A cutting die and device for forming an inverted trapezoidal flat copper wire

Abstract

The application discloses a cutting die and device for forming inverted trapezoidal flat copper wire, which comprises a lower die base and an upper die base. Two lower cutting knives are arranged on the lower die base, and a profiling groove is arranged on the lower cutting knives. A first forming step is arranged at the front end of the profiling groove, and the first forming step is a right-angle trapezoid. Two guide columns are arranged on the upper die base, and a cutting block and a profiling boss are arranged between the two guide columns. Each profiling boss comprises a first boss and a second boss. The shape of the cutting block corresponds to the gap hole between the two lower cutting knives. The height difference between the first boss and the second boss corresponds to the groove depth difference between the first groove and the second groove. A second forming step is arranged between the second boss and the cutting block, and the second forming step is a right-angle trapezoid. Each first forming step and each second forming step are arranged in mirror image symmetry. The application can form inverted trapezoidal flat copper wire at one time, and has the advantages of less process, short time consumption and high material utilization rate.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of flat wire motors, and specifically discloses a cutting die and device for forming an inverted trapezoidal flat copper wire. BACKGROUND

[0002] In the long run, miniaturization and high speed will be the main development trend of new energy vehicle motors, and miniaturization inevitably requires a substantial increase in motor power density. To achieve the increase in motor power density, adopting a "flat wire motor" technology has become a better choice in the motor industry in recent years.

[0003] A flat wire motor is a new type of motor. Compared with a traditional motor, under the same conditions, the flat wire motor has stronger magnetic field strength and power density, better thermal conductivity, and lower temperature rise, and is therefore widely used in new energy vehicle electric drive systems. However, the flat wire motor has a complex process, many processing procedures, and a manufacturing and processing difficulty much greater than that of a round wire, and has a relatively high cost. A traditional flat copper wire cutting device uses an X-shaped cutting tooling, the structure of which is shown in Chinese patents CN214720174U and CN112952140A. Although the tooling has a simple structure design, after the flat copper wire is cut by using the tooling, the end of the flat copper wire is sharp rather than flat, so that the flat copper wire cut by the tooling needs to be additionally cut after being installed on the flat wire motor before being welded, otherwise the flat copper wire cannot be well welded and conducted. At the same time, based on the cutting procedure of the flat copper wire, the flat shape is also completed, which causes additional scrap of the flat copper wire. As can be seen from the above, the forming method of the flat copper wire in the prior art includes two steps, i.e., first forming a flat copper wire with a sharp end based on the X-shaped cutting tooling shown in CN214720174U and CN112952140A, and then machining the flat copper wire with a sharp end into a flat copper wire with an inverted trapezoidal end. This scheme has the defects of many procedures, long time consumption, and low material utilization rate, and therefore urgently needs to develop a cutting die and device for one-time forming of an inverted trapezoidal flat copper wire. SUMMARY

[0004] In view of the technical problems in the prior art, the application provides a cutting die and device for forming an inverted trapezoidal flat copper wire, which can one-time form an inverted trapezoidal flat copper wire and has the advantages of few procedures, short time consumption, and high material utilization rate.

