Enameled flat wire painting mold and painting method

Abstract

The present invention relates to an enameled flat wire painting mold and a painting method, wherein the mold comprises a hollow mold sleeve and a hollow mold core detachably mounted on the front end of the mold sleeve; the inner diameter of the mold sleeve is larger than the size of the flat wire; the flat wire passes through the mold sleeve and the mold core from the rear end of the mold sleeve forward; the mold sleeve is filled with paint liquid; the inner diameter of the mold core gradually decreases along the direction of the flat wire passing through to the end opening which is slightly larger than the size of the flat wire, and the shape of the end opening of the mold core is the same as the shape of the flat wire; the present invention uses mold painting to replace the simple felt painting method, thereby avoiding the hair on the felt adhering to the conductor and improving the surface quality of the enameled wire; the painting mold can be repeatedly used and has a long service life; the enameled flat wire produced has stable size and uniform paint film, and is particularly suitable for mass production.

Description

Technical Field

[0001] The invention relates to the field of enameled wire production, and in particular to an enameled flat wire painting die and a painting method. Background Art

[0002] Flat enameled wire refers to a wire obtained by drawing, extruding or rolling oxygen-free copper rods or round copper wires through dies of certain specifications, and then coating them with insulating varnish multiple times to form a winding wire.

[0003] Existing flat wire enameled wire coating generally adopts the method of felt coating. The hair on the felt easily adheres to the conductor, resulting in poor surface quality of the enameled wire and a short service life, requiring frequent replacement of the felt.

[0004] In addition, the flat wire needs to be dried after being coated with insulating paint, and it shrinks after drying. When coating, due to the surface tension of the liquid, the insulating paint will automatically flow to the four R corners, which can easily cause the paint film to be "bone-shaped" or "dog-bone-shaped". At the same time, it will cause the coating film in the central part of the long side of the flat wire to become thinner, and cracks will appear when the enameled flat wire is bent, causing the electrical performance and adhesion of the product to fail to meet the standard requirements. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides an enameled flat wire painting mold and painting method, which uses mold painting instead of the simple felt painting method, avoiding the hair on the felt adhering to the conductor, improving the surface quality of the enameled wire, and the painting mold can be used repeatedly and has a long service life. The enameled flat wire produced has stable size and uniform paint film, which is particularly suitable for mass production.

[0006] The technical solutions of the present invention are as follows:

[0007] A painting mold for an enameled flat wire comprises a hollow mold sleeve and a hollow mold core detachably mounted on the front end of the mold sleeve; the inner diameter of the mold sleeve is larger than the size of the flat wire; the flat wire passes through the mold sleeve and the mold core from the rear end of the mold sleeve; the mold sleeve is filled with paint liquid; the inner diameter of the mold core gradually decreases along the direction of the flat wire's passage to a point where the end opening is slightly larger than the size of the flat wire, and the shape of the end opening of the mold core is the same as that of the flat wire.

[0008] Wherein, the outer surface of the mold sleeve is provided with a groove for installation on the machine platform.

[0009] Among them, a thermistor ring is provided on the outer sleeve of the opening at the end of the mold core; a heat-conducting ring is provided on the outer sleeve of the thermistor ring; a plurality of semiconductor cooling plates are connected between the thermistor ring and the heat-conducting ring; the semiconductor cooling plates force heat energy to be transferred between the thermistor ring and the heat-conducting ring.

[0010] wherein, an air guide ring is provided on the outer end surface of the thermal sensitive ring; the inner ring surface of the air guide ring has an arc surface that is smoothly convex toward one side of the flat wire along the axis direction of the flat wire, and the inner diameter gradually decreases from the end away from the opening of the core end to the end close to the opening of the core end; the inner ring surface of the thermal sensitive ring also has an arc surface that is smoothly convex toward one side of the flat wire along the axis direction of the flat wire, and the inner diameter gradually decreases from the end away from the opening of the core end to the end close to the opening of the core end; an obtuse angle is formed at the junction of the inner ring of the thermal sensitive ring and the inner ring of the heat conductive ring; an annular first air outlet slit is attached to the outer end of the air guide ring along its circumference; the first air outlet slit is connected to an annular first air guide cavity; one or more first air inlet pipes pressurize the air into the first air guide cavity; a magatama-shaped uniform air block is provided along the circumference of the first air guide cavity; the uniform air block divides the first air guide cavity into an air pressurization cavity and an air acceleration cavity; the first air outlet slit is connected to the outlet end of the air acceleration cavity.

