CN218517567U

CN218517567U - Single-wheel spinning closing-in device suitable for lathe

Info

Publication number: CN218517567U
Application number: CN202221997278.7U
Authority: CN
Inventors: 魏林; 陈迎春; 赵勇; 贺勇
Original assignee: Sichuan Aerospace Zhongtian Power Equipment Co ltd
Current assignee: Sichuan Aerospace Zhongtian Power Equipment Co ltd
Priority date: 2022-07-29
Filing date: 2022-07-29
Publication date: 2023-02-24
Anticipated expiration: 2032-07-29

Abstract

The utility model discloses a single-wheel spinning closing-in device suitable for a lathe, which relates to the technical field of part spinning processing and solves the technical problems of complex structure and high cost of the existing equipment, and comprises a core mold mechanism and a spinning wheel mechanism; the core mold mechanism comprises a base, a pressing ring, a molding die, a conical surface buckle, a first nut and a positioning shaft, wherein the base, the pressing ring, the molding die and the conical surface buckle are sequentially sleeved on the positioning shaft coaxially, the base is connected with the positioning shaft, one surface of the base is provided with a positioning round-corner conical hole, one surface of the molding die, which is far away from the pressing ring, is provided with a ring groove along the circumferential direction, an embedded part is formed between the ring groove and the first conical hole, one surface of the conical surface buckle, which faces the molding die, is provided with an embedded groove matched with the embedded part along the circumferential direction, and the outer wall of one end, which extends out of the conical surface buckle, of the positioning shaft is provided with a first external thread part which is in threaded connection with the first nut through the first external thread part; the spinning wheel mechanism is used for spinning a workpiece fixed on the core mould mechanism; the utility model has the advantages of low cost, durability and reliable quality.

Description

Single-wheel spinning closing-in device suitable for lathe

Technical Field

The utility model relates to a part spinning processing technology field, more specifically relate to a single round spinning binding off device suitable for lathe.

Background

Spinning is a process for forming a metal hollow rotating member. During the rotation of the blank along with the spindle of the machine tool, the spinning wheel is fed radially, so that the blank is stressed and undergoes a continuous local deformation. The spinning closing-in belongs to one of the spinning forming methods, and the mouth of the metal hollow rotating part can be reduced to a certain size through the spinning closing-in.

In industrial production, a special spinning closing-in device is mostly adopted to carry out the spinning closing-in operation of parts. The special spinning closing-in equipment usually adopts coreless die spinning, and in order to ensure that parts are not unstable in the processing process, double-wheel or three-wheel spinning is often used. Namely, in the processing process, two (three) selecting wheels synchronously apply pressure to the circle center at the evenly distributed positions of the circumference. The special spinning equipment can realize high necking rate, but the equipment structure is more complex and the price is higher.

For some processing plants with smaller scale or product batch, the spinning necking operation requirement of the metal hollow rotating part is sometimes required, but in consideration of production cost, the method is not suitable for purchasing a special spinning necking device, and finally, the product structure can be only processed in an external cooperation mode or changed at the expense of product performance.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide an: in order to solve the technical problem, the utility model provides a single round spinning binding off device suitable for lathe.

The utility model discloses a realize above-mentioned purpose and specifically adopt following technical scheme:

a single-wheel spinning closing-in device suitable for a lathe comprises a core die mechanism and a spinning wheel mechanism;

the core mold mechanism comprises a base, a pressing ring, a molding die, a conical surface buckle, a first nut and a positioning shaft, wherein the base, the pressing ring, the molding die and the conical surface buckle are sequentially sleeved on the positioning shaft coaxially, the base is connected with the positioning shaft, one surface of the base is circumferentially provided with a positioning round-corner conical hole matched with the outer wall of one end of a workpiece, the outer contour of the pressing ring is matched with the inner wall of the workpiece, the center of the molding die is provided with a first through hole, the inner wall of one end, away from the pressing ring, of the first through hole is circumferentially provided with a first conical hole, one surface, away from the pressing ring, of the molding die is circumferentially provided with a ring groove, an embedding part is formed between the ring groove and the first conical hole, the center of the conical surface buckle is provided with a guide hole matched with the positioning shaft, one surface, facing the molding die, of the conical surface buckle is circumferentially provided with an embedding groove matched with the embedding part, the outer wall of one end, extending out of the conical surface buckle, of the positioning shaft is provided with a first external thread part in threaded connection with the first nut;

the spinning wheel mechanism is used for spinning a workpiece fixed on the core die mechanism.

