Pulse current and ultrasonic vibration composite titanium alloy tube auxiliary bending device and method

Abstract

A pulse current and ultrasonic vibration composite titanium alloy tube auxiliary bending device and method belongs to the technical field of aviation engine component manufacturing. The device includes a reaction frame, a tube bending drive cylinder, a first tube bending support roller, a second tube bending support roller, a tube bending pressure head, a first electrode clamp, a second electrode clamp, a DC pulse power supply, an ultrasonic transducer and an ultrasonic generator. The pulse current and ultrasonic vibration composite titanium alloy tube auxiliary bending device and method of the present invention jointly introduce pulse current assisted forming technology and ultrasonic vibration residual stress removal technology into the bending forming of titanium alloy tubes. The pulse current generates Joule heating effect and electroplastic effect in the local area where the bending deformation section of the titanium alloy tube is located, which can avoid the deterioration of the overall microstructure and mechanical properties of the titanium alloy tube. In the bending deformation process of the titanium alloy tube, the residual stress is removed by applying ultrasonic vibration, which greatly improves the bending forming accuracy of the titanium alloy tube.

Description

Technical Field

[0001] The present invention belongs to the technical field of aerospace engine parts manufacturing, and in particular relates to a pulse current and ultrasonic vibration composite titanium alloy tube auxiliary bending device and method. Background Art

[0002] Titanium alloy, with its advantages of low density, corrosion resistance, and high strength, has become a key material for aircraft and aero-engines. The piping system is a crucial component of an aero-engine, carrying the fuel, lubricating oil, air, and other media required for its operation and also ensuring the implementation of functions such as engine system control and condition monitoring. With the increasing thrust-to-weight ratio requirements of new-generation aero-engines, reducing the weight of external piping is crucial for improving aero-engine performance. Therefore, the use of titanium alloy as a piping system material has become an inevitable trend in aero-engine design and manufacturing.

[0003] However, due to the complex functions and characteristics of the piping system, the manufacturing process of titanium alloy tubes involves a large number of bending and forming processes, as well as connection and assembly processes. Titanium alloy tubes can only be installed in the machine after the bending and forming accuracy meets the requirements. Therefore, how to achieve precise bending and forming of titanium alloy tubes and overcome the insufficient bending and forming accuracy of titanium alloy tubes has become an urgent bottleneck problem that needs to be solved.

[0004] At present, the bending of titanium alloy tubes is mainly achieved by conventional tube bending machines at room temperature. However, due to the characteristics of titanium alloy with low elastic modulus and high yield strength, the elastic deformation during the bending of titanium alloy tubes is large, resulting in low forming accuracy after bending. If bending is performed under overall heat treatment conditions, although the forming accuracy can be improved, the overall heat treatment has the disadvantage of long thermal cycle time, which easily leads to deterioration of the microstructure and mechanical properties of the titanium alloy tube. Summary of the Invention

[0005] In response to the problems existing in the prior art, the present invention provides a pulse current and ultrasonic vibration composite titanium alloy tube assisted bending device and method, which jointly introduces pulse current assisted forming technology and ultrasonic vibration residual stress removal technology into the bending forming of titanium alloy tubes. The pulse current generates Joule heating effect and electroplastic effect in the local area where the bending deformation section of the titanium alloy tube is located, which can avoid the deterioration of the overall microstructure and mechanical properties of the titanium alloy tube. During the bending deformation process of the titanium alloy tube, the residual stress is removed by applying ultrasonic vibration, which greatly improves the bending forming accuracy of the titanium alloy tube.

[0006] In order to achieve the above-mentioned objectives, the present invention adopts the following technical solutions: a pulse current and ultrasonic vibration composite titanium alloy tube auxiliary bending device, comprising a reaction frame, a bending tube drive cylinder, a first bending tube support roller, a second bending tube support roller, a bending tube pressure head, a first electrode chuck, a second electrode chuck, a DC pulse power supply, an ultrasonic transducer and an ultrasonic generator; the bending tube drive cylinder is vertically fixed on the lower surface of the top plate of the reaction frame, and the piston rod of the bending tube drive cylinder faces downward; the ultrasonic transducer is coaxially fixed on the bottom end of the piston rod of the bending tube drive cylinder; the bending tube pressure head is coaxially fixed on the bottom end of the ultrasonic transducer; the ultrasonic generator is electrically connected to the ultrasonic transducer; the first bending tube support roller and the second bending tube support roller are both vertically fixed on the upper surface of the bottom plate of the reaction frame; the first electrode chuck and the second electrode chuck are respectively fixed at the two ends of the bending deformation section of the titanium alloy tube; the positive and negative poles of the DC pulse power supply are electrically connected to the first electrode chuck and the second electrode chuck, respectively.

