center virtual line extracted in Step 4, connect the upper end of the straight line segment with one end of the virtual line on the same side along the direction of the groove to construct straight line 1; connect the lower end of the straight line segment with one end of the virtual line on the same side along the direction of the groove to construct straight line 2; construct straight line 3 at a certain angle to straight line 2 with the length of the straight line segment being the nominal value of the rounded line; construct straight line 4 at 90° to straight line 3, completing the construction of all lines;

[0010] Step 6: Construct the rounded envelope sweep surface and surface trimming of the straight line segment; Based on the straight line 4 constructed in Step 5, establish a sweep surface along the center virtual line of Step 4; Use the trimming function to trim the rounded surface of the original straight line segment to form the trimmed rounded surface.

[0011] Step 7: Construct the envelope sweep surface and surface trimming between adjacent straight line segments; along the groove direction, establish the sweep surface for the rounded corner segments between straight line segments according to Step 6; use the trimming function to trim the rounded surface of the original straight line part to form the trimmed rounded surface.

[0012] Step 8, stitching the newly constructed sweeping surfaces; complete the creation of all sweeping surfaces according to steps 4-7, and use the stitching function to stitch the newly constructed sweeping surfaces to form a complete transition envelope surface;

[0013] Step 9, Sew the rounded pieces together; sew the rounded surface formed in step 6 along the groove in one go to form a new rounded surface;

[0014] Step 10, Program Generation: The CNC program is generated based on the newly generated envelope and rounded surfaces from Steps 8 and 9.

[0015] Step 11: Output the CNC program to complete the CNC machining of the part.

[0016] Compared with the prior art, the advantages of this invention are:

[0017] It can solve the processing risks of overcutting and undercutting at the source, improve the surface integrity of the tenon groove side rounding and achieve 100% qualification. The model of the turbine disk tenon groove side rounding is constructed and CNC machined. The rounding shape is complete, without overcutting or undercutting, meeting the accuracy requirements. It avoids the scrapping of parts due to overcutting and undercutting at the source, achieving 100% qualification in one processing and creating higher value. Attached Figure Description

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0019] Figure 1 This is a flowchart of a method for constructing a turbine disk tenon groove side rounding model according to the present invention.

[0020] Figure 2 This is a schematic diagram of the turbine disk tenon and groove structure of the present invention;

[0021] Figure 3 This is a schematic diagram of the rounded side of the turbine disk tenon groove model of the present invention;

[0022] Figure 4 This is a schematic diagram of the rounded center virtual line for sequentially extracting straight segments along the groove shape according to the present invention;

[0023] Figure 5 This is a schematic diagram illustrating the positional annotations of the rounded straight lines and other related lines used in the construction of the present invention.

[0024] Figure 6This is a schematic diagram illustrating the construction of the rounded envelope sweeping surface of the straight segment and the surface trimming of the present invention;

[0025] Figure 7 This is a schematic diagram of the construction of the fillet sweep surface QS1 between straight line segments according to the present invention;

[0026] Figure 8 This is a schematic diagram of the construction of the fillet extension surface QS2 between straight line segments according to the present invention;

[0027] Figure 9 This is a schematic diagram of the construction of the fillet extension surface QS3 between straight line segments according to the present invention;

[0028] Figure 10 This is a schematic diagram of the QS4 sweeping surface for constructing the fillet transition envelope between straight line segments according to the present invention;

[0029] Figure 11 This is a schematic diagram of the construction of the fillet rounding between straight line segments NEW2 according to the present invention;

[0030] Figure 12 A schematic diagram of the complete transition envelope surface SP1 constructed for the parts of this invention;

[0031] Figure 13 This is a schematic diagram of the new rounded surface SP2 of the part of the present invention. Detailed Implementation

[0032] The present invention will be further explained below with reference to specific implementation schemes, but it is not limited to the present invention. The structures, proportions, sizes, etc. shown in the accompanying drawings are only used to complement the content disclosed in the specification, so as to enable those skilled in the art to understand and read, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effect and purpose that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0033] This invention addresses the machining risks of overcutting and undercutting during the rounding of the tenon groove sides of turbine disks, which can lead to parts being scrapped due to exceeding tolerances. To improve the surface integrity control and achieve 100% pass rate for the rounding of the tenon groove sides, thereby extending service life, a novel model construction method for rounding the tenon groove sides of turbine disks is invented. This method solves the machining risks of overcutting and undercutting from the source, improving the surface integrity and achieving 100% pass rate for the rounding of the tenon groove sides. Taking a turbine disk part of a certain type of aero-engine as an example, the model construction scheme for the rounding of the tenon groove sides is formulated. The invention will be further described below with reference to the accompanying drawings and embodiments.

[0034] The overall process is as follows Figure 1 As shown.

[0035] 1) Construct the mortise and tenon structure model of the part. Complete the model of the mortise and tenon structure according to the design requirements, such as... Figure 2 ;

[0036] 2) Construct the mortise rounding according to the center difference. Create the mortise rounding on the computer, constructing it according to the center difference R0.55mm, such as... Figure 3 ;

[0037] 3) Extract rounded surfaces in a sheet-like manner to form multiple sheets. On a computer, the rounded surfaces are extracted sequentially along the groove shape to form multiple extraction surfaces;

[0038] 4) Sequentially extract the virtual center lines of the rounded corners of straight segments along the groove. Select along the groove. Figure 4 In the line segment rounding 1 and line segment rounding 2, select the Extract Virtual Curve command to form the rounding center virtual curves 1 and 2, as shown. Figure 4 ;

