A magnetic shielding structure for a DC induction heating device

Abstract

The present invention provides a magnetic shielding structure for a DC induction heating device, belonging to the technical field of DC induction heating. The magnetic shielding structure is sleeved on the workpiece gripper of the DC induction heating device to isolate the magnetic field between the workpiece gripper and the two iron cores of the DC induction heating device. It includes a supporting outer cylinder, and a shielding inner cylinder that can axially slide is arranged inside the supporting outer cylinder. Both the supporting outer cylinder and the shielding inner cylinder are coaxial with the rotation axis of the workpiece gripper. The present invention uses a high-permeability material as the magnetic shielding structure, reducing the magnetic field intensity in the workpiece gripper area at both ends of the metal workpiece, and avoiding the occurrence of overheating at both ends of the metal workpiece and the workpiece gripper during the heating process. The magnetic shielding structure is a fixed structure and does not rotate with the workpiece, workpiece gripper, motor, etc., with good stability and safe use. The shielding range can be adjusted, improving the practicality and achieving a good shielding effect. It is applicable to all DC induction heating occasions, including superconducting DC induction heating and permanent magnet DC induction heating.

Description

Technical Field

[0001] The present invention relates to the technical field of DC induction heating, and particularly relates to a magnetic shielding structure for a DC induction heating device. Background Art

[0002] Compared with the traditional AC induction heating technology, the superconducting DC induction heating technology has higher heating efficiency, which can reach more than 80%, about 30% higher than the traditional AC induction heating technology, and is more energy-saving and environmentally friendly. In the superconducting DC induction heating technology, the metal workpiece rotates driven by a motor in the transverse DC magnetic field generated by the superconducting magnet, so as to induce alternating eddy currents inside it, and generate Joule heat due to its own resistance, and then be heated.

[0003] However, the superconducting DC induction heating also has certain defects. When heating a metal workpiece, it is necessary to have a workpiece gripper in close contact with the workpiece. For example, an aluminum rod needs to be fixed by the gripper and then rotate at a low speed or medium-high speed driven by the motor. Therefore, during the heating process, the workpiece gripper is inevitably heated at the same time. The heating of the workpiece gripper will lead to a reduction in the energy utilization rate of the induction heater, which is contrary to the original intention when the superconducting DC induction heating technology was proposed. In order to firmly grip the aluminum rod, the workpiece gripper usually uses stainless steel material with a higher density and hardness than the preheated workpiece, and there is no non-conductive material that can be used to replace it. At the same time, during the heating process of the metal workpiece, the workpiece will become soft as the temperature rises. Especially when the diameter of the aluminum rod is large, the temperature at both ends is the highest, which will seriously affect the stability of the workpiece gripper to grip the workpiece. Summary of the Invention

[0004] The purpose of the present invention is to provide a magnetic shielding structure for a DC induction heating device that can reduce the magnetic field intensity in the workpiece gripper area and at both ends of the workpiece, and prevent the workpiece gripper from being heated or reduce the heat generated in the workpiece gripper, so as to solve at least one of the technical problems existing in the above background art.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] The present invention provides a magnetic shielding structure for a DC induction heating device, and the magnetic shielding structure is sleeved on the workpiece gripper of the DC induction heating device for isolating the magnetic field between the workpiece gripper and the two iron cores of the DC induction heating device;

[0007] The magnetic shielding structure includes a support outer cylinder, and a shielding inner cylinder that can slide axially along the support outer cylinder is arranged inside the support outer cylinder;

[0008] Both the support outer cylinder and the shielding inner cylinder are coaxial with the rotation axis of the workpiece gripper.

[0009] Preferably, a sliding part for axially sliding the shielding inner cylinder along the supporting outer cylinder is installed on the outer wall of the shielding inner cylinder.

[0010] Preferably, a plurality of axial slideways are evenly arranged on the inner wall of the supporting outer cylinder, and the sliding part includes a plurality of axial slide rails corresponding to the axial slideways.

