Novel chopstick-shaped electric heating tube and preparation method thereof

Abstract

The chopstick-shaped novel electric heating tube comprises a tube body, a tube connector, an insulating column, a wiring terminal and an electric heating wire, the electric heating wire extends in the axial direction of the tube body, the two ends of the electric heating wire are connected with the wiring terminal, and the middle section of the electric heating wire is provided with a linear section so as to prevent the situation that the electric heating wire spirally protrudes to make contact with the tube wall during extrusion forming; the chopstick shape is formed through bending and D-shaped stamping, so that the electric heating tube has higher adaptability and efficiency during use and can be better matched with an equipment structure, the design flexibility is improved, the middle section of the electric heating wire is provided with the linear section, the spiral wire is prevented from being in contact with the tube wall during forming, and the service life of the electric heating tube is prolonged. The device effectively reduces the contact pressure of the electric heating wire in the pipe, reduces the damage risk of the electric heating wire, prolongs the service life of the product, improves the safety of the product, guarantees the quality control of each link through the precise numerical control wire winding, powder filling, stamping and other process steps, effectively avoids defective products in production, and guarantees the high performance of the final product.

Description

Technical Field

[0001] The present invention specifically relates to a novel electric heating tube in the shape of chopsticks and a preparation method thereof. Background Art

[0002] The electric heating tube in the shape of chopsticks is called chopstick tube because its structure is very similar to chopsticks. Its surface load is generally designed between 5W / CM2 and 8W / CM2 and is used for isolating the dry burning state of water. Although the chopstick-shaped structure can be adapted to narrow or irregular spaces to meet the integration requirements of special equipment, its disadvantages are also obvious, as follows:

[0003] 1. Since the U-shaped part at the bottom of the tube needs to be completely folded into the shape of chopsticks, the helical resistance wire here is very easy to touch the tube wall, resulting in electric leakage.

[0004] 2. When the electric heating tube is folded into the shape of chopsticks, fracture layers will appear in the magnesium powder during bending and stretching, generating voids. At this time, the resistance wire at the bent part is very easy to break during the tube bending and oil pressure process. Summary of the Invention

[0005] Aiming at the deficiencies in the prior art, the purpose of the present invention is to provide a novel electric heating tube in the shape of chopsticks, and also provide a specific preparation method.

[0006] The technical solution adopted by the present invention to solve its technical problems is:

[0007] A novel electric heating tube in the shape of chopsticks, including a bent tube body, a tube interface integrally formed at the port part of the tube body, an insulating column screwed into the tube interface for fixed installation, a wiring terminal welded on the insulating column, and an electric heating wire installed inside the tube body. The tube body is a prefabricated tube body formed by stamping a whole straight tube into a D shape, and the final chopstick-shaped tube body is formed by secondary stamping on the annealed prefabricated part; the electric heating wire extends along the axial direction of the tube body, and its two ends are respectively connected to the wiring terminals, and a straight section is provided in the middle section of the electric heating wire to prevent the spiral from protruding and contacting the tube wall during the extrusion molding.

[0008] Preferably, the tube interface adopts a threaded or snap structure for sealing connection with external equipment.

[0009] Furthermore, the present invention also provides a preparation method for a novel electric heating tube in the shape of chopsticks, including the following steps:

[0010] Stock cutting: Prepare the raw materials of metal tubes and electric heating wires.

[0011] Wire winding: Use a numerical control wire winding machine to wind the electric heating wire into a spiral shape, and leave a 40mm straight section 51 in the middle section to ensure that this section is located in the central area of the tube body during subsequent stamping and forming, avoiding the spiral wire from contacting the tube wall.

[0012] Wire feeding, resistance measurement, and welding wire: Load the heating wire into the tube body, aligning the straight section with the axis of the tube body;

[0013] Powder filling: Fill the tube body with magnesium oxide powder with a purity of ≥98%, and through vibration combined with mechanical rolling, make the powder density ≥2.6 g / cm 3 , ensuring uniform heat conduction;

[0014] Headstock: Machine the tube interface structure, and correspondingly insert a rubber head to block the tube body to prevent the leakage of magnesium oxide powder;

[0015] D-shaped stamping: Use a hydraulic press to stamp the tube body into a D-shaped cross-section, control the stamping deformation rate ≤15%, and avoid cracking;

[0016] 1050°C high-temperature annealing: Anneal in a nitrogen environment at a temperature of 1050°C ± 10°C for 40 minutes to eliminate stamping stress and refine grains, improving the subsequent bending plasticity;

[0017] Bending into a U-shape: Bend the annealed D-shaped tube body into a U-shape, ensuring that the bending arc matches the final chopstick-shaped structure;

[0018] One-step stamping forming: Process the U-shaped tube body into a chopstick-shaped structure through a single stamping;

[0019] Moisture removal: Dry at 80 - 120°C for 2 - 4 hours to completely remove the residual moisture in the magnesium oxide powder and prevent insulation failure;

[0020] Sealing: Pull out the rubber head from the tube interface, connect the insulating column with a terminal to the heating wire lead, then screw the insulating column into the tube interface, and finally fix the terminal to the insulating column by silver brazing or resistance welding to ensure airtightness;

[0021] Testing: Conduct resistance, insulation withstand voltage, and leakage current tests on the assembled electric heating tube. After confirmation, it can be packaged as a finished product.