[0005] The application discloses a cutting die for forming an inverted trapezoidal flat copper wire, which comprises a lower die and an upper die. The lower die comprises a lower die seat, a through hole coaxially arranged on the lower die seat, and two lower cutting knives arranged in the through hole. The two lower cutting knives are arranged in mirror symmetry with respect to the central axis of the through hole. The projection shape of each lower cutting knife in the plane perpendicular to the central axis of the through hole comprises a rectangular part and an isosceles trapezoidal part. The two isosceles trapezoidal parts are arranged in opposite directions. A profiling groove for bearing the flat copper wire is arranged on the upper end surface of each lower cutting knife. The profiling groove comprises a first groove corresponding to the varnish section of the flat copper wire and a second groove corresponding to the unvarnished section of the flat copper wire. The front end of the second groove is provided with a first forming step for forming the end of the flat copper wire into an inverted trapezoidal shape. The projection shape of the first forming step in the plane perpendicular to the central axis of the through hole is an isosceles trapezoid. The projection shape of the first forming step on the center symmetry plane of the profiling groove is a right-angled trapezoid. The hypotenuse of the right-angled trapezoid forms an obtuse angle with the groove bottom of the second groove. The upper die comprises an upper die seat and two guide columns arranged on the upper die seat and matched with the through hole. The two guide columns are arranged in mirror symmetry with respect to the central axis of the through hole. A cutting block for switching the flat copper wire and a profiling boss corresponding to the two profiling grooves are arranged between the two guide columns. The two profiling bosses are arranged in mirror symmetry with respect to the cutting block. Each profiling boss comprises a first boss matched with the first groove and a second boss matched with the second groove. The shape of the cutting block corresponds to the gap hole between the two lower cutting knives. The height difference between the first boss and the second boss corresponds to the groove depth difference between the first groove and the second groove. A second forming step matched with the first forming step is arranged between the second boss and the cutting block. The projection shape of the second forming step on the center symmetry plane of the guide column is a right-angled trapezoid. The projection shape of the second forming step in the plane perpendicular to the central axis of the through hole is an isosceles trapezoid. Each first forming step and each second forming step are arranged in mirror symmetry. A through hole is formed on the upper end surface of the second boss. A pin and a spring are inserted into the through hole.

[0006] In a preferred embodiment of the application, the through hole is a stepped hole comprising a square hole section and a circular hole end. The cross-sectional area of the square hole section is smaller than that of the circular hole end. A pair of symmetrically arranged guide grooves are formed on the opposite inner walls of the square hole section and extend along the central axis of the through hole.

[0007] In a preferred embodiment of the present invention, the pin includes a square shaft segment and a circular shaft segment. The shape of the square shaft segment corresponds to the shape of the square hole segment, and the shape of the circular shaft segment corresponds to the shape of the circular hole end. A guide shaft is provided on the square shaft segment and arranged perpendicularly to its central axis. The shape and position of the guide shaft correspond to those of the guide groove.

[0008] In a preferred embodiment of the present invention, the upper mold base is further provided with an air inlet for blowing out residue from the lower cutter.

[0009] In a preferred embodiment of the present invention, the projection shape of the cutting block in a plane perpendicular to the central axis of the through hole includes a square portion and two isosceles trapezoidal portions. The two isosceles trapezoidal portions are arranged symmetrically with respect to the square portion. The short side of the isosceles trapezoidal portion is equal to the side length of the square portion, and the slope of the hypotenuse of the isosceles trapezoidal portion is equal to the slope of the hypotenuse of the isosceles trapezoidal portion of the lower cutter.

[0010] In a preferred embodiment of the present invention, inclined surfaces are provided on the two opposite end faces of the lower cutter to facilitate the discharge of residue, and the distance between the two inclined surfaces gradually increases from top to bottom.

[0011] In a preferred embodiment of the present invention, the end of the second groove is provided with a through notch extending in an axial direction perpendicular to its plane of symmetry, and the through notch communicates with the second groove.

[0012] In a preferred embodiment of the present invention, the difference between the groove depth of the first groove and the groove depth of the second groove is k·2+s·c, where k is the thickness of the enamel coating of the flat copper wire, s is the thickness of the flat copper wire, and c is the coefficient of thermal expansion of the flat copper wire.

[0013] In a preferred embodiment of the present invention, the initial flat copper wire is cubic in shape, and the cubic flat copper wire includes enamel segments and unenamel segments arranged at intervals.

[0014] The present invention also discloses a device for forming flat copper wire with inverted trapezoidal ends for motors, including a press and a cutting mold for forming inverted trapezoidal flat copper wire. The lower mold is provided on the fixed end of the press, and the upper mold is provided on the pressing head end of the press.

