CN116532563B - Spinning and expanding integrated device and method for shape memory alloy pipe joint with inner ribs - Google Patents

Abstract

The application belongs to the technical field of pipe joint processing, and discloses a spinning and expanding integrated device and a spinning and expanding integrated method for a pipe joint with an inner rib shape memory alloy. The device mainly comprises a screw rod, a core mold formed by encircling three split mold halves, a dovetail block, a position stopping clamping sleeve and the like, wherein dovetail keys at the lower ends of the three split mold halves are matched with dovetail grooves of a flange plate, the dovetail block is fixed in the dovetail grooves through screws, spherical protrusions on the outer surface of the screw rod are corresponding spiral grooves on the inner walls of the split mold halves, the spiral grooves of the split mold halves are contacted with the spherical protrusions of the screw rod, the thread track between the screw rod and the flange plate is consistent with the spiral track of the spiral grooves on the inner walls of the core mold, the spiral grooves are gradually shallower, and the position stopping clamping sleeve is fixed with the core mold through bolts. The application has reasonable design, can realize the real-time expansion of the pipe joint after the spin forming of the memory alloy pipe joint with the internal ribs, and can avoid the problem that the pipe joint can not be demolded due to the existence of annular or crossed internal ribs after the expansion of the pipe joint.

Description

Integrated device and method for spinning and expanding diameter of shape memory alloy pipe joint with inner rib

technical field

The invention belongs to the technical field of pipe joint processing, and relates to spinning and diameter-expanding forming of pipe fittings with inner ribs, in particular to an integrated device and method for spinning and expanding diameter of shape memory alloy pipe joints with inner ribs.

Background technique

Pipe joints are a basic part of pipeline connection engineering. Pipe joints based on shape memory alloy (SMA) have the characteristics of simple structure, easy assembly and high connection reliability. They have been used in aviation, transportation and petrochemical industries. It is widely used in various fields of fluid transportation.

The diameter of the shape memory alloy pipe joint after forming or processing is usually slightly smaller than the outer diameter of the pipe to be connected, and then the pipe joint is passed through a diameter-expanding mandrel under low temperature conditions to make the inner diameter slightly larger than the outer diameter of the pipe, and maintain the martensitic state. During installation, the pipe joint is placed at the pipe connection position, and then the pipe joint is heated to cause austenitic phase transformation of its material. Due to the shape memory effect, the pipe joint is completely or to some extent restored to the size before the expansion, and it is held tightly for connection. At the same time, the inner rib of the inner wall presses the outer surface of the pipe fitting, so that the connection has high connection strength and excellent sealing performance.

At present, the inner ribs on the inner wall of the pipe joint usually include inner ring ribs, cross ribs, longitudinal ribs and the like. The external strong spinning forming of characteristic components with internal ribs is a complex spinning forming method, which combines various spinning forming processes such as the forming of curved busbar workpieces and the forming of workpieces with internal ribs. Due to the obvious uneven deformation of the material under local strong loading during the spinning forming process, the deformed tube blank often breaks and the internal ribs are not filled enough, which leads to the limitation of the forming height of the ribs, especially for the cross rib tube section. Furthermore, spinning with internal ribs has always had the problem of difficult demoulding, and the existing mold has a complex structure and high cost. Before the memory alloy pipe joint is matched with the pipeline, it is necessary to rely on professional equipment to properly expand the diameter for the normal assembly in the later stage, resulting in high energy consumption and low efficiency of the existing process.

Therefore, it is urgent to find a forming device and high-efficiency process method for shape memory alloy pipe joints containing internal ribs that solve the above technical problems.

Contents of the invention

The purpose of the present invention is to provide an integrated device and method for spinning and expanding the diameter of shape memory alloy pipe joints with inner ribs, and at the same time solve the difficulty of spinning and demoulding of shape memory alloy pipe joints with inner ring ribs or cross ribs or longitudinal ribs and forming For technical issues related to pipe joint expansion, a set of forming dies is used to produce shape memory alloy pipe joints that can be directly used for pipe connection with high efficiency and high precision.