[0011] Among them, a blowing device is respectively provided outside the air guide ring and outside the two short sides of the flat wire; the blowing device includes a flat ring-shaped second air outlet slit extending as a whole along the length direction of the flat wire; the second air outlet slit is connected to a ring-shaped second air guide cavity; one or more second air inlet pipes pressurize the air into the second air guide cavity; the second air outlet slit blows out a wind film with a flat and long ring-shaped cross-section toward the flat wire, and drives the air behind the second air outlet slit to pass through the space enclosed by the second air outlet slit and blow out toward the flat wire, forming a continuous surface wind pressure.

[0012] The air entering the second air guide cavity is heated; and a heating wire mesh is provided behind the second air outlet slit to heat the air being blown out.

[0013] Wherein, the corresponding blowing devices outside the two long sides of the flat wire are respectively provided with wind guide covers which gradually change from wide opening to narrow opening; the wind guide covers guide the airflow after the collision of the two blowing devices to flow outwards.

[0014] The mold sleeve includes a paint coating part at the front and a paint feeding part at the rear, and an inner sleeve is provided inside the paint feeding part; the front end of the inner sleeve is reduced in diameter and is in close contact with the surface of the flat wire; the inner sleeve and the mold sleeve enclose a paint feeding cavity; the sealing sliding sleeve in the paint feeding cavity is provided with an annular paint feeding piston; the paint feeding piston includes a shovel body ring forming an outer ring, a retreat ring close to the inner ring and a rear seat ring at the rear; the forward extension length of the shovel body ring gradually decreases from the outer ring to the inner ring to form a shovel head shape; the outer peripheral surface of the shovel body ring is sealed and slidably with the inner wall of the mold sleeve abutment; the outer circumference of the retreat ring and the inner circumference of the shovel body ring are sealed and slidably abutted; the inner circumference of the retreat ring and the outer circumference of the inner sleeve are sealed and slidably abutted; a spring is provided between the retreat ring and the rear seat ring; the shovel body ring and the rear seat ring are fixedly connected or integrally formed; a plurality of linear drive rods are connected to the rear seat ring, driving the paint feed piston to reciprocate back and forth along the paint feed chamber; one or more paint feed ports are provided on the mold sleeve to squeeze paint into the paint feed chamber; the reciprocating motion of the paint feed piston periodically closes and opens the paint feed port.

[0015] A flat wire enameling method, using the enameled flat wire painting mold, comprises the following steps:

[0016] ① The flat wire passes through the inner sleeve, the front part of the mold sleeve, the mold core, the heat-sensitive ring and the air guide ring in sequence; the mold sleeve paint coating part and the paint inlet cavity are filled with paint liquid; the paint liquid evenly adheres to the surface of the flat wire in the paint coating part to form a paint film;

[0017] ② During the painting process, the heat and temperature of the thermosensitive ring are controlled by the semiconductor refrigeration sheet, causing the thermosensitive ring to expand and contract, thereby accurately controlling the inner diameter of the thermosensitive ring and thus controlling the thickness of the paint film;

[0018] ③ During the painting process, an annular airflow is blown out from the first air outlet slit. Under the Coanda effect, the annular airflow flows along the convex surface of the inner ring of the air guide ring and expands outward due to the obtuse recoil at the junction with the heat transfer ring, thus forming a pushing wind pressure. On the one hand, it shapes the paint film, and on the other hand, it reduces the paint liquid from squeezing out of the gap.

[0019] ④ During the painting process, the second air outlet slit squeezes out a heated annular air film and drives the air heated by the heated screen at the rear to pass through the space enclosed by the second air outlet slit and move forward, thereby forming wind pressure on the two short sides of the flat wire and pushing excess paint liquid to flow toward the long side, thus preventing paint liquid from accumulating at the corners of the flat wire and causing the paint film to become "bone-shaped", and also preventing the paint film from becoming thinner in the central part of the long side of the flat wire;

[0020] ⑤ During the painting process, the linear drive rod pushes the paint feed piston forward in the paint feed chamber, and the shovel ring moves forward and seals the paint feed port. During this process, the retreat ring squeezes the spring backward to make room to make up for the space occupied by the shovel ring during its forward movement, thereby preventing the paint liquid from being squeezed back to the paint feed port before the shovel ring closes the paint feed port; at the same time, it also reduces excessive pressurization of the paint liquid in the mold sleeve and the paint feed chamber, causing excessive paint pressure; when the paint feed piston advances to its limit, it retreats and returns, exposing the paint feed port again to replenish the paint liquid; at the same time, a certain negative pressure is generated in the paint feed chamber, which causes the paint liquid squeezed into the gap between the mold core and the flat wire to shrink, thereby avoiding deposition and solidification there.