[0015] The application has the advantages that the application can form the inverted trapezoidal flat copper wire in one step, has the advantages of less process, short time consumption and high material utilization rate; the application is designed by the difference of groove depth between the first groove and the second groove, the difference of height between the first boss and the second boss, and the difference of height is designed to compensate the influence of the straightness caused by the difference of height (since the flat copper wire needs to be welded subsequently, the paint skin must be removed at the cutting position of the cutting knife, and the height difference exists between the place where the paint skin is removed and the place where the internal copper wire is exposed, which directly affects the straightness of the copper wire after cutting), so as to ensure the straightness of the copper wire after cutting; further, the first forming step and the second forming step are introduced, so that the inverted T-shaped end of the flat copper wire can be formed in one step, which is convenient for the flat copper wire to pass through the mold hole without being easily blocked, and the material loss of the flat copper wire is small, and the flat copper wire can be directly welded; further, the through hole is formed on the upper end face of the second boss, the pin and the spring are inserted in the through hole, and when the device is pressed to cut the flat copper wire, the two ends of the cut flat copper wire can be pressed tightly to effectively prevent the position deviation of the copper wire from causing the cutting position deviation when the flat copper wire is cut, so as to ensure the forming quality of the inverted trapezoidal end of the flat copper wire.

[0016] Further, the through hole of the application is a stepped hole, which includes a square hole section and a circular hole end, the square hole section is in communication with the upper end face of the second boss, the cross-sectional area of the square hole section is smaller than that of the circular hole end, a pair of symmetrically arranged guide grooves are formed on the opposite inner walls of the square hole section, the guide grooves are arranged along the central axis of the through hole, the pin includes a square shaft section and a circular shaft section, the shape of the square shaft section corresponds to that of the square hole section, the shape of the circular shaft section corresponds to that of the circular hole end, a guide shaft is arranged on the square shaft section and perpendicular to the central axis, and the guide shaft is arranged corresponding to the shape and position of the guide groove; this structure design not only facilitates installation, but also can ensure that the two ends of the cut flat copper wire can be pressed tightly when the device is pressed to cut the flat copper wire, so as to effectively prevent the position deviation of the copper wire from causing the cutting position deviation when the flat copper wire is cut, and ensure the forming quality of the inverted trapezoidal end of the flat copper wire.

[0017] Further, the upper die seat of the application is also provided with an air inlet hole for blowing away the residues in the lower cutting knife, which is more conducive to ensuring the clearance of the paint skin residues and copper wire residues in the profiled groove.

[0018] Further, the projection shape of the cutting block of the present application in the plane perpendicular to the central axis of the through hole comprises a square part and two isosceles trapezoidal parts, the two isosceles trapezoidal parts are symmetrically arranged relative to the square part, the length of the short side of the isosceles trapezoidal part is equal to the length of the side of the square part, and the slope of the hypotenuse of the isosceles trapezoidal part is equal to the slope of the hypotenuse of the isosceles trapezoidal part of the lower cutting knife, the structure design not only enables the cut flat copper wire to smoothly pass through the hole, but also enables the cut flat copper wire to present an inverted trapezoid, thereby enabling the flat copper wire to be directly welded;

[0019] Further, the two end faces of the lower cutting knife of the present application are provided with inclined surfaces for facilitating the discharge of residues, and the spacing between the two inclined surfaces gradually increases from top to bottom, which can facilitate the discharge of copper residues after cutting;

[0020] Further, the end of the second groove is provided with a through notch extending in the axial direction perpendicular to the symmetry plane of the second groove, and the through notch communicates with the second groove, which forms a residue discharge step, and the existence of the residue discharge step can be used for air blowing of the copper wire paint residue;

[0021] Further, the difference between the groove depth of the first groove and the groove depth of the second groove = k·2 + s·c, wherein k is the thickness of the paint of the flat copper wire, s is the thickness of the flat copper wire, and c is the thermal expansion coefficient of the flat copper wire, and the structure can ensure the straightness of the flat copper wire processing. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a lower die schematic view of a cutting die for forming an inverted trapezoidal flat copper wire of the present application;

