A titanium alloy sheet local heat / electricity / ultrasound multi-field coupling assisted incremental forming device and a method for using the same

Abstract

A kind of titanium alloy plate local heat / electricity / ultrasonic multi-field coupling assisted progressive forming device and its use method, relate to a kind of titanium alloy plate progressive forming device and its use method.The present application is to solve the technical problems of the existing titanium alloy plate progressive forming method relatively slow heating speed, high energy consumption, poor product quality.The device of the present application realizes two-stage heating by local non-contact heating and pulse current self-resistance heating, improves the heating rate, improves the material plasticity by the "electroplasticity" effect generated by pulse current, reduces the material deformation resistance by the "ultrasonic softening" effect generated by ultrasonic field, improves the formability, and improves the forming quality by multi-field coupling.The present application realizes the reduction of material deformation resistance and plasticity by the coupling of heat, electricity and ultrasonic multi-energy field in the deformation process of sheet metal, and significantly improves the formability of material.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of titanium alloy plate progressive forming device and its using method. BACKGROUND

[0002] Progressive forming is a kind of metal sheet plastic processing technology that realizes sheet deformation by using flexible loading and local plastic deformation.The technology combines numerical control and computer technology, and can realize the integration of product design and manufacturing from modeling to forming processing, without mold, thereby greatly reducing manufacturing cost.Progressive forming can realize highly automated manufacturing of complex shape shell components, with high product surface quality, short development cycle, and obvious advantages for manufacturing of customized and small batch products, so the technology has wide application prospects in manufacturing fields such as transportation, aerospace, energy equipment, etc.

[0003] For titanium alloy plate progressive forming, it is very difficult to form titanium alloy components at room temperature due to large deformation resistance and insufficient plasticity of the material at room temperature, and usually needs to be formed by heating.In hot field assisted progressive forming, the method of heating the whole plate has relatively slow heating speed, high energy consumption, and needs large and complex heating equipment, while local heating can realize rapid heating and save equipment energy consumption.On the other hand, single hot field assisted progressive forming will inevitably cause serious local thinning, wrinkling, warping, instability and rupture, etc., when forming complex shape components due to large plastic deformation, resulting in a decrease in component qualification rate.Therefore, how to further improve the forming limit of progressive forming under single hot field is the key to improving the quality of progressive forming of complex shape titanium alloy components. SUMMARY

[0004] The present application is to solve the technical problems of slow heating speed, high energy consumption and poor product quality of the existing progressive forming method of titanium alloy plate, and to provide a kind of titanium alloy plate local thermal / electric / ultrasonic multi-field coupling assisted progressive forming device and its using method.

[0005] The titanium alloy plate local thermal / electric / ultrasonic multi-field coupling assisted progressive forming device of the present application is composed of a forming rack 1, a motion control system 2, a heating power supply 3, a pulse current generator 4, a mechanical arm 5, a blank holder bolt 6, a blank holder plate 7, a first insulating block 8, a second insulating block 10, a loading tool head 11, a heat insulation plate 12, a vibrator 13, an ultrasonic generator 14, a movable electrode head 15, an electric resistance heater 16, an insulating plate 17, a spring 18, an electrode head carrier 19 and an infrared temperature sensor 20.

[0006] The forming rack 1 is composed of a bottom plate 1-1, four supporting columns 1-3 and a top plate 1-2; the bottom plate 1-1 and the top plate 2 are arranged in parallel, and the four supporting columns 1-3 are evenly distributed between the bottom plate 1-1 and the top plate 1-2; the center of the top plate 1-2 is a hollow structure;

[0007] The center of the blank holder 7 is a hollow structure, the blank holder 7 is fixed above the top plate 1-2 through a plurality of blank holder bolts 6, a gap is left between the blank holder 7 and the top plate 1-2, four first insulating blocks 8 are arranged in the gap between the blank holder 7 and the top plate 1-2, and the four first insulating blocks 8 are evenly arranged in two layers;

[0008] The movable electrode head 15 is a cylindrical structure, is composed of a symmetrical first subcomponent 15-3 and a second subcomponent 15-4 through a mechanical connection mode, the inside of the movable electrode head 15 is a cavity structure, the resistance heater 16 is arranged in the cavity, the first subcomponent 15-3 is provided with two through holes 15-2 for penetrating wires, the two ends of the wires are connected with the resistance heater 16 and the heating power supply 3 respectively, and the heating power supply 3 is arranged outside the movable electrode head 15; the top of the movable electrode head 15 is an inner concave spherical surface structure, and the contact ball component 15-1 is arranged in the inner concave spherical surface structure and is in rolling connection;

