An electromagnetic inductor for induction heating

Abstract

The application relates to the technical field of electromagnetic induction heating, and discloses an electromagnetic inductor for induction heating, which is used for induction heating of a workpiece, and the workpiece is divided into a plurality of heating areas adjacent to each other according to shape mutation positions of a to-be-processed area of the workpiece; the electromagnetic inductor comprises a conductor and a magnetic conductor; the conductor is used for transmitting an alternating electric field; and the magnetic conductor is used for conducting an alternating magnetic field to the workpiece to be heated; the magnetic conductor is in a U shape, the magnetic conductor is wrapped outside the conductor, the widths of two side plates of the magnetic conductor are Y1 and Y2 respectively, the width of a top plate of the magnetic conductor is Y3, Y3>=Y1, and Y3>=Y2; under the premise that the thickness of each magnetic conductor is the same, the size parameter of the magnetic conductor is defined as Y1+Y2+Y3; a plurality of magnetic conductors are stacked and combined to form a magnetic conductor group, one heating area corresponds to one magnetic conductor group, and the size parameters of the magnetic conductors in adjacent magnetic conductor groups are different. The size of the magnetic conductor is changed according to the structure of the workpiece, and the heating effect on different positions of the workpiece is improved.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic inductor technology, and more particularly to an electromagnetic inductor suitable for induction heating. Background Technology

[0002] Induction hardening utilizes electromagnetic induction to generate eddy currents within the workpiece, thereby heating it. It offers advantages such as minimal workpiece deformation, reduced oxidation and decarburization during heat treatment, high production efficiency, and energy-saving and environmentally friendly processes that can be mechanized or automated. Workpieces that have undergone induction hardening typically exhibit residual stress on their surface. Due to the skin effect, induction hardening results in a better austenitizing temperature compared to resistance furnace hardening. The higher superheat leads to a greater degree of complete austenitization and higher surface hardness, all of which contribute to improved part lifespan.

[0003] However, existing induction hardening technology has certain limitations. One of the most critical factors affecting induction heating is the inductor design. Especially for some products with irregular structures, traditional inductor designs can lead to poor heating effects at locations with abrupt changes in holes, slots, or geometric shapes. Some parts cannot even effectively heat locations with abrupt changes, which means that such products currently need to continue to use integral hardening or carburizing, thus limiting the application of induction hardening.

[0004] Therefore, an electromagnetic inductor that can effectively heat the abrupt changes in the position of the part is needed. Summary of the Invention

[0005] This invention addresses the existing technical problems by providing an electromagnetic inductor for induction heating.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: an electromagnetic inductor for induction heating, used to induction heat a workpiece, wherein the workpiece to be processed area is divided into several adjacent heating areas according to the abrupt change in shape, the electromagnetic inductor includes a conductor and a magnetic conductor, the conductor is used to transmit an alternating electric field, and the magnetic conductor is used to conduct an alternating magnetic field into the workpiece to be heated.

[0007] The magnetic conductor is U-shaped and surrounds the outside of the conductor. The widths of the two side plates of the magnetic conductor are Y1 and Y2, respectively, and the width of the top plate of the magnetic conductor is Y3, where Y3≥Y1 and Y3≥Y2. Under the premise that the thickness of each magnetic conductor is the same, the size parameter of the magnetic conductor is defined as Y1+Y2+Y3.

[0008] Multiple magnetic conductors are stacked and combined to form a magnetic conductor group, with one heating area corresponding to one magnetic conductor group. The size parameters of the magnetic conductors in adjacent magnetic conductor groups are different.

[0009] Based on the above technical solution, the present invention adjusts the magnetic induction intensity at the corresponding position of the workpiece by changing the size parameters of the magnetic conductor, thereby achieving uniform heat treatment processing of workpieces with abrupt changes such as grooves and holes.

[0010] To achieve ease of use and equipment stability, the above technical solution can be improved as follows:

[0011] Furthermore, it is applicable to workpieces with a planar rectangular groove of depth D1 on the surface to be processed, where D1 < 3mm. The workpiece is divided into two heating zones by the planar rectangular groove. Specifically, the planar rectangular groove itself is designated as the first heating zone, and the area outside the planar rectangular groove is designated as the second heating zone.