[0007] The first bend pipe supporting roller and the second bend pipe supporting roller are distributed in left-right mirror symmetry relative to the bend pipe pressure head, and the first bend pipe supporting roller and the second bend pipe supporting roller are used to place the titanium alloy tube.

[0008] The bending deformation section of the titanium alloy tube is located between the first bend tube supporting roller and the second bend tube supporting roller.

[0009] The first electrode clamp and the second electrode clamp are distributed in a left-right mirror-symmetrical manner relative to the elbow press.

[0010] An infrared temperature measuring probe is arranged obliquely above the bending deformation section of the titanium alloy tube. The infrared temperature measuring probe is fixedly connected to the lower surface of the top plate of the reaction frame through a hanging frame. The infrared temperature measuring probe is electrically connected to a temperature display.

[0011] A pulse current and ultrasonic vibration composite titanium alloy tube assisted bending method, using the pulse current and ultrasonic vibration composite titanium alloy tube assisted bending device, includes the following steps:

[0012] Step 1: Place the titanium alloy tube to be bent horizontally on the first tube bending support roller and the second tube bending support roller;

[0013] Step 2: Fixing and clamping the first electrode chuck and the second electrode chuck to two ends of the bending deformation section of the titanium alloy tube respectively;

[0014] Step 3: Connect the first electrode chuck and the second electrode chuck to the positive and negative poles of a DC pulse power supply through wires respectively;

[0015] Step 4: Start the DC pulse power supply to heat the bent and deformed section of the titanium alloy tube through the pulse current;

[0016] Step 5: Use an infrared temperature measuring probe to measure the temperature of the bending deformation section of the titanium alloy tube in real time until the real-time temperature of the bending deformation section of the titanium alloy tube reaches a set value;

[0017] Step 6: Start the pipe bending drive cylinder, and the piston rod of the pipe bending drive cylinder drives the ultrasonic transducer and the pipe bending pressure head to move downward synchronously, and bend the bending deformation section of the titanium alloy tube by the pipe bending pressure head until the bending deformation section of the titanium alloy tube reaches a specified bending angle; at the same time, start the ultrasonic generator to make the ultrasonic transducer output ultrasonic vibration, and the ultrasonic vibration output by the ultrasonic transducer is transmitted to the bending deformation section of the titanium alloy tube by the pipe bending pressure head;

[0018] Step 7: The bending deformation section of the titanium alloy tube is kept at a set temperature for a set time, and at the same time, ultrasonic vibration is continuously applied to the bending deformation section of the titanium alloy tube through an ultrasonic transducer for a set time;

[0019] Step 8: Turn off the DC pulse power supply and the ultrasonic generator, end the heating and ultrasonic vibration of the bending deformation section of the titanium alloy tube, and at the same time, the piston rod of the bending drive cylinder drives the ultrasonic transducer and the bending pressure head to move up and reset;

[0020] Step 9: After the temperature of the bending deformation section of the titanium alloy tube cools to room temperature, first remove the first electrode chuck and the second electrode chuck from the titanium alloy tube, and then remove the titanium alloy tube from the first bending tube support roller and the second bending tube support roller, and the titanium alloy tube bending work is completed.

[0021] In step 4, the operating parameters of the DC pulse power supply are: pulse current density is 2A / mm 2 ~20A / mm 2 , voltage is 1V~15V, and pulse current frequency is 20Hz~100Hz.

[0022] In step five, the temperature setting value is 450°C to 750°C, and the temperature control accuracy is ±20°C.

[0023] In step six, the ultrasonic vibration parameters are: ultrasonic vibration power ≥ 1 kW, ultrasonic vibration frequency ≥ 18 kHz.

[0024] In step seven, the setting time for heat preservation and the setting time for applying ultrasonic vibration are 5s to 30s.