[0011] Preferably, an axial limiting hole penetrating the cylinder wall is provided on the supporting outer cylinder, and the sliding part further includes a handle protruding from the axial limiting hole.

[0012] Preferably, pulleys are provided on the axial slide rails, and the pulleys roll along the axis of the supporting outer cylinder.

[0013] Preferably, a plurality of blind holes penetrating the cylinder wall corresponding to the axial slideways are provided on the front end cylinder wall of the supporting outer cylinder, rollers are arranged in the blind holes, the rollers roll along the axis of the supporting outer cylinder, and the diameter of the rollers is larger than the thickness of the supporting outer cylinder.

[0014] Preferably, the outer diameter of the shielding inner cylinder is smaller than the distance between the two iron cores.

[0015] Preferably, a fixing table is further included, a bracket is installed on the fixing table, and the supporting outer cylinder is installed on the bracket.

[0016] Preferably, the number of the axial slideways is five.

[0017] Preferably, the shielding inner cylinder is made of a high-permeability magnetic material, and the sliding part is made of a non-magnetic metal material.

[0018] Advantages of the present invention: Using a high-permeability magnetic material as the magnetic shielding structure, the magnetic field that should have passed through the workpiece gripper is attracted into the shielding layer, so that the magnetic field passes through the shielding layer, reducing the magnetic field intensity in the area of the workpiece gripper; reducing the magnetic field intensity at both ends of the metal workpiece and the workpiece gripper, avoiding the occurrence of overheating at both ends of the metal workpiece during the heating process, and effectively reducing the heat generated in the workpiece gripper; the magnetic shielding structure is a fixed structure and does not rotate with the workpiece, workpiece gripper, motor, etc., with good stability and safe use; the shielding range can be adjusted, improving the practicability to achieve the best shielding effect; applicable to all DC induction heating occasions, including superconducting DC induction heating and permanent magnet DC induction heating, whether the permanent magnet rotates or the workpiece rotates.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description, which will become obvious from the following description, or will be understood through the practice of the present invention. Description of the Drawings

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 3D view of the magnetic shielding structure for the DC induction heating device according to the embodiment of the present invention.

[0022] Figure 2 Structural diagram of the support outer cylinder of the magnetic shielding structure for the DC induction heating device according to the embodiment of the present invention.

[0023] Figure 3 Structural diagram of the shielding inner cylinder of the magnetic shielding structure for the DC induction heating device according to the embodiment of the present invention.

[0024] Figure 4 Schematic diagram of the working principle of the DC induction heating device according to the embodiment of the present invention.

[0025] Figure 5 Schematic diagram of the installation and use state of the DC induction heating device according to the embodiment of the present invention.

[0026] Wherein: 1 - workpiece gripper; 2 - iron core; 3 - magnetic field; 4 - support outer cylinder; 5 - shielding inner cylinder; 6 - sliding part; 7 - axial slideway; 8 - axial slide rail; 9 - axial limit hole; 10 - handle; 11 - pulley; 12 - blind hole; 13 - roller; 14 - fixed table; 15 - bracket; 16 - workpiece to be processed. Detailed implementation manners

[0027] The following will describe in detail the implementation manners of the present invention. The examples of the implementation manners are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The implementation manners described through the drawings are exemplary and are only used to explain the present invention, and cannot be construed as a limitation to the present invention.

[0028] Those skilled in the art of this technology can understand that, unless otherwise defined, all terms (including technical terms and scientific terms) used here have the same meaning as the general understanding of those of ordinary skill in the art in the field to which the present invention belongs. It should also be understood that terms such as those defined in a general dictionary should be understood to have a meaning consistent with the meaning in the context of the prior art, and will not be interpreted with an idealized or overly formal meaning unless defined as here.

[0029] Those skilled in the art can understand that, unless specifically stated otherwise, the singular forms "a", "an", "the", and "said" used herein may also include the plural forms. It should be further understood that the term "comprising" used in the specification of the present invention means the presence of the described features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, and / or their groups.