The present invention is realized by adopting the following technical solutions:

An integrated spinning device for shape memory alloy pipe joints with internal ribs, including a flange, a mandrel, a screw rod, a dovetail block, and a stop ferrule; a threaded hole is provided in the middle of the flange, and the The screw rod is threadedly connected to the threaded hole of the flange through its lower end; the screw rod is equipped with a mandrel, and the mandrel is surrounded by a plurality of split mold petals. The surface of the flange is provided with a plurality of dovetail grooves along the radial direction with the threaded hole as the center; the bottom surface of each split mold is provided with a dovetail key, and all the split mold flaps are inserted into the dovetail grooves through the dovetail keys on the bottom surface and then closed. into a mandrel. The screw rod is provided with one or more spherical protrusions, and the plurality of spherical protrusions are located on the same helix and are consistent with the thread trajectory in the threaded hole in the middle of the flange, and the inner wall of the core mold corresponds to each The spherical protrusion is provided with a section of helical groove, that is, all the helical grooves are also located on the same helical line; the spherical protrusion is located in the corresponding helical groove, and the depth of the helical groove is from deep to shallow, and When the spherical protrusion moves along the helical line, the mandrel is driven to produce radial movement. A dovetail block for realizing the radial positioning of the lower end of the mandrel is installed in the dovetail groove; a stop ferrule for realizing the radial positioning of the upper end of the mandrel is installed at the upper end of the mandrel. The outer peripheral surface of the mandrel is provided with a plurality of inner rib grooves for forming inner ribs on the inner wall of the pipe joint.

Further preferably, the core mold is surrounded by three identical split mold halves. The number of said dovetail grooves is 3, corresponding to 3 split mold parts respectively. The upper end of the core mold is limited by the stop ferrule, and the lower end of the core mold is limited by the dovetail block placed in the dovetail groove, which restrains the radial movement of the core mold enclosed by the three split mold halves and ensures the reliability of spinning.

Further preferably, the pipe joint is installed outside the mandrel by screws to achieve axial positioning, so as to prevent axial movement of the pipe joint relative to the mold half during spinning.

Further preferably, the screw rod is provided with four spherical protrusions; the inner wall of the mandrel is correspondingly provided with four sections of helical grooves; ensuring uniform force and deformation of the memory alloy pipe joint during diameter expansion.

When in use, the tightening direction of the threaded connection between the screw rod and the flange is opposite to the rotation direction of the main shaft of the spinning machine, so as to avoid loosening of the device during the spinning process. The radial movement of the split mold part is limited by the stop ferrule and the dovetail block in the dovetail groove. The dovetail groove restricts the axial and circumferential movement of the split mold part. The memory alloy pipe joint and the split part are connected by bolts. , to prevent the axial movement of the pipe joint relative to the split mold part during spinning. After the spinning is completed, disassemble the stop ferrule, the dovetail block in the dovetail groove and the screw fixing the memory alloy pipe joint. There are four spherical protrusions evenly distributed in the axial and circumferential directions on the outer surface of the screw rod, corresponding to There are also four evenly distributed spiral grooves on the inner wall of the split mold to ensure that the memory alloy pipe joint is evenly stressed and deformed when the diameter is expanded. In the initial state, the spherical protrusion is located in the deepest part of the spiral groove. Moving in the spiral groove, because the spiral groove is a structure that gradually becomes shallower, the spherical protrusion drives the three mold halves to move outward in a consistent radial direction. During the diameter expansion process, the rotation degree of the screw rod is determined according to the size, material and process requirements of the alloy tube.

