Pulse current auxiliary micro-correction method for titanium alloy welding pipeline of aero-engine

Abstract

The invention discloses a pulse current-assisted micro-sizing method for a titanium alloy welding pipeline of an aero-engine. The method comprises the following steps: manufacturing a sizing tool; the titanium alloy welding pipeline is fixedly clamped into the shape correcting tool, and meanwhile cold shape correcting positioning of the pipeline is completed; electrodes are installed at the two ends of the titanium alloy welding pipeline shape correcting section; connecting the electrode to a direct-current pulse power supply through a wire; a direct-current pulse power supply is started, and the shape correction section of the titanium alloy welding pipeline is heated through pulse current; performing real-time temperature measurement on the shape correction section of the titanium alloy welding pipeline through a temperature measurer until the real-time temperature of the shape correction section of the titanium alloy welding pipeline reaches a set value; carrying out heat preservation on the shape correction section of the titanium alloy welding pipeline at a set temperature value for a set time; the direct-current pulse power supply is turned off, and heating of the titanium alloy welding pipeline shape correcting section is ended till the temperature of the titanium alloy welding pipeline shape correcting section is cooled to the normal temperature; and the titanium alloy welding pipeline is detached from the shape correction tool, and pulse current auxiliary micro shape correction of the titanium alloy welding pipeline is finished.

Description

Technical Field

[0001] The invention belongs to the technical field of manufacturing aircraft engine parts, and in particular relates to a pulse current assisted micro-correction method for titanium alloy welding pipelines of aircraft engines. Background Art

[0002] Titanium alloy has the advantages of low density, corrosion resistance and high strength, and has become one of the main materials for aircraft and aircraft engines. The pipeline system is an important part of the aircraft engine. It not only carries the fuel, lubricating oil, air and other media required for the operation of the aircraft engine, but also provides guarantees for the realization of functions such as aircraft engine system control and status monitoring. With the increase in the thrust-to-weight ratio requirements of the new generation of aircraft engines, reducing the weight of external pipelines is of great significance to the improvement of aircraft engine performance, and the selection of titanium alloy as the pipeline system material has become an inevitable trend in the design and manufacture of aircraft engines.

[0003] However, due to the complex functions and characteristics of the pipeline system, the manufacturing process of titanium alloy pipelines involves not only bending and forming, but also connection and assembly processes, which are prone to problems such as out-of-tolerance or shape changes. Micro-calibration is required, and only after meeting the dimensional accuracy requirements can it be installed. Therefore, how to achieve precise manufacturing of titanium alloy pipelines and overcome the lack of manufacturing precision of titanium alloy pipelines has become an urgent bottleneck problem that needs to be solved.

[0004] At present, the micro-shaping of titanium alloy welded pipes is mainly carried out manually at room temperature, and the shaping range is highly dependent on the operator's experience. However, due to the small elastic modulus and high yield strength of titanium alloy, its elastic deformation is large, resulting in low shaping efficiency and poor shaping accuracy of traditional micro-shaping methods. If micro-shaping is performed by overall heat treatment, although the shaping accuracy can be improved, the overall heat treatment has the disadvantage of a long thermal cycle time, which can easily lead to deterioration of the microstructure and mechanical properties of the titanium alloy pipe. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a pulse current assisted micro-shaping method for titanium alloy welding pipelines of aircraft engines, which introduces pulse current assisted forming technology into the micro-shaping of titanium alloy pipelines. The pulse current generates Joule heating effect and electroplastic effect only in the local area where the shaping section of the titanium alloy pipeline is located, which can avoid the deterioration of the overall microstructure and mechanical properties of the titanium alloy pipeline, and at the same time greatly improve the shaping efficiency and shaping accuracy of the titanium alloy pipeline.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme: a pulse current assisted micro-correction method for titanium alloy welding pipeline of an aero-engine, comprising the following steps:

[0007] Step 1: Make the shape correction tool;

[0008] Step 2: Fix and clamp the titanium alloy welded pipeline into the shaping tooling, and complete the cold shaping positioning of the titanium alloy welded pipeline at the same time;

[0009] Step 3: Install the first electrode and the second electrode at both ends of the shaping section of the titanium alloy welding pipeline;

[0010] Step 4: Connect the first electrode and the second electrode to the positive and negative electrodes of a DC pulse power supply through wires respectively;