[0030] In the description of this patent, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing this patent and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this patent.

[0031] In the description of this patent, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected to", and "set" should be understood in a broad sense. For example, it can be fixedly connected and set, or detachably connected and set, or integrally connected and set. For those of ordinary skill in the art, the specific meanings of the above terms in this patent can be understood according to specific circumstances.

[0032] For the convenience of understanding the present invention, the following further explains the present invention with specific embodiments in conjunction with the drawings, and the specific embodiments do not constitute a limitation to the embodiments of the present invention.

[0033] Those skilled in the art should understand that the drawings are only schematic diagrams of the embodiments, and the components in the drawings are not necessarily essential for implementing the present invention.

[0034] Embodiment

[0035] As Figures 1 to 5 shown, the embodiment of the present invention provides a magnetic shielding structure for a DC induction heating device. The magnetic shielding structure is sleeved on the workpiece gripper 1 of the DC induction heating device and is used to isolate the magnetic field 3 between the workpiece gripper 1 and the two iron cores 2 of the DC induction heating device, thereby reducing the heating degree at both ends of the workpiece and effectively suppressing the heating temperature rise of the workpiece gripper 1.

[0036] The magnetic shielding structure includes a support outer cylinder 4, and a shielding inner cylinder 5 that can slide axially along the support outer cylinder 4 is arranged inside the support outer cylinder 4. Both the support outer cylinder 4 and the shielding inner cylinder 5 are coaxial with the rotation axis of the workpiece gripper 1. The magnetic shielding effect of the shielding inner cylinder 5 is mainly achieved by being made of a high-permeability material.

[0037] On the outer wall of the shielding inner cylinder 5, a sliding part 6 is installed to enable the shielding inner cylinder 5 to slide axially along the supporting outer cylinder 4. A plurality of axial sliding grooves 7 are uniformly arranged on the inner wall of the supporting outer cylinder 4. The sliding part 6 includes a plurality of axial sliding rails 8 corresponding to the axial sliding grooves 7. An axial limiting hole 9 penetrating the cylinder wall is provided on the supporting outer cylinder 4. The sliding part 6 further includes a handle 10 protruding from the axial limiting hole 9.

[0038] On the axial sliding rail 8, a pulley 11 is provided, and the pulley 11 rolls axially along the supporting outer cylinder 4. On the front end cylinder wall of the supporting outer cylinder 4, a plurality of blind holes 12 penetrating the cylinder wall and corresponding to the axial sliding grooves 7 are provided. In the blind holes 12, rollers 13 are provided, and the rollers 13 roll axially along the supporting outer cylinder 4. The diameter of the rollers 13 is larger than the thickness of the supporting outer cylinder 4.

[0039] The outer diameter of the shielding inner cylinder 5 is smaller than the distance between the two iron cores 2.

[0040] It further includes a fixed platform 14. On the fixed platform 14, a bracket 15 is installed, and the supporting outer cylinder 4 is installed on the bracket 15. By using the fixed platform 14 and the bracket 15, the supporting outer cylinder and the shielding inner cylinder can be coaxially aligned with the workpiece gripper, realizing uniform shielding of the magnetic fields at both ends of the workpiece gripper and the workpiece.

[0041] The number of the axial sliding grooves 7 is 5, and the number of the axial sliding rails corresponds to the number of the axial sliding grooves to ensure that the shielding inner cylinder 5 can stably slide in the supporting outer cylinder 4.

[0042] In practical applications, the number of the axial sliding grooves is not limited by the above number, and those skilled in the art can set the number of the axial sliding grooves according to specific situations.

