A milling method for machining fir-tree-shaped high-vortex blade damping groove

Abstract

The invention discloses a milling method for machining a fir-tree-shaped high-vortex blade damping groove. The specific steps of the milling method for machining the fir-tree-shaped high-vortex blade damping groove are as follows: step one, using a Ф2R1 ball milling cutter to roughly mill the damping groove; selecting the Ф2R1 ball milling cutter to perform layered milling on the damping groove, removing the excess, and ensuring that each machined surface has a 0.3-0.6 mm machining excess; the milling method for the fir-tree-shaped high-vortex blade damping groove reasonably mills the entire complex damping groove from the bevel, side, straight surface, and bottom surface. The machining method only requires a three-coordinate CNC milling machine to complete the machining, and the machining time does not exceed 30 minutes. Through the machining verification of multiple high-vortex blades, the resonance generated by the blades when the engine is working can be effectively prevented, the risk of blade breakage is reduced, and the service life of the blades installed on the engine is extended.

Description

Technical Field

[0001] The invention relates to a complex damping groove of an extended section of a fir-tree-shaped high-vortex blade and the technical field of milling processing application of a three-coordinate milling machine, and in particular provides a milling method for processing the damping groove of a fir-tree-shaped high-vortex blade. Background Art

[0002] High-vortex blades are important components of aviation turbine engines. The high-speed rotating blades are responsible for sucking high-temperature and high-pressure airflow into the burner to maintain the operation of the engine. When the engine is working, strong vibration or resonance may cause metal fatigue of the blades. In order to prevent fatigue fracture, a damping groove is designed in the blade extension section, and the damper is inserted into the groove to prevent resonance. The damping groove has a complex shape, a narrow space and a deep depth. The complex damping groove milling method invented in this invention can effectively remove the excess in the groove when using a three-coordinate CNC milling machine, ensuring that the processing size of the narrow width and deep depth of the damping groove is qualified, meeting the effect of preventing the resonance of the engine.

[0003] People are eager to obtain a milling method for fir-tree-shaped high-vortex blade damping grooves with excellent technical effects. Summary of the invention

[0004] The purpose of the present invention is to provide a milling method for fir-tree-shaped high-vortex blade damping grooves with excellent technical effects. The method can be used for milling complex damping grooves in the extended section of aviation fir-tree-shaped high-pressure turbine working blades. The damper can be smoothly inserted into the damping groove by using the processing method, and only a three-coordinate milling machine is required to complete the processing. The processing size and accuracy meet the requirements of the drawings, and it has a good effect on preventing blade resonance and reducing the risk of blade breakage.

[0005] The specific steps of the milling method for machining the fir-tree-shaped high-vortex blade damping groove are as follows:

[0006] Step 1: Use Ф2R1 ball milling cutter to rough mill the damping groove; see the attached Figure 7 The extended damping groove has a top width of about 3.9mm, a groove depth of about 3.5mm, a groove bottom width of two R0.9 transitions, and a straight line width of less than 0.5mm. To prevent the tool from hitting the tool during milling, a tool with a smaller diameter is selected during rough milling to meet the processing requirements. A Ф2R1 ball milling cutter is used to perform layered milling of the damping groove, and the excess is removed to ensure that each processing surface has a processing allowance of 0.3-0.6mm;

[0007] Step 2: Use Ф2R1 ball milling cutter to finish mill the long inclined surface of the damping groove; see the attached Figure 8 The extended damping groove has a 30° bevel, one end of which is connected to the edge plate, and the other end is a fillet R0.9 0 -0.2, milling is performed in 3 passes; since the UU view only represents the schematic diagram of the damping groove with the groove bottom, there is no groove bottom in the middle part, when milling the bevel, use the Ф2R1 ball milling cutter to fine mill the long bevel of the damping groove; milling is performed in 3 passes; ensure that the angle dimension of the straight surface of the long bevel of the damping groove is 30°±30', and the groove depth The machining is qualified; the two air inlet and exhaust sides at the bottom of the groove are not milled in place;

[0008] Step 3: Use Ф2R1 ball milling cutter to finish mill the intake and exhaust sides of the damping groove; see the attached Fig. 9 and attached Fig.10 , milling is performed in two steps to ensure that the side wall thickness of the damping groove is 1.2mm±0.05mm and 3.3mm±0.05mm, and the groove depth is Control Slot width Control

[0009] Step 4: Use Ф2R1 ball milling cutter to finish mill the air inlet and exhaust sides of the damping groove; see the attached Fig.11 and attached Fig.12 , milling is done in 2 cuts to ensure the slot width The processing is qualified, and the wall thickness is not less than 0.7mm.

[0010] Step 5: Use a Ф1R0.5 ball milling cutter to fine-mill the exhaust side bottom surface and the intake side bottom surface of the damping groove; see the attached Fig.13 and attached Fig.14 , since steps 1 to 3 have already rough-milled the groove bottom for many times, the groove bottom radius R0.9 of the exhaust side bottom and the intake side bottom is smoothly transitioned, and fine-milling is performed directly with one cut to ensure the groove depth size The processing is qualified and the entire damping groove processing steps are completed.