[0021] The present invention has the following beneficial effects:

[0022] 1. The present invention uses mold painting to replace the simple felt painting method, which avoids the hair on the felt adhering to the conductor and improves the surface quality of the enameled wire. The painting mold can be used repeatedly and has a long service life. The enameled flat wire produced has stable size and uniform paint film, which is particularly suitable for mass production.

[0023] 2. The present invention is provided with a thermistor ring, which, in combination with a heat-conducting ring and a semiconductor refrigeration sheet, can quickly and accurately adjust and control the temperature of the thermistor ring, thereby utilizing the thermal expansion and contraction of the thermistor ring to control the inner diameter of the thermistor ring, thereby controlling the gap between the thermistor ring and the flat wire surface, thereby controlling and adjusting the thickness of the paint film, improving the uniformity and dimensional stability of the paint film, and reducing the occurrence of the paint liquid being squeezed out of the gap; in addition, the inner ring surface of the thermistor ring is a special inclined surface, combined with the design of the air guide ring and the first air outlet slit, utilizing the Coanda effect, so that the annular wind film blown out from the first air outlet slit adheres to the inclined surface of the inner ring of the air guide ring and flows, and impacts the obtuse angle at the junction with the thermistor ring and quickly diffuses outward, thereby forming a pushing wind pressure, which on the one hand shapes the paint film, and on the other hand reduces the occurrence of the paint liquid being squeezed out of the gap.

[0024] 3. The present invention is provided with second air outlet slits on the outside of the short sides of the flat wire. The second air outlet slits extrude the heated annular air film outward, and drive the air heated by the heated wire mesh at the rear to pass through the space enclosed by the second air outlet slits forward, thereby forming wind pressure on the two short sides of the flat wire, pushing excess paint liquid to flow toward the long side, avoiding the accumulation of paint liquid at the corners of the flat wire to cause the paint film to be "bone-shaped", and also avoiding the paint film in the central part of the long side of the flat wire from becoming thinner; since the wind speed and pressure of the annular air film are greater than those of the fluid injected in the middle, the isobaric line drawn according to the pressure is just an inward concave arc, which coincides with the arc surface of the short side of the flat wire. Therefore, the wind pressure formed on the short side of the flat wire by the second air outlet slit can evenly act on the arc surface of the short side of the flat wire, thereby further improving the uniformity of the flat wire paint film; and since the design can blow out uniform hot air, and the hot air temperature can be simply and controllable, the drying process or the preliminary drying and shaping process can be completed at the same time, thereby simplifying the subsequent processing steps or providing effective pre-guarantee for subsequent processing.

[0025] 4. The present invention uses an inner sleeve to separate the internal space of the mold sleeve into a paint coating section and a paint feeding section, and uses a specially designed paint feeding piston to realize the cyclic opening and closing of the paint feeding port. Since the air feeding piston is designed with a shovel ring, a retreat ring, a rear seat ring and a spring, the retreat ring can squeeze the spring backward to make room during the forward movement, thereby making up for the space occupied by the shovel ring during the forward movement, thereby avoiding the paint liquid being squeezed to flow back to the paint feeding port before the shovel ring closes the paint feeding port; at the same time, it also reduces the excessive pressurization of the paint liquid in the mold sleeve and the paint feeding chamber, which causes the paint liquid pressure to be too high; when the paint feeding piston advances to the limit, It moves backward to expose the paint inlet again for replenishing the paint liquid; at the same time, a certain negative pressure is generated in the paint inlet chamber, which causes the paint liquid squeezed into the gap between the mold core and the flat wire to shrink, avoiding deposition and solidification there; and in the process of cyclic reciprocating motion, it can not only effectively replenish the paint liquid consumed by gluing, but also promote the flow of the paint liquid, increase the friction movement between the paint liquid and the surface of the flat wire, thereby helping the paint liquid to adhere firmly to the surface of the flat wire; at the same time, it ensures the uniformity of the paint liquid material, avoids dead corner deposition, solidified fragments and impurities, etc., and helps to improve the uniformity, fixation and stability of the paint film. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic structural diagram of a flat wire painting die according to the first embodiment of the present invention;