[0025] Beneficial effects of the present invention:

[0026] The pulse current and ultrasonic vibration composite titanium alloy tube auxiliary bending device and method of the present invention jointly introduces pulse current assisted forming technology and ultrasonic vibration residual stress removal technology into the bending forming of titanium alloy tubes. The pulse current generates Joule heating effect and electroplastic effect in the local area where the bending deformation section of the titanium alloy tube is located, which can avoid the deterioration of the overall microstructure and mechanical properties of the titanium alloy tube. During the bending deformation process of the titanium alloy tube, residual stress is removed by applying ultrasonic vibration, which greatly improves the bending forming accuracy of the titanium alloy tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic structural diagram of a pulse current and ultrasonic vibration composite titanium alloy tube auxiliary bending device (before tube bending) of the present invention;

[0028] Figure 2 This is a schematic structural diagram of a pulse current and ultrasonic vibration composite titanium alloy tube auxiliary bending device (after tube bending) of the present invention;

[0029] In the figure, 1 is a reaction frame, 2 is a bending drive cylinder, 3 is a first bending support roller, 4 is a second bending support roller, 5 is a bending pressure head, 6 is a first electrode chuck, 7 is a second electrode chuck, 8 is a DC pulse power supply, 9 is an ultrasonic transducer, 10 is an ultrasonic generator, 11 is a titanium alloy tube, 12 is an infrared temperature probe, 13 is a hoisting frame, and 14 is a temperature display. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] like Figure 1 、 2 As shown, a pulse current and ultrasonic vibration composite titanium alloy tube auxiliary bending device includes a reaction frame 1, a tube bending drive cylinder 2, a first tube bending support roller 3, a second tube bending support roller 4, a tube bending pressure head 5, a first electrode clamp 6, a second electrode clamp 7, a DC pulse power supply 8, an ultrasonic transducer 9 and an ultrasonic generator 10; the tube bending drive cylinder 2 is vertically fixed on the lower surface of the top plate of the reaction frame 1, and the piston rod of the tube bending drive cylinder 2 is downward; the ultrasonic transducer 9 is coaxially fixed on the tube bending drive cylinder 2; the bend pressure head 5 is coaxially fixed on the bottom end of the ultrasonic transducer 9; the ultrasonic generator 10 is electrically connected to the ultrasonic transducer 9; the first bend support roller 3 and the second bend support roller 4 are both vertically fixed on the upper surface of the bottom plate of the reaction frame 1; the first electrode chuck 6 and the second electrode chuck 7 are respectively fixed at the two ends of the bending deformation section of the titanium alloy tube 11; the positive and negative poles of the DC pulse power supply 8 are electrically connected to the first electrode chuck 6 and the second electrode chuck 7 respectively.

[0032] In this embodiment, the DC pulse power supply 8 and the ultrasonic generator 10 are both arranged on the upper surface of the top plate of the reaction frame 1 .

[0033] The first bend pipe supporting roller 3 and the second bend pipe supporting roller 4 are distributed in left-right mirror symmetry relative to the bend pipe pressing head 5 , and the first bend pipe supporting roller 3 and the second bend pipe supporting roller 4 are used to place the titanium alloy tube 11 .

[0034] The bending deformation section of the titanium alloy tube 11 is located between the first bend tube supporting roller 3 and the second bend tube supporting roller 4 .

[0035] The first electrode clamp 6 and the second electrode clamp 7 are distributed in a mirror-symmetrical manner relative to the elbow press 5 .

[0036] An infrared temperature probe 12 is provided obliquely above the bending deformation section of the titanium alloy tube 11 . The infrared temperature probe 12 is fixedly connected to the lower surface of the top plate of the reaction frame 1 through a hanging bracket 13 . The infrared temperature probe 12 is electrically connected to a temperature display 14 .

[0037] In this embodiment, the temperature display 14 is arranged on the upper surface of the top plate of the reaction frame 1 .

[0038] A pulse current and ultrasonic vibration composite titanium alloy tube assisted bending method, using the pulse current and ultrasonic vibration composite titanium alloy tube assisted bending device, includes the following steps:

[0039] Step 1: Place the titanium alloy tube 11 to be bent horizontally on the first tube bending support roller 3 and the second tube bending support roller 4;

[0040] In this embodiment, the material of the titanium alloy tube 11 is TA16, the outer diameter of the titanium alloy tube 11 is φ18 mm, the wall thickness of the titanium alloy tube 11 is 1 mm, the length of the titanium alloy tube 11 is 200 mm, and the set bending angle of the bending deformation section of the titanium alloy tube 11 is 120°±1°;