Furthermore, the rotary wheel mechanism comprises a rotary wheel, a wheel shaft and a cutter body, the wheel shaft penetrates through the cutter body along the radial direction of the cutter body, one end of the wheel shaft extends to the outside of the cutter body, the wheel shaft is connected with the cutter body, the rotary wheel is sleeved on the wheel shaft, and the rotary wheel is rotatably connected with the wheel shaft.

Furthermore, one end, far away from the external thread part I, of the positioning shaft is connected with a first clamping head, a blind hole matched with the first clamping head is formed in the surface, back to the compression ring, of the base, and the first clamping head and the base are fixed through a set screw.

Furthermore, a lightening hole I, a lightening hole II, a lightening hole III and a lightening hole IV are respectively arranged on the base, the compression ring, the mould and the conical surface buckle.

Further, the tire is divided into four parts, namely a block I, a block II, a block III and a block IV, wherein the arc length of the inner side of the block II is larger than that of the outer side.

Furthermore, a bearing mounting hole is formed in the center of the front face of the rotary wheel, a tapered roller bearing is arranged in the bearing mounting hole, and a bearing cover is arranged on the face, back to the cutter body, of the rotary wheel.

Furthermore, one end of the wheel shaft close to the rotary wheel is connected with a second clamping head, the other end of the wheel shaft extends out of the cutter body, the outer wall of the extending part is provided with a second external thread part, and the second external thread part is in threaded connection with a second nut.

Furthermore, a spring washer is sleeved on the second external thread part and is positioned between the second nut and the cutter body.

Furthermore, a limiting hole communicated with the bearing mounting hole is formed in the center of the back of the rotary wheel, a pressing ring is arranged in the limiting hole, one end of the pressing ring is in contact with the tapered roller bearing, and the other end of the pressing ring extends out of the limiting hole and is in contact with the cutter body.

Furthermore, the outer profile of the spinning wheel consists of a conical surface I and a spherical surface I, wherein the spherical surface I is close to the front surface of the spinning wheel and protrudes out of the end surface of the spinning wheel.

The utility model has the advantages as follows:

1. the utility model can screw the first nut in the direction of the base under the guiding action of the positioning shaft through the matching of the base, the compression ring, the molding die, the conical surface fastener, the first nut, the positioning shaft, the positioning round angle conical hole, the first through hole, the first conical hole, the annular groove, the embedded part, the embedded groove, the first external thread part and the first nut, and the nut applies pressure to the conical surface fastener to tightly fix the workpiece in the positioning round angle conical hole; through the cooperation of mandrel mechanism and spinning wheel mechanism, utilize mandrel mechanism to fix the work piece steadily earlier, the single spinning wheel mechanism of rethread carries out the spinning binding off to the work piece, the utility model discloses under the condition that does not have special spinning binding off equipment, use lathe can realize the spinning binding off operation of the hollow gyration part of metal of turboprop engine flame tube part or similar structure and carry out terminal surface machining, have low cost, durable, the reliable advantage of quality.

2. The utility model discloses a be greater than the arc length in the outside with the arc length of four bibliographic categories branch and the inboard of piece two is cut apart into to the type child, and processing is accomplished the back, strikes piece two gently along the centre of a circle direction of type child, takes out piece two, takes out piece three, piece four and piece one again in proper order, and the staff of being convenient for dismantles work.

