A preheating device for smoothing the aluminum sheath of cable

Abstract

The application relates to a preheating device for smoothing the aluminum sleeve of a cable before extrusion, which comprises a hollow box, the two side walls of the box are respectively provided with cable passing openings, an induction coil is arranged in the inner cavity of the box, the induction coil is coaxially arranged with the passing openings, a transformer for being connected with a power supply is arranged in the inner cavity of the box, one end of the induction coil is electrically connected with a positive electrode connecting terminal of the transformer, and the other end is electrically connected with a negative electrode connecting terminal of the transformer. The application has the effect of uniformly electrifying the aluminum sleeve of the cable.

Description

Technical Field

[0001] This application relates to the field of cable manufacturing, and in particular to a preheating device for aluminum sheath extrusion of smooth aluminum sheathed cables. Background Technology

[0002] During the production of smooth aluminum-sheathed cables, an additional layer of asphalt is coated on the outside of the aluminum sheath for corrosion protection. However, the partially molten asphalt comes into direct contact with the room-temperature aluminum sheath and cools rapidly, forming lumps. This prevents the asphalt from being evenly coated on the aluminum sheath surface and may even cause the lumps to detach. Therefore, the cable needs to be preheated before applying the asphalt.

[0003] Currently, Chinese Patent CN203366861U discloses a cable aluminum sheath preheating device, which includes a base, a bracket fixedly connected to the base, and a hot air gun for preheating the cable aluminum sheath. The bracket is circular, and the cable with the aluminum sheath passes through the center of the bracket. Four hot air guns are evenly arranged along the circumference of the circular bracket, with the air outlet of each gun aimed at the cable with the aluminum sheath. As the cable with the aluminum sheath is evenly conveyed through the preheating device, the hot air guns preheat the cable's aluminum sheath.

[0004] Regarding the aforementioned technologies, the inventors believe that the following defects exist: When multiple hot air guns simultaneously heat the cable with hot air, the hot air will create turbulence near the cable. The part of the aluminum sleeve directly facing the hot air gun will receive more heat and the temperature will rise faster; while the part not directly facing the hot air gun will rise slower. This will lead to uneven heating of the aluminum sleeve. The uneven temperature of the aluminum sleeve after preheating may affect the subsequent asphalt coating. Summary of the Invention

[0005] To improve the uniformity of preheating of cable aluminum sheaths, this application provides a preheating device for smooth aluminum sheath cables before extrusion.

[0006] This application provides a preheating device for smooth aluminum-sheathed cables before aluminum sheath extrusion, which adopts the following technical solution: A preheating device for aluminum sheath extrusion of a smooth aluminum-sheathed cable includes a hollow box with openings on both side walls for cable passage. An induction coil is installed in the inner cavity of the box and is coaxially arranged with the openings. A transformer for connection to a power source is installed in the inner cavity of the box. One end of the induction coil is electrically connected to the positive terminal of the transformer, and the other end is electrically connected to the negative terminal of the transformer.

[0007] By employing the above technical solution, the smooth aluminum-sheathed cable is threaded into the coil through the opening. When an alternating current of a certain frequency is passed through the coil via a transformer, an alternating magnetic field is generated around it. The medium-frequency alternating current acts on the aluminum sheath, and the electromagnetic induction effect of the alternating magnetic field induces a closed eddy current in the aluminum sheath. The electrical energy of the high-density current on the surface of the aluminum sheath of the smooth aluminum-sheathed cable is converted into heat energy, raising the surface temperature, thus achieving surface heating. Induction heating heats the entire section of the aluminum sheath more uniformly than existing technologies, resulting in more similar temperatures across different parts of the sheath. Furthermore, induction heating offers advantages over existing technologies, such as higher heating efficiency and lower noise.

[0008] Optionally, the induction coil is made of hollow copper tube, and one end of the induction coil is provided with a cooling water inlet pipe, and the other end of the induction coil is provided with a cooling water outlet pipe.

[0009] By adopting the above technical solution, the coil is cooled by circulating cooling water inside the hollow copper tube, preventing the positive and negative terminals of the coil from overheating.

[0010] Optionally, a partition is fixedly connected to the inner cavity of the box, which divides the space of the box into upper and lower spaces. The induction coil is located above the partition, and the transformer is located below the partition. Both the positive and negative terminals of the induction coil are connected to copper plates for conducting electricity. The copper plates pass through the partition and are connected to the transformer. An insulating bracket is fixedly connected at the position where the copper plates pass through the partition.