[0011] Step 5: Start the DC pulse power supply to heat the shaping section of the titanium alloy welding pipeline through the pulse current;

[0012] Step 6: Use a temperature measuring instrument to measure the temperature of the shape-correcting section of the titanium alloy welding pipeline in real time until the real-time temperature of the shape-correcting section of the titanium alloy welding pipeline reaches the set value;

[0013] Step 7: Keep the calibrated section of the titanium alloy welded pipeline at a set temperature for a set time;

[0014] Step 8: Turn off the DC pulse power supply to end the heating of the titanium alloy welding pipeline shaping section until the temperature of the titanium alloy welding pipeline shaping section cools to room temperature;

[0015] Step nine: Remove the titanium alloy welding pipeline from the shaping tooling, and the pulse current assisted micro-shaping of the titanium alloy welding pipeline is completed.

[0016] The shape correction tool is divided into a micro-straightening tool and a micro-bending tool.

[0017] The micro-straightening tool comprises a micro-straightening tool base plate, a micro-straightening pipeline fixed support, a micro-straightening pipeline fixed pressure plate, a micro-straightening pipeline fixed clamping screw, a micro-straightening pipeline auxiliary positioning support seat, a pipeline micro-straightening reaction force support seat and a pipeline micro-straightening force screw; the micro-straightening pipeline fixed support, the pipeline micro-straightening reaction force support seat and the micro-straightening pipeline auxiliary positioning support seat are fixedly installed on the upper surface of the micro-straightening tool base plate in a straight line sequence; the micro-straightening pipeline fixed pressure plate is arranged on the top of the micro-straightening pipeline fixed support, and the micro-straightening pipeline fixed pressure plate and the micro-straightening pipeline fixed support are connected by the micro-straightening pipeline fixed clamping screw, and the titanium The non-alignment section of the alloy welded pipeline passes through between the micro-straightening pipeline fixed pressure plate and the micro-straightening pipeline fixed support; a pipeline auxiliary positioning groove is provided on the top of the micro-straightening pipeline auxiliary positioning support seat, and the non-alignment section of the titanium alloy welded pipeline passes through the pipeline auxiliary positioning groove; a pipeline through hole is provided on the top of the pipeline micro-straightening reaction force support seat, and the alignment section of the titanium alloy welded pipeline is located in the pipeline through hole, and the pipeline micro-straightening force screw is vertically installed on the pipeline micro-straightening reaction force support seat above the pipeline through hole, and the pipeline micro-straightening force screw is in abutment contact with the alignment section of the titanium alloy welded pipeline.

[0018] When the titanium alloy welding pipeline needs micro-straightening, the micro-straightening tool is used. First, the titanium alloy welding pipeline to be straightened is passed through the micro-straightening pipeline fixed pressure plate and the micro-straightening pipeline fixed support, and then through the pipeline through-hole of the pipeline micro-straightening reaction force support seat, and then through the pipeline auxiliary positioning groove of the micro-straightening pipeline auxiliary positioning support seat, until the straightening section of the titanium alloy welding pipeline is in the pipeline through-hole of the pipeline micro-straightening reaction force support seat, and then tighten the micro-straightening pipeline fixing clamping screw to straighten the titanium alloy welding pipeline. The non-alignment section on one side of the pipeline is pressed and fixed between the micro-straightening pipeline fixed pressure plate and the micro-straightening pipeline fixed support, and finally the pipeline micro-straightening force screw is screwed to apply radial thrust to the shaping section of the titanium alloy welded pipeline until the cold shaping of the titanium alloy welded pipeline shaping section is completed. During the cold shaping process, the non-alignment section on the other side of the titanium alloy welded pipeline will only slide axially in the pipeline auxiliary positioning groove of the micro-straightening pipeline auxiliary positioning support seat. At this time, the cold shaping and positioning work of the titanium alloy welded pipeline is completed.