[0043] The shielding inner cylinder 5 is made of high-permeability magnetic materials, such as silicon steel sheets, alloys formed by various iron products and rare earth elements, such as high-permeability (Fe Si B)98(Cu Nb)2 amorphous alloy. The sliding part 6 is made of non-magnetic metal materials, such as tungsten carbide, non-magnetic cemented carbides such as YSN15, YSN30 and W85, YEN21 non-magnetic cermet materials, high non-magnetic steels belonging to the austenite of the Fe—Mn—Al—C series, and various non-magnetic steels such as 20Mn23AlV, 45Mn17Al3(917), 30Mn20Al3, 40Mn18Cr3, 40Mn18Cr4V, 50Mn18Cr4V.

[0044] Figure 4The figure shows a schematic diagram of the basic working principle of a DC induction heater. The DC induction heater shown in the figure mainly includes an iron core 2, a workpiece to be processed 16, and a workpiece gripper 1. The air gap formed by the iron core 2 is the heating area of the DC induction heater, and a transverse magnetic field 3 is distributed in the heating area. Here, it is mainly to illustrate the basic working principle of the DC induction heater, so only the heating area part of the DC induction heater is shown in Figure 4 where the superconducting coil or other magnetic field source that generates the magnetic field 3 and the motor used to drive the rotation of the aluminum rod to be heated are not shown. When the DC induction heater is working normally, the workpiece gripper 1 is integrated with the rotating shaft of the driving motor. The metal workpiece (i.e., the workpiece to be processed 16) is clamped by the workpiece grippers 1 at both ends and rotates in the transverse magnetic field 3 in the iron core air gap driven by the motor. Since the metal workpiece continuously cuts the magnetic induction lines during rotation, eddy currents will be generated inside it, and Joule heat will be generated under the action of its own resistance. The Joule heat will be converted into the thermal energy required for the temperature rise of the metal workpiece.

[0045] Figure 5 The figure shows a schematic diagram of the installation position of the magnetic shielding structure in the DC induction heater. The magnetic shielding structure adopts a telescopic structure with an inner and outer cylinder sleeved manner, and mainly includes a shielding inner cylinder 5 as the magnetic shielding layer and a support outer cylinder 4 as the support structure. The magnetic shielding structure is installed around the workpiece gripper 1. The outer cylinder is located on both sides of the iron core, coaxial with the metal workpiece, and is immovable; the inner cylinder is sleeved inside the outer cylinder and can slide left and right in the outer cylinder. It is also coaxial with the workpiece, and its outer diameter is smaller than the width of the air gap formed by the iron core and larger than the outer diameter of the workpiece gripper. In this way, it can ensure that the inner cylinder enters the heating area to cover the workpiece gripper, so as to achieve the purpose of magnetic shielding for the workpiece gripper, and can slide in the outer cylinder to adjust its magnetic shielding range, that is, the depth of the inner cylinder entering the heating area.

[0046] Figure 1 The figure shows a schematic diagram of a telescopic magnetic shielding structure with an inner and outer cylinder sleeved manner. The magnetic shielding structure mainly includes a support outer cylinder 4, a shielding inner cylinder 5, and a platform 6 for fixing the magnetic shielding structure. Axial limiting holes 9 penetrating the cylinder wall are provided in the middle parts of the front and rear sides of the support outer cylinder 4. There are rollers 13 for assisting the sliding of the inner cylinder at the right edge position of the outer cylinder. The diameter of the rollers 13 is larger than the wall thickness of the outer cylinder. In this embodiment, 5 rollers 13 are evenly distributed, but not limited to 5. A fixing bracket is provided on the lower side of the outer cylinder. Handles are provided on both the front and rear sides of the inner cylinder, and the handles cooperate with the axial limiting holes 9 on both the front and rear sides of the outer cylinder, which can ensure that the inner cylinder does not slide out of the outer cylinder when sliding in the outer cylinder, and can also prevent the inner cylinder from rotating around the axis.