[0023] Figure 2 is a profiled groove schematic view of a cutting die for forming an inverted trapezoidal flat copper wire of the present application;

[0024] Figure 3 is a first forming step schematic view of a cutting die for forming an inverted trapezoidal flat copper wire of the present application;

[0025] Figure 4 is a sectional view of a cutting die for forming an inverted trapezoidal flat copper wire of the present application;

[0026] Figure 5 is a lower die schematic view of a cutting die for forming an inverted trapezoidal flat copper wire of the present application;

[0027] Figure 6 is a top view of the upper die of the cutting die for forming an inverted trapezoidal flat copper wire of the present application;

[0028] Figure 7 is a lower die schematic view of a cutting die for forming an inverted trapezoidal flat copper wire of the present application;

[0029] Figure 8 is the upper die of the cutting die for forming inverted trapezoidal flat copper wire of the present application;

[0030] Figure 9 is the sectional view of the upper die of the cutting die for forming inverted trapezoidal flat copper wire of the present application;

[0031] Figure 10 is the second forming step of the cutting die for forming inverted trapezoidal flat copper wire of the present application;

[0032] Figure 11 is the pin of the cutting die for forming inverted trapezoidal flat copper wire of the present application;

[0033] Figure 12 is the pin of the cutting die for forming inverted trapezoidal flat copper wire of the present application;

[0034] Figure 13 is the cooperation of the upper die and the lower die of the cutting die for forming inverted trapezoidal flat copper wire of the present application;

[0035] Figure 14 is the cooperation sectional view of the upper die and the lower die of the cutting die for forming inverted trapezoidal flat copper wire of the present application;

[0036] Figure 15 is the flat copper wire formed by the cutting die for forming inverted trapezoidal flat copper wire of the present application;

[0037] In the figure: 1-lower die; 2-upper die; 3-through hole; 4-lower cutter; 5-profiling groove; 6-first forming step; 7-guide column; 8-profiling boss; 9-second forming step; 10-through hole; 11-pin; 12-guide groove; 13-air inlet hole; 14-through notch; 15-cutting block; 41-inclined surface; 51-first groove; 52-second groove; 81-first boss; 82-second boss; 111-square shaft section; 112-circular shaft section. DETAILED DESCRIPTION