[0009] The bottom of the electrode head carrier 19 is provided with a pulley, the electrode head carrier 19 is arranged on the bottom plate 1-1 and is in sliding connection, and a motion mechanism controlled by electricity is arranged in the electrode head carrier 19; the spring 18 is fixed above the electrode head carrier 19, the insulating plate 17 is fixed above the spring 18, the movable electrode head 15 is fixed above the insulating plate 17, and the test probe of the infrared temperature sensor 20 is arranged on the movable electrode head 15;

[0010] The second insulating block 10 is fixed on the side wall of the loading tool head 11, the other end of the second insulating block 10 is connected with the movable end of the mechanical arm 5, the loading tool head 11 is arranged in the center hollow structure of the blank holder 7 and the top plate 1-2, the top of the loading tool head 11 is fixed with the heat insulation plate 12, the top of the heat insulation plate 12 is fixed with the vibrator 13, and the vibrator 13 is connected with the ultrasonic generator 14 through wires;

[0011] The signal output end of the motion control system 2 is connected with the signal input end of the mechanical arm 5 and the signal input end of the motion mechanism controlled by electricity in the electrode head carrier 19 respectively; the motion control system 2 is an existing device, which is not the application point of the application.

[0012] One end of the pulse current generator 4 is connected with the loading tool head 11, and the other end is connected with the movable electrode head 15.

[0013] The design principle of the device is:

[0014] The preformed sheet 9 is clamped between four first insulating blocks 8, two of which are arranged above and below the sheet 9, and the sheet 9 is clamped and fixed by the edge pressing bolt 6, and the first insulating blocks 8 are used to prevent the sheet 9 from conducting electricity with the top plate 1-2 and the edge pressing plate 7;

[0015] The bottom end of the loading tool head 11 is in close contact with the upper surface of the sheet 9, the contact ball component 15-1 is in close contact with the lower surface of the sheet 9, and the central axis of the loading tool head 11 coincides with the central axis of the contact ball component 15-1;

[0016] The present application provides a thermal field by the resistance heater 16 installed in the movable electrode head 15, and realizes non-contact heating of the loading deformation zone of the sheet 9;

[0017] The present application forms a closed loop through the mutual connection of the pulse current generator 4, the loading tool head 11, the sheet 9 and the movable electrode head 15, and establishes an electric field in the loading deformation zone of the sheet 9 to provide pulse current; on the one hand, the pulse current can make the material generate self-resistance heating through the electric current "Joule heating effect" to provide a thermal field, assist the heating of the resistance heater 16, realize two-stage heating, and improve the heating rate of the local loading deformation zone of the sheet 9; on the other hand, the "electroplasticity" effect can be generated in the sheet 9 through the pulse current to improve the forming limit of the material.

[0018] The upper end of the movable electrode head 15 has a concave spherical surface structure so that the contact ball component 15-1 is embedded therein to realize the free sliding of the contact ball component 15-1; the first sub-component 15-3 and the second sub-component 15-4 are connected and combined by mechanical connection methods such as bolt connection, which can realize the embedded assembly and removal of the resistance heater 16;

[0019] The electrode head carrier 19 is provided with an electrically controlled movement mechanism, and the movement trajectory of the electrode head carrier 19 is controlled by the movement control system 2, which can move in a straight line in each direction on the bottom plate 1-1, so as to drive the movable electrode head 15 to move below the sheet 9 along with the movement of the loading tool head 11, and always keep the central axis of the loading tool head 11 coinciding with the central axis of the contact ball component 15-1; the spring 18 is always in a compressed state, so as to tightly press the sheet 9 by the contact ball component 15-1 to realize the electrification of the sheet 9. Specifically, it is necessary to ensure that the spring 18 is in a compressed state when the movable electrode head 15 is at its highest point position, and does not exceed the elastic limit when the movable electrode head 15 is at its lowest point position. An infrared temperature sensor 20 is installed on the movable electrode head 15 to monitor the temperature of the loading deformation zone of the sheet 9.