3. The utility model discloses an installation tapered roller bearing reduces the frictional force that produces when spinning wheel is rotatory, can also improve the bearing capacity when receiving radial and the monoaxial spinning feed force.

4. The utility model discloses a set up the clamping ring, not only can compress tightly tapered roller bearing's inner circle to make and keep the certain distance between spinning wheel and the cutter body, avoid taking place to interfere.

5. The utility model discloses well external profile of spinning wheel comprises conical surface one and sphere one is close to the front of spinning wheel and the terminal surface of sphere one protrusion spinning wheel, and sphere one can increase the working area of working face as the working face of spinning wheel.

Drawings

Fig. 1 is a schematic structural diagram of the present invention;

FIG. 2 is a schematic structural view of the base of the present invention;

FIG. 3 is a schematic structural view of the middle pressure ring of the present invention;

FIG. 4 is a schematic structural view of a medium sized tire according to the present invention;

FIG. 5 is a schematic structural view of the middle cone buckle of the present invention;

FIG. 6 is a schematic structural view of a positioning shaft of the present invention;

FIG. 7 is a schematic structural view of the middle rotary wheel of the present invention;

FIG. 8 is a schematic view of the structure of the bearing cap of the present invention;

fig. 9 is a schematic structural view of the center axle of the present invention;

fig. 10 is a schematic structural view of a cutter body in the present invention;

fig. 11 is an enlarged view of a position a in the present invention.

Reference numerals: 1-a core mould mechanism; 2-a spinning wheel mechanism; 3-a base; 4, a first through hole; 5-pressing a ring; 6-positioning a round taper hole; 7-molding the tire; 8-ring groove; 9-a tabling groove; 10-a chimeric moiety; 11-a taper hole I; 12-conical surface buckle; 13-external thread part one; 14-a first nut; 15-a pilot hole; 16-a cutter body; 17-a spring washer; 18-nut two; 19-an axle; 20-a spinning wheel; 21-a bearing cap; 22-chuck two; 23-tapered roller bearings; 24-pressing a ring; 25-positioning the shaft; 26-set screws; 27-lightening holes I; 28-a chuck; 29-chamfering one; 30-blind holes; 31-lightening holes II; 32-conical surface two; 33-fillet two; 34-block one; 35-block two; 36-block three; 37-block four; 38-lightening holes III; 39-cone three; a fourth cone surface is 40; 41-lightening holes IV; 42-chamfering II; 43-chuck one; 44-cone one; 45-sphere one; 46-bearing mounting holes; 47-a limiting hole; 48-external thread part two; 49-a workpiece; 50-screw holes.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

Example 1

As shown in fig. 1, the present embodiment provides a single-wheel spinning necking device suitable for a lathe, which comprises a core mold mechanism 1 and a spinning wheel mechanism 2;

the core mold mechanism 1 comprises a base 3, a pressing ring 5, a molding die 7, a conical surface buckle 12, a nut I14 and a positioning shaft 25, the base 3, the pressing ring 5, the molding die 7 and the conical surface buckle 12 are sequentially sleeved on the positioning shaft 25 coaxially, the base 3 is connected with the positioning shaft 25, one surface of the base 3 is circumferentially provided with a positioning round-corner conical hole 6 matched with the outer wall of one end of a workpiece 49, the outer contour of the pressing ring 5 is matched with the inner wall of the workpiece 49, the center of the molding die 7 is provided with a through hole I4, the inner wall of one end, far away from the pressing ring 5, of the through hole I4 is circumferentially provided with a conical hole I11, one surface, far away from the pressing ring 5, of the molding die 7 is circumferentially provided with a ring groove 8, an embedding part 10 is formed between the ring groove 8 and the conical hole I11, the center of the conical surface buckle 12 is provided with a guide hole 15 matched with the positioning shaft 25, one surface of the conical surface buckle 12 is circumferentially provided with an embedding groove 9 matched with the embedding part 10, one surface, extending out of one end of the molding die 7 of the positioning shaft 25 is circumferentially provided with a first external threaded part 13;

in order to match the forming shape of the workpiece 49, in this embodiment, the outer profile of the pressing ring 5 is composed of a second conical surface 32 and a second rounded corner 33, the outer profile of the mold 7 is a composite profile composed of a third conical surface 39, a fourth conical surface 40 and a transition rounded corner, the composite profile is the spinning closed inner profile of the workpiece 49, wherein the third conical surface 39 reserves the rebound quantity of 2-5 degrees according to the rebound calculation.