The integrated forming method of spinning and expanding the diameter of the shape memory alloy pipe joint with internal ribs applied to the above-mentioned device includes the following steps:

(1), Assemble spinning tooling and tube blank

The flange is fixedly connected to the spinning machine through the hole; the screw rod is connected to the flange through the thread at the end; the ends of the three split mold parts are matched with the corresponding dovetail grooves on the flange and then enclosed to form a core mold, and the spherical protrusion on the outer surface of the screw rod is required to match the deepest spiral groove on the inner surface of the mandrel; the three dovetail blocks are respectively fixed in the corresponding dovetail grooves by screws to realize the radial positioning of the lower end of the mandrel; the memory alloy The tube blank is set outside the mandrel, and the axial positioning is realized by screws; the stop ferrule is connected with the upper end of the mandrel by screws to realize the radial positioning of the upper end of the mandrel.

(2), spinning forming

The rotary wheel is screwed in from the side close to the stop ferrule. Before spinning, heat the memory alloy tube blank and tooling at the same time with a heating gun. When the memory alloy tube blank is heated up to the end temperature of austenite transformation, it will start after reaching the predetermined temperature. Spinning, under the action of the rotation of the spindle and the extrusion of the rotary wheel, a shape memory alloy pipe joint workpiece with inner ribs is formed.

(3), expanding diameter forming

After the spinning is finished, cool down the tube blank below the martensitic transformation start temperature of the memory alloy material; when expanding the diameter, remove the dovetail block, the stop ferrule and the screw on the pipe joint, and unscrew the screw rod to the flange for a certain amount of time. distance, during this process: the spherical protrusion slides in the spiral groove, and drives the three split mold halves to move radially outward, and then exerts radial force on the memory alloy pipe joint to realize diameter expansion.

(4), pick up

After the diameter expansion is completed, rotate the screw rod in the opposite direction, and install the dovetail block to exert an inward radial force on the mandrel, so as to ensure that there is a sufficient gap between the pipe joint and the mandrel to ensure the smooth demoulding of the pipe joint.

Due to the shape memory effect, the memory alloy pipe joint after expansion can be heated to above the end temperature of austenite transformation to return to the pipe diameter after spinning or the pipe diameter becomes smaller to a certain extent, so as to achieve interference with the pipe fittings to be connected Cooperate.

Compared with prior art, the present invention has following advantage:

1. The invention expands the diameter in real time through spinning forming, and the expanded pipe joint can avoid the problem that the pipe joint cannot be demolded due to the existence of ring-shaped or cross inner ribs, and can continuously perform spinning and diameter expansion processes, The manufacturing efficiency of memory alloy pipe joints containing ring-shaped inner ribs or intersecting inner ribs or longitudinal ribs is effectively improved, and the production cost is significantly reduced.

2. The present invention can realize the precision forming of inner ring ribs, cross ribs or longitudinal ribs of shape memory alloy pipe joints, without leaving traces of mechanical processing on the inner ribs, and improve the mechanical properties of memory alloy pipe joints.

The invention has a reasonable design, and can realize the real-time diameter expansion after partial disassembly after the memory alloy pipe joint with internal ribs is formed. The problem that the pipe joint cannot be demolded has good practical application and promotion value.

Description of drawings

Fig. 1 shows the schematic diagram of the spinning forming structure of the spinning and expanding integrated device.

Fig. 2 shows a schematic top view of the integrated device for spinning and expanding diameters.

Fig. 3 shows the A-A sectional view in Fig. 2 .

Fig. 4 shows a schematic diagram of the diameter expanding forming structure of the spinning diameter expanding integrated device.

Fig. 5 shows a schematic structural view of a core mold formed by enclosing three split mold halves.

FIG. 6 shows a left side view of FIG. 5 .

Figure 7 shows a wireframe diagram of the mandrel.

Fig. 8 shows a schematic diagram of the structure of the screw rod.

Fig. 9 shows a schematic diagram of the structure of the dovetail block.

FIG. 10 shows a left side view of FIG. 9 .