[0038] The technical solutions of the present application (including the preferred technical solutions) will be described in further detail below by means of the accompanying drawings and by listing some optional embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0039] As Figures 1-14The application discloses a cutting die for forming an inverted trapezoidal flat copper wire, which comprises a lower die 1 and an upper die 2. The lower die 1 comprises a lower die seat, and a through hole 3 is coaxially arranged on the lower die seat. Two lower cutting knives 4 are arranged in the through hole 3. The two lower cutting knives 4 are mirror-symmetrically arranged relative to the central axis of the through hole 3. The projection shape of each lower cutting knife 4 in the plane perpendicular to the central axis of the through hole 3 comprises a rectangular part and an isosceles trapezoidal part. The two isosceles trapezoidal parts are oppositely spaced. A profiling groove 5 for bearing the flat copper wire is arranged on the upper end surface of each lower cutting knife 4. The profiling groove 5 comprises a first groove 51 corresponding to the lacquer segment of the flat copper wire and a second groove 52 corresponding to the un-lacquered segment of the flat copper wire. The front end of the second groove 52 is provided with a first forming step 6 for forming the end of the flat copper wire into an inverted trapezoidal shape. The projection shape of the first forming step 6 in the plane perpendicular to the central axis of the through hole 3 is an isosceles trapezoid. The projection shape of the first forming step 6 on the central symmetry plane of the profiling groove 5 is a right-angled trapezoid. The hypotenuse of the right-angled trapezoid forms an obtuse angle with the groove bottom of the second groove 52. The upper die 2 comprises an upper die seat. Two guide columns 7 are arranged on the upper die seat and are used for guiding the through hole 3. The two guide columns 7 are mirror-symmetrically arranged relative to the central axis of the through hole 3. A cutting block 15 for switching the flat copper wire and a profiling boss 8 corresponding to the two profiling grooves 5 are arranged between the two guide columns 7. The two profiling bosses 8 are mirror-symmetrically arranged relative to the cutting block 15. Each profiling boss 8 comprises a first boss 81 for cooperating with the first groove 51 and a second boss 82 for cooperating with the second groove 52. The shape of the cutting block 15 corresponds to the gap hole between the two lower cutting knives 4. The height difference between the first boss 81 and the second boss 82 corresponds to the groove depth difference between the first groove 51 and the second groove 52. A second forming step 9 for cooperating with the first forming step 6 is arranged between the second boss 82 and the cutting block 15. The projection shape of the second forming step 9 on the central symmetry plane of the guide column 7 is a right-angled trapezoid. The projection shape of the second forming step 9 in the plane perpendicular to the central axis of the through hole 3 is an isosceles trapezoid. Each first forming step 6 and each second forming step 9 are mirror-symmetrically arranged. A through hole 10 is formed on the upper end surface of the second boss 82. A pin 11 and an elastic piece are inserted into the through hole 10. The cooperation of the first forming step 6 and the second forming step 9 can make the end of the square flat copper wire present an inverted trapezoidal shape by extrusion. Assuming that the size of the flat copper wire is 1.55 mm*3.45 mm, and the size of the un-lacquered segment is 1.4 mm*3.3 mm, the size of the formed flat copper wire is about (1.1-1.2) mm*(3.0-3.1) mm. The inverted trapezoidal flat copper wire formed by the structural design of the first forming step 6 and the second forming step 9 can have the following two advantages: 1. The inverted trapezoidal flat copper wire can be more conveniently passed through the die hole and is not easy to be stuck; and 2. The material loss of the inverted trapezoidal flat copper wire is small, and the inverted trapezoidal flat copper wire can be directly welded.

[0040] Preferably, the presence of the pin 11 and the spring can stably hold the copper wire during the deformation of the flat copper wire (i.e. when the cutting die is pressed to punch, the two ends of the cut flat copper wire can be pressed to effectively prevent the position deviation of the copper wire from causing the cutting position deviation when the cutting block 15 punches the flat copper wire), ensuring that it does not shift, because there is always a gap between the flat copper wire and the profiling groove 5, so the pin 11 and the spring can cooperate with the upper die 2 to stably hold the flat copper wire, the pin 11 and the spring are assembled as follows: first, the pin is installed in the through hole 10, then the spring is installed, and finally the lower die 1 is fixed on the base of the press. When the die retracts, the spring naturally elongates and the pin extends out. When the die is pressed down, the pin presses the copper wire, and the pressing force is equal to the amount of compression of the spring. The size of the pressing force can be adjusted by freely replacing the spring.

[0041] Preferably, the through hole 10 is a stepped hole, which includes a square hole section and a circular hole end. The square hole section communicates with the upper end surface of the second boss 82, and the cross-sectional area of the square hole section is smaller than that of the circular hole end. A pair of symmetrically arranged guide grooves 12 are formed on the opposite inner walls of the square hole section.

[0042] Preferably, the pin 11 includes a square shaft section 111 and a circular shaft section 112. The shape of the square shaft section 111 corresponds to that of the square hole section, and the shape of the circular shaft section 112 corresponds to that of the circular hole end. A guide shaft is arranged on the square shaft section 111 and perpendicular to the central axis thereof, and the guide shaft is arranged corresponding to the shape and position of the guide groove 12.

[0043] Preferably, the upper die seat is further provided with an air inlet hole 13 for blowing off residues in the lower cutting knife 4. After the air inlet hole 13 is ventilated, it can blow off the paint residues and copper wire residues located in the groove of the lower die 1.