[0027] Figure 2 This is a schematic structural diagram of a flat wire painting die according to a second embodiment of the present invention;

[0028] Figure 3 For the present invention Figure 2 A magnified view of the position of the middle circle A;

[0029] Figure 4 For the present invention Figure 2 Enlarged view of the position of the middle circle B;

[0030] Figure 5 This is a schematic diagram of the working of the blowing device in the second embodiment of the present invention.

[0031] The reference numerals in the figures are as follows:

[0032] 1. Mold sleeve; 2. Mold core; 3. Flat wire; 4. Paint liquid; 51. Thermosensitive ring; 52. Heat-conducting ring; 53. Semiconductor refrigeration plate; 54. Air guide ring; 55. First air outlet slit; 56. First air guide cavity; 57. Air uniform block; 61. Second air outlet slit; 62. Second air guide cavity; 63. Heating screen; 64. Air guide cover; 7. Inner sleeve; 71. Paint inlet cavity; 72. Paint inlet piston; 73. Shovel body ring; 74. Retreat ring; 75. Recoil ring; 76. Spring; 77. Linear drive rod; 78. Paint inlet. DETAILED DESCRIPTION

[0033] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Example 1:

[0035] See also Figure 1 A coating mold for enameled flat wires comprises a hollow mold sleeve 1 and a hollow mold core 2 detachably mounted on the front end of the mold sleeve 1; the inner diameter of the mold sleeve 1 is larger than the size of the flat wire 3; the flat wire 3 passes through the mold sleeve 1 and the mold core 2 from the rear end of the mold sleeve 1; the mold sleeve 1 is filled with paint liquid 4; the inner diameter of the mold core 2 gradually decreases along the direction of the flat wire 3 to a point where the end opening is slightly larger than the size of the flat wire 3, and the shape of the end opening of the mold core 2 is the same as that of the flat wire 3.

[0036] Furthermore, the outer surface of the mold sleeve 1 is provided with a groove for installation on a machine platform.

[0037] Example 2:

[0038] See also Figures 2 to 5 On the basis of Example 1, further, a thermistor ring 51 is provided on the outer sleeve of the end opening of the mold core 2; a heat-conducting ring 52 is provided on the outer sleeve of the thermistor ring 51; a plurality of semiconductor cooling plates 53 are connected between the thermistor ring 51 and the heat-conducting ring 52; the semiconductor cooling plates 53 force heat energy to be transferred between the thermistor ring 51 and the heat-conducting ring 52.

[0039] Furthermore, an air guide ring 54 is provided on the outer end surface of the thermal ring 51; the inner ring surface of the air guide ring 54 has a smooth convex arc surface toward the side of the flat wire 3 along the axial direction of the flat wire 3, and the inner diameter gradually decreases from the end away from the end opening of the core 2 to the end close to the end opening of the core 2; the inner ring surface of the thermal ring 51 also has a smooth convex arc surface toward the side of the flat wire 3 along the axial direction of the flat wire 3, and the inner diameter gradually decreases from the end away from the end opening of the core 2 to the end close to the end opening of the core 2; the inner ring of the thermal ring 51 An obtuse angle is formed at the junction with the inner ring of the heat-conducting ring 54; an annular first air outlet slit 55 is attached to the outer end of the air guide ring 54 along its circumference; the first air outlet slit 55 is connected to an annular first air guide cavity 56; one or more first air inlet pipes pressurize and feed air into the first air guide cavity 56; a magatama-shaped uniform air block 57 is provided along the circumference of the first air guide cavity 56; the uniform air block 57 separates the first air guide cavity 56 into an air compression cavity and an air acceleration cavity; the first air outlet slit 55 is connected to the outlet end of the air acceleration cavity.

[0040] Furthermore, a blowing device is respectively provided outside the air guide ring 54 and outside the two short sides of the flat wire 3; the blowing device includes a flat ring-shaped second air outlet slit 61 extending as a whole along the length direction of the flat wire 3; the second air outlet slit 61 is connected to a ring-shaped second air guide cavity 62; one or more second air inlet pipes pressurize and introduce air into the second air guide cavity 62; the second air outlet slit 61 blows out a wind film with a flat and long ring-shaped cross-section toward the flat wire 3, and drives the air behind the second air outlet slit 61 to pass through the space enclosed by the second air outlet slit 61 and blow out toward the flat wire 3, forming a continuous surface wind pressure.