[0012] The electromagnetic sensor covers the first area to be heated and the second area to be heated. The electromagnetic sensor is provided with a first magnetic conductor group and a second magnetic conductor group. The first magnetic conductor group is adapted to the first area to be heated, and the second magnetic conductor group is adapted to the second area to be heated.

[0013] set up:

[0014] The dimensional parameter a of the magnetic conductors in the first magnetic conductor group is Y1 + Y2 + Y3;

[0015] The dimensional parameter b of the magnetic conductors in the second magnetic conductor group is Y1'+Y2'+Y3';

[0016] Then a = b + 1.5 × D1.

[0017] Furthermore, the width dimensions of the magnetic conductors in the first magnetic conductor group are Y1≤6.5mm, Y2≤6.5mm, and Y3≤6.5mm.

[0018] Furthermore, the width dimensions of the magnetic conductors in the second magnetic conductor group are Y1'≤5.5mm, Y2'≤5.5mm, and Y3'≤5.5mm.

[0019] Furthermore, the difference between any two of the width dimensions Y1, Y2, and Y3 of the magnetic conductors in the first magnetic conductor group is ≤1.5mm.

[0020] Furthermore, this method is applicable to workpieces with corner grooves on their surfaces to be processed. The corner groove includes a first groove wall and a second groove wall arranged at an angle. At the intersection of the first groove wall and the second groove wall, there is an arc-shaped groove with a cross-section of radius R, where R < 12 mm. The depth of the arc-shaped groove in the direction perpendicular to the first groove wall is D2, where D2 < 3 mm. The depth of the arc-shaped groove in the direction perpendicular to the second groove wall is D3, where D3 < 2 mm. The workpiece is divided into two heating zones, a corner zone and a non-corner zone, with the corner as the boundary.

[0021] The electromagnetic sensor is an L-shaped sensor adapted to the workpiece, and it is provided with a first magnetic conductor group and a second magnetic conductor group. The first magnetic conductor group is adapted to the corner area, and the second magnetic conductor group is adapted to the non-corner area.

[0022] The dimensional parameter a of the magnetic conductors in the first magnetic conductor group is Y1 + Y2 + Y3;

[0023] The dimensional parameter b of the magnetic conductors in the second magnetic conductor group is Y1'+Y2'+Y3';

[0024] And a = b + R / 2 + D2 + 2 × D3.

[0025] Furthermore, the first magnetic conductor group covers the same length L in the directions of the first and second slot walls, and the length L = 3 × R + D2 + D3.

[0026] The beneficial effects of this invention are: based on the structure of the workpiece, this invention changes the size of the magnetic conductor on the induction coil, so that different magnetic flux is generated at different positions of the inductor when the alternating current passes through the induction coil, thereby improving the heating effect on different positions of the workpiece, improving the quality of the heat treatment process of the workpiece, promoting the use of induction heating on different workpieces, expanding the applicability of induction heating, making it more energy-efficient and environmentally friendly, and reducing energy consumption. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the electromagnetic sensor of the present invention;

[0028] Figure 2 This is a cross-sectional schematic diagram of Embodiment 1 of the present invention;

[0029] Figure 3 The effect of heat treatment using traditional methods on a workpiece with a planar rectangular groove.

[0030] Figure 4 The heat treatment effect diagram of the planar rectangular groove workpiece using the scheme in Example 1;

[0031] Figure 5 This is a cross-sectional schematic diagram of Embodiment 2 of the present invention;

[0032] Figure 6 A schematic diagram illustrating the effect of traditional heat treatment on a workpiece with a right-angled groove.

[0033] Figure 7 The heat treatment effect diagram of the workpiece with right-angle groove using the scheme of Example 2 is shown.

[0034] The attached diagram is labeled as follows: 1. Conductor; 2. Magnetic conductor; 3. Workpiece. Detailed Implementation

[0035] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0036] This invention discloses an electromagnetic inductor for induction heating, used to induction heat a workpiece 3. The area to be processed of the workpiece 3 is divided into several adjacent heating areas according to the abrupt change in shape. The electromagnetic inductor includes a conductor 1 and a magnetic conductor 2. The conductor 1 is used to transmit an alternating electric field, and the magnetic conductor 2 is used to conduct an alternating magnetic field into the workpiece 3 to be heated.