[0019] The micro-bend tooling includes a micro-bend tooling base plate, a micro-bend pipeline fixing support, a micro-bend pipeline fixing pressure plate, a micro-bend pipeline fixing clamping screw, a micro-bend pipeline positioning support seat, a micro-bend pipeline positioning sleeve, a micro-bend pipeline positioning sleeve, a micro-bend pipeline guide limit screw and a micro-bend pipeline clamping screw; the micro-bend pipeline fixing support is fixedly installed on the upper surface of the micro-bend tooling base plate, the micro-bend pipeline fixing pressure plate is arranged on the top of the micro-bend pipeline fixing support, the micro-bend pipeline fixing pressure plate and the micro-bend pipeline fixing support are connected by the micro-bend pipeline fixing clamping screw, and the non-calibration section of the titanium alloy welded pipeline passes between the micro-bend pipeline fixing pressure plate and the micro-bend pipeline fixing support; the micro-bend pipeline positioning support seat is fixedly installed on the upper surface of the micro-bend tooling base plate, and the micro-bend pipeline positioning support seat and the micro-bend pipeline fixing support are connected. There is an angle between the central axes of the bent pipeline fixed supports; the micro-calibration bent pipeline positioning sleeve is fixedly installed in the micro-calibration bent pipeline positioning support seat, and the micro-calibration bent pipeline positioning sleeve is coaxially installed in the micro-calibration bent pipeline positioning sleeve, and the micro-calibration bent pipeline positioning sleeve has only axial freedom of movement relative to the micro-calibration bent pipeline positioning sleeve; a guide oblong hole is opened on the upper cylinder wall of the micro-calibration bent pipeline positioning sleeve, and the micro-calibration bent pipeline guide limit screw is vertically installed on the top of the micro-calibration bent pipeline positioning support seat, and the micro-calibration bent pipeline guide limit screw extends into the guide oblong hole; the non-calibration section of the titanium alloy welded pipeline is coaxially inserted and matched with the micro-calibration bent pipeline positioning sleeve; the micro-calibration bent pipeline clamping screw is installed on the cylinder wall of the micro-calibration bent pipeline positioning sleeve, and the micro-calibration bent pipeline clamping screw is in abutment contact with the non-calibration section of the titanium alloy welded pipeline.

[0020] When the titanium alloy welded pipeline needs micro-bending, a micro-bending tool is used. First, the non-bending section on one side of the titanium alloy welded pipeline to be shaped is passed between the micro-bending pipeline fixed pressure plate and the micro-bending pipeline fixed support until the pipe mouth of the non-bending section on the other side of the titanium alloy welded pipeline is in front of the tube mouth of the micro-bending pipeline positioning sleeve. Then, the micro-bending pipeline fixing clamping screw is tightened to clamp and fix the non-bending section on one side of the titanium alloy welded pipeline between the micro-bending pipeline fixed pressure plate and the micro-bending pipeline fixed support. Subsequently, an external force is applied to the non-bending section on the other side of the titanium alloy welded pipeline to complete the cold shaping of the shaping section of the titanium alloy welded pipeline, and at the same time, the titanium The pipe mouth of the non-aligned section on the other side of the alloy welded pipeline is coaxial with the tube mouth of the micro-bend pipeline positioning sleeve, and then the micro-bend pipeline positioning sleeve is pushed forward axially until the non-aligned section on the other side of the titanium alloy welded pipeline is inserted into the micro-bend pipeline positioning sleeve. At this time, the external force applied to the non-aligned section on the other side of the titanium alloy welded pipeline is removed. Restricted by the micro-bend pipeline positioning sleeve, the cold-aligned state of the shaping section of the titanium alloy welded pipeline can still be maintained. Finally, tighten the micro-bend pipeline clamping screw to fix the non-aligned section on the other side of the titanium alloy welded pipeline and the micro-bend pipeline positioning sleeve together. At this time, the cold-aligned positioning work of the titanium alloy welded pipeline is completed.

[0021] Beneficial effects of the present invention:

[0022] The pulse current assisted micro-shaping method for titanium alloy welding pipelines of aircraft engines of the present invention introduces pulse current assisted forming technology into the micro-shaping of titanium alloy pipelines. The pulse current generates Joule heating effect and electroplastic effect only in the local area where the shaping section of the titanium alloy pipeline is located, which can avoid the deterioration of the overall microstructure and mechanical properties of the titanium alloy pipeline, and at the same time greatly improve the shaping efficiency and shaping accuracy of the titanium alloy pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the micro-alignment tooling of the present invention (viewing angle 1);

[0024] Figure 2 It is a structural schematic diagram of the micro-alignment tooling of the present invention (viewing angle 2);