[0041] Furthermore, the air entering the second air guide cavity 62 is heated; a heating screen 63 is provided behind the second air outlet slit 61 to heat the air being blown out.

[0042] Furthermore, wind guide covers 64 with a gradual change from wide opening to narrow opening are respectively provided outside the two long sides of the flat wire 3 corresponding to the blowing devices; the wind guide covers 64 guide the airflow after the collision of the two blowing devices to flow outwards.

[0043] Furthermore, the mold sleeve 1 includes a paint coating portion at the front and a paint feeding portion at the rear, and an inner sleeve 7 is provided inside the paint feeding portion; the front end of the inner sleeve 7 is shrunken and closely contacts the surface of the flat wire 3; the inner sleeve 7 and the mold sleeve 1 enclose a paint feeding cavity 71; a ring-shaped paint feeding piston 72 is provided in the paint feeding cavity 71; the paint feeding piston 72 includes a shovel body ring 73 forming an outer ring, a retreat ring 74 close to the inner ring, and a rear seat ring 75 at the rear; the forward extension length of the shovel body ring 73 gradually decreases from the outer ring to the inner ring to form a shovel head shape; the outer peripheral surface of the shovel body ring 73 is sealed and slidably abutted against the inner wall of the mold sleeve 1; The outer circumference of the retreat ring 74 is sealed and slidably abutted against the inner circumference of the shovel body ring 73; the inner circumference of the retreat ring 74 is sealed and slidably abutted against the outer circumference of the inner sleeve 7; a spring 76 is provided between the retreat ring 74 and the rear seat ring 75; the shovel body ring 73 and the rear seat ring 75 are fixedly connected or integrally formed; a plurality of linear drive rods 77 are connected to the rear seat ring 75 to drive the paint feeding piston 72 to reciprocate back and forth along the paint feeding chamber 71; one or more paint feeding ports 78 are provided on the mold sleeve 1 to squeeze paint into the paint feeding chamber 71; the reciprocating motion of the paint feeding piston 72 periodically closes and opens the paint feeding port 78.

[0044] A flat wire enameling method, using the enameled flat wire painting mold, comprises the following steps:

[0045] ① The flat wire 3 passes through the inner sleeve 7, the front part of the mold sleeve 1, the mold core 2, the heat-sensitive ring 51, and the air guide ring 54 in sequence; the paint coating part of the mold sleeve 1 and the paint inlet cavity 71 are filled with paint liquid 4; the paint liquid 4 is evenly attached to the surface of the flat wire 3 in the paint coating part to form a paint film;

[0046] ② During the painting process, the heat and temperature of the thermosensitive ring 51 are controlled by the semiconductor cooling sheet 53, causing the thermosensitive ring 51 to expand and contract, thereby accurately controlling the inner diameter of the thermosensitive ring 51 and thus controlling the thickness of the paint film;

[0047] ③ During the painting process, an annular airflow is blown out from the first air outlet slit 55. Under the Coanda effect, the annular airflow adheres to the convex surface of the inner ring of the air guide ring 54 and expands outward due to the obtuse recoil at the junction with the heat conductive ring 52, thereby generating a pushing wind pressure. On the one hand, it shapes the paint film, and on the other hand, it reduces the paint liquid 4 from squeezing out of the gap.

[0048] ④ During the painting process, the second air outlet slits 61 squeeze out a heated annular air film, and drive the air heated by the heated screen 63 at the rear to pass through the space enclosed by the second air outlet slits 61 and move forward, thereby forming wind pressure on the two short sides of the flat wire 3, pushing the excess paint liquid 4 to flow toward the long sides, preventing the paint liquid 4 from accumulating at the corners of the flat wire 3 and causing the paint film to become "bone-shaped", and also preventing the paint film from becoming thinner in the central part of the long side of the flat wire 3;