[0011] By adopting the above technical solution, the space inside the enclosure is divided by a partition to protect the transformer located below the partition, while reducing the impact of the external environment on the temperature rise of the cable aluminum sheath.

[0012] Optionally, a lifting mechanism is provided below the housing. The lifting mechanism includes several support rods extending longitudinally through the lower end of the housing. Each support rod is threadedly connected to a driving component, and an end face bearing is sleeved on the support rod between the driving component and the housing. A drive assembly for driving the driving component to rotate is provided on the outer wall of the housing.

[0013] By adopting the above technical solution, the drive component can be rotated by adjusting the component, thereby driving the support rod to move vertically, and thus adjusting the height of the box to use the height of the cable.

[0014] Optionally, the drive assembly includes a drive motor fixedly connected to the outer wall of the housing, a drive sprocket coaxially fixed to the output shaft of the drive motor, and a lifting sprocket, which is meshed with the drive sprocket by a chain.

[0015] By adopting the above technical solution, the drive motor drives the lifting sprocket to rotate through the active sprocket, thereby realizing the control of lifting and lowering of the box.

[0016] Optionally, the lower end of the support rod is provided with casters.

[0017] By adopting the above technical solution, the preheating device can be moved easily.

[0018] Optionally, the housing is provided with a bending moment assembly that applies pressure to the induction coil and causes it to bend downwards.

[0019] By adopting the above technical solution, the cable is suspended when passing through the preheating device. Therefore, its middle position will bend downward under the action of gravity, which may cause the cable to be not coaxial with the induction coil, thus affecting the uniformity of the temperature rise of the cable aluminum sheath. To address this, the bending moment assembly applies pressure to the induction coil to make it bend downward, so that the degree of bending is close to that of the cable. The cable is always located in the center of the induction coil, so that the temperature rise of the cable aluminum sheath is uniform.

[0020] Optionally, the bending moment assembly includes a pressure block and an electric cylinder that drives the pressure block to move vertically. The electric cylinder is fixedly connected to the housing, and the pressure block is fixedly connected to the telescopic end of the electric cylinder. The pressure block is located directly above the center of the induction coil, and the pressure block is made of insulating material.

[0021] By adopting the above technical solution, the electric pusher cylinder can precisely control the movement position of the pressure block, thereby precisely controlling the bending degree of the induction coil.

[0022] In summary, this application includes at least one of the following beneficial technical effects: 1. By using an induction coil to heat the aluminum sleeve of an induction heating cable as a whole, the heating is more uniform compared to existing technologies, resulting in more consistent temperatures across the aluminum sleeve. Furthermore, induction heating offers advantages over existing technologies such as higher heating efficiency and lower noise. 2. By using a partition to separate the induction coil and the transformer, the transformer located below the partition is protected, while the impact of the external environment on the temperature rise of the cable aluminum sheath is also reduced; 3. Apply pressure to the induction coil through the bending moment component to bend it downwards, making its bending degree close to that of the cable. The cable is always located in the center of the induction coil, so that the aluminum sheath of the cable has a uniform temperature rise. Attached Figure Description

[0023] Figure 1 This is a partial sectional view of the overall structure used in Embodiment 1 of this application.

[0024] Figure 2 yes Figure 1 Side view.

[0025] Figure 3 This is a cross-sectional view of Embodiment 2 of this application used to illustrate the bending moment component.

[0026] Figure 4 This is a perspective view of Embodiment 3 of this application used to illustrate the reheating mechanism.

[0027] Figure 5 This is a schematic diagram of the reheating mechanism used in Embodiment 3 of this application.

[0028] Explanation of reference numerals in the attached drawings: 1. Housing; 12. Partition; 13. Coil; 131. Cooling water inlet pipe; 132. Cooling water outlet pipe; 14. Insulating support; 16. Copper plate; 17. Through port; 18. Cable protection sleeve; 2. Lifting mechanism; 21. Support rod; 22. End face bearing; 23. Caster wheel; 24. Drive assembly; 241. Drive motor; 242. Drive sprocket; 243. Lifting sprocket; 244. Chain; 3. Transformer; 4. Mounting bracket; 5. Reheating mechanism; 51. Fixing plate; 52. Support shaft; 53. First heating plate; 54. Second heating plate; 55. First connecting rod; 56. Second connecting rod; 57. Moving assembly; 571. Rotating shaft; 572. First gear; 573. First rack; 574. Second gear; 575. Second rack; 576. Moving motor; 6. Conveyor belt; 7. Bending moment assembly; 71. Electric push cylinder; 72. Pressure block; 73. Arc-shaped groove. Detailed Implementation

[0029] The following is in conjunction with the appendix Figure 1-5 This application will be described in further detail.

