Heating wire cold-drawing die and adjusting method thereof

Abstract

The invention discloses a heating wire cold-drawing die and an adjusting method thereof.The heating wire cold-drawing die comprises a main die body, a first fixing ring and a third fixing ring, the first fixing ring and the third fixing ring are coaxially arranged, the main die body penetrates through the first fixing ring, the third fixing ring is located on the left side of the main die body and the left side of the first fixing ring, and the first fixing ring is provided with a plurality of second pressing blocks; the second pressing blocks abut against the outer wall of the main mold body, the positions of the second pressing blocks can be adjusted in the radial direction of the main mold body, the multiple second pressing blocks are evenly distributed in the circumferential direction of the main mold body, multiple cameras are evenly distributed and installed on the inner circumferential wall of the third fixing ring, the cameras and the second pressing blocks are arranged in a left-right one-to-one correspondence mode, and the outer circumferential wall of the cold-drawn heating wire is evenly divided into multiple cambered surfaces ad. The camera is in one-to-one correspondence with the cambered surface ad in a shooting area of the outer wall of the heating wire. According to the heating wire cold-drawing die and the adjusting method thereof, the forming quality of a product is improved, and the service life of the product is prolonged.

Description

Technical Field

[0001] This invention relates to the field of cold drawing technology, and more specifically, to a cold drawing die for heating wire and its adjustment method. Background Technology

[0002] Heating wire is a core functional component of electric heating equipment. To improve insulation performance and safety, industrial applications widely use composite heating wires with a metal tube and internal insulating filler. The quality of its forming directly determines heating efficiency, insulation reliability, and service life. Cold drawing is a key process for achieving precise outer diameter and dense structure in this type of composite heating wire. A die applies radial constraint and axial tension to the heating wire to achieve the target dimensional requirements. Traditional cold drawing dies for composite heating wires cannot detect minor wear on the outer wall of the heating wire in time during use. By the time it is detected, the wear is already quite severe, resulting in lower overall forming quality and affecting product lifespan, especially for products with thinner walls. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a heating wire cold drawing die and its adjustment method to improve product forming quality and service life.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a heating wire cold drawing die for cold drawing heating wire, comprising a main die body, a first fixing ring, and a third fixing ring. The first fixing ring and the third fixing ring are coaxially arranged. The main die body passes through the first fixing ring. The third fixing ring is located on the left side of the main die body and the first fixing ring. The first fixing ring is equipped with a plurality of second pressure blocks. The second pressure blocks abut against the outer wall of the main die body. The position of the second pressure blocks can be adjusted radially along the main die body. A plurality of second pressure blocks are evenly distributed along the circumference of the main die body. A plurality of cameras are evenly distributed on the inner circumferential wall of the third fixing ring. The cameras are arranged in a one-to-one correspondence with the second pressure blocks. After cold drawing, the outer circumferential wall of the heating wire is evenly divided into a plurality of arc surfaces ad. The shooting area of ​​the camera on the outer wall of the heating wire corresponds one-to-one with the arc surface ad.

[0005] Furthermore, the main mold body is provided with a first channel and a second channel, the first channel is located to the left of the second channel, and the diameter of the first channel is larger than the diameter of the second channel.

[0006] Furthermore, the second pressure block is inserted into the first fixing ring on the side away from the main mold body, and the first fixing ring is slidably connected to the second pressure block.

[0007] Furthermore, it includes a second fixing ring, into which the first fixing ring is inserted. The second fixing ring is equipped with a drive component, which is an electric rotary actuator. The drive component corresponds one-to-one with the second pressure block. A rotating drum is installed at the output end of the drive component. The rotating drum is connected to the first pressure block. The rotation of the rotating drum drives the first pressure block to rotate. The first pressure block is threadedly inserted into the first fixing ring. The side of the first pressure block away from the rotating drum abuts against the second pressure block.