[0037] The magnetic conductor 2 is U-shaped and surrounds the outside of the conductor 1. The widths of the two side plates of the magnetic conductor 2 are Y1 and Y2, respectively, and the width of the top plate of the magnetic conductor 2 is Y3. (Refer to...) Figure 2 As shown, magnetic lines of force enter the workpiece 3 through the two side plates of the magnetic conductor 2. All magnetic lines of force need to pass through the top plate of the magnetic conductor 2. Therefore, the width Y3 of the top plate is greater than Y1 and Y2 to prevent the magnetic conductor 2 from burning out due to excessive heat, thus ensuring the service life of the electromagnetic inductor. Assuming each magnetic conductor 2 has the same thickness, the dimensional parameters of the magnetic conductor 2 are defined as Y1+Y2+Y3. Multiple magnetic conductors 2 are stacked and combined to form a magnetic conductor group, with one heating area corresponding to one magnetic conductor group. The dimensional parameters of the magnetic conductors 2 within adjacent magnetic conductor groups are different.

[0038] Example 1:

[0039] Please refer to Figures 1 to 4 As shown, this embodiment provides a sensor suitable for a workpiece 3 with a planar rectangular groove of depth D1 on the surface to be processed. The conductor 1 is an induction coil, specifically a copper induction coil, and the magnetic conductor 2 is composed of multiple silicon steel sheets stacked together.

[0040] In this example, the depth D1 of the planar rectangular groove is 2mm. Workpiece 3 is divided into two heating zones by the planar rectangular groove. Specifically, the planar rectangular groove itself is designated as the first heating zone. (See [link to relevant documentation]). Figure 2 In area A, the area outside the planar rectangular groove is the second heating zone. See [link / reference]. Figure 2 Regions B and C (both regions B and C belong to the second heating zone);

[0041] The electromagnetic sensor covers the first area to be heated and the second area to be heated. The electromagnetic sensor is provided with a first magnetic conductor group and a second magnetic conductor group. The first magnetic conductor group is adapted to the first area to be heated, and the second magnetic conductor group is adapted to the second area to be heated.

[0042] set up:

[0043] The dimensional parameter a of the magnetic conductor 2 in the first magnetic conductor group is Y1 + Y2 + Y3 = 5mm + 5mm + 6mm = 16mm;

[0044] The dimensional parameter b of the magnetic conductor 2 in the second magnetic conductor group is Y1'+Y2'+Y3'=4mm+4mm+5mm=13mm;

[0045] The following formula applies between a and b:

[0046] a = b + 1.5 × D1.

[0047] Therefore, based on the above formula, after setting the size parameters of the magnetic conductor 2 in the first magnetic conductor group or the size parameters of the magnetic conductor 2 in the second magnetic conductor group and determining the depth D of the planar rectangular groove, the size parameters of the magnetic conductor in the other magnetic conductor group can be deduced.

[0048] The difference between any two of the width dimensions Y1, Y2, and Y3 of the magnetic conductor 2 in the first magnetic conductor group is ≤1.5mm, and the closer they are, the better. This ensures that the magnetic flux of the magnetic field lines passing through the inside of the magnetic conductor 2 is as consistent as possible, ensuring that the magnetic conductor 2 heats up normally and avoiding local overheating.

[0049] For example, in this embodiment, given that the depth of the rectangular groove on the workpiece 3 is D1 = 2mm, and the size parameters of the magnetic conductor 2 in the second magnetic conductor group are Y1' = 4mm, Y2' = 4mm, and Y3' = 5mm, we can calculate that b = Y1' + Y2' + Y3' = 13.

[0050] Based on a = b + 1.5 × D1, we get a = 16 mm;

[0051] In the first magnetic conductor group, the difference between any two of the width dimensions Y1, Y2, and Y3 of the magnetic conductor 2 is ≤1.5mm, and when compared individually, Y3 is greater than or equal to Y1 and Y2. Therefore, Y1≤5mm, Y2≤5mm, and Y3≤6mm can be selected. Alternatively, Y1=4.5mm, Y2=5.5mm, and Y3=6mm can be selected, which can also ensure that a=16mm.