[0022] Furthermore, in the D-shaped stamping step of the tube body, one side of the tube body is stamped into a plane, and the other side remains arc-shaped.

[0023] Advantages of the present invention:

[0024] The chopstick-shaped formed by bending and D-shaped stamping of the present invention enables the electric heating tube to have higher adaptability and efficiency during use, be better matched with the equipment structure, increase the flexibility of the design. Moreover, a straight section is provided in the middle section of the heating wire, which avoids the contact between the spiral wire and the tube wall during forming, effectively reduces the contact pressure of the heating wire inside the tube, reduces the risk of damage to the heating wire, thereby improving the service life and safety of the product. At the same time, through precise numerical control wire winding, powder filling, stamping and other technological steps, the quality control of each link is ensured, effectively avoiding defective products in production and guaranteeing the high performance of the final product. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a structural diagram of a novel electric heating tube in the shape of chopsticks according to the present invention;

[0026] Figure 2 is Figure 1 sectional view of;

[0027] Figure 3 is Figure 1 sectional view of. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the embodiments given are not intended to limit the present invention.

[0029] Embodiment

[0030] A novel electric heating tube in the shape of chopsticks, as Figures 1-3 shown, includes a bent tube body 1, a tube interface 2 integrally formed at the port part of the tube body 1, an insulating column 3 screwed into the tube interface 2 for fixed installation, a terminal 4 welded on the insulating column 3, and a heating wire 5 installed inside the tube body 1.

[0031] The tube interface 2 adopts a threaded or snap structure for sealed connection with the insulating column 3.

[0032] The tube body 1 is a prefabricated tube body formed by stamping a whole straight tube into a D shape, and the final chopstick-shaped tube body is formed by secondary stamping on the annealed prefabricated part;

[0033] The heating wire 5 extends along the axial direction of the tube body 1, and its two ends are respectively connected to the terminal 5. Moreover, a straight section 51 is provided in the middle section of the heating wire 5 to prevent the spiral protrusion from contacting the tube wall during extrusion forming.

[0034] A preparation method of a novel electric heating tube in the shape of chopsticks includes the following steps:

[0035] Stock cutting: Prepare metal pipe materials and heating wire raw materials;

[0036] Wire winding: Use a numerically controlled wire winding machine to wind the heating wire 5 into a spiral shape, leaving a 40-mm straight section 51 in the middle section, ensuring that this section is located in the central area of the pipe body during subsequent stamping, to prevent the spiral wire from contacting the pipe wall;

[0037] Wire insertion, resistance measurement, and wire welding: Insert the heating wire 5 into the pipe body 1, aligning the straight section 51 with the axis of the pipe body 1;

[0038] Powder filling: Fill the pipe body 1 with magnesium oxide powder with a purity of ≥98%, and use vibration in combination with mechanical rolling to make the powder density ≥2.6 g / cm 3 , ensuring uniform heat conduction;

[0039] Headstock: Machine the structure of the pipe interface 2 and correspondingly insert a rubber head to seal the pipe body 1 to prevent the leakage of magnesium oxide powder;

[0040] D-shaped stamping: Use a hydraulic press to stamp the pipe body 1 into a D-shaped cross-section, controlling the stamping deformation rate ≤15% to avoid cracking;

[0041] 1050°C high-temperature annealing: Anneal in a nitrogen environment at a temperature of 1050°C ± 10°C for 40 minutes to eliminate stamping stress and refine the grains, improving the subsequent bending plasticity;

[0042] Bending into a U shape: Bend the annealed "D"-shaped pipe body 1 into a U shape, ensuring that the bending arc matches the final chopstick-shaped structure;

[0043] One-step stamping forming: Process the U-shaped pipe body 1 into a chopstick-shaped structure through single stamping;

[0044] Moisture removal: Dry at 80 - 120°C for 2 - 4 hours to completely remove the residual moisture in the magnesium oxide powder and prevent insulation failure;

[0045] Sealing: Pull out the rubber head from the pipe interface 2, connect the insulating column 3 with the terminal 4 to the heating wire lead, then screw the insulating column 3 into the pipe interface 2, and finally fix the terminal to the insulating column by silver brazing or resistance welding to ensure airtightness;

[0046] Testing: Test the assembled electric heating tube for resistance, insulation withstand voltage, and leakage current. After confirmation, it can be packaged as a finished product.

[0047] It should be further noted that in the wire winding step, there is a skip section design with a straight section 51 in the middle section of the heating wire 5, which has the following advantages:

[0048] 1. Reducing contact with the pipe wall: The design of the straight section can prevent the heating wire from generating spiral protrusions during the forming process, avoiding direct contact between the heating wire and the pipe wall, thus reducing the problems of heating wire damage or local overheating that may be caused by extrusion or friction;

[0049] 2. Uniform heating: The existence of the straight section enables the heating wire to be evenly distributed along the axial direction of the pipe body, resulting in more uniform heating. This avoids local overheating caused by the bending or uneven contact of the heating wire, improving the heating efficiency and the service life of the equipment.