[0008] Furthermore, the first pressing block includes an extension, which is polygonal in shape. The extension is inserted into a rotating cylinder, and the inner wall of the rotating cylinder is a polygon corresponding to the extension.

[0009] Furthermore, the second fixing ring has fixing covers installed at both ends of its axial direction. The main mold body passes through the fixing covers, and the fixing cover on the left side is fixedly connected to the first fixing ring.

[0010] Furthermore, the contact surface between the second pressure block and the main mold is an arc surface, and the contact length between the second pressure block and the main mold is greater than half the length of the main mold body.

[0011] The present invention also adopts the following technical solution: a method for adjusting a heating wire cold drawing die, used to adjust the heating wire cold drawing die, comprising the following steps:

[0012] Step S1: Apply a black marking solution to the outer wall of the heating wire. The outer wall of the heating wire is gray. Divide the color gradient of the marking solution and the outer wall of the heating wire into i regions, denoted as λ. i ;

[0013] Step S2: The color obtained by the camera in the shooting area on the outer wall of the heating wire is recorded as S. i ;

[0014] Step S3: Place S i With λ i By comparison, the lightest chromaticity S was obtained. i The corresponding λ i And the darkest color, S i The corresponding λ i Calculate the difference between the two values ​​of i, and denote it as Δi;

[0015] Step S4: When Δi≥1, select the lightest chromatic S. i The radial position of the second pressure block corresponding to the area is adjusted to move closer to the main mold body.

[0016] Furthermore, in step S4, the lightest chroma S is... i The radial distance of the second pressure block corresponding to the region toward the main mold body is Δi×0.0013mm.

[0017] Furthermore, in step S2, S... iDivide the heating wire circumferentially into three equal parts, namely arc surface ab, arc surface bc, and arc surface cd, denoted as S. i1 S i2 S i3 , will S i1 S i2 S i3 With λ i In contrast, when S i2 When the color is lightest, only adjust this S. i The radial position of the second pressing block corresponding to the region, when S i1 or S i3 When the color is lightest, adjust the S value simultaneously. i Region and S i1 or S i3 Adjacent S i The radial position of the second pressure block corresponding to the region.

[0018] In summary, the present invention has the following beneficial effects:

[0019] Eight sets of circumferentially distributed second pressure block adjustment components are used, which, through a servo-electric rotary actuator and threaded drive, achieve radial micro-adjustment at the 0.0013mm level. Furthermore, a camera monitors the forming surface to eliminate detection lag, resulting in uniform wall thickness after cold drawing of the heating wire and improving its subsequent service life. Simultaneously, it significantly reduces wear on the mold body from one side of the heating wire, extending the mold body's lifespan. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view of an embodiment;

[0021] Figure 2 for Figure 1 A cross-sectional view along the MM direction;

[0022] Figure 3 This is a cross-sectional view of the extension and the rotating cylinder in the embodiment;

[0023] Figure 4 for Figure 1 A cross-sectional view along the NN direction;

[0024] Figure 5 for Figure 4 A partial schematic diagram;

[0025] Figure 6 for Figure 4 A schematic diagram of the outer wall of the heating wire after it has been unfolded.

[0026] Reference numerals: Main mold body 1, first channel 11, second channel 12, first fixing ring 2, rotating cylinder 3, driving component 31, first pressure block 4, extension 41, second pressure block 42, second fixing ring 5, fixing cover 51, third fixing ring 6, camera 61, guide block 62, heating wire 7, filler 71. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] like Figures 1-6 As shown, this embodiment discloses a cold drawing die for heating wire 7, used for cold drawing of heating wire 7, including a main die body 1, a first fixing ring 2, a second fixing ring 5, and a third fixing ring 6. Figure 1 As shown, the main mold body 1 is provided with a first channel 11 and a second channel 12. The first channel 11 is located to the left of the second channel 12. The diameter of the first channel 1111 is larger than the diameter of the second channel 12. The second channel 12 is the feed hole of the heating wire 7. The first channel 1111 is the cold drawing forming hole of the heating wire 7. The heating wire 7 includes an internal filler 71 for insulation. The cold-drawn heating wire 7 is guided by the guide block 62 and pulled out and wound up by external force.