In this embodiment, the first nut 14 is a hexagonal nut with shoulder.

The spinning roller mechanism 2 is used for spinning a workpiece 49 fixed to the core mold mechanism 1.

The utility model discloses a base 3, clamping ring 5, child 7, conical surface buckle 12, nut 14, location axle 25, location fillet taper hole 6, through-hole 4, taper hole 11, annular 8, gomphosis portion 10, gomphosis groove 9, the cooperation of external screw thread portion 13 and nut 14, can be under the guiding action of location axle 25, screw up nut 14 to the direction of base 3, nut 14 exerts pressure to conical surface buckle 12, fixes work piece 49 tightly in location fillet taper hole 6; through the cooperation of mandrel mechanism 1 and spinning wheel mechanism 2, utilize mandrel mechanism 1 to fix work piece 49 steadily earlier, the single spinning wheel mechanism 2 of rethread carries out the spinning binding off to work piece 49, the utility model discloses under the condition that does not have special spinning binding off equipment, use lathe can realize the spinning binding off operation of the hollow gyration part of metal of turboprop engine flame tube part or similar structure and carry out terminal surface machining, have low cost, durable, the reliable advantage of quality.

Example 2

The present embodiment is explained with respect to a specific structure of the swivel mechanism 2 on the basis of embodiment 1.

As shown in fig. 2, the spinning wheel mechanism 2 includes a spinning wheel 20, a wheel shaft 19 and a cutter body 16, the wheel shaft 19 penetrates through the cutter body 16 along a radial direction of the cutter body 16 and has one end extending to an outside of the cutter body 16, the wheel shaft 19 is connected with the cutter body 16, the spinning wheel 20 is sleeved on the wheel shaft 19, and the spinning wheel 20 is rotatably connected with the wheel shaft 19.

Example 3

This embodiment is explained with respect to the connection structure of the positioning shaft 25 and the base 3 on the basis of the above-described embodiments.

As shown in fig. 1, 2 and 6, one end of the positioning shaft 25, which is far away from the first external thread portion 13, is connected with a first chuck 43, one side of the base 3, which is away from the press ring 5, is provided with a blind hole 30 matched with the first chuck 43, and the first chuck 43 and the base 3 are fixed through a set screw 26.

In addition, in order to facilitate the base 3 to be clamped on the lathe, one end of the base 3 is provided with a chuck 28, the diameter of the chuck 28 is smaller than that of the other end of the base 3, and the outer wall of the large end of the base 3 is provided with a chamfer 29 to avoid the rotating wheel 20 from interfering with the rotating wheel when in work.

Preferably, the position of the positioning shaft 25 near the first male thread portion 13 is provided with a second chamfer 42, which serves as a guide when the tapered buckle 12 is assembled.

Example 4

This embodiment is based on the above-described embodiments, and an optimized explanation is made about the weight reduction process of the present invention.

As shown in fig. 2 to 5, the base 3, the press ring 5, the tire 7 and the cone buckle 12 are respectively provided with a lightening hole one 27, a lightening hole two 31, a lightening hole three 38 and a lightening hole four 41.

In the embodiment, the first lightening holes 27 are four and are uniformly distributed along the circumferential direction of the base 3; the number of the second lightening holes 31 is one, and the second lightening holes are formed in the center of the compression ring 5; the number of the lightening holes III 38 is one, the lightening holes III are arranged in the center of one surface of the molding die 7 facing the press ring 5, and the diameter of each lightening hole III 38 can be larger than that of the through hole I4; the four lightening holes 41 are four and are evenly distributed along the circumferential direction of the conical surface buckle 12.