[0011] The milling method of the fir-tree-shaped high-vortex blade damping groove performs reasonable milling of the entire complex damping groove from the bevel, side, straight surface, and bottom surface. The processing method only requires a three-coordinate CNC milling machine to complete the processing, and the processing time does not exceed 30 minutes. Through the processing verification of multiple high-vortex blades, it can effectively prevent the resonance of the blades when the engine is working, reduce the risk of blade breakage, and extend the service life of the engine installed blades. The use of this milling technology provides convenient operation for the processing of the damping groove, and provides a processing precedent for the processing of the damping groove of the high-vortex blades of the fifth and sixth generation engines. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments:

[0013] Figure 1is the plane diagram of the damping slot;

[0014] Figure 2 The side view of the damping groove Figure Ⅰ ;

[0015] Figure 3 The side view of the damping groove Figure II ;

[0016] Figure 4 is a three-dimensional schematic diagram of the damping groove;

[0017] Figure 5 for Figure 4 Schematic diagram of the UU section;

[0018] Figure 6 for Figure 4 Schematic diagram of the middle VV section;

[0019] Figure 7 This is a schematic diagram of the rough milling damping groove position;

[0020] Figure 8 This is a schematic diagram of the position of the long inclined surface of the fine milling damping groove;

[0021] Fig. 9 This is a schematic diagram of the side position of the fine milling air intake side;

[0022] Fig.10 This is a schematic diagram of the side position of the exhaust side after fine milling;

[0023] Fig.11 This is a schematic diagram of the fine milling of the air inlet side of the damping groove;

[0024] Fig.12 The exhaust side of the damping groove is milled straight;

[0025] Fig.13 To fine-mill the bottom surface of the air inlet side of the damping groove;

[0026] Fig.14 To fine-mill the bottom surface of the exhaust edge of the damping groove;

[0027] Fig.15 This is a schematic diagram of the cross-section of the damping groove of the high vortex blade of a fourth-generation engine;

[0028] Fig.16 for Fig.15 Schematic diagram of the AA section. DETAILED DESCRIPTION

[0029] Example 1

[0030] The specific steps of the milling method for machining the fir-tree-shaped high-vortex blade damping groove are as follows:

[0031] Step 1: Use Ф2R1 ball milling cutter to rough mill damping groove 1; see the attached Figure 7 The extended damping groove has a top width of about 3.9mm, a groove depth of about 3.5mm, a groove bottom width of two R0.9 transitions, and a straight line width of less than 0.5mm. To prevent the tool from hitting the tool during milling, a tool with a smaller diameter is selected during rough milling to meet the processing requirements. A Ф2R1 ball milling cutter is used to perform layered milling on the damping groove 1, and the excess is removed to ensure that each processing surface has a processing allowance of 0.3-0.6mm;

[0032] Step 2: Use Ф2R1 ball milling cutter to finish mill the long inclined surface of the damping groove; see the attached Figure 8 The extended damping groove has a 30° bevel, one end of which is connected to the edge plate, and the other end is a fillet R0.9 0 -0.2 , milling is performed in 3 cuts; since the UU view only represents the schematic diagram of the damping groove with the groove bottom, there is no groove bottom in the middle part. When milling the bevel, ensure that the angle dimension of the long bevel of the damping groove is 30°±30', and the groove depth The machining is qualified; the two air inlet and exhaust sides at the bottom of the groove are not milled in place;

[0033] Step 3: Use Ф2R1 ball milling cutter to finish mill the intake and exhaust sides of the damping groove; see the attached Fig. 9 and attached Fig.10 , milling is performed in two steps to ensure that the side wall thickness of the damping groove is 1.2mm±0.05mm and 3.3mm±0.05mm, and the groove depth is Control Slot width Control

[0034] Step 4: Use Ф2R1 ball milling cutter to finish mill the air inlet and exhaust sides of the damping groove; see the attached Fig.11 and attached Fig.12 , milling is done in 2 cuts to ensure the slot width The processing is qualified, and the wall thickness is not less than 0.7mm.

[0035] Step 5: Use a Ф1R0.5 ball milling cutter to fine-mill the exhaust side bottom surface and the intake side bottom surface of the damping groove; see the attached Fig.13 and attached Fig.14 , since steps 1 to 3 have already rough-milled the groove bottom for many times, the groove bottom radius R0.9 of the exhaust side bottom and the intake side bottom is smoothly transitioned, and fine-milling is performed directly with one cut to ensure the groove depth size The processing is qualified and the entire damping groove processing steps are completed.

Claims

1. A milling method for machining a fir-tree-shaped high-vortex blade damping groove, characterized in that: The specific steps of the milling method for machining the fir-tree-shaped high-vortex blade damping groove are as follows: Step 1, using a Φ2R1 ball milling cutter to roughly mill the damping groove (1); using the Φ2R1 ball milling cutter to perform layered milling on the damping groove (1), removing the excess, and ensuring that a machining allowance of 0.3 to 0.6 mm is left on each machined surface; Step 2: Use Ф2R1 ball milling cutter to mill the long inclined surface of the damping groove; perform milling in 3 steps; ensure that the angle dimension of the straight surface of the long inclined surface of the damping groove is 30°±30', and the groove depth is Qualified processing; Step 3: Use Ф2R1 ball milling cutter to finish mill the intake and exhaust sides of the damping groove; perform milling in two steps to ensure that the wall thickness of the damping groove side is 1.2mm±0.05mm and 3.3mm±0.05mm, and the groove depth is qualified. Control Slot width Control Step 4: Use a Ф2R1 ball milling cutter to mill the air inlet and exhaust sides of the damping groove; perform milling in two steps to ensure the groove width. The processing is qualified, and the wall thickness is not less than 0.7mm; Step 5: Use a Ф1R0.5 ball milling cutter to fine-mill the exhaust and intake bottom surfaces of the damping groove; make a smooth transition to the groove bottom radius R0.9 of the exhaust and intake bottom surfaces, and perform fine milling directly with one cut to ensure the groove depth size The processing is qualified and the entire damping groove processing steps are completed.

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