[0044] Preferably, the projection shape of the cutting block 15 in the plane perpendicular to the central axis of the through hole 3 includes a square part and two isosceles trapezoidal parts. The two isosceles trapezoidal parts are symmetrically arranged relative to the square part, the length of the short side of the isosceles trapezoidal part is equal to the length of the side of the square part, and the slope of the hypotenuse of the isosceles trapezoidal part is equal to the slope of the hypotenuse of the isosceles trapezoidal part of the lower cutting knife 4. It can be understood that the cutting block 15 as a whole is similar to an H type, which corresponds to the shape of the through hole 3 on the lower die 1.

[0045] Preferably, the two opposite end surfaces of the lower cutting knife 4 are provided with inclined surfaces 41 for facilitating the discharge of residues, and the distance between the two inclined surfaces 41 gradually increases from top to bottom.

[0046] Preferably, the end of the second groove 52 is provided with a through notch 14 extending in the axial direction perpendicular to the symmetry plane thereof, and the through notch 14 communicates with the second groove 52.

[0047] Preferably, the difference between the groove depth of the first groove 51 and the groove depth of the second groove 52 = k*2 + s*c, wherein k is the thickness of the paint of the flat copper wire, s is the thickness of the flat copper wire, and c is the thermal expansion coefficient of the flat copper wire. With this structure design, the height difference between the paint-removed section and the non-paint-removed section of the flat copper wire can be avoided, and the deformation of the copper wire caused by cutting can be avoided. Since the flat copper wire needs to be welded subsequently, the paint needs to be removed at the cutting position. After the paint is removed, there is a height difference between the place with paint and the place with exposed internal copper wire. This height difference directly affects the straightness of the copper wire after cutting. The cutting knife height difference needs to be designed to compensate for the influence of the height difference on the straightness.

[0048] Preferably, the initial flat copper wire is in a cubic shape, and the cubic flat copper wire includes paint sections and non-paint sections arranged at intervals.

[0049] The application further discloses a device for forming a flat copper wire with an inverted trapezoidal end head for a flat wire motor, which comprises a press and a cutting die for forming an inverted trapezoidal flat copper wire.

[0050] Those skilled in the art will easily understand that the above is only a preferred embodiment of the application, and does not limit the application. Any modification, combination, replacement, improvement, etc. made under the spirit and principle of the application is included in the protection scope of the application.

Claims

1. A cutting die for forming inverted trapezoidal flat copper wire, characterized in that: The device includes a lower mold (1) and an upper mold (2). The lower mold (1) includes a lower mold base, on which a through hole (3) is coaxially provided. Two lower cutters (4) are provided in the through hole (3). The two lower cutters (4) are arranged mirror-symmetrically with respect to the central axis of the through hole (3). The projection shape of each lower cutter (4) in a plane perpendicular to the central axis of the through hole (3) includes a rectangular part and an isosceles trapezoidal part. The two isosceles trapezoidal parts are arranged relatively alternately. A contoured groove (5) for carrying flat copper wire is provided on the upper end surface of each lower cutter (4). The contoured groove (5) includes a first groove (51) corresponding to the enamel section of the flat copper wire and a groove corresponding to the unenamel section of the flat copper wire. The corresponding second groove (52) has a first forming step (6) at its front end for forming the end of the flat copper wire into an inverted trapezoid. The projection shape of the first forming step (6) in the plane perpendicular to the central axis of the through hole (3) is an isosceles trapezoid. The projection shape of the first forming step (6) on the central symmetry plane of the contoured groove (5) is a right trapezoid. The hypotenuse of the right trapezoid forms an obtuse angle with the bottom of the second groove (52). The upper mold (2) includes an upper mold base. The upper mold base is provided with two guide posts (7) that cooperate with and guide the through hole (3). The two guide posts (7) are relative to the center of the through hole (3). The mandrel is arranged in a mirror-symmetrical manner. Between the two guide posts (7) is a cutting block (15) for switching flat copper wires and a contouring boss (8) arranged corresponding to the two contouring grooves (5). The two contouring bosses (8) are arranged in a mirror-symmetrical manner with respect to the cutting block (15). Each contouring boss (8) includes a first boss (81) for engaging with the first groove (51) and a second boss (82) for engaging with the second groove (52). The shape of the cutting block (15) corresponds to the shape of the gap hole between the two lower cutters (4). The height difference between the first boss (81) and the second boss (82) corresponds to the height difference between the first groove (51) and the second groove (52). The groove depth difference between the second grooves (52) corresponds to the groove depth difference between the second boss (82) and the cutting block (15). A second forming step (9) is provided between the second boss (82) and the cutting block (15) for cooperating with the first forming step (6). The projection shape of the second forming step (9) on the central symmetry plane of the guide post (7) is a right trapezoid. The projection shape of the second forming step (9) in the plane perpendicular to the central axis of the through hole (3) is an isosceles trapezoid. Each first forming step (6) and each second forming step (9) are arranged in a mirror symmetric manner. A through hole (10) is machined on the upper end surface of the second boss (82). A pin (11) and a spring are inserted into the through hole (10).