Example 5

This embodiment is on the basis of the above-mentioned embodiment, about convenient to detach the utility model discloses optimize the explanation.

As shown in fig. 4, the tire 7 is divided into four parts, block one 34, block two 35, block three 36 and block four 37, wherein the arc length of the inner side of block two 35 is greater than the arc length of the outer side.

In the present embodiment, the first block 34 is cut out at 120 ° with the center of the tire 7 as a base point, the second block 35 is cut out at 10 ° with the point outside the tire 7 as a base point, and the third block 36 and the fourth block 37 are symmetrical with respect to the diameter of the tire 7.

The utility model discloses a be greater than the arc length in the outside with the arc length of the inboard of four bibliographic categories branch and two 35 of being cut apart into of type child 7, processing is accomplished the back, strikes two 35 blocks gently along the centre of a circle direction of type child 7, takes out two 35 blocks, takes out three 36, four 37 of blocks and a 34 in proper order again, and the staff of being convenient for dismantles work.

Example 6

The present embodiment is based on the above-described embodiments, and an optimized explanation is made about the friction force reduction process of the present invention.

As shown in fig. 1 and 8, a bearing mounting hole 46 is formed at the center of the front surface of the rotary wheel 20, a tapered roller bearing 23 is disposed in the bearing mounting hole 46, and a bearing cover 21 is disposed on the surface of the rotary wheel 20 facing away from the cutter body 16.

In this embodiment, four screw holes 50 are formed in the circumferential direction on the large end surface of the rotor 20, and the bearing cap 21 is fixed to the rotor 20 by screwing four countersunk screws. The bearing cap 21 can press the outer ring of the tapered roller bearing 23 against the rollers.

Wherein, the bearing mounting hole 46 is in transition fit with the outer ring of the tapered roller bearing 23, and the wheel axle 19 is in interference fit with the inner ring of the tapered roller bearing 23.

The utility model discloses an installation tapered roller bearing 23 reduces the frictional force that produces when spinning wheel 20 is rotatory, can also improve the bearing capacity when receiving radial and the monoaxial spinning feeding power.

Example 7

The present embodiment is explained with respect to a specific structure of the wheel axle 19 on the basis of the above-described embodiments.

As shown in fig. 1 and 9, one end of the wheel shaft 19 close to the rotary wheel 20 is connected with a second chuck 22, the other end extends out of the cutter body 16, the outer wall of the extending part is provided with a second external thread part 48, and the second external thread part 48 is in threaded connection with a second nut 18.

In this embodiment, the second nut 18 is a hexagonal nut with fine teeth.

Furthermore, the second external thread part 48 is sleeved with a spring washer 17, and the spring washer 17 is positioned between the second nut 18 and the cutter body 16, so that the rotary wheel mechanism 2 can be more firmly installed, and looseness during use is avoided.

Example 8

The present embodiment is further optimized and explained with respect to the present invention on the basis of the above embodiments.

As shown in fig. 11, a limiting hole 47 communicating with the bearing mounting hole 46 is formed in the center of the back surface of the rotary wheel 20, a pressing ring 24 is disposed in the limiting hole 47, and one end of the pressing ring 24 contacts with the tapered roller bearing 23, and the other end thereof extends out of the limiting hole 47 and contacts with the cutter body 16.

The utility model discloses a set up clamping ring 24, not only can compress tightly tapered roller bearing 23's inner circle to make and keep the certain distance between spinning wheel 20 and the cutter body 16, avoid taking place to interfere.

Example 9

The present embodiment is described in detail with reference to the shape of the spinning wheel 20 based on the above embodiments.