[0039] 5) Construct the rounded lines and other related lines for the straight segments. Taking the rounded line segment 1 in step 4 as an example, construct all the straight lines. The method can be used to construct the related lines for all the arcs of the straight segments. First, select to extract the virtual line 1 of the rounded center, such as... Figure 5 As shown, construct line L1 by connecting the upper end of a straight segment to the right of the virtual line on the same side along the direction of the groove; construct line L2 by connecting the lower end of a straight segment to the right of the virtual line on the same side along the direction of the groove; construct line L3 by forming a 10°-15° angle with line L2, being coplanar with lines L1 and L2, positioned between L1 and L2, and having a length equal to the nominal rounded value of R0.55mm. This is to prepare for constructing line L4 and establishing the transition envelope surface later; construct line L4 by forming a 90° angle with line L3, being coplanar with lines L1 and L2, and having a length of 0.4mm-0.5mm. It is recommended to select a length within 75%-100% of the nominal rounded length of R0.55mm to ensure a certain transition distance. Complete the construction of all lines, as shown. Figure 5 ;

[0040] 6) Construct the rounded envelope sweep surface and trim the surface of the straight line segment. Based on the straight line L4 constructed in step 5, a sweep surface is established with the virtual line 1 of the rounding center as the direction, forming the sweep surface S1. The original straight line segment rounded surface is trimmed using the trimming function to form the trimmed rounded surface NEW1, as shown below. Figure 6 Complete the rounding envelope sweeping surface and trimming of the original rounded surface for all straight line segments in sequence;

[0041] 7) Construct the envelope sweep surface and surface trimming between adjacent straight line segments. After trimming all sweep surfaces and fillet surfaces along the groove direction, taking the fillet portion between straight line segment fillet 1 and straight line segment fillet 2 as an example, construct the envelope sweep surface of the fillet surface between the two, using B1 as the section line and B2 as the sweep line to form the sweep surface QS1, and form line B3, as shown. Figure 7 The rounded surfaces formed by the rounded portions of the two straight segments directly yield endpoints 1 and 2. These endpoints are then connected to the two ends of line B3 to form lines B5 and B4 respectively. Using B3 as the cross-section line and B5 and B4 as guide lines, the extended surface QS2 is formed. Figure 8 And by using trimming, part of the inside of the rounded surface is trimmed away to form trimmed surface QS3, and B6 is formed, as shown. Figure 9 Select B8 and B7 as section lines and B6 as the guide line to create the transition envelope sweep surface QS4, as shown below. Figure 10 The trimming function is used to trim the original straight section to create a rounded surface NEW2, as shown below. Figure 11 Follow these steps to complete the envelope sweep and rounded surface trimming between all adjacent straight line segments;

[0042] 8) Stitching the newly constructed swept surfaces. Complete the creation of all swept surfaces according to steps 4-7, and use the stitching function to stitch the newly constructed swept surfaces to form a complete transition envelope surface SP1, as shown below. Figure 12 ;

[0043] 9) Sew the rounded surface of the piece together; sew the rounded surface formed in step 6 along the groove in one go to form a new rounded surface SP2, as shown. Figure 13 ;

[0044] 10) Program Generation. Using a computer, select surfaces SP1 and SP2 from steps 8 and 9 to generate the CNC program;

[0045] 11) Output the CNC program to complete the CNC machining of the parts.

[0046] Matters not covered in this invention are common knowledge.

[0047] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for constructing a model with rounded edges on the tenon groove of a turbine disk, characterized in that: Includes the following steps: Step 1: Construct the mortise and tenon structure model of the part; complete the model of the mortise and tenon structure according to the design requirements; Step 2: Construct the tenon groove and round it according to the center difference; The tenon and groove rounding is created on the computer, and the structure is built according to the center difference; Step 3: Extract rounded surfaces in a sheet-like manner to form multiple sheets; Step 4: Extract the virtual center lines of the rounded corners of the straight segments sequentially along the groove shape; Step 5: Construct rounded lines for straight line segments and other related lines; Step 6: Construct the rounded envelope sweep surface of the straight line segment and trim the curved surface; Step 7: Construct the envelope sweep surface and surface trimming between adjacent line segments; Step 8, stitching the newly constructed sweeping surfaces; complete the creation of all sweeping surfaces according to steps 4-7, and use the stitching function to stitch the newly constructed sweeping surfaces to form a complete transition envelope surface; Step 9, Sew the rounded pieces together; sew the rounded surface formed in step 6 along the groove in one go to form a new rounded surface; Step 10, Program Generation: The CNC program is generated based on the newly generated envelope and rounded surfaces from Steps 8 and 9. Step 11: Output the CNC program to complete the CNC machining of the part; In step 5, construct the rounded straight line segment and other related lines; according to the rounded center virtual line extracted in step 4, connect the upper end of the straight line segment with one end of the virtual line on the same side along the direction of the groove to construct straight line 1; connect the lower end of the straight line segment with one end of the virtual line on the same side along the direction of the groove to construct straight line 2; construct straight line 3 at a certain angle to straight line 2 with the length of the straight line segment being the nominal value of the rounded line; construct straight line 4 at 90° to straight line 3, thus completing the construction of all lines.

2. The method for constructing a turbine disk tenon groove side rounding model according to claim 1, characterized in that: In step 6, based on the straight line 4 constructed in step 5, a sweep surface is established along the central virtual line of step 4; the trimming function is used to trim the rounded surface of the original straight line to form a trimmed rounded surface.

3. The method for constructing a turbine disk tenon groove side rounding model according to claim 1, characterized in that: In step 7, the rounded corner segments between straight segments are swept along the groove direction according to step 6; the original straight part is trimmed by using the trimming function to form a trimmed rounded surface.

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