In the figure: 1-flange, 101-dovetail groove, 102-hole, 2-mandrel, 201-split mold, 202-dovetail key, 203-spiral groove, 204-ring groove, 3-screw rod , 301-spherical protrusion, 302-lower end thread, 4-dovetail block, 5-stop ferrule, 6-screw, 7-pipe joint, 701-inner ring rib.

Detailed ways

In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in conjunction with specific embodiments of the present application and corresponding drawings. Apparently, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in this application, those skilled in the art can obtain other embodiments without making creative efforts.

Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

An integrated spinning device for shape memory alloy pipe joints with internal ribs, as shown in Figures 1, 2, and 3, including a flange plate 1, a mandrel 2, a screw rod 3, a dovetail block 4, and a stop card Set of 5 and other components.

As shown in FIG. 3 , a threaded hole is provided in the middle of the flange 1 , and the screw rod 3 is vertically connected to the threaded hole of the flange 1 through the thread 302 at its lower end. The screw rod 3 is equipped with a mandrel 2 outside.

In this embodiment, as shown in FIGS. 5 , 6 and 7 , the core mold 2 is surrounded by three identical split mold halves 201 . The outer peripheral surface of the mandrel is provided with a plurality of inner rib grooves for forming inner ribs on the inner wall of the pipe joint; for example, the outer peripheral surface of the mandrel 2 is provided with three ring grooves 204 for forming the inner ring rib 701 of the inner wall of the pipe joint 7, similarly The outer peripheral surface of the mandrel 2 is provided with corresponding intersecting grooves or longitudinal grooves for forming intersecting ribs or longitudinal ribs on the inner wall of the pipe joint 7 .

As shown in Figures 2 and 3, three dovetail grooves 101 are provided on the surface of the flange 1 centered on the threaded hole in the radial direction, corresponding to the split mold parts 201 respectively. A dovetail key 202 is provided on the bottom surface of each split mold half 201 . In this way, the three split mold halves 201 are respectively inserted into the dovetail groove 101 through the dovetail keys 202 on their bottom surfaces and then enclosed to form the mandrel 2 .

As shown in FIG. 8 , at least one spherical protrusion 301 is provided outside the screw rod 3 . In this embodiment, the screw rod 3 is provided with four spherical protrusions 301 , and the four spherical protrusions 301 are located on the same helical line and are consistent with the thread trajectory in the threaded hole in the middle of the flange 1 .

As shown in Figure 7, the inner wall of the mandrel 2 is provided with a section of helical groove 203 corresponding to each spherical protrusion 301, that is, the four sections of helical groove 203 are also located on the same helical line, and are also connected to the threaded hole in the middle of the flange 1. The internal thread trajectory is consistent. And the depth of each helical groove 203 is from deep to shallow.

As shown in Figures 3 and 4, each spherical protrusion 301 is located in the corresponding helical groove 203, and the depth of the helical groove 203 gradually becomes shallower, and makes the spherical protrusion 301 drive the mandrel 2 when moving along the helical line Radial movement is generated to realize expanding and forming.

As shown in Figures 9 and 10, the dovetail block 4 is provided with screw holes, and the three dovetail blocks 4 are respectively fixed in the dovetail groove 101 by screws 6. As shown in FIGS. 2 and 3 , a dovetail block 4 for realizing radial positioning of the lower end of the mandrel 2 is installed in each dovetail groove 101 . The upper end of the mandrel 2 is equipped with a stop ferrule 5 for realizing the radial positioning of the upper end of the mandrel 2 , and the stop ferrule 5 is fixed on the upper end of the mandrel 2 by screws 6 .

As shown in FIG. 3 , during spinning, the tube blank is installed outside the mandrel 2 through screws 6 to achieve axial positioning, and the tube blank is processed into a pipe joint 7 . In the spinning forming stage, the device includes a flange 1, three dovetail blocks 4, three split mold parts 201, a screw rod 3, and a stop ferrule 5; the screw rod 3 is connected to the flange of the spinning machine through threads The disk 1 is screwed together, and the dovetail keys 202 at the ends of the three split mold parts 201 cooperate with the three dovetail grooves 101 of the flange 1 one by one, and the empty space in the dovetail groove 101 is filled by the dovetail block 4, which limits the mandrel. The radial movement of the end, the stop ferrule 5 and the upper end of the mandrel 2 enclosed by the three split mold halves 201 are fixed with screws 6, thereby fully limiting the radial movement of the mandrel 2, the memory alloy tube The joint and the mandrel are fixed with screws 6 to prevent axial sliding of the pipe joint.