As shown in fig. 7 and 10, the outer profile of the spinning wheel 20 is composed of a first conical surface 44 and a first spherical surface 45, the first spherical surface 45 is close to the front surface of the spinning wheel 20, and the first spherical surface 45 protrudes out of the end surface of the spinning wheel 20.

The utility model discloses well profile of spinning wheel 20 comprises a conical surface 44 and a sphere 45 is close to the front of spinning wheel 20 and the terminal surface of a sphere 45 protrusion spinning wheel 20, and a sphere 45 can increase the working area of working face as the working face of spinning wheel 20.

The utility model discloses a theory of operation does:

installing the base 3 on a three-jaw chuck of a lathe to clamp, loading a workpiece 49, attaching the end surface and the profile of the small end part of the workpiece 49 to the positioning round-corner taper hole 6, loading the pressing ring 5 into the workpiece 49, and attaching the end surface and the profile of the small end of the pressing ring 5 to the inner profile of the small end of the workpiece 49; placing the molding dies 7 in the workpiece 49 block by block, attaching the large end of the molding die 7 to the large end of the pressing ring 5, sleeving the conical surface buckle 12 on the positioning shaft 25 and installing the conical surface buckle in the direction of the base 3, and basically attaching the end surfaces of the conical surface buckle 12 to the molding dies 7 under the matching action of the embedding groove 9 and the embedding part 10; and (3) a first nut 14 is arranged, the conical surface buckle 12 is completely pressed, the molded tire 7 is spread in the pressing process, the molded tire 7 is pressed and aligned to form a complete molded tire 7, the molded tire 7 can be stably and no longer spread after being spread to a designed size under the limiting action of the embedding groove 9, and the outer profile of the molded tire 7 meets the spinning profile requirement of the workpiece 49. The spinning wheel mechanism 2 is mounted on a lathe carriage through a cutter body 16 and fastened, and the front surface of the spinning wheel 20 faces the tail of the lathe. The angle of the turning tool holder is adjusted so that the center portion of the spherical surface one 45 of the rotary wheel 20 faces the workpiece 49 as much as possible. And (3) starting the lathe, rotating the core die mechanism 1 along with the main shaft of the lathe, and manually controlling the lathe saddle to move towards the radial direction and the axial direction so that the spinning wheel 20 reaches the spinning initial position of the workpiece 49 and lightly contacts the workpiece 49. The manual control spinning wheel 20 performs spinning feeding from left to right along the molded surface of the molded tire 7, so that the molded surface of the workpiece 49 is attached to the molded tire 7. And rotating the tool rest, machining the end face of the workpiece 49 to a required size by using a turning tool which is arranged on the frame in other tool positions in advance, and withdrawing the tool rest. And (3) removing the first nut 14 and the conical surface buckle 12 in sequence, lightly knocking the second block 35 of the mould 7 along the circle center direction, taking out the second block 35, then taking out the third block 36, the fourth block 37 and the first block 34 in sequence, taking out the press ring 5, and finally taking out the workpiece 49.

Claims

1. A single-wheel spinning closing-in device suitable for a lathe is characterized by comprising a core die mechanism (1) and a spinning wheel mechanism (2);

mandrel mechanism (1) includes base (3), clamping ring (5), molding die (7), conical surface buckle (12), nut (14), location axle (25), base (3) clamping ring (5) molding die (7) with conical surface buckle (12) are just established with the axle center in proper order on location axle (25), base (3) are connected with location axle (25), and outer wall assorted location fillet taper hole (6) with work piece (49) one end is seted up along circumference in the one side of base (3), the outline of clamping ring (5) with the inner wall phase-match of work piece (49), through-hole (4) have been seted up in the center department of molding die (7), the inner wall of the one end of clamping ring (5) is kept away from along circumference to through-hole (4) begins to have conical hole (11), and annular (8) have been seted up along circumference in the one side of clamping ring (5) in molding die (7), form gomphosis portion (10) between annular (8) and the conical hole (11), and set up in the center department of conical surface buckle (12) with conical surface buckle (25) the conical surface buckle (15) the one end of conical surface buckle (10) and set up the one matched with conical surface buckle (25) one side of locating shaft (10), one side of jogged with one side jogged locating shaft (10) set up in the one side of locating groove (10) and set up in the conical surface buckle (10) one side of conical surface buckle (25) and set up in the conical surface buckle (10) one side of conical surface buckle (12) one side of conical surface buckle (25) and the one side of conical surface buckle (10) and set up in the one side of conical surface buckle (10) and the one side of conical surface buckle (25) and set up in the one side of conical surface buckle (10) and the outer wall of conical surface buckle (10) and set up (13) And is screwed with the first nut (14) through the first external thread part (13);