[0020] The movement control system 2 can control the movement of the mechanical arm 5 and the electrode head carrier 19 respectively, and realize the synchronous movement of the loading tool head 11 and the movable electrode head 15.

[0021] The ultrasonic field transmitting system composed of the ultrasonic generator 14 and the vibrator 13 is connected with the loading tool head 11, and provides an ultrasonic field for the deformation area of the sheet metal 9 in contact with the loading tool head 11, so that the sheet metal 9 is reduced in flow stress through "ultrasonic softening" in the deformation process, thereby improving the formability; the vibrator 13 is connected with the loading tool head 11 through the heat insulation plate 12.

[0022] The use method of the titanium alloy sheet local thermal / electric / ultrasonic multi-field coupling assisted incremental forming device is as follows:

[0023] I. The conductive lubricating oil is uniformly applied on the surface of the contact ball component 15-1 of the loading tool head 11 and the movable electrode head 15; the titanium alloy sheet 9 is cut and fixed on the forming rack 1, the sheet metal 9 is clamped and fixed by the edge pressing bolt 6, and two first insulating blocks 8 are arranged above and below the sheet metal 9; the bottom end of the loading tool head 11 is in close contact with the upper surface of the sheet metal 9, the contact ball component 15-1 is in close contact with the lower surface of the sheet metal 9, and the central axis of the loading tool head 11 and the central axis of the contact ball component 15-1 always coincide;

[0024] First, the heating power supply 3 is started to preheat the movable electrode head 15 to 400-450 DEG C by the resistance heater 16;

[0025] Second, the pulse current generator 4 is started to realize two-stage heating of the sheet metal 9 to be deformed by pulse current, and the ultrasonic generator 14 is started to apply an ultrasonic field to the sheet metal 9;

[0026] The voltage of the pulse current generator 4 is 10-24 V, the current is 200-1000 A, and the duty cycle is 25-75 %;

[0027] The ultrasonic frequency of the ultrasonic generator 14 is 20-30 kHz;

[0028] Third, when the temperature of the local deformation area of the sheet metal 9 detected by the infrared temperature sensor 20 reaches 600-690 DEG C, the motion control system 2 is started to drive the loading tool head 11 to load and deform the sheet metal 9 according to the set processing motion track, and the electrode head carrier 19 is controlled by the motion control system 2 to drive the contact ball component 15-1 to move so that the central axis of the loading tool head 11 and the central axis of the contact ball component 15-1 always coincide; after the forming is completed, the heating power supply 3, the pulse current generator 4 and the ultrasonic generator 14 are sequentially turned off, and the formed part is taken out from the forming rack 1.

[0029] Compared with the prior art, the present application has the following beneficial effects:

[0030] (1) The present invention achieves two-stage local heating of the deformation zone of the sheet metal 9 by means of resistance heater 16 and pulse current heating, which has fast heating speed and low energy consumption;

[0031] (2) The present invention uses multiple energy fields of heat, electricity and ultrasound to couple the deformation process of sheet 9, thereby reducing the deformation resistance of the material and plasticizing it, and significantly improving the formability of the material.

[0032] (3) The present invention generates a softening effect through the combined action of thermal field and ultrasound, which reduces residual stress, reduces the degree of springback, and improves the shape and size accuracy of the formed component.

[0033] (4) This invention improves the quality and pass rate of incremental forming manufacturing of complex structure titanium alloy shell products. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the localized thermal / electrical / ultrasonic multi-field coupling assisted progressive forming device for titanium alloy plates in Specific Implementation Method 1;

[0035] Figure 2 for Figure 1 Enlarged view of region I within the dashed box;

[0036] Figure 3 This is a three-dimensional schematic diagram of the movable electrode head 15 in the first specific embodiment;

[0037] Figure 4 This is a schematic diagram of the movable electrode head 15 after being disassembled in the first specific implementation method. Detailed Implementation

[0038] Specific Implementation Method 1: This implementation method is a device for localized thermal / electrical / ultrasonic multi-field coupling assisted progressive forming of titanium alloy plates, such as... Figures 1-4 As shown, it is specifically composed of a forming table 1, a motion control system 2, a heating power supply 3, a pulse current generator 4, a robotic arm 5, a pressing bolt 6, a pressing plate 7, a first insulating block 8, a second insulating block 10, a loading tool head 11, a heat insulation plate 12, a vibrator 13, an ultrasonic generator 14, a movable electrode head 15, a resistance heater 16, an insulating plate 17, a spring 18, an electrode head carrier 19, and an infrared temperature sensor 20.

