Induction heat treatment apparatus, quenching system, and induction heat treatment method

Abstract

The present disclosure relates to an induction heat treatment apparatus, a quenching system, and an induction heat treatment method. The induction heat treatment apparatus is used for induction heating of a workpiece (101). The induction heat treatment apparatus comprises an inductor assembly (1), the inductor assembly (1) is configured to surround the workpiece (101), and to move relative to the workpiece (101) along a preset path to perform scanning. The inductor assembly (1) comprises: a first induction frame (11), connected to a power supply; a second induction frame (12), disposed at an interval from the first induction frame (11) along a first direction (x), the second induction frame (12) being electrically connected to the first induction frame (11); and a third induction frame (13), the third induction frame (13) being in parallel connection with the second induction frame (12). The current directions in the first induction frame (11), the second induction frame (12), and the third induction frame (13) are the same.

Description

Induction heat treatment device, quenching system and induction heat treatment method

[0001] Cross-reference to related applications

[0002] The present disclosure is based on and claims priority to Chinese application No. 202410521518.3, filed on April 28, 2024, the disclosure of which is hereby incorporated by reference in its entirety into the present disclosure. TECHNICAL FIELD

[0003] The present disclosure relates to an induction heat treatment device, a quenching system and an induction heat treatment method. BACKGROUND

[0004] Induction heat treatment is an efficient and energy-saving heat treatment process. In order to improve the wear resistance of the workpiece surface, induction quenching treatment is required for the workpiece surface. By obtaining a hardened layer and surface hardness that meet the technical requirements, the wear resistance and performance of the workpiece surface are improved. The inductor is connected to a high-frequency or medium-frequency power supply through a transformer, which is an important component for electromagnetic induction heating of the workpiece. The process requirements are high, and the design of the structure directly affects the efficiency of the induction heat treatment and the quality of the product.

[0005] For the case that the entire surface of the workpiece needs to be induction treated, when the inductor is heated to the end position of the workpiece, the electromagnetic field is distorted, the end face cuts the alternating magnetic induction lines, and the end chamfer position has a high heating speed, which makes it difficult to achieve uniform heating at the end. The end hardening layer is often deep or shallow, and the depth of the hardening layer is uneven. This phenomenon is also known as the sharp corner effect.

[0006] SUMMARY

[0007] Embodiments of the present disclosure provide an induction heat treatment device, a quenching system and an induction heat treatment method, which can improve the uniformity of induction heat treatment.

[0008] According to a first aspect of the present disclosure, an induction heat treatment device is provided for induction heating of a workpiece. The induction heat treatment device includes an inductor assembly configured to surround the workpiece and move relative to the workpiece along a predetermined path for scanning. The inductor assembly includes:

[0009] a first induction frame connected to a power supply;

[0010] a second induction frame spaced apart from the first induction frame along a first direction and disposed on a first side of the first induction frame, the second induction frame being electrically connected to the first induction frame; and

[0011] a third induction frame spaced apart from the first induction frame along the first direction on a second side of the first induction frame, the third induction frame being electrically connected to the first induction frame, and the third induction frame being connected in parallel with the second induction frame.

[0012] The current directions in the first induction frame, the second induction frame and the third induction frame are the same.

[0013] In some embodiments, the first induction frame, the second induction frame and the third induction frame are arranged in planes which are perpendicular to the first direction.

[0014] In some embodiments, the central axes of the first induction frame, the second induction frame and the third induction frame coincide.

[0015] In some embodiments, the induction heat treatment device further comprises:

[0016] a first connecting beam for connecting the first induction frame to the power supply, the first connecting beam extending along a second direction, the second direction being perpendicular to the first direction; and

[0017] a second connecting beam for connecting the second induction frame and the third induction frame to the power supply, at least a length of the second connecting beam extending along the second direction, the second connecting beam and the first connecting beam being spaced apart along a third direction, the third direction being perpendicular to the first direction and the second direction.

[0018] In some embodiments, the first induction frame, the second induction frame, the third induction frame, the first connecting beam and the second connecting beam are hollow structures, and the induction heat treatment device further comprises:

[0019] two cooling water joints respectively arranged at the ends of the first connecting beam and the second connecting beam away from the inductor assembly, one of the two cooling water joints being for flowing in cooling water and the other being for flowing out cooling water.

[0020] In some embodiments, the induction heat treatment device further comprises:

[0021] a bottom plate perpendicular to the second direction, the bottom plate being connected to the ends of the first connecting beam and the second connecting beam away from the inductor assembly, the bottom plate being connected to the power supply; and

[0022] an insulating plate connected to the bottom plate and perpendicular to the third direction, the insulating plate being arranged between the first connecting beam and the second connecting beam.

[0023] In some embodiments, the inductor assembly further comprises:

[0024] a first connecting section extending along the second direction, the first connecting section being connected to the first induction frame, and the first connecting section being spaced apart from the first connecting beam along the third direction;

[0025] two second connecting sections each extending along the second direction, the two second connecting sections each being connected to the second induction frame, and the two second connecting sections being spaced apart along the third direction; and

[0026] two third connecting segments, each extending along the second direction, the two third connecting segments being connected to the third induction frame and being spaced apart along the third direction.

[0027] In some embodiments, the inductor assembly further comprises:

[0028] a first transition segment connected between the first connecting segment and the second connecting segment close to the first connecting beam, the first transition segment extending along the first direction; and / or

[0029] a second transition segment connected between the first connecting segment and the third connecting segment close to the first connecting beam, the second transition segment extending along the first direction; and / or

[0030] a third transition segment connected between the second connecting segment and the second connecting segment away from the first connecting beam, the third transition segment extending along the first direction; and / or

[0031] a fourth transition segment connected between the third connecting segment and the second connecting segment away from the first connecting beam, the fourth transition segment extending along the first direction.

[0032] In some embodiments, the inductor assembly further comprises:

[0033] a magnetic conductor provided on at least one of the first induction frame, the second induction frame and the third induction frame.

[0034] In some embodiments, the magnetic conductor comprises a plurality of silicon steel sheets, the plurality of silicon steel sheets being adjacently arranged along a circumferential direction of the