[0050] 3. Improve stability and safety: The reduced contact between the heating wire and the pipe wall helps to lower the risk of short circuits and electrical failures. At the same time, avoiding the close contact between the heating wire and the pipe wall reduces the possibility of the heating wire breaking or deforming due to thermal expansion, enhancing the safety of the equipment.

[0051] 4. Enhance compressive resistance: The design of the straight section makes the structure of the heating wire more stable, enabling it to better withstand external pressure and reducing the impact of mechanical pressure generated during the installation or use of the equipment on the heating wire, thus extending the service life of the electric heating pipe.

[0052] 5. Adapt to the production process: Through this design, the bent part of the heating wire can better adapt to the stamping and forming requirements of the pipe body during the production process, thus avoiding the adverse effects caused by excessive extrusion of the spiral wire and ensuring a smoother production process.

[0053] It should be further noted that during the D-shaped stamping step of the pipe body 1, one side of the pipe body 1 is stamped into a flat surface, while the other side remains arc-shaped.

[0054] It should be further noted that during the step of bending the "D"-shaped pipe body 1 into a U shape, the bending speed is controlled ≤ 10 mm / s to avoid instantaneous stress concentration.

[0055] The above embodiments of the present invention do not limit the protection scope of the present invention. The implementation manners of the present invention are not limited to this. All kinds of modifications, substitutions or changes made to the above structure of the present invention according to the above content of the present invention, in accordance with the common general knowledge and customary means in the art, without departing from the above basic technical idea of the present invention, shall fall within the protection scope of the present invention.

Claims

1. A novel electric heating tube in the shape of chopsticks, comprising a bent tube body, a tube interface integrally formed at the port part of the tube body, an insulating column screwed into the tube interface for fixed installation, a wiring terminal welded on the insulating column, and a heating wire installed inside the tube body, characterized in that: The tube body is a prefabricated tube body formed by integrally stamping a straight tube into a D shape. After annealing, the prefabricated part is stamped twice to form the final chopstick-shaped tube body. The heating wire extends along the axial direction of the tube body, and its two ends are respectively connected to the terminal blocks. A straight section is provided in the middle section of the heating wire to prevent the spiral protrusion from contacting the tube wall during extrusion molding.

2. The novel electric heating tube in the shape of chopsticks according to claim 1, characterized in that, The tube interface adopts a threaded or snap structure for sealing connection with external equipment.

3. A preparation method of the novel electric heating tube in the shape of chopsticks according to claims 1-2, characterized in that, It includes the following steps: Blanking: Prepare the raw materials of metal tubes and heating wires. Wire winding: Use a numerical control wire winding machine to wind the heating wire into a spiral shape, with a 40-mm straight section 51 reserved in the middle section, ensuring that this section is located in the central area of the tube body during subsequent stamping and forming, and preventing the spiral wire from contacting the tube wall. Wire insertion, resistance measurement, and wire soldering: Insert the heating wire into the tube body, and align the straight section with the axis of the tube body. Powder filling: Fill magnesium oxide powder with a purity of ≥98% into the tube body, and through vibration combined with mechanical rolling, make the powder density ≥2.6 g / cm 3 , ensuring uniform heat conduction; Head processing: Process the tube interface structure, and correspondingly insert a rubber head to block the tube body to prevent the leakage of magnesium oxide powder. D-shaped stamping: Use a hydraulic press to stamp the tube body into a D-shaped cross-section, controlling the stamping deformation rate ≤ 15% to avoid cracking. 1050°C high-temperature annealing: Anneal in a nitrogen environment at a temperature of 1050°C ± 10°C for 40 minutes to eliminate stamping stress and refine grains, and improve the subsequent bending plasticity. Bending into a U shape: Bend the annealed D-shaped tube body into a U shape, ensuring that the bending arc matches the final chopstick-shaped structure. One-step stamping forming: Process the U-shaped tube body into a chopstick-shaped structure through single stamping. Moisture removal: Dry at 80 - 120°C for 2 - 4 hours to completely remove the residual moisture in the magnesium oxide powder and prevent insulation failure. Sealing: Pull out the rubber head from the tube interface, connect the insulating column with the terminal block to the lead wire of the heating wire, then screw the insulating column into the tube interface, and finally fix the terminal block on the insulating column by silver brazing or resistance welding to ensure airtightness.

4. The preparation method of the novel electric heating tube in the shape of chopsticks according to claim 3, characterized in that, Testing: Conduct resistance, insulation withstand voltage, and leakage current tests on the assembled electric heating tube. After confirmation, it can be packaged as a finished product. In the D-shaped stamping step of the tube body, one side of the tube body is stamped into a flat surface, and the other side remains arc-shaped.

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