In the diameter expanding forming stage, the device needs to disassemble the stop ferrule 5, the dovetail block 4 and the assembled screws; the spherical protrusions 301 on the outer surface of the screw rod 3 correspond to the spiral grooves 203 on the inner wall of the split mold part 201 respectively, and the The spiral groove 202 of the phantom petal 201 is in contact with the spherical protrusion 301 of the screw rod 3, the thread track between the lower end thread 302 of the screw rod 3 and the flange 1 and the spiral track of the spiral groove 203 on the inner wall of the mandrel 2 Consistently, the spiral groove 203 gradually becomes shallower in depth, and the screw rod 3 is rotated, and the spherical protrusion 301 drives the split mold part 201 to move in the radial direction.

During specific implementation, the material of the device is made of hot work die steel H13 steel. Shape memory alloy materials include but are not limited to iron-based shape memory alloys and copper-based shape memory alloys; inner ribs of shape memory alloy pipe joints include but are not limited to longitudinal ribs, circumferential ribs and cross ribs. The method of the invention avoids the problem that the longitudinal ribs are difficult to demould after spinning, and solves the problem that the circumferential ribs and cross ribs cannot be demolded after spinning.

An integrated forming method for spinning and expanding the diameter of a shape memory alloy pipe joint with internal ribs, comprising the following steps:

(1), Assemble spinning tooling and tube blank

Fix the spinning tooling on the spinning machine. The spinning tooling structure includes a flange 1, which is fixedly connected to the spinning machine through the hole 102; the screw rod 3 is connected to the flange 1 through the end thread; three split molds with the same size and shape The ends of 201 are all matched with the corresponding dovetail grooves 101 on the flange 1 to form the core mold 2, and the spherical protrusion 301 on the outer surface of the screw rod 3 is required to be in the deepest part of the spiral groove 203 on the inner surface of the core mold 2 Cooperate; the three dovetail blocks 4 are respectively fixed in the corresponding dovetail grooves 101 by screws 6 to realize the radial positioning of the lower end of the mandrel 2; The stop ferrule 5 is connected with the upper end of the mandrel 2 through the screw 6 to realize the radial positioning of the upper end of the mandrel 2 .

(2), spinning forming

The rotary wheel is screwed in from the side close to the stop ferrule 5. Before spinning, the FeMnSiCr shape memory alloy tube blank and tooling are heated at the same time with a heating gun in advance, and the temperature is measured by a temperature measuring gun. When the overall temperature of the memory alloy tube blank reaches 800°C (Above the end temperature of the austenite transformation of the memory alloy material), the spinning forming is carried out one by one; It is 18% to 20%, and the feed ratio is 1.2 to 1.6mm/r; under the rotation of the spindle of the spinning machine and the extrusion of the rotary wheel, a shape memory alloy pipe joint workpiece with inner ribs is formed, that is, a memory alloy pipe The blank is formed into a pipe joint 7 .

(3), expanding diameter forming

After spinning, cool down the pipe joint to below 6°C (below the martensitic transformation start temperature of the memory alloy material); when expanding the diameter, remove the dovetail block 4, the stop ferrule 5 and the screw 6 on the pipe joint 7, Screw the screw rod 3 to the flange 1 for a certain distance, during this process, the spherical protrusion 301 slides in the spiral groove 203, and drives the three split mold petals 201 to move radially outward, that is, the screw rod The core mold enclosed by the three split mold petals undergoes relative helical motion, and the spherical protrusion on the outer surface of the screw rod applies a load to the spiral groove on the inner surface of the core mold to gradually expand the diameter, and then exerts a radial force on the memory alloy pipe joint , to achieve diameter expansion forming.