[0025] Figure 3 Schematic diagram of the structure of the micro-bending tool of the present invention (viewing angle 1);

[0026] Figure 4 Schematic diagram of the structure of the micro-bending tool of the present invention (viewing angle 2);

[0027] In the figure, 1 is a titanium alloy welding pipeline, 2 is a first electrode, 3 is a second electrode, 4 is a DC pulse power supply, 5 is a micro-straightening tooling base plate, 6 is a micro-straightening pipeline fixed support, 7 is a micro-straightening pipeline fixed pressure plate, 8 is a micro-straightening pipeline fixed clamping screw, 9 is a micro-straightening pipeline auxiliary positioning support seat, 10 is a pipeline micro-straightening reaction force support seat, 11 is a pipeline micro-straightening force screw, 12 is a micro-bending tooling base plate, 13 is a micro-bending pipeline fixed support, 14 is a micro-bending pipeline fixed pressure plate, 15 is a micro-bending pipeline fixed clamping screw, 16 is a micro-bending pipeline positioning support seat, 17 is a micro-bending pipeline positioning sleeve, 18 is a micro-bending pipeline positioning sleeve, 19 is a micro-bending pipeline guide limit screw, 20 is a micro-bending pipeline clamping screw, and 21 is a guide oblong hole. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] A pulse current assisted micro-correction method for titanium alloy welding pipeline of an aero-engine comprises the following steps:

[0030] Step 1: Make the shape correction tool;

[0031] Step 2: Fix and clamp the titanium alloy welded pipe 1 into the shaping tooling, and complete the cold shaping positioning of the titanium alloy welded pipe 1 at the same time;

[0032] Step 3: Install the first electrode 2 and the second electrode 3 at both ends of the shaping section of the titanium alloy welding pipeline 1;

[0033] Step 4: Connect the first electrode 2 and the second electrode 3 to the positive and negative electrodes of the DC pulse power supply 4 through wires respectively;

[0034] Step 5: starting the DC pulse power supply 4 to heat the shaping section of the titanium alloy welding pipeline 1 through the pulse current;

[0035] Step 6: Use a temperature measuring instrument to measure the temperature of the shaping section of the titanium alloy welding pipeline 1 in real time until the real-time temperature of the shaping section of the titanium alloy welding pipeline 1 reaches a set value;

[0036] Step 7: Keep the calibrated section of the titanium alloy welding pipeline 1 at a set temperature for a set time;

[0037] Step 8: Turn off the DC pulse power supply 4 to end the heating of the shaping section of the titanium alloy welding pipe 1 until the temperature of the shaping section of the titanium alloy welding pipe 1 cools to room temperature;

[0038] Step nine: Remove the titanium alloy welding pipeline 1 from the shaping tooling, and the pulse current assisted micro-shaping of the titanium alloy welding pipeline 1 is completed.

[0039] The shape correction tool is divided into a micro-straightening tool and a micro-bending tool.

[0040] like Figure 1 , 2As shown, the micro-straightening tooling includes a micro-straightening tooling base plate 5, a micro-straightening pipeline fixed support 6, a micro-straightening pipeline fixed pressure plate 7, a micro-straightening pipeline fixed clamping screw 8, a micro-straightening pipeline auxiliary positioning support seat 9, a pipeline micro-straightening reaction force support seat 10 and a pipeline micro-straightening force screw 11; the micro-straightening pipeline fixed support 6, the pipeline micro-straightening reaction force support seat 10 and the micro-straightening pipeline auxiliary positioning support seat 9 are fixedly installed on the upper surface of the micro-straightening tooling base plate 5 in a straight line sequence; the micro-straightening pipeline fixed pressure plate 7 is arranged on the top of the micro-straightening pipeline fixed support 6, and the micro-straightening pipeline fixed pressure plate 7 and the micro-straightening pipeline fixed support 6 are connected by the micro-straightening pipeline fixed clamping screw 8. The non-alignment section of the titanium alloy welded pipeline 1 passes through between the micro-straightening pipeline fixed pressure plate 7 and the micro-straightening pipeline fixed support 6; a pipeline auxiliary positioning groove is provided on the top of the micro-straightening pipeline auxiliary positioning support seat 9, and the non-alignment section of the titanium alloy welded pipeline 1 passes through the pipeline auxiliary positioning groove; a pipeline through hole is provided on the top of the pipeline micro-straightening reaction force support seat 10, and the alignment section of the titanium alloy welded pipeline 1 is located in the pipeline through hole, and the pipeline micro-straightening force screw 11 is vertically installed on the pipeline micro-straightening reaction force support seat 10 above the pipeline through hole, and the pipeline micro-straightening force screw 11 is in contact with the alignment section of the titanium alloy welded pipeline 1.