[0047] Figure 2The figure shows a schematic diagram of the outer cylinder structure of a telescopic magnetic shielding structure in the form of an inner and outer cylinder set. On the other side of the inner cylinder wall relative to the circular wheel, there is a trapezoidal axial slideway 7. In the embodiment, there are 5 slideways evenly distributed, but not limited to 5. The slideways do not completely penetrate along the inner cylinder wall.

[0048] Figure 3 The figure shows a schematic diagram of the inner cylinder structure of a telescopic magnetic shielding structure in the form of an inner and outer cylinder set. A sliding part 6 made of non-magnetic metal material with pulleys 11 installed is provided. The pulleys 11 are installed in the trapezoidal cross-section stretching bodies (i.e., axial slide rails 8) protruding from the sliding part 6. There are 5 trapezoidal cross-section stretching bodies evenly distributed in a ring along the sliding part, but not limited to 5. It mainly cooperates with the axial slideways. The function of the pulleys 11 is to make it easier for the inner cylinder to slide in the outer cylinder. At the same time, the handles are also installed on both sides of the sliding part. The magnetic shielding effect of the inner cylinder is mainly achieved by being made of high-permeability materials. The inner and outer diameters of the magnetic shielding cylinder are the same as those of the sliding part and are fixed coaxially together. The total length of the sliding part 9 and the magnetic shielding cylinder is the same as or longer than that of the outer cylinder.

[0049] In summary, the magnetic shielding structure described in the embodiment of the present invention for a DC induction heating device, that is, adding a circle of high-permeability materials around the workpiece gripper to form a shielding layer, guiding the magnetic field that should pass through the area where the workpiece gripper is located to the shielding layer, so as to reduce the magnetic field in the workpiece gripper area and at both ends of the workpiece, achieving the purpose that the workpiece gripper is not heated or reducing the heat generated in the workpiece gripper, and at the same time, it can also solve the problem of overheating at both ends of the workpiece.

[0050] Using high-permeability materials as the magnetic shielding structure, attracting the magnetic field that should pass through the workpiece gripper into the shielding layer, so that the magnetic field passes through the shielding layer, which can reduce the magnetic field in the workpiece gripper area. It can be used to reduce the magnetic field intensity at both ends of the metal workpiece and solve the phenomenon of overheating at both ends of the metal workpiece during the heating process. The magnetic shielding structure adopted is a fixed structure and does not rotate with the workpiece, workpiece gripper, motor, etc.

[0051] In specific applications, the magnetic shielding structure adopted is but not limited to a cylindrical shape, fixed around the workpiece gripper, maintaining an appropriate distance from the workpiece gripper, and adopting but not limited to a telescopic structure to facilitate the feeding and grasping of metal workpieces.

[0052] The adopted magnetic shielding telescopic structure adopts but not limited to the inner and outer cylinder set method. In the adopted inner and outer cylinder set method, the outer cylinder is a support structure, made of non-magnetic materials, but not limited to a cylindrical shape, and is fixed and immovable; the inner cylinder is a magnetic shielding cylinder and can slide freely in the outer cylinder. This can ensure the integrity of the magnetic shielding cylinder and can also adjust the shielding range to achieve the best shielding effect.

[0053] In the inner and outer cylinder sleeving method adopted by the magnetic shielding telescopic structure, a slideway is provided between the inner cylinder and the outer cylinder to prevent the magnetic shielding cylinder from rotating around the axis. In the inner and outer cylinder sleeving method adopted, rotatable round wheels are evenly arranged in a ring along the outer wall of the inner cylinder on the side far from the workpiece on the outer surface of the inner cylinder, facilitating the sliding of the inner cylinder. A circle of round wheels is also provided on the side of the outer cylinder close to the workpiece, which also facilitates the sliding of the inner cylinder.