[0041] Step 2: Fix and clamp the first electrode clamp 6 and the second electrode clamp 7 to the two ends of the bending deformation section of the titanium alloy tube 11 respectively;

[0042] Step 3: Connect the first electrode chuck 6 and the second electrode chuck 7 to the positive and negative poles of the DC pulse power supply 8 through wires respectively;

[0043] Step 4: Start the DC pulse power supply 8 and heat the bending deformation section of the titanium alloy tube 11 through the pulse current; wherein the working parameters of the DC pulse power supply 8 are: the pulse current density is 2A / mm 2 ~20A / mm 2 , voltage is 1V~15V, pulse current frequency is 20Hz~100Hz;

[0044] In this embodiment, the pulse current density is set to 7.5A / mm 2 , the voltage is set to 3V, and the pulse current frequency is set to 20Hz;

[0045] Step 5: Using the infrared temperature measuring probe 12, measure the temperature of the bending deformation section of the titanium alloy tube 11 in real time until the real-time temperature of the bending deformation section of the titanium alloy tube 11 reaches a set value; wherein the set temperature value is 450°C to 750°C, and the temperature control accuracy is ±20°C;

[0046] In this embodiment, the temperature setting value is set to 500°C ± 20°C;

[0047] Step 6: Start the pipe bending drive cylinder 2, and the piston rod of the pipe bending drive cylinder 2 drives the ultrasonic transducer 9 and the pipe bending press 5 to move downward synchronously, and bend the bending deformation section of the titanium alloy tube 11 through the pipe bending press 5 until the bending deformation section of the titanium alloy tube 11 reaches a set bending angle; at the same time, start the ultrasonic generator 10 to make the ultrasonic transducer 9 output ultrasonic vibration, and the ultrasonic vibration output by the ultrasonic transducer 9 is transmitted to the bending deformation section of the titanium alloy tube 11 by the pipe bending press 5; wherein, the ultrasonic vibration parameters are: ultrasonic vibration power ≥1kW, ultrasonic vibration frequency ≥18kHz;

[0048] In this embodiment, the ultrasonic vibration power is set to 1.2 kW and the ultrasonic vibration frequency is set to 20 kHz;

[0049] Step 7: The bending deformation section of the titanium alloy tube 11 is kept at a set temperature for a set time, and ultrasonic vibration is continuously applied to the bending deformation section of the titanium alloy tube 11 by the ultrasonic transducer 9 for a set time; wherein the holding setting time and the ultrasonic vibration application setting time are 5s to 30s;

[0050] In this embodiment, the heat preservation setting time and the ultrasonic vibration application setting time are both set to 20s;

[0051] Step 8: Turn off the DC pulse power supply 8 and the ultrasonic generator 10, ending the heating and application of ultrasonic vibration to the bending deformation section of the titanium alloy tube 11. At the same time, the piston rod of the bending drive cylinder 2 drives the ultrasonic transducer 9 and the bending pressure head 5 to move upward and reset;

[0052] Step nine: After the temperature of the bending deformation section of the titanium alloy tube 11 cools to room temperature, first remove the first electrode chuck 6 and the second electrode chuck 7 from the titanium alloy tube 11, and then remove the titanium alloy tube 11 from the first bending support roller 3 and the second bending support roller 4, and the titanium alloy tube bending work is completed.

[0053] In this embodiment, the bending angle of the bent deformation section of the bent titanium alloy tube is measured, and the measured value is 120.3°, which meets the design requirements.

[0054] The solutions in the embodiments are not intended to limit the scope of protection of the present invention. All equivalent implementations or modifications that do not depart from the scope of protection of the present invention are included in the scope of protection of the present invention.