2. The cutting die for forming inverted trapezoidal flat copper wire according to claim 1, characterized in that: The through hole (10) is a stepped hole, which includes a square hole segment and a circular hole end. The square hole segment is connected to the upper end face of the second boss (82). The cross-sectional area of ​​the square hole segment is less than the cross-sectional area of ​​the circular hole end. The inner walls of the square hole segment are machined with only a pair of symmetrically arranged guide grooves (12). The guide grooves (12) extend along the central axis of the through hole (3).

3. The cutting die for forming inverted trapezoidal flat copper wire according to claim 2, characterized in that: The pin (11) includes a square shaft segment (111) and a circular shaft segment (112). The shape of the square shaft segment (111) corresponds to the shape of the square hole segment, and the shape of the circular shaft segment (112) corresponds to the shape of the circular hole end. A guide shaft is provided on the square shaft segment (111) and is arranged perpendicular to its central axis. The shape and position of the guide shaft correspond to those of the guide groove (12).

4. The cutting die for forming inverted trapezoidal flat copper wire according to claim 1, characterized in that: The upper mold base is also provided with an air inlet (13) for blowing out residue from the lower cutter (4).

5. The cutting die for forming inverted trapezoidal flat copper wire according to claim 1, characterized in that: The projection shape of the cutting block (15) in a plane perpendicular to the central axis of the through hole (3) includes a square part and two isosceles trapezoidal parts. The two isosceles trapezoidal parts are arranged symmetrically with respect to the square part. The short side of the isosceles trapezoidal part is equal to the side length of the square part, and the slope of the hypotenuse of the isosceles trapezoidal part is equal to the slope of the hypotenuse of the isosceles trapezoidal part of the lower cutter (4).

6. The cutting die for forming inverted trapezoidal flat copper wire according to claim 1, characterized in that: The two opposite end faces of the lower cutter (4) are provided with inclined surfaces (41) to facilitate the discharge of residue, and the distance between the two inclined surfaces (41) gradually increases from top to bottom.

7. The cutting die for forming inverted trapezoidal flat copper wire according to claim 1, characterized in that: The end of the second groove (52) is provided with a through notch (14) extending in an axial direction perpendicular to its plane of symmetry, and the through notch (14) communicates with the second groove (52).

8. The cutting die for forming inverted trapezoidal flat copper wire according to claim 1, characterized in that: The difference between the groove depth of the first groove (51) and the groove depth of the second groove (52) is k·2+s·c, where k is the thickness of the coating of the flat copper wire, s is the thickness of the flat copper wire, and c is the coefficient of thermal expansion of the flat copper wire.

9. The cutting die for forming inverted trapezoidal flat copper wire according to claim 1, characterized in that: The initial flat copper wire is cubic in shape, and the cubic flat copper wire includes enamel-coated segments and unenamel-coated segments arranged at intervals.

10. A device for forming flat wire motors with flat copper wire having inverted trapezoidal ends, characterized in that: The device includes a press and a cutting die for forming inverted trapezoidal flat copper wire as described in any one of claims 1-9, wherein the lower die (1) is provided on the fixed end of the press and the upper die (2) is provided on the pressing head end of the press.

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