[0049] ⑤ During the painting process, the linear drive rod 77 pushes the paint feed piston 72 forward in the paint feed chamber 71, and the shovel ring 73 moves forward and seals the paint feed port 78. During this process, the retreat ring 74 squeezes the spring 76 backward to make room to make up for the space occupied by the shovel ring 73 during its forward movement, thereby preventing the paint liquid 4 from being squeezed back to the paint feed port 78 before the shovel ring 73 closes the paint feed port 78; at the same time, it also reduces the excessive pressurization of the paint liquid 4 in the mold sleeve 1 and the paint feed chamber 71, causing the paint liquid 4 to have excessive pressure; when the paint feed piston 72 advances to its limit, it retreats and returns, exposing the paint feed port 78 to replenish the paint liquid 4; at the same time, a certain negative pressure is generated in the paint feed chamber 71, which causes the paint liquid 4 squeezed into the gap between the mold core 2 and the flat wire 3 to shrink, thereby avoiding deposition and solidification there.

[0050] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention's description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An enameled flat wire painting die, characterized by: The invention comprises a hollow mold sleeve (1) and a hollow mold core (2) detachably mounted on the front end of the mold sleeve (1); the inner diameter of the mold sleeve (1) is larger than the size of the flat wire (3); the flat wire (3) passes through the mold sleeve (1) and the mold core (2) from the rear end of the mold sleeve (1); the mold sleeve (1) is filled with paint liquid (4); the inner diameter of the mold core (2) gradually decreases along the direction in which the flat wire (3) passes until the end opening is slightly larger than the size of the flat wire (3), and the shape of the end opening of the mold core (2) is the same as that of the flat wire (3); The end opening of the core (2) is covered with a thermosensitive ring (51); the outer spacing of the thermosensitive ring (51) is covered with a heat-conducting ring (52); a plurality of semiconductor cooling fins (53) are connected between the thermosensitive ring (51) and the heat-conducting ring (52); the semiconductor cooling fins (53) force heat energy to be transferred between the thermosensitive ring (51) and the heat-conducting ring (52); an air guide ring (54) is provided on the outer end surface of the thermosensitive ring (51); the inner ring surface of the air guide ring (54) has a smooth convex arc surface toward one side of the flat wire (3) along the axis direction of the flat wire (3), and the inner diameter gradually decreases from the end away from the end opening of the core (2) to the end close to the end opening of the core (2); the inner ring surface of the thermosensitive ring (51) also has a smooth convex arc surface toward the flat wire (3) along the axis direction of the flat wire (3) 3) a smooth convex arc surface on one side, and the inner diameter gradually decreases from the end away from the end opening of the mold core (2) to the end close to the end opening of the mold core (2); an obtuse angle is formed at the junction of the inner ring of the thermal ring (51) and the inner ring of the air guide ring (54); an annular first air outlet slit (55) is attached to the outer end of the air guide ring (54) along its circumference; the first air outlet slit (55) is connected to an annular first air guide cavity (56); one or more first air inlet pipes pressurize and feed air into the first air guide cavity (56); a jade-shaped uniform air block (57) is provided along the circumference of the first air guide cavity (56); the uniform air block (57) separates the first air guide cavity (56) into an air pressurization cavity and an air acceleration cavity; the first air outlet slit (55) is connected to the outlet end of the air acceleration cavity; A blowing device is respectively provided outside the air guide ring (54) and outside the two short sides of the flat wire (3); the blowing device comprises a flat annular second air outlet slit (61) extending along the length direction of the flat wire (3); the second air outlet slit (61) is connected to a second annular air guide cavity (62); one or more second air inlet pipes pressurize and introduce air into the second air guide cavity (62); the second air outlet slit (61) blows out a wind film with a flat and long annular cross section in the direction of the flat wire (3), and drives the air behind the second air outlet slit (61) to pass through the space enclosed by the second air outlet slit (61) and blow out in the direction of the flat wire (3), thereby forming a continuous planar wind pressure; The air entering the second air guide cavity (62) is heated; a heating screen (63) is provided behind the second air outlet slit (61) to heat the air blown out; The mold sleeve (1) includes a paint coating part at the front and a paint feeding part at the rear, and an inner sleeve (7) is provided inside the paint feeding part; the front end of the inner sleeve (7) is shrunken to be in close contact with the surface of the flat wire (3); the inner sleeve (7) and the mold sleeve (1) enclose a paint feeding cavity (71); the sealing sliding sleeve in the paint feeding cavity (71) is provided with an annular paint feeding piston (72); the paint feeding piston (72) includes a shovel body ring (73) forming an outer ring, a retreat ring (74) close to the inner ring and a rear seat ring (75) at the rear; the forward extension length of the shovel body ring (73) gradually decreases from the outer ring to the inner ring to form a shovel head shape; the outer peripheral surface of the shovel body ring (73) is sealed and slidably abutted against the inner wall of the mold sleeve (1); the retreat ring The outer peripheral surface of the (74) seals and slides against the inner peripheral surface of the shovel body ring (73); the inner peripheral surface of the retreat ring (74) seals and slides against the outer peripheral surface of the inner sleeve (7); a spring (76) is provided between the retreat ring (74) and the rear seat ring (75); the shovel body ring (73) and the rear seat ring (75) are fixedly connected or integrally formed; a plurality of linear drive rods (77) are connected to the rear seat ring (75) to drive the paint feeding piston (72) to reciprocate along the paint feeding chamber (71); one or more paint feeding ports (78) are provided on the mold sleeve (1) to squeeze paint into the paint feeding chamber (71); the reciprocating motion of the paint feeding piston (72) periodically closes and opens the paint feeding port (78).