Claims

1. A pulse current and ultrasonic vibration composite titanium alloy tube assisted bending method, which adopts a pulse current and ultrasonic vibration composite titanium alloy tube assisted bending device, the device includes a reaction frame, a bending tube drive cylinder, a first bending tube support roller, a second bending tube support roller, a bending tube pressure head, a first electrode chuck, a second electrode chuck, a DC pulse power supply, an ultrasonic transducer and an ultrasonic generator; the bending tube drive cylinder is vertically fixed on the lower surface of the top plate of the reaction frame, and the piston rod of the bending tube drive cylinder faces downward; the ultrasonic transducer is coaxially fixed on the bottom end of the piston rod of the bending tube drive cylinder; the bending tube pressure head is coaxially fixed on the bottom end of the ultrasonic transducer; the ultrasonic generator is electrically connected to the ultrasonic transducer; the first bending tube support roller and the second bending tube support roller are both vertically fixed on the upper surface of the bottom plate of the reaction frame; the first electrode chuck and The second electrode chuck is respectively fixedly mounted at both ends of the bending deformation section of the titanium alloy tube; the positive and negative poles of the DC pulse power supply are electrically connected to the first electrode chuck and the second electrode chuck respectively; an infrared temperature measuring probe is provided obliquely above the bending deformation section of the titanium alloy tube, and the infrared temperature measuring probe is fixedly connected to the lower surface of the top plate of the reaction frame through a hanging bracket, and the infrared temperature measuring probe is electrically connected to a temperature display; the first bend support roller and the second bend support roller are distributed in a left-right mirror symmetric manner relative to the bend pressure head, and the first bend support roller and the second bend support roller are used to place the titanium alloy tube; the bending deformation section of the titanium alloy tube is located between the first bend support roller and the second bend support roller; the first electrode chuck and the second electrode chuck are distributed in a left-right mirror symmetric manner relative to the bend pressure head; it is characterized in that The method comprises the following steps: Step 1: Place the titanium alloy tube to be bent horizontally on the first tube bending support roller and the second tube bending support roller; Step 2: Fixing and clamping the first electrode chuck and the second electrode chuck to two ends of the bending deformation section of the titanium alloy tube respectively; Step 3: Connect the first electrode chuck and the second electrode chuck to the positive and negative poles of a DC pulse power supply through wires respectively; Step 4: Start the DC pulse power supply to heat the bent and deformed section of the titanium alloy tube through the pulse current; Step 5: Use an infrared temperature measuring probe to measure the temperature of the bending deformation section of the titanium alloy tube in real time until the real-time temperature of the bending deformation section of the titanium alloy tube reaches a set value; Step 6: Start the pipe bending drive cylinder, and the piston rod of the pipe bending drive cylinder drives the ultrasonic transducer and the pipe bending pressure head to move downward synchronously, and bend the bending deformation section of the titanium alloy tube by the pipe bending pressure head until the bending deformation section of the titanium alloy tube reaches a specified bending angle; at the same time, start the ultrasonic generator to make the ultrasonic transducer output ultrasonic vibration, and the ultrasonic vibration output by the ultrasonic transducer is transmitted to the bending deformation section of the titanium alloy tube by the pipe bending pressure head; Step 7: The bending deformation section of the titanium alloy tube is kept at a set temperature for a set time, and at the same time, ultrasonic vibration is continuously applied to the bending deformation section of the titanium alloy tube through an ultrasonic transducer for a set time; Step 8: Turn off the DC pulse power supply and the ultrasonic generator, end the heating and ultrasonic vibration of the bending deformation section of the titanium alloy tube, and at the same time, the piston rod of the bending drive cylinder drives the ultrasonic transducer and the bending pressure head to move up and reset; Step 9: After the temperature of the bending deformation section of the titanium alloy tube cools to room temperature, first remove the first electrode chuck and the second electrode chuck from the titanium alloy tube, and then remove the titanium alloy tube from the first bending tube support roller and the second bending tube support roller, and the titanium alloy tube bending work is completed.

2. The pulse current and ultrasonic vibration composite titanium alloy tube assisted bending method according to claim 1, characterized in that: In step 4, the operating parameters of the DC pulse power supply are: pulse current density is 2A / mm 2 ~20A / mm 2 , voltage is 1V~15V, and pulse current frequency is 20Hz~100Hz.

3. The pulse current and ultrasonic vibration composite titanium alloy tube assisted bending method according to claim 1, characterized in that: In step five, the temperature setting value is 450°C to 750°C, and the temperature control accuracy is ±20°C.

4. The pulse current and ultrasonic vibration composite titanium alloy tube assisted bending method according to claim 1, characterized in that: In step six, the ultrasonic vibration parameters are: ultrasonic vibration power ≥ 1 kW, ultrasonic vibration frequency ≥ 18 kHz.

5. The pulse current and ultrasonic vibration composite titanium alloy tube assisted bending method according to claim 1, characterized in that: In step seven, the setting time for heat preservation and the setting time for applying ultrasonic vibration are 5s to 30s.

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