[0052] Based on the structure of the workpiece 3, this invention changes the magnitude of the magnetic flux on the magnetic conductor 2 at different positions on the inductor, thereby achieving uniform heating of the workpiece 3 and ensuring effective heating even at abrupt changes in position. Figure 3 The effect of heat treatment using traditional methods on a workpiece with a planar rectangular groove. Figure 4The diagram shows the heat treatment effect of the scheme in Example 1 on a planar rectangular groove workpiece. It can be seen that when processing planar rectangular groove workpieces using traditional processes, the treatment layer thickness is insufficient at the planar rectangular groove locations, and the layer is also uneven at non-planar rectangular groove locations. The heat treatment layer using the scheme in this embodiment is more uniform. It can also meet the hardening layer requirements of the groove structure on workpiece 3, and residual compressive stress can exist on the surface of workpiece 3, which can improve product quality and service life, and promote the widespread use of electromagnetic induction heating on irregularly shaped workpieces 3. Specific Implementation Example 2

[0054] Please refer to Figures 5 to 7 As shown, in this example, the workpiece 3 to be processed is a workpiece with a right-angled groove.

[0055] This invention discloses a workpiece 3 suitable for processing workpieces with corner grooves on their surfaces. The corner groove includes a first groove wall and a second groove wall arranged at an angle. At the intersection of the first and second groove walls, an arc-shaped groove with a cross-sectional radius R < 12 mm is provided. The depth of the arc-shaped groove perpendicular to the first groove wall is D2 < 3 mm, and the depth of the arc-shaped groove perpendicular to the second groove wall is D3 < 2 mm. The workpiece 3 is divided into two heating zones, a corner zone and a non-corner zone, with the corner as the boundary. (See details for the corner zone.) Figure 5 For area D in the diagram, see the non-corner area. Figure 5 Region E in the text.

[0056] The electromagnetic sensor is an L-shaped sensor adapted to the workpiece 3, and is provided with a first magnetic conductor group and a second magnetic conductor group. The first magnetic conductor group is adapted to the corner area, and the second magnetic conductor group is adapted to the non-corner area.

[0057] The dimensional parameter a of the magnetic conductor 2 in the first magnetic conductor group is Y1 + Y2 + Y3;

[0058] The dimensional parameter b of the magnetic conductor 2 in the second magnetic conductor group is Y1'+Y2'+Y3';

[0059] And a = b + R / 2 + D2 + 2 × D3.

[0060] In this embodiment, the corner groove includes a groove wall 1 and a groove wall 2 arranged at right angles. The radius of the arc groove is R = 8mm, the depth is D2 = 1mm, and the depth is D3 = 0.5mm. The width of the magnetic conductor 2 in the first magnetic conductor group is Y1 = 6mm, Y2 = 5mm, and Y3 = 6mm, so a = 17mm.

[0061] Based on a = b + R / 2 + D2 + 2 × D3, we can calculate b = 11 mm. The width of the magnetic conductor 2 in the second magnetic conductor group can be Y1' = 4 mm, Y2' = 3 mm, Y3' = 4 mm, or Y1' = 3 mm, Y2' = 4 mm, Y3' = 4 mm.

[0062] The first magnetic conductor assembly covers the same length L in both the first and second directions of the slot wall, and the length L = 3 × R + D2 + D3. In this embodiment, the length L = 3 × 8 + 1 + 0.5 = 25.5 mm.