[0041] When the titanium alloy welding pipeline 1 needs micro-straightening, the micro-straightening tool is used. First, the titanium alloy welding pipeline 1 to be shaped is passed through between the micro-straightening pipeline fixed pressure plate 7 and the micro-straightening pipeline fixed support 6, and then passed through the pipeline through-hole of the pipeline micro-straightening reaction force support seat 10, and then passed through the pipeline auxiliary positioning groove of the micro-straightening pipeline auxiliary positioning support seat 9, until the shaped section of the titanium alloy welding pipeline 1 is in the pipeline through-hole of the pipeline micro-straightening reaction force support seat 10, and then the micro-straightening pipeline fixing clamping screw 8 is tightened to straighten the titanium alloy welding pipeline 1. The non-alignment section on one side of the pipe 1 is pressed and fixed between the micro-straightening pipe fixed pressure plate 7 and the micro-straightening pipe fixed support 6, and finally the pipe micro-straightening force screw 11 is screwed to apply a radial thrust to the alignment section of the titanium alloy welded pipe 1 until the cold alignment of the alignment section of the titanium alloy welded pipe 1 is completed. During the cold alignment process, the non-alignment section on the other side of the titanium alloy welded pipe 1 will only slide axially in the pipe auxiliary positioning groove of the micro-straightening pipe auxiliary positioning support seat 9. At this time, the cold alignment and positioning work of the titanium alloy welded pipe 1 is completed.

[0042] Embodiment 1

[0043] In this embodiment, the titanium alloy welded pipeline 1 needs micro-straightening. The initial straightness of the titanium alloy welded pipeline 1 before straightening is 1.8 mm, and the target straightness of the titanium alloy welded pipeline 1 after straightening is ±0.3 mm. During the cold straightening positioning, the cold deformation of the straightening section of the titanium alloy welded pipeline 1 is adjusted to 2.3 mm by screwing the pipeline micro-straightening force screw 11. In the subsequent heating stage, the pulse current is set to 5 A / mm 2 The set heating temperature is 500°C and the holding time is 2 minutes. After correction, the straightness of the titanium alloy welded pipe 1 is measured. The straightness measurement result is 0.2mm, which meets the design requirements.

[0044] like Figure 3 , 4 As shown, the micro-bend tooling includes a micro-bend tooling base plate 12, a micro-bend pipeline fixing support 13, a micro-bend pipeline fixing pressure plate 14, a micro-bend pipeline fixing clamping screw 15, a micro-bend pipeline positioning support seat 16, a micro-bend pipeline positioning sleeve 17, a micro-bend pipeline positioning sleeve 18, a micro-bend pipeline guide limit screw 19 and a micro-bend pipeline clamping screw 20; the micro-bend pipeline fixing support 13 is fixedly installed on the upper surface of the micro-bend tooling base plate 12, and the micro-bend pipeline fixing support 13 is fixedly installed on the upper surface of the micro-bend tooling base plate 12, and the micro-bend pipeline fixing pressure plate 14 is fixedly installed on the upper surface of the micro-bend pipeline fixing support 13. The correction bend pipeline fixing plate 14 is arranged on the top of the micro correction bend pipeline fixing support 13, and the micro correction bend pipeline fixing plate 14 and the micro correction bend pipeline fixing support 13 are connected by the micro correction bend pipeline fixing clamping screw 15, and the non-correction section of the titanium alloy welded pipeline 1 passes through between the micro correction bend pipeline fixing plate 14 and the micro correction bend pipeline fixing support 13; the micro correction bend pipeline positioning support seat 16 is fixedly installed on the upper surface of the micro correction bend tooling bottom plate 12, and the micro correction bend pipeline positioning support seat There is an angle between 16 and the central axis of the micro-bend pipeline fixed support 13; the micro-bend pipeline positioning sleeve 17 is fixedly installed in the micro-bend pipeline positioning support seat 16, and the micro-bend pipeline positioning sleeve 18 is coaxially installed inside the micro-bend pipeline positioning sleeve 17, and the micro-bend pipeline positioning sleeve 18 has only axial freedom of movement relative to the micro-bend pipeline positioning sleeve 17; a guide oblong hole 21 is opened on the upper cylinder wall of the micro-bend pipeline positioning sleeve 18, The micro-bend pipeline guide limit screw 19 is vertically installed on the top of the micro-bend pipeline positioning support seat 16, and the micro-bend pipeline guide limit screw 19 extends into the guide oblong hole 21; the non-alignment section of the titanium alloy welded pipeline 1 is coaxially inserted and matched with the micro-bend pipeline positioning sleeve 18; the micro-bend pipeline clamping screw 20 is installed on the cylinder wall of the micro-bend pipeline positioning sleeve 18, and the micro-bend pipeline clamping screw 20 is in abutment contact with the non-alignment section of the titanium alloy welded pipeline 1.