[0029] like Figure 1 , Figure 2 As shown, both the first fixing ring 2 and the third fixing ring 6 are annular structures, coaxially arranged. The main mold body 1 passes through the first fixing ring 2, and the third fixing ring 6 is located to the left of the main mold body 1 and the first fixing ring 2. The first fixing ring 2 is inserted into the second fixing ring 5, and the outer diameter of the first fixing ring 2 is smaller than the inner diameter of the second fixing ring 5. Fixing caps 51 are installed at both ends of the second fixing ring 5 axially. The main mold body 1 passes through the fixing caps 51, and the fixing cap 51 located on the left side is fixedly connected to the first fixing ring 2. The main mold body 1 passes through the fixing caps 51.

[0030] like Figure 1 , Figure 2As shown, a first fixing ring 2 is equipped with multiple second pressure blocks 42, which are evenly distributed circumferentially along the first fixing ring 2. The second pressure blocks 42 are slidably inserted into the first fixing ring 2 on the side furthest from the main mold body 1, and the first fixing ring 2 is slidably connected to the second pressure blocks 42. Preferably, there are eight second pressure blocks 42. The second pressure blocks 42 abut against the outer wall of the main mold body 1, and the contact surface between the second pressure blocks 42 and the main mold body 1 is an arc surface. The contact length between the second pressure blocks 42 and the main mold body 1 is greater than half the length of the main mold body 1. The position of the second pressure blocks 42 can be adjusted radially along the main mold body 1. Specifically, the second fixed ring 5 is equipped with a drive component 31, which is an electric rotary actuator. The drive component 31 corresponds one-to-one with the second pressure block 42. A rotating drum 3 is installed at the output end of the drive component 31. The rotating drum 3 is connected to a first pressure block 4. Rotation of the rotating drum 3 drives the first pressure block 4 to rotate. The first pressure block 4 is threadedly inserted into the first fixed ring 2, and the side of the first pressure block 4 away from the rotating drum 3 abuts against the second pressure block 42. Figure 3 As shown, the first pressure block 4 includes an extension 41, which is polygonal in shape. The extension 41 is inserted into the rotating cylinder 3, and the inner wall of the rotating cylinder 3 is a polygon corresponding to the extension 41. Preferably, the extension 41 is hexagonal. The rotating cylinder 3 rotates to screw the first pressure block 4 into or out of the first fixing ring 2, thereby changing the pressure of the second pressure block 42 on the main mold body 1. The center position of the main mold body 1 can be finely adjusted by the eight second pressure blocks 42, so that the wear between the outer wall of the heating wire 7 and the inner wall of the main mold body 1 is more uniform during cold drawing. In specific applications, the thread pitch of the first pressure block 4 is selected to be 0.5mm, that is, when the first pressure block 4 rotates 360°, the distance between the second pressure block 42 and the main mold body 1 can be adjusted by 0.5mm. The rotation accuracy of the driving component 31 is less than ±0.1°. The rotation angle of the first pressure block 4 is set to 1°, and the distance between the second pressure block 42 and the main mold body 1 can theoretically be adjusted by 0.0013mm each time, thereby achieving a fine adjustment effect.

[0031] Multiple cameras 61 are evenly installed on the inner circumferential wall of the third fixing ring 6. The cameras 61 are set one-to-one with the second pressure block 42. After cold drawing, the outer circumferential wall of the heating wire 7 is divided into multiple arc surfaces ad. Preferably, the number of arc surfaces ad is 8. The shooting area of ​​the camera 61 on the outer wall of the heating wire 7 corresponds one-to-one with the arc surface ad, that is, each camera 61 captures the image information of the corresponding arc surface ad.