[0039] The forming frame 1 is a fixed integral structure consisting of a base plate 1-1, four support columns 1-3, and a top plate 1-2; the base plate 1-1 and the top plate 1-2 are arranged in parallel, and the four support columns 1-3 are evenly distributed between the base plate 1-1 and the top plate 1-2; the center of the top plate 1-2 is a hollow structure.

[0040] The center of the blank holder plate 7 is a hollow structure, the blank holder plate 7 is fixed above the top plate 1-2 by a plurality of blank holder bolts 6, a gap is left between the blank holder plate 7 and the top plate 1-2, four first insulating blocks 8 are arranged in the gap between the blank holder plate 7 and the top plate 1-2, and the four first insulating blocks 8 are evenly arranged in two layers;

[0041] The movable electrode head 15 is a cylindrical structure, is fixedly composed of a symmetrical first subcomponent 15-3 and a second subcomponent 15-4 through a mechanical connection mode, the inside of the movable electrode head 15 is a hollow structure, the resistance heater 16 is arranged in the hollow, the first subcomponent 15-3 is provided with two through holes 15-2 for penetrating wires, the two ends of the wires are connected with the resistance heater 16 and the heating power supply 3 respectively, and the heating power supply 3 is arranged outside the movable electrode head 15; the top of the movable electrode head 15 is an inner concave spherical surface structure, and the contact ball component 15-1 is arranged in the inner concave spherical surface structure and is in rolling connection;

[0042] The bottom of the electrode head carrier 19 is provided with a pulley, the electrode head carrier 19 is arranged on the bottom plate 1-1 and is in sliding connection, and a motor mechanism is arranged in the electrode head carrier 19; the spring 18 is fixed above the electrode head carrier 19, the insulating plate 17 is fixed above the spring 18, the movable electrode head 15 is fixed above the insulating plate 17, and the test probe of the infrared temperature sensor 20 is arranged on the movable electrode head 15;

[0043] The side wall of the loading tool head 11 is fixed with the second insulating block 10, the other end of the second insulating block 10 is connected with the movable end of the mechanical arm 5, the loading tool head 11 is arranged in the center hollow structure of the blank holder plate 7 and the top plate 1-2, the top of the loading tool head 11 is fixed with the heat insulation plate 12, the top of the heat insulation plate 12 is fixed with the vibrator 13, and the vibrator 13 is connected with the ultrasonic generator 14 through wires;

[0044] The signal output end of the motion control system 2 is connected with the signal input end of the mechanical arm 5 and the signal input end of the motor mechanism in the electrode head carrier 19 respectively;

[0045] One end electrode of the pulse current generator 4 is connected with the loading tool head 11, and the other end electrode is connected with the movable electrode head 15.

[0046] The device design principle of the embodiment is as follows:

[0047] The preformed plate 9 is clamped between the four first insulating blocks 8, two first insulating blocks 8 are arranged above and below the plate 9 respectively, and the plate 9 is clamped and fixed through the blank holder bolts 6, and the first insulating blocks 8 are used to prevent the plate 9 from being in conduction with the top plate 1-2 and the blank holder plate 7;

[0048] The bottom end of the loading tool head 11 is in close contact with the upper surface of the sheet metal 9, the contact ball component 15-1 is in close contact with the lower surface of the sheet metal 9, and the central axis of the loading tool head 11 coincides with the central axis of the contact ball component 15-1;

[0049] The present application provides a thermal field by the resistance heater 16 installed in the movable electrode head 15, and realizes non-contact heating of the loading deformation zone of the sheet metal 9.

[0050] The present application forms a closed loop through the mutual connection of the pulse current generator 4, the loading tool head 11, the sheet metal 9 and the movable electrode head 15, and establishes an electric field in the loading deformation zone of the sheet metal 9 to provide pulse current. On the one hand, the pulse current can make the material generate self-resistance heating through the electric current "Joule heating effect" to provide a thermal field, assist the heating of the resistance heater 16, realize two-stage heating, and improve the heating rate of the local loading deformation zone of the sheet metal 9. On the other hand, the "electroplasticity" effect can be generated in the sheet metal 9 through the pulse current, so that the forming limit of the material is improved.