[0045] When the titanium alloy welding pipeline 1 needs micro-bending, a micro-bending tool is used. First, the non-bending section on one side of the titanium alloy welding pipeline 1 to be shaped is passed through between the micro-bending pipeline fixed pressure plate 14 and the micro-bending pipeline fixed support 13, until the pipe mouth of the non-bending section on the other side of the titanium alloy welding pipeline 1 is in front of the tube mouth of the micro-bending pipeline positioning sleeve 18, and then the micro-bending pipeline fixing clamping screw 15 is tightened to press and fix the non-bending section on one side of the titanium alloy welding pipeline 1 between the micro-bending pipeline fixed pressure plate 14 and the micro-bending pipeline fixed support 13, and then an external force is applied to the non-bending section on the other side of the titanium alloy welding pipeline 1 to complete the cold shaping of the shaping section of the titanium alloy welding pipeline 1, and at the same time, the titanium The pipe mouth of the non-aligning section on the other side of the titanium alloy welded pipeline 1 is coaxial with the pipe mouth of the micro-alignment pipeline positioning sleeve 18, and then the micro-alignment pipeline positioning sleeve 18 is pushed forward axially until the non-aligning section on the other side of the titanium alloy welded pipeline 1 is inserted into the micro-alignment pipeline positioning sleeve 18. At this time, the external force applied to the non-aligning section on the other side of the titanium alloy welded pipeline 1 is removed. Restricted by the micro-alignment pipeline positioning sleeve 18, the cold-alignment state of the shaping section of the titanium alloy welded pipeline 1 can still be maintained. Finally, the micro-alignment pipeline clamping screw 20 is tightened to fix the non-alignment section on the other side of the titanium alloy welded pipeline 1 and the micro-alignment pipeline positioning sleeve 18 together. At this time, the cold-alignment and positioning work of the titanium alloy welded pipeline 1 is completed.

[0046] Embodiment 2

[0047] In this embodiment, the titanium alloy welding pipeline 1 needs to be fine-bent. During the cold-forming positioning, the angle between the central axis of the micro-bend pipeline positioning support seat 16 and the micro-bend pipeline fixed support 13 is set to 129°. The initial bending angle of the titanium alloy welding pipeline 1 before shaping is 132°, and the target bending angle after shaping is 130°. The allowable error is ±0.5°. By applying external force, the bending angle of the titanium alloy welding pipeline 1 is cold-formed to 129°, that is, the cold deformation amount is adjusted to 3°, and the micro-bend pipeline positioning sleeve 18 is used for positioning and fixing. In the subsequent heating stage, the pulse current is set to 5A / mm 2 The set heating temperature is 500°C and the holding time is 2 minutes. After correction, the bending angle of the titanium alloy welded pipe 1 is measured. The bending angle measurement result is 130.3°, which meets the design requirements.

[0048] The solutions in the embodiments are not intended to limit the protection scope of the present invention. All equivalent implementations or changes that do not deviate from the present invention are included in the protection scope of the present invention.