[0032] A method for adjusting a cold-drawing die for a heating wire, comprising the following steps:

[0033] Step S1: Apply a marking liquid to the outer peripheral wall of the heating wire 7. The marking liquid is epoxy-modified crosslinked acrylic ink, black in color, and has a heat resistance temperature exceeding 80°C, which is higher than the forming temperature (80°C) of the cold drawing process. This is to ensure the marking liquid is not affected by the temperature rise during cold drawing and to ensure reliable marking.

[0034] The outer wall of the heating wire 7 (made of aluminum alloy) is gray. The color of the marking liquid and the outer wall of the heating wire 7 are divided into i regions according to the gradient of color, and denoted as λ. i The preferred value for i is 8.

[0035] Step S2: The color obtained by camera 61 in the shooting area on the outer wall of heating wire 7 is recorded as S. i ,like Figure 4 , Figure 5 As shown, there are 8 cameras in total, each with an S... i For a given curved surface ad, there are 8 regions, denoted as S1-S8.

[0036] Step S3: Place S i With λ i By comparison, the lightest chromaticity S was obtained. i The corresponding λ i And the darkest color, S i The corresponding λ i Calculate the difference between the two i values, denoted as Δi; the lightest chromaticity S i This indicates that the area is subject to significant wear and tear.

[0037] Step S4: When Δi≥1, select the lightest chromatic S. i The radial position of the second pressure block 42 corresponding to the region (left and right corresponding) is adjusted to move closer to the main mold body 1. That is, the depth of the corresponding first pressure block 4 screwed into the first fixing ring 2 is adjusted to compress the main mold body 1 and finely adjust the cold drawing center position in the opposite direction, thereby reducing unilateral wear, ensuring the uniformity of the wall thickness of the heating wire 7, and improving the molding quality and service life. The second pressure block 42 opposite to the second pressure block 42 on the adjustment side does not need to be adjusted because the adjustment size is very small (micrometer level), and the machine can be stopped during adjustment.

[0038] In step S4, the lightest color S is... i The radial distance of the second pressure block 42 corresponding to the region toward the main mold body 1 is Δi×0.0013mm, that is, the rotation angle of the first pressure block 4 is Δi×1°.

[0039] As a further setting, in step S2, S... i Divide the heating wire into three equal parts along its circumference: arc surface ab, arc surface bc, and arc surface cd, denoted as S. i1 S i2 S i3 , will S i1 S i2 S i3 With λ i In contrast, when S i2 When the color is lightest, only adjust this S.i The radial position of the second pressing block 42 corresponding to the region, when S i1 or S i3 When the color is lightest, adjust the S value simultaneously. i Region and S i1 or S i3 Adjacent S i The radial position of the second pressure block 42 corresponding to the area is determined to address the issue that the limited number of second pressure blocks 42 (8) leads to detection position deviation and reduced adjustment efficiency.

[0040] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A cold drawing die for heating wire, used for cold drawing of heating wire (7), characterized in that, The system includes a main mold body (1), a first fixing ring (2), and a third fixing ring (6). The first fixing ring (2) and the third fixing ring (6) are coaxially arranged. The main mold body (1) passes through the first fixing ring (2). The third fixing ring (6) is located on the left side of the main mold body (1) and the first fixing ring (2). The first fixing ring (2) is equipped with multiple second pressure blocks (42). The second pressure blocks (42) abut against the outer wall of the main mold body (1). The position of the second pressure blocks (42) can be adjusted radially along the main mold body (1). Multiple second pressure blocks (42) are evenly distributed along the circumference of the main mold body (1). Multiple cameras (61) are evenly distributed on the inner circumferential wall of the third fixing ring (6). The cameras (61) are arranged in a one-to-one correspondence with the second pressure blocks (42) on the left and right sides. After cold drawing, the outer circumferential wall of the heating wire (7) is divided into multiple arc surfaces ad. The shooting area of ​​the camera (61) on the outer wall of the heating wire (7) corresponds one-to-one with the arc surface ad.