the spinning wheel mechanism (2) is used for spinning a workpiece (49) fixed on the core die mechanism (1).

2. The single-wheel spinning necking device applicable to the lathe according to claim 1, wherein the spinning wheel mechanism (2) comprises a spinning wheel (20), a wheel shaft (19) and a cutter body (16), the wheel shaft (19) penetrates through the cutter body (16) along the radial direction of the cutter body (16) and extends to the outside of the cutter body (16) at one end, the wheel shaft (19) is connected with the cutter body (16), the spinning wheel (20) is sleeved on the wheel shaft (19), and the spinning wheel (20) is rotatably connected with the wheel shaft (19).

3. The single-wheel spinning necking device applicable to the lathe according to claim 1, wherein a first clamping head (43) is connected to one end, away from the first external thread part (13), of the positioning shaft (25), a blind hole (30) matched with the first clamping head (43) is formed in one surface, away from the pressing ring (5), of the base (3), and the first clamping head (43) and the base (3) are fixed through a set screw (26).

4. The single-wheel spinning necking device suitable for the lathe according to claim 1, wherein a lightening hole I (27), a lightening hole II (31), a lightening hole III (38) and a lightening hole IV (41) are respectively formed in the base (3), the press ring (5), the mould (7) and the conical surface fastener (12).

5. Single wheel spinning necking device for lathes, according to claim 1, characterized in that the shaped tyre (7) is divided into four parts, respectively a block one (34), a block two (35), a block three (36) and a block four (37), wherein the arc length of the inner side of the block two (35) is greater than the arc length of the outer side.

6. The single-wheel spinning necking device applicable to the lathe according to claim 2, wherein a bearing mounting hole (46) is formed in the center of the front surface of the spinning wheel (20), a tapered roller bearing (23) is arranged in the bearing mounting hole (46), and a bearing cover (21) is arranged on the surface of the spinning wheel (20) opposite to the cutter body (16).

7. The single-wheel spinning necking device applicable to the lathe according to claim 2, wherein a second chuck (22) is connected to one end of the wheel shaft (19) close to the spinning wheel (20), the other end of the wheel shaft extends out of the cutter body (16), an external threaded part II (48) is arranged on the outer wall of the extending part, and a second nut (18) is screwed on the external threaded part II (48).

8. The single-wheel spinning necking device applicable to the lathe according to claim 7, wherein a spring washer (17) is sleeved on the second external thread part (48), and the spring washer (17) is located between the second nut (18) and the cutter body (16).

9. The single-wheel spinning necking device applicable to the lathe according to claim 6, wherein a limiting hole (47) communicated with the bearing mounting hole (46) is formed in the center of the back surface of the spinning wheel (20), a pressing ring (24) is arranged in the limiting hole (47), one end of the pressing ring (24) is in contact with the tapered roller bearing (23), and the other end of the pressing ring extends out of the limiting hole (47) and is in contact with the cutter body (16).

10. The single-wheel spinning necking device applicable to the lathe according to claim 2, wherein the outer profile of the spinning wheel (20) is composed of a first conical surface (44) and a first spherical surface (45), the first spherical surface (45) is close to the front surface of the spinning wheel (20), and the first spherical surface (45) protrudes out of the end surface of the spinning wheel (20).