2. The enameled flat wire coating die according to claim 1, characterized in that: The outer surface of the mold sleeve (1) is provided with a groove for mounting on a machine platform.

3. The enameled flat wire coating die according to claim 1, characterized in that: The corresponding blowing devices on the two long sides of the flat wire (3) are also provided with wind guide covers (64) with a gradual change from a wide opening to a narrow opening; the wind guide covers (64) guide the airflow after the two blowing devices collide to flow outwards.

4. A method for enameling a flat wire, using the enameled flat wire coating die according to any one of claims 1 to 3, comprising the following steps: ① The flat wire (3) passes through the inner sleeve (7), the front of the mold sleeve (1), the mold core (2), the heat-sensitive ring (51) and the air guide ring (54) in sequence; the paint coating portion of the mold sleeve (1) and the paint inlet cavity (71) are filled with paint liquid (4); the paint liquid (4) is evenly attached to the surface of the flat wire (3) in the paint coating portion to form a paint film; ② During the painting process, the heat and temperature of the thermosensitive ring (51) are controlled by the semiconductor cooling plate (53), so as to cause the thermosensitive ring (51) to expand and contract, thereby accurately controlling the inner diameter of the thermosensitive ring (51) and thus controlling the thickness of the paint film; ③ During the painting process, the first air outlet slit (55) blows out an annular airflow. Under the Coanda effect, the annular airflow flows along the inner convex surface of the air guide ring (54) and expands outwards due to the blunt-angle recoil at the junction with the heat conducting ring (52), thereby forming a pushing wind pressure, which on the one hand shapes the paint film and on the other hand reduces the situation of the paint liquid (4) being squeezed out from the gap; ④ During the painting process, the second air outlet slit (61) squeezes out the heated annular air film and drives the air heated by the heated screen (63) at the rear to pass through the space enclosed by the second air outlet slit (61) and move forward, thereby forming wind pressure on the two short sides of the flat wire (3) and pushing the excess paint liquid (4) to flow toward the long side, thus preventing the paint liquid (4) from accumulating at the corners of the flat wire (3) to form a "bone-shaped" paint film and also preventing the paint film in the central part of the long side of the flat wire (3) from becoming thinner; ⑤ During the painting process, the linear drive rod (77) pushes the paint feeding piston (72) forward in the paint feeding chamber (71), and the shovel body ring (73) moves forward and seals the paint feeding port (78). During this process, the retreat ring (74) presses the spring (76) backward to make room to make up for the space occupied by the shovel body ring (73) during the forward movement, thereby preventing the paint liquid (4) from being squeezed into the paint feeding port (78) before the shovel body ring (73) closes the paint feeding port (78). ) at the backflow point; at the same time, it also reduces the excessive pressurization of the paint liquid (4) in the mold sleeve (1) and the paint inlet chamber (71) causing the paint liquid (4) to be over-pressurized; when the paint inlet piston (72) advances to the limit and then retreats, the paint inlet port (78) is exposed again to replenish the paint liquid (4); at the same time, a certain negative pressure is generated in the paint inlet chamber (71), and the negative pressure causes the paint liquid (4) squeezed into the gap between the mold core (2) and the flat wire (3) to shrink, thereby avoiding deposition and solidification there.

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