[0030] Example 1: Reference Figure 1 and Figure 2 A preheating device for extruding aluminum sheathed cables includes a hollow box 1, which is vertically arranged. Cable passage openings 17 are provided on both side walls of the box 1, and cable protective sleeves 18 are fixed to the outer wall of the box 1, outside the openings 17, by screws. A lifting mechanism 2 for driving the box 1 to move up and down is provided below the box 1, and the lifting mechanism 2 is connected to the lower end of the box 1.

[0031] Reference Figure 1 and Figure 2The inner wall of the housing 1 is fixed with a horizontal partition 12 by screws. An induction coil 13 is installed in the inner cavity of the housing 1 above the partition 12. The axis of the induction coil 13 is horizontal and coaxial with the opening 17. The positive and negative terminals of the induction coil 13 are fixed to two copper plates 16 by bolts. The copper plates 16 extend through the partition 12 to below the partition 12. To improve safety, an insulating bracket is fixedly connected to the position where the copper plates 16 pass through the partition 12. The insulating bracket is fixedly connected to the partition 12.

[0032] Reference Figure 1 A transformer 3 connected to a power source is fixedly installed inside the housing 1 and below the partition 12. The positive and negative terminals of the transformer 3 are connected to two copper plates 16 respectively, thereby energizing the coil 13. Under the electromagnetic induction of the magnetic field, a closed induced current-eddy current is generated in the aluminum sheath outside the cable. The electrical energy of the high-density current on the surface of the aluminum sheath is converted into heat energy, causing the temperature of the aluminum sheath surface to rise.

[0033] Reference Figure 1 The induction coil 13 is made of hollow copper tube, and one end of the induction coil 13 is fixed and connected to the cooling water inlet pipe 131, while the other end of the induction coil 13 is fixed and connected to the cooling water outlet pipe 132.

[0034] Reference Figure 1 and Figure 2 The lifting mechanism 2 includes four support rods 21 that slide longitudinally through the lower end of the housing 1, with each support rod 21 positioned at one of the four corners of the lower end of the housing 1 and arranged vertically. A caster wheel 23 is fixed to the lower end of each support rod 21 by screws. Flat grooves are formed on both radial sides of each support rod 21, and the holes at the lower end of the housing 1 through which the support rods 21 pass are oblong in shape, matching the cross-section of the support rods 21, thereby restricting their rotation.

[0035] Reference Figure 1 and Figure 2 The support rod 21 is threadedly connected to a driving component, and an end face bearing 22 is sleeved on the support rod 21 between the driving component and the housing 1. The driving component supports the housing 1 through the end face bearing 22. A driving assembly 24 is provided on the outer wall of the housing 1 to drive the driving component to rotate. The driving assembly 24 drives the driving component to rotate, thereby pushing the housing 1 to move up and down to realize the lifting and lowering of the housing 1.

[0036] Reference Figure 1 and Figure 2The drive assembly 24 includes a drive motor 241 fixed to the outer wall of the housing 1 by screws. The drive motor 241 is a cycloidal pinwheel reducer motor, and a drive sprocket 242 is coaxially fixed to the output shaft of the drive motor 241. The driving component is a lifting sprocket 243. The drive assembly 24 also includes a chain 244, which meshes with the four lifting sprockets 243 and the drive sprocket 242, so that the rotation of the drive motor 241 can simultaneously drive the rotation of the four lifting sprockets 243.

[0037] The implementation principle of Embodiment 1 of this application is as follows: A smooth aluminum-sheathed cable is inserted into the coil 13 through the through-hole 17. When an alternating current of a certain frequency is passed through the coil 13 by the transformer 3, an alternating magnetic field is generated around it. The medium-frequency alternating current acts on the metal aluminum sheath. The electromagnetic induction effect of the alternating magnetic field causes the metal aluminum sheath to generate a closed induced current. The electrical energy of the high-density current on the surface of the aluminum sheath of the smooth aluminum-sheathed cable is converted into heat energy, which raises the surface temperature. Compared with the prior art, the heating is more uniform and the temperature of each part of the aluminum sheath is closer.