2. The heating wire cold drawing die according to claim 1, characterized in that, The main mold body (1) is provided with a first channel (11) and a second channel (12). The first channel (11) is located to the left of the second channel (12), and the diameter of the first channel (11) is larger than the diameter of the second channel (12).

3. The heating wire cold drawing die according to claim 1, characterized in that, The second pressure block (42) is inserted into the first fixing ring (2) on the side away from the main mold body (1), and the first fixing ring (2) is slidably connected to the second pressure block (42).

4. The heating wire cold drawing die according to claim 3, characterized in that, Includes a second fixing ring (5), the first fixing ring (2) is inserted into the second fixing ring (5), the second fixing ring (5) is equipped with a driving component (31), the driving component (31) is an electric rotary actuator, the driving component (31) corresponds one-to-one with the second pressure block (42), the output end of the driving component (31) is equipped with a rotating drum (3), the rotating drum (3) is connected to a first pressure block (4), the rotating drum (3) rotates and drives the first pressure block (4) to rotate, the first pressure block (4) is threadedly inserted into the first fixing ring (2), the side of the first pressure block (4) away from the rotating drum (3) abuts against the second pressure block (42).

5. A heating wire cold drawing die according to claim 4, characterized in that, The first pressing block (4) includes an extension (41), the extension (41) is polygonal in shape, the extension (41) is inserted into the rotating cylinder (3), and the inner wall of the rotating cylinder (3) is a polygon corresponding to the extension (41).

6. The heating wire cold drawing die according to claim 4, characterized in that, The second fixing ring (5) has fixing covers (51) installed at both ends of its axial direction. The main mold body (1) passes through the fixing covers (51), and the fixing cover (51) located on the left side is fixedly connected to the first fixing ring (2).

7. A heating wire cold drawing die according to claim 4, characterized in that, The contact surface between the second pressure block (42) and the main mold body (1) is an arc surface, and the contact length between the second pressure block (42) and the main mold body (1) is greater than half the length of the main mold body (1).

8. A method for adjusting a heating wire cold drawing die, used to adjust the heating wire cold drawing die according to any one of claims 1-7, characterized in that, Includes the following steps: Step S1: the outer wall of the heating wire (7) is painted with a marking liquid, the marking liquid is black, the outer wall of the heating wire (7) is gray, the marking liquid and the color of the outer wall of the heating wire (7) are evenly divided into i areas according to the gradient, respectively marked as λ i ; Step S2: The color obtained by the camera (61) in the shooting area on the outer wall of the heating wire (7) is denoted as S. i ; Step S3: Place S i With λ i By comparison, the lightest chromaticity S was obtained. i The corresponding λ i And the darkest color, S i The corresponding λ i Calculate the difference between the two values ​​of i, and denote it as Δi; Step S4: When Δi≥1, select the lightest chromatic S. i The radial position of the second pressure block (42) corresponding to the region is adjusted to move closer to the main mold body (1).

9. The method for adjusting a heating wire cold drawing die according to claim 8, characterized in that, In step S4, the lightest color S is... i The radial position of the second pressure block (42) corresponding to the region approaches the main mold body (1) by a distance of Δi×0.0013mm.

10. The method for adjusting a heating wire cold drawing die according to claim 8, characterized in that, In step S2, S i The heating wire (7) is divided into three equal parts along its circumference: arc surface ab, arc surface bc, and arc surface cd, denoted as S. i1 S i2 S i3 , will S i1 S i2 S i3 With λ i In contrast, when S i2 When the color is lightest, only adjust this S. i The radial position of the second pressing block (42) corresponding to the region, when S i1 or S i3 When the color is lightest, adjust the S value simultaneously. i Region and S i1 or S i3 Adjacent S i The radial position of the second pressure block (42) corresponding to the region.

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