[0051] The upper end of the movable electrode head 15 has a concave spherical surface structure so that the contact ball component 15-1 is embedded therein to realize the free sliding of the contact ball component 15-1; the first sub-component 15-3 and the second sub-component 15-4 are connected and combined by mechanical connection such as bolt connection, so that the embedded assembly and removal of the resistance heater 16 can be realized.

[0052] The electrode head carrier 19 is provided with an electrically controlled movement mechanism, and the movement trajectory of the electrode head carrier 19 is controlled by the movement control system 2. The electrode head carrier 19 can move in a straight line in each direction on the base plate 1-1, so as to drive the movable electrode head 15 to move below the sheet metal 9 along with the movement of the loading tool head 11, and always keep the central axis of the loading tool head 11 coinciding with the central axis of the contact ball component 15-1. The spring 18 is always in a compressed state, so as to tightly press the contact ball component 15-1 against the sheet metal 9 to realize the electrification of the sheet metal 9. Specifically, it is necessary to ensure that the spring 18 is in a compressed state when the movable electrode head 15 is at its highest point position, and does not exceed the elastic limit when the movable electrode head 15 is at its lowest point position. An infrared temperature sensor 20 is installed on the movable electrode head 15 to monitor the temperature of the loading deformation zone of the sheet metal 9.

[0053] The movement control system 2 can control the movement of the mechanical arm 5 and the electrode head carrier 19 respectively, so as to realize the synchronous movement of the loading tool head 11 and the movable electrode head 15.

[0054] The ultrasonic field transmitting system composed of the ultrasonic generator 14 and the vibrator 13 is connected with the loading tool head 11, and provides an ultrasonic field for the deformation area of the sheet metal 9 in contact with the loading tool head 11, so that the sheet metal 9 reduces the flow stress through "ultrasonic softening" in the deformation process, thereby improving the formability; the vibrator 13 is connected with the loading tool head 11 through the heat insulation plate 12.

[0055] Specific implementation two: the difference between this embodiment and the specific implementation one is that the material of the movable electrode head 15 is alloy steel. The others are the same as the specific implementation one.

[0056] Specific implementation three: the difference between this embodiment and the specific implementation one or two is that the material of the loading tool head 11 is alloy steel. The others are the same as the specific implementation one or two.

[0057] Specific implementation four: the difference between this embodiment and any one of the specific implementation one to three is that the material of the first insulating block 8 is mica. The others are the same as any one of the specific implementation one to three.

[0058] Specific implementation five: the difference between this embodiment and the specific implementation four is that the material of the insulating plate 17 is polyimide. The others are the same as the specific implementation four.

[0059] Specific implementation six: the difference between this embodiment and the specific implementation five is that the material of the heat insulation plate 12 is polyimide. The others are the same as the specific implementation five.

[0060] Specific implementation seven: the difference between this embodiment and the specific implementation six is that the material of the contact ball component 15-1 is alloy steel. The others are the same as the specific implementation six.

[0061] Specific implementation eight: the difference between this embodiment and the specific implementation seven is that the contact ball component 15-1 is a solid ball structure. The others are the same as the specific implementation seven.

[0062] Specific implementation nine: the use method of the titanium alloy sheet local thermal / electrical / ultrasonic multi-field coupling assisted incremental forming device in the specific implementation one is as follows:

[0063] I. The contact ball part 15-1 of the loading tool head 11 and the movable electrode head 15 are evenly coated with conductive lubricating oil; the titanium alloy sheet 9 is cut and fixed on the forming rack 1, the sheet 9 is clamped and fixed by the edge clamping bolt 6, the bottom end of the loading tool head 11 is in close contact with the upper surface of the sheet 9, the contact ball part 15-1 is in close contact with the lower surface of the sheet 9, and the central axis of the loading tool head 11 and the central axis of the contact ball part 15-1 always coincide;

[0064] First, the heating power supply 3 is turned on to preheat the movable electrode head 15 to 400-450℃ by the resistance heater 16;

[0065] Second, the pulse current generator 4 is started to realize two-stage heating of the deformed area of the sheet 9 by pulse current, and the ultrasonic generator 14 is started to apply an ultrasonic field to the sheet 9;

[0066] The voltage of the pulse current generator 4 is 10-24V, the current is 200-1000A, and the duty cycle is 25-75%;