[0038] When it is necessary to adjust the height of the housing 1, the drive motor 241 can be turned on. The drive motor 241 drives four lifting sprockets 243 to move up and down along the support rod 21, thereby facilitating the adjustment of the height of the housing 1. In turn, the inlet center height of this device can be controlled according to the size of the outer diameter of the smooth aluminum sheathed cable.

[0039] Example 2: Reference Figure 3 The difference between this embodiment and Embodiment 1 is that: The housing 1 contains a bending moment assembly 7 that applies pressure to the induction coil 13 and bends it downwards. The bending moment assembly 7 includes a pressure block 72 made of insulating material and an electric actuator 71 that drives the pressure block 72 to move vertically. The electric actuator 71 is fixedly connected to the upper end of the housing 1, and its telescopic end passes through the housing 1 and is fixedly connected to the pressure block 72. The pressure block 72 is located directly above the middle position of the induction coil 13, and its lower end has an arc-shaped groove 73, the inner diameter of which is the same as the outer diameter of the induction coil 13.

[0040] The implementation principle of Embodiment 2 of this application is as follows: When the cable passes through the preheating device, it is in a suspended state. Therefore, its middle position will bend downward under the action of gravity, which may cause the cable to be not coaxial with the induction collar, thus affecting the uniformity of the temperature rise of the cable aluminum sheath. To this end, the bending moment component 7 applies pressure to the induction coil 13 to make it bend downward, so that its bending degree is close to the bending degree of the cable. The cable is always located in the center position of the induction coil 13, so that the cable aluminum sheath has a uniform temperature rise.

[0041] Example 3: Reference Figure 4The difference between this embodiment and Embodiment 1 is that: A vertical mounting bracket 4 is installed on the outside of the housing 1 and on the side near the extruder. The mounting bracket 4 is equipped with a reheating mechanism 5 for secondary preheating of the cable. During the process of pulling the cable to the extruder, if the extruder malfunctions, the cable pulling will be stopped and the extruder will be repaired. However, since some of the cable aluminum sleeves have already been preheated and moved out of the housing 1, the temperature of these cable aluminum sleeves will gradually decrease during the repair process. Therefore, the reheating mechanism 5 can be activated to reheat the preheated cable aluminum sleeves that have been moved out of the housing 1 to prevent the cable aluminum sleeve temperature from dropping.

[0042] Reference Figure 4 and 5 The preheating mechanism 5 includes a fixed plate 51 welded to the mounting frame 4 and located above the cable. The fixed plate 51 is vertically arranged, and a horizontal support shaft 52 is welded directly above the fixed plate 51 and is arranged along the cable's forward direction. The support shaft 52 is rotatably connected to a first heating plate 53 and a second heating plate 54 via bearings. Both the first heating plate 53 and the second heating plate 54 are arc-shaped and located on opposite sides of the cable, with their respective concave arc sides facing the cable.

[0043] Reference Figure 5 The first heating plate 53 is fixed to a first connecting rod 55 by screws at one end near the support shaft 52, and the second heating plate 54 is fixed to a second connecting rod 56 by screws at one end near the support shaft 52. The first connecting rod 55 and the second connecting rod 56 intersect each other. The fixing plate 51 is provided with a moving assembly 57 for driving the first heating plate 53 and the second heating plate 54 to move towards each other, so that the first heating plate 53 and the second heating plate 54 can be adjusted in position for heating according to cables of different diameters.

[0044] Reference Figure 4 and Figure 5The movable component 57 includes a rotating shaft 571 rotatably connected to the fixed plate 51 via a bearing. The axial direction of the rotating shaft 571 is parallel to the axial direction of the support shaft 52, and the rotating shaft 571 is located directly above the support shaft 52. A first gear 572 is coaxially fixed to the rotating shaft 571. A first rack 573 in an arc shape is welded to the first connecting rod 55. The arc-shaped concave side of the first rack 573 faces the rotating shaft 571 and the first rack 573 is located above the rotating shaft 571. The first rack 573 meshes with the first gear 572, and the first rack 573 is centered on the support shaft 52. A second gear 574 is coaxially fixed to the rotating shaft 571. A second rack 575 in an arc shape is welded to the second connecting rod 56. The concave side of the arc-shaped rack 575 is away from the rotating shaft 571, and the rack 575 is located below the rotating shaft 571. The diameter of the second gear 574 is smaller than the diameter of the first gear 572. The rack 575 meshes with the second gear 574, and the rack 575 is centered on the support shaft 52. A moving motor 576 is fixed to the side wall of the fixing plate 51 away from the rotating shaft 571 by screws. The output shaft of the moving motor 576 is coaxially fixed to the rotating shaft 571.