Claims

1. A pulse current assisted micro-correction method for titanium alloy welding pipelines of aircraft engines, characterized in that: The steps include: Step 1: Make the shape correction tooling; Step 2: Fix and clamp the titanium alloy welded pipeline into the shaping tooling, and complete the cold shaping positioning of the titanium alloy welded pipeline at the same time; Step 3: Install the first electrode and the second electrode at both ends of the shaping section of the titanium alloy welding pipeline; Step 4: Connect the first electrode and the second electrode to the positive and negative electrodes of a DC pulse power supply through wires respectively; Step 5: Start the DC pulse power supply to heat the shaping section of the titanium alloy welding pipeline through the pulse current; Step 6: Use a temperature measuring instrument to measure the temperature of the shape-correcting section of the titanium alloy welding pipeline in real time until the real-time temperature of the shape-correcting section of the titanium alloy welding pipeline reaches the set value; Step 7: Keep the calibrated section of the titanium alloy welded pipeline at a set temperature for a set time; Step 8: Turn off the DC pulse power supply to end the heating of the titanium alloy welding pipeline shaping section until the temperature of the titanium alloy welding pipeline shaping section cools to room temperature; Step nine: Remove the titanium alloy welding pipeline from the shaping tooling, and the pulse current assisted micro-shaping of the titanium alloy welding pipeline is completed.

2. The pulse current assisted micro-correction method for titanium alloy welding pipeline of an aircraft engine according to claim 1, characterized in that: The shape correction tool is divided into a micro-straightening tool and a micro-bending tool.

3. The pulse current assisted micro-correction method for titanium alloy welding pipeline of an aircraft engine according to claim 2, characterized in that: The micro-straightening tool comprises a micro-straightening tool base plate, a micro-straightening pipeline fixed support, a micro-straightening pipeline fixed pressure plate, a micro-straightening pipeline fixed clamping screw, a micro-straightening pipeline auxiliary positioning support seat, a pipeline micro-straightening reaction force support seat and a pipeline micro-straightening force screw; the micro-straightening pipeline fixed support, the pipeline micro-straightening reaction force support seat and the micro-straightening pipeline auxiliary positioning support seat are fixedly installed on the upper surface of the micro-straightening tool base plate in a straight line sequence; the micro-straightening pipeline fixed pressure plate is arranged on the top of the micro-straightening pipeline fixed support, and the micro-straightening pipeline fixed pressure plate and the micro-straightening pipeline fixed support are connected by the micro-straightening pipeline fixed clamping screw, and the titanium The non-alignment section of the alloy welded pipeline passes through between the micro-straightening pipeline fixed pressure plate and the micro-straightening pipeline fixed support; a pipeline auxiliary positioning groove is provided on the top of the micro-straightening pipeline auxiliary positioning support seat, and the non-alignment section of the titanium alloy welded pipeline passes through the pipeline auxiliary positioning groove; a pipeline through hole is provided on the top of the pipeline micro-straightening reaction force support seat, and the alignment section of the titanium alloy welded pipeline is located in the pipeline through hole, and the pipeline micro-straightening force screw is vertically installed on the pipeline micro-straightening reaction force support seat above the pipeline through hole, and the pipeline micro-straightening force screw is in abutment contact with the alignment section of the titanium alloy welded pipeline.

4. The pulse current assisted micro-correction method for titanium alloy welding pipeline of an aircraft engine according to claim 3, characterized in that: When the titanium alloy welding pipeline needs micro-straightening, the micro-straightening tool is used. First, the titanium alloy welding pipeline to be straightened is passed through the micro-straightening pipeline fixed pressure plate and the micro-straightening pipeline fixed support, and then through the pipeline through-hole of the pipeline micro-straightening reaction force support seat, and then through the pipeline auxiliary positioning groove of the micro-straightening pipeline auxiliary positioning support seat, until the straightening section of the titanium alloy welding pipeline is in the pipeline through-hole of the pipeline micro-straightening reaction force support seat, and then tighten the micro-straightening pipeline fixing clamping screw to straighten the titanium alloy welding pipeline. The non-alignment section on one side of the pipeline is pressed and fixed between the micro-straightening pipeline fixed pressure plate and the micro-straightening pipeline fixed support, and finally the pipeline micro-straightening force screw is screwed to apply radial thrust to the shaping section of the titanium alloy welded pipeline until the cold shaping of the titanium alloy welded pipeline shaping section is completed. During the cold shaping process, the non-alignment section on the other side of the titanium alloy welded pipeline will only slide axially in the pipeline auxiliary positioning groove of the micro-straightening pipeline auxiliary positioning support seat. At this time, the cold shaping and positioning work of the titanium alloy welded pipeline is completed.