[0067] The ultrasonic frequency of the ultrasonic generator 14 is 20-30kHz;

[0068] Third, when the temperature of the local deformed area of the sheet 9 detected by the infrared temperature sensor 20 reaches 600-690℃, the motion control system 2 is started to drive the mechanical arm 5 to load the sheet 9 according to the set processing motion track, and the motion control system 2 controls the electrode head carrier 19 to drive the contact ball part 15-1 to move so that the central axis of the loading tool head 11 and the central axis of the contact ball part 15-1 always coincide; after forming, the heating power supply 3, the pulse current generator 4 and the ultrasonic generator 14 are turned off in turn, and the formed part is taken out from the forming rack 1.

[0069] Specific implementation method ten: the difference between this embodiment and specific implementation method nine is that the sheet 9 is a TA brand series titanium alloy sheet, and the surface oxide skin is removed before being fixed on the forming rack 1 to ensure conductivity. The others are the same as specific implementation method nine.

[0070] The beneficial effects of the present embodiment compared with the prior art are:

[0071] (1) The present embodiment realizes two-stage local heating of the deformed area of the sheet 9 by resistance heater 16 and pulse current heating, which has fast heating speed and low energy consumption;

[0072] (2) The present embodiment realizes reduction of material deformation resistance and plasticization by coupling heat, electricity and ultrasonic energy fields in the deformation process of the sheet 9, which significantly improves the formability of the material;

[0073] (3) The present embodiment produces a softening effect through the combined action of a thermal field and ultrasound, reduces residual stress, reduces the degree of springback, and improves the shape and size accuracy of the formed component.

[0074] (4) The present embodiment improves the quality and qualification rate of the progressive forming manufacturing of complex structure titanium alloy shell products.

Claims

1. A method of using a localized thermal / electrical / ultrasonic multi-field coupling assisted progressive forming device for titanium alloy plates, wherein the localized thermal / electrical / ultrasonic multi-field coupling assisted progressive forming device for titanium alloy plates is composed of a forming table (1), a motion control system (2), a heating power supply (3), a pulse current generator (4), a robotic arm (5), a pressing bolt (6), a pressing plate (7), a first insulating block (8), a second insulating block (10), a loading tool head (11), a heat insulation plate (12), a vibrator (13), an ultrasonic generator (14), a movable electrode head (15), a resistance heater (16), an insulating plate (17), a spring (18), an electrode head carrier (19), and an infrared temperature sensor (20); The forming frame (1) is a fixed integral structure consisting of a base plate (1-1), four support columns (1-3), and a top plate (1-2); the base plate (1-1) and the top plate (1-2) are arranged in parallel, and the four support columns (1-3) are evenly distributed between the base plate (1-1) and the top plate (1-2); the center of the top plate (1-2) is hollow. The center of the pressure plate (7) is hollow. The pressure plate (7) is fixed to the top plate (1-2) directly above by multiple pressure bolts (6). There is a gap between the pressure plate (7) and the top plate (1-2). Four first insulating blocks (8) are set in the gap between the pressure plate (7) and the top plate (1-2). The four first insulating blocks (8) are evenly placed in two layers, upper and lower. The movable electrode head (15) is a cylindrical structure, which is composed of a symmetrical first sub-component (15-3) and a second sub-component (15-4) fixed by mechanical connection. The interior of the movable electrode head (15) is a cavity structure, and the resistance heater (16) is placed in the cavity. The first sub-component (15-3) is provided with two through holes (15-2) for passing through wires. The two ends of the wires are respectively connected to the resistance heater (16) and the heating power supply (3). The heating power supply (3) is located outside the movable electrode head (15). The top of the movable electrode head (15) is a concave spherical structure, and the contact ball component (15-1) is placed in the concave spherical structure and is rolled. The electrode head carrier (19) is provided with a pulley at the bottom. The electrode head carrier (19) is set on the base plate (1-1) and is slidably connected. The electrode head carrier (19) is provided with an electrically controlled motion mechanism. A spring (18) is fixed above the electrode head carrier (19). An insulating plate (17) is fixed above the spring (18). A movable electrode head (15) is fixed above the insulating plate (17). The test probe of the infrared temperature sensor (20) is set on the movable electrode head (15). A second insulating block (10) is fixed on the side wall of the loading tool head (11). The other end of the second insulating block (10) is connected to the movable end of the robotic arm (5). The loading tool head (11) is set in the central hollow structure of the pressure plate (7) and the top plate (1-2). A heat insulation plate (12) is fixed on the top of the loading tool head (11). A vibrator (13) is fixed on the top of the heat insulation plate (12). The vibrator (13) is connected to the ultrasonic generator (14) by a wire. The signal output terminal of the motion control system (2) is connected to the signal input terminal of the robotic arm (5) and the signal input terminal of the electrically controlled motion mechanism in the electrode head carrier (19), respectively. One end electrode of the pulse current generator (4) is connected to the loading tool head (11), and the other end electrode is connected to the movable electrode head (15); Its features The method of using the localized thermal / electrical / ultrasonic multi-field coupling assisted progressive forming device for titanium alloy plates is as follows:

1. Apply conductive lubricating oil evenly to the surface of the contact ball component (15-1) of the loading tool head (11) and the movable electrode head (15); cut the titanium alloy plate (9) and fix it on the forming table (1). The plate (9) is sandwiched between four first insulating blocks (8). Two first insulating blocks (8) are set above and below the plate (9). The plate (9) is clamped and fixed by the edge bolt (6); the bottom end of the loading tool head (11) is in close contact with the upper surface of the plate (9), the contact ball component (15-1) is in close contact with the lower surface of the plate (9), and the central axis of the loading tool head (11) and the central axis of the contact ball component (15-1) always coincide. First, turn on the heating power supply (3) and use the resistance heater (16) to preheat the movable electrode head (15) to 400℃~450℃; 2. Start the pulse current generator (4) to use the pulse current to achieve secondary heating of the deformation zone of the sheet (9), and at the same time start the ultrasonic generator (14) to apply an ultrasonic field to the sheet (9); The voltage of the pulse current generator (4) is 10V~24V, the current is 200A~1000A, and the duty cycle is 25%~75%; The ultrasonic frequency of the ultrasonic generator (14) is 20kHz~30kHz; 3. When the temperature of the local deformation area of ​​the sheet metal (9) detected by the infrared temperature sensor (20) reaches 600℃~690℃, the motion control system (2) is activated so that the robotic arm (5) drives the loading tool head (11) to load and deform the sheet metal (9) according to the set processing motion trajectory. At the same time, the motion control system (2) controls the electrode head carrier (19) to drive the contact ball component (15-1) to move so that the central axis of the loading tool head (11) and the central axis of the contact ball component (15-1) always coincide. After the forming is completed, the heating power supply (3), pulse current generator (4) and ultrasonic generator (14) are turned off in sequence, and the formed part is taken out from the forming table (1).

2. The method of using the localized thermal / electrical / ultrasonic multi-field coupling assisted progressive forming device for titanium alloy plates according to claim 1, characterized in that... The movable electrode head (15) is made of alloy steel.

3. The method of using the localized thermal / electrical / ultrasonic multi-field coupling assisted progressive forming device for titanium alloy plates according to claim 1, characterized in that... The loading tool head (11) is made of alloy steel.

4. The method of using the localized thermal / electrical / ultrasonic multi-field coupling assisted progressive forming device for titanium alloy plates according to claim 1, characterized in that... The first insulating block (8) is made of mica.

5. The method of using the localized thermal / electrical / ultrasonic multi-field coupling assisted progressive forming device for titanium alloy plates according to claim 1, characterized in that... The insulating board (17) is made of polyimide.

6. The method of using the localized thermal / electrical / ultrasonic multi-field coupling assisted progressive forming device for titanium alloy plates according to claim 1, characterized in that... The heat insulation board (12) is made of polyimide.

7. The method of using the localized thermal / electrical / ultrasonic multi-field coupling assisted progressive forming device for titanium alloy plates according to claim 1, characterized in that... The contact ball component (15-1) is made of alloy steel.

8. The method of using the localized thermal / electrical / ultrasonic multi-field coupling assisted progressive forming device for titanium alloy plates according to claim 7, characterized in that... The contact ball component (15-1) is a solid ball structure.

9. The method of using the localized thermal / electrical / ultrasonic multi-field coupling assisted progressive forming device for titanium alloy plates according to claim 1, characterized in that... The plate (9) is a TA series titanium alloy plate. Before it is fixed on the forming frame (1), the surface oxide scale is removed to ensure conductivity.

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