[0045] Reference Figure 5 To facilitate the smoother advancement of the cable, a conveyor belt 6 is fixedly installed below the cable in the mounting bracket 4, and the conveyor belt 6 is attached to the cable.

[0046] The implementation principle of Embodiment 2 of this application is as follows: When the extruder malfunctions, the traction cable is stopped, and the extruder is repaired. However, since some of the cable aluminum sleeves have already been preheated and removed from the housing 1, the temperature of these cable aluminum sleeves will gradually decrease during the repair process. Therefore, the preheated cable aluminum sleeves that have been removed from the housing 1 can be reheated by turning on the first heating plate 53 and the second heating plate 54 to prevent the cable aluminum sleeve temperature from dropping. Secondly, the moving motor 576 can be turned on and driven according to the cable diameter. The rotating shaft 571 rotates, driving the first gear 572 and the second gear 574 to rotate synchronously. Since the first rack 573 meshes with the first gear 572 and the second rack 575 meshes with the second gear 574, the first rack 573 drives the first connecting rod 55 to move, and the second rack 575 drives the second connecting rod 56 to move. This allows the positions of the first heating plate 53 and the second heating plate 54 to be adjusted, changing the distance between the first heating plate 53 / 2 and the second heating plate 54 and the cable, thus improving the preheating effect. The above are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be included within the scope of protection of this application.

Claims

1. A preheating device for aluminum sheath extrusion of a smooth aluminum-sheathed cable, characterized in that: The enclosure includes a hollow housing (1), with cable passage openings (17) on both side walls. An induction coil (13) is installed inside the housing (1), coaxially positioned with the openings (17). A transformer (3) for connection to a power source is also installed inside the housing (1). One end of the induction coil (13) is electrically connected to the positive terminal of the transformer (3), and the other end is electrically connected to the negative terminal of the transformer (3). The housing (1) is provided with a bending moment assembly (7) that applies pressure to the induction coil (13) and bends it downwards; the bending moment assembly (7) includes a pressure block (72) and an electric push cylinder (71) that drives the pressure block (72) to move vertically. The electric push cylinder (71) is fixedly connected to the housing (1), and the pressure block (72) is fixedly connected to the telescopic end of the electric push cylinder (71). The pressure block (72) is located directly above the middle position of the induction coil (13), and the pressure block (72) is made of insulating material.

2. The preheating device for extruding aluminum sheath of a smooth aluminum-sheathed cable according to claim 1, characterized in that: The induction coil (13) is made of hollow copper tube, and a cooling water inlet pipe (131) is provided at one end of the induction coil (13), and a cooling water outlet pipe (132) is provided at the other end of the induction coil (13).

3. The preheating device for extruding the aluminum sheath of a smooth aluminum-sheathed cable according to claim 1, characterized in that: The inner cavity of the box (1) is fixedly connected to a partition (12), which divides the space of the box (1) into upper and lower spaces. The induction coil (13) is located above the partition (12), and the transformer (3) is located below the partition (12). The positive and negative terminals of the induction coil (13) are both connected to copper plates (16) for conducting electricity. The copper plates (16) pass through the partition (12) and are connected to the transformer (3). An insulating bracket (14) is fixedly connected at the position where the copper plates (16) pass through the partition (12).

4. The preheating device for extruding aluminum sheath of a smooth aluminum-sheathed cable according to claim 1, characterized in that: A lifting mechanism (2) is provided below the box (1). The lifting mechanism (2) includes a plurality of support rods (21) that pass through the lower end of the box (1) longitudinally. The support rods (21) are threadedly connected to a driving component. The support rods (21) are fitted with an end face bearing (22) located between the driving component and the box (1). The outer wall of the box (1) is provided with a driving assembly (24) for driving the driving component to rotate.

5. The preheating device for extruding aluminum sheath of a smooth aluminum-sheathed cable according to claim 4, characterized in that: The drive assembly (24) includes a drive motor (241) fixedly connected to the outer wall of the housing (1). The output shaft of the drive motor (241) is coaxially fixed with a drive sprocket (242). The drive component is a lifting sprocket (243). The lifting sprocket (243) is meshed with the drive sprocket (242) and connected to a chain (244).

6. The preheating device for extruding aluminum sheath of a smooth aluminum-sheathed cable according to claim 4, characterized in that: The lower end of the support rod (21) is provided with a caster wheel (23).

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