[0054] In the inner and outer cylinder sleeving method adopted, the slideway on the inner wall of the outer cylinder is not completely penetrated. Therefore, the sliding range of the inner cylinder in the outer cylinder is limited and it will not slide out of the outer cylinder. Horizontal grooves penetrating the cylinder wall are opened at the middle positions on both sides of the outer cylinder, and handles perpendicular to the cylinder wall are provided on both sides of the outer wall of the inner cylinder. Through the cooperation of the horizontal grooves and the handles, the inner cylinder can move in the outer cylinder without sliding out. It is applicable to all DC induction heating occasions, including superconducting DC induction heating and permanent magnet DC induction heating, and is applicable whether the permanent magnet rotates or the workpiece rotates.

[0055] Those of ordinary skill in the art can understand that the components in the device in the embodiments of the present invention can be distributed in the device of the embodiments according to the description of the embodiments, or can be correspondingly changed and located in one or more devices different from the embodiments. The components of the above embodiments can be combined into one component, or can be further split into multiple sub-components.

[0056] As described above, only the preferred specific embodiments of the present invention are given, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A magnetic shielding structure for a DC induction heating device, characterized in that: The magnetic shielding structure is sleeved on the workpiece gripper (1) of the DC induction heating device for isolating the magnetic field (3) between the workpiece gripper (1) and the two iron cores (2) of the DC induction heating device; The magnetic shielding structure includes a support outer cylinder (4), and a shielding inner cylinder (5) that can slide axially along the support outer cylinder (4) is arranged inside the support outer cylinder (4); both the support outer cylinder (4) and the shielding inner cylinder (5) are coaxial with the rotation axis of the workpiece gripper (1); wherein, the outer diameter of the shielding inner cylinder (5) is smaller than the air gap width formed by the iron cores and larger than the outer diameter of the workpiece gripper (1), ensuring that the shielding inner cylinder (5) enters the heating area to cover the workpiece gripper, so as to achieve the purpose of magnetic shielding of the workpiece gripper. The shielding inner cylinder (5) slides in the support outer cylinder (4) to adjust its magnetic shielding range, that is, the depth of the inner cylinder entering the heating area; A sliding part (6) for sliding the shielding inner cylinder (5) axially along the support outer cylinder (4) is installed on the outer wall of the shielding inner cylinder (5); a plurality of axial slideways (7) are evenly arranged on the inner wall of the support outer cylinder (4), and the sliding part (6) includes a plurality of axial slide rails (8) corresponding to the axial slideways (7); the axial slideways (7) on the inner wall of the support outer cylinder (4) do not all penetrate the support outer cylinder (4), ensuring that the shielding inner cylinder (5) will not slide out of the support outer cylinder (4); an axial limiting hole (9) penetrating the cylinder wall is provided on the support outer cylinder (4), and the sliding part (6) further includes a handle (10) protruding from the axial limiting hole (9). Pulleys (11) are provided on the axial slide rails (8), and the pulleys (11) roll axially along the support outer cylinder (4).

2. The magnetic shielding structure for a DC induction heating device according to claim 1, characterized in that: A plurality of blind holes (12) penetrating the cylinder wall corresponding to the axial slideways (7) are provided on the front end cylinder wall of the support outer cylinder (4), rollers (13) are arranged in the blind holes (12), the rollers (13) roll axially along the support outer cylinder (4), and the diameter of the rollers (13) is larger than the thickness of the support outer cylinder (4).

3. The magnetic shielding structure for a DC induction heating device according to claim 2, characterized in that: The outer diameter of the shielding inner cylinder (5) is smaller than the distance between the two iron cores (2).

4. The magnetic shielding structure for a DC induction heating device according to claim 3, characterized in that: It further includes a fixed table (14), a bracket (15) is installed on the fixed table (14), and the support outer cylinder (4) is installed on the bracket (15).

5. The magnetic shielding structure for a DC induction heating device according to claim 4, characterized in that: The number of the axial slideways (7) is 5.

6. The magnetic shielding structure for a DC induction heating device according to any one of claims 1-5, characterized in that: The shielding inner cylinder (5) is made of a high-permeability magnetic material, and the sliding part (6) is made of a non-magnetic metal material.

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