[0063] This invention, based on the actual structure of the grooved workpiece 3, changes the size of the magnetic conductor 2 on the conductor 1, thereby generating different magnetic fluxes at different positions of the electromagnet, as shown in the reference. Figure 6 and Figure 7 As shown, the electromagnetic inductor of the present invention can significantly improve the heat treatment effect at the corner groove of workpiece 3 (wherein the area of ​​the cross-section represents the depth of the heat treatment layer of workpiece 3). Obviously, Figure 7 The workpiece treated with this method has a more uniform heat treatment layer depth, which generates compressive stress at the corner groove, improves the heat treatment process quality of workpiece 3, and especially improves the fatigue life of the parts, thus promoting the widespread use of induction heating and electromagnetic induction heating on irregularly shaped workpieces 3.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An electromagnetic inductor for induction heating, for induction heating of a workpiece (3) whose zone to be worked is divided into a number of heating zones adjacent to one another according to shape discontinuities, characterized in that, The electromagnetic sensor includes a conductor (1) and a magnetic conductor (2). The conductor (1) is used to transmit an alternating electric field, and the magnetic conductor (2) is used to transmit an alternating magnetic field to the workpiece (3) to be heated. The magnetic conductor (2) is U-shaped and surrounds the outside of the conductor (1). The widths of the two side plates of the magnetic conductor (2) are Y1 and Y2, respectively, and the width of the top plate of the magnetic conductor (2) is Y3, where Y3≥Y1 and Y3≥Y2. Under the premise that the thickness of each magnetic conductor (2) is the same, the size parameter of the magnetic conductor (2) is defined as Y1+Y2+Y3. Multiple magnetic conductors (2) are stacked and combined to form a magnetic conductor group. One heating area corresponds to one magnetic conductor group. The size parameters of the magnetic conductors (2) in adjacent magnetic conductor groups are different. The workpiece (3) has a planar rectangular groove with a depth of D1 on the surface to be processed, where D1 < 3 mm. The workpiece (3) is divided into two heating areas by the planar rectangular groove. Specifically, the planar rectangular groove itself is set as the first heating area, and the area outside the planar rectangular groove is the second heating area. The electromagnetic sensor covers the first area to be heated and the second area to be heated. The electromagnetic sensor is provided with a first magnetic conductor group and a second magnetic conductor group. The first magnetic conductor group is adapted to the first area to be heated, and the second magnetic conductor group is adapted to the second area to be heated. set up: The dimensional parameter a of the magnetic conductor (2) in the first magnetic conductor group is Y1+Y2+Y3; The dimensional parameter b of the magnetic conductor (2) in the second magnetic conductor group is Y1'+Y2'+Y3'; Then a = b + 1.5 × D1; Alternatively, the workpiece (3) has a corner groove on its surface to be processed. The corner groove includes a groove wall 1 and a groove wall 2 arranged at an angle. At the intersection of the groove wall 1 and the groove wall 2, there is an arc-shaped groove with a cross-section of radius R, and R < 12 mm. The depth of the arc-shaped groove in the direction perpendicular to the groove wall 1 is D2, and D2 < 3 mm. The depth of the arc-shaped groove in the direction perpendicular to the groove wall 2 is D3, and D3 < 2 mm. The workpiece (3) is divided into two heating areas, a corner area and a non-corner area, with the corner as the boundary. The electromagnetic sensor is an L-shaped sensor adapted to the workpiece (3), and is provided with a first magnetic conductor group and a second magnetic conductor group. The first magnetic conductor group is adapted to the corner area, and the second magnetic conductor group is adapted to the non-corner area. The dimensional parameter a of the magnetic conductor (2) in the first magnetic conductor group is Y1+Y2+Y3; The dimensional parameter b of the magnetic conductor (2) in the second magnetic conductor group is Y1'+Y2'+Y3'; And a = b + R / 2 + D2 + 2 × D3.

2. The electromagnetic induction device of claim 1, wherein When the workpiece (3) has a planar rectangular groove with a depth of D1 on the surface to be processed, the width dimensions of the magnetic conductor (2) in the first magnetic conductor group are Y1≤6.5mm, Y2≤6.5mm, and Y3≤6.5mm.

3. The electromagnetic induction device of claim 2, wherein, When the workpiece (3) has a planar rectangular groove with a depth of D1 on the surface to be processed, the width dimensions of the magnetic conductor (2) in the second magnetic conductor group are Y1'≤5.5mm, Y2'≤5.5mm, and Y3'≤5.5mm.

4. The electromagnetic sensor according to claim 1 or 2, characterized in that, When the workpiece (3) has a planar rectangular groove with a depth of D1 on the surface to be processed, the difference between any two of the width dimensions Y1, Y2, and Y3 of the magnetic conductor (2) in the first magnetic conductor group is ≤1.5mm.

5. The electromagnetic sensor according to claim 1, characterized in that, When the workpiece (3) has a corner groove on the surface to be processed, the first magnetic conductor group covers the same length L in the direction of the first groove wall and the second groove wall, and the length L = 3 × R + D2 + D3.

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