5. The pulse current assisted micro-correction method for titanium alloy welding pipeline of an aircraft engine according to claim 2, characterized in that: The micro-bend tooling includes a micro-bend tooling base plate, a micro-bend pipeline fixing support, a micro-bend pipeline fixing pressure plate, a micro-bend pipeline fixing clamping screw, a micro-bend pipeline positioning support seat, a micro-bend pipeline positioning sleeve, a micro-bend pipeline positioning sleeve, a micro-bend pipeline guide limit screw and a micro-bend pipeline clamping screw; the micro-bend pipeline fixing support is fixedly installed on the upper surface of the micro-bend tooling base plate, the micro-bend pipeline fixing pressure plate is arranged on the top of the micro-bend pipeline fixing support, the micro-bend pipeline fixing pressure plate and the micro-bend pipeline fixing support are connected by the micro-bend pipeline fixing clamping screw, and the non-calibration section of the titanium alloy welded pipeline passes between the micro-bend pipeline fixing pressure plate and the micro-bend pipeline fixing support; the micro-bend pipeline positioning support seat is fixedly installed on the upper surface of the micro-bend tooling base plate, and the micro-bend pipeline positioning support seat and the micro-bend pipeline fixing support are connected. There is an angle between the central axes of the bent pipeline fixed supports; the micro-calibration bent pipeline positioning sleeve is fixedly installed in the micro-calibration bent pipeline positioning support seat, and the micro-calibration bent pipeline positioning sleeve is coaxially installed in the micro-calibration bent pipeline positioning sleeve, and the micro-calibration bent pipeline positioning sleeve has only axial freedom of movement relative to the micro-calibration bent pipeline positioning sleeve; a guide oblong hole is opened on the upper cylinder wall of the micro-calibration bent pipeline positioning sleeve, and the micro-calibration bent pipeline guide limit screw is vertically installed on the top of the micro-calibration bent pipeline positioning support seat, and the micro-calibration bent pipeline guide limit screw extends into the guide oblong hole; the non-calibration section of the titanium alloy welded pipeline is coaxially inserted and matched with the micro-calibration bent pipeline positioning sleeve; the micro-calibration bent pipeline clamping screw is installed on the cylinder wall of the micro-calibration bent pipeline positioning sleeve, and the micro-calibration bent pipeline clamping screw is in abutment contact with the non-calibration section of the titanium alloy welded pipeline.

6. The pulse current assisted micro-correction method for titanium alloy welding pipeline of an aircraft engine according to claim 5, characterized in that: When the titanium alloy welded pipeline needs micro-bending, a micro-bending tool is used. First, the non-bending section on one side of the titanium alloy welded pipeline to be shaped is passed between the micro-bending pipeline fixed pressure plate and the micro-bending pipeline fixed support until the pipe mouth of the non-bending section on the other side of the titanium alloy welded pipeline is in front of the tube mouth of the micro-bending pipeline positioning sleeve. Then, the micro-bending pipeline fixing clamping screw is tightened to clamp and fix the non-bending section on one side of the titanium alloy welded pipeline between the micro-bending pipeline fixed pressure plate and the micro-bending pipeline fixed support. Subsequently, an external force is applied to the non-bending section on the other side of the titanium alloy welded pipeline to complete the cold shaping of the shaping section of the titanium alloy welded pipeline, and at the same time, the titanium The pipe mouth of the non-aligned section on the other side of the alloy welded pipeline is coaxial with the tube mouth of the micro-bend pipeline positioning sleeve, and then the micro-bend pipeline positioning sleeve is pushed forward axially until the non-aligned section on the other side of the titanium alloy welded pipeline is inserted into the micro-bend pipeline positioning sleeve. At this time, the external force applied to the non-aligned section on the other side of the titanium alloy welded pipeline is removed. Restricted by the micro-bend pipeline positioning sleeve, the cold-aligned state of the shaping section of the titanium alloy welded pipeline can still be maintained. Finally, tighten the micro-bend pipeline clamping screw to fix the non-aligned section on the other side of the titanium alloy welded pipeline and the micro-bend pipeline positioning sleeve together. At this time, the cold-aligned positioning work of the titanium alloy welded pipeline is completed.

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