(4), pick up

After the diameter expansion is completed, the shape memory alloy pipe joint with internal ribs is disassembled. Rotate the screw rod 3 in the opposite direction, and install the dovetail block 4 to exert an inward radial force on the mandrel 2, so as to ensure that there is a sufficient gap between the pipe joint 7 and the mandrel 2 to ensure that the pipe joint 7 is demoulded smoothly. It should be noted here that the thickness of the inner rib of the shape memory alloy pipe joint will not affect the demoulding between the pipe joint and the mandrel.

Due to the shape memory effect, the memory alloy pipe joint after expansion can be heated to above the end temperature of austenite transformation to return to the pipe diameter after spinning or the pipe diameter becomes smaller to a certain extent, so as to achieve interference with the pipe fittings to be connected Cooperate.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than limit them. Although detailed descriptions have been made with reference to the embodiments of the present invention, those of ordinary skill in the art should understand that the technical solutions of the present invention are modified Or equivalent replacements do not deviate from the spirit and scope of the technical solutions of the present invention, and all of them should be included in the protection scope of the claims of the present invention.

Claims (10)

1. An integrated device for spinning and expanding diameter of shape memory alloy pipe joints with internal ribs, including flange (1), mandrel (2), screw rod (3), dovetail block (4), stop card A sleeve (5); it is characterized in that: the middle part of the flange (1) is provided with a threaded hole, and the screw rod (3) is connected to the threaded hole of the flange (1) through its lower end thread (302); The screw rod (3) is equipped with a mandrel (2), and the mandrel (2) is surrounded by a plurality of split mold halves (201); The surface of the flange (1) is provided with a plurality of dovetail grooves (101) along the radial direction with the threaded hole as the center; each split mold half (201) is provided with a dovetail key (202) on the bottom surface, and all split mold halves (201) inserts the dovetail key (202) on its bottom surface into the dovetail groove (101) and encloses it to form a mandrel (2); The screw rod (3) is provided with one or more spherical protrusions (301), and the plurality of spherical protrusions (301) are located on the same helical line and are connected to the threads in the threaded hole in the middle of the flange (1). The trajectory is consistent, and the inner wall of the mandrel (2) is provided with a section of spiral groove (203) corresponding to each spherical protrusion (301), that is, all the spiral grooves (203) are also located on the same helical line; the spherical The protrusion (301) is located in the corresponding spiral groove (203), the depth of the spiral groove (203) gradually becomes shallower, and makes the spherical protrusion (301) drive the mandrel (2 ) produces radial movement; The dovetail groove (101) is equipped with a dovetail block (4) for realizing the radial positioning of the lower end of the mandrel (2); the upper end of the mandrel (2) is equipped with a stop ferrule (5); The outer peripheral surface of the mandrel (2) is provided with a plurality of inner rib grooves for forming inner ribs on the inner wall of the pipe joint (7); During spinning, the memory alloy tube blank is set outside the mandrel (2), and the axial positioning is realized by the screw (6); the spinning wheel of the spinning machine is screwed in from the side close to the stop ferrule (5), Before spinning, the memory alloy tube blank and the device are heated to a predetermined temperature at the same time, and the shape memory alloy pipe joint workpiece with internal ribs is formed under the extrusion of the spinning wheel; When expanding the diameter, remove the dovetail block (4), the stop ferrule (5) and the screw (6) on the pipe joint (7), and unscrew the screw rod (3) to the flange (1) for a certain distance. During this process: the spherical protrusion (301) slides in the spiral groove (203), and drives the split mold part (201) to move radially outward, and then exerts a radial force on the memory alloy pipe joint to realize expansion. path. 2. The integrated device for spinning and expanding the diameter of a shape memory alloy pipe joint with internal ribs according to claim 1, characterized in that: the dovetail block (4) is fixed to the dovetail groove (101) by screws (6) )Inside. 3. The integrated device for spinning and expanding the diameter of a shape memory alloy pipe joint with internal ribs according to claim 2, characterized in that: the stop ferrule (5) is fixed to the mandrel by screws (6) (2) Upper end. 4. The integrated device for spinning and expanding the diameter of a shape memory alloy pipe joint with internal ribs according to claim 3, characterized in that: the mandrel (2) consists of three identical split mold halves (201 ) is enclosed. 5. The integrated device for spinning and expanding the diameter of a shape memory alloy pipe joint with internal ribs according to claim 4, characterized in that: the number of the dovetail grooves (101) is 3, corresponding to 1 respectively Split mold valve (201). 6. The integrated device for spinning and expanding the diameter of a shape memory alloy pipe joint with internal ribs according to claim 5, characterized in that: the pipe joint (7) is installed on the mandrel (2) through screws (6) ) to achieve axial positioning. 7. The integrated device for spinning and expanding the diameter of a shape memory alloy pipe joint with internal ribs according to claim 6, characterized in that: the screw rod (3) is provided with four spherical protrusions (301) ; The inner wall of the mandrel (2) is correspondingly provided with 4 sections of spiral grooves (203). 8 . The integrated device for spinning and expanding diameter of shape memory alloy pipe joints with internal ribs according to claim 7 , characterized in that the device is made of hot work die steel H13 steel. 9. The integrated device for spinning and expanding the diameter of a shape memory alloy pipe joint with internal ribs according to claim 8, characterized in that: the material of the pipe joint (7) is iron-based shape memory alloy or copper-based Shape Memory Alloys. 10. An integrated forming method of spinning and expanding the diameter of a shape memory alloy pipe joint with internal ribs, characterized in that it includes the following steps: S1. Assemble spinning tooling and tube blank The flange (1) is fixedly connected with the spinning machine through the hole (102); the screw rod (3) is connected with the flange (1) through the thread at the end; The corresponding dovetail grooves (101) on the blue plate (1) are matched to form the mandrel (2), and the spherical protrusion (301) on the outer surface of the screw rod (3) is required to be in contact with the inner surface of the mandrel (2). The deepest part of the spiral groove (203) matches; the three dovetail blocks (4) are respectively fixed in the corresponding dovetail groove (101) by screws (6) to realize the radial positioning of the lower end of the mandrel (2); the memory alloy tube blank Set outside the mandrel (2) and achieve axial positioning through the screw (6); the stop ferrule (5) is connected with the upper end of the mandrel (2) through the screw (6) to realize the diameter of the upper end of the mandrel (2) Orientation; S2, spinning forming The rotary wheel is screwed in from the side close to the stop ferrule (5). Before spinning, use a heating gun to heat the memory alloy tube blank and tooling at the same time, and raise the temperature to above the austenite transformation end temperature of the tube blank. Start spinning, and form a shape memory alloy pipe joint workpiece with internal ribs under the rotation of the spindle of the spinning machine and the extrusion of the spinning wheel; S3, diameter expanding forming After the spinning is finished, cool down the tube blank below the martensitic transformation start temperature of the memory alloy material; when expanding the diameter, remove the dovetail block (4), the stop ferrule (5) and the screw on the pipe joint (7) ( 6), screw the screw rod (3) to the flange (1) for a certain distance, during this process: the spherical protrusion (301) slides in the spiral groove (203), and drives the three split mold parts (201) moving outward in the radial direction, and then applying a radial force to the memory alloy pipe joint to realize diameter expansion; S4. Pick up After the diameter expansion is completed, rotate the screw rod (3) in the opposite direction, and install the dovetail block (4) to exert an inward radial force on the mandrel (2), so as to ensure that there is a gap between the pipe joint (7) and the mandrel (2). Sufficient clearance ensures smooth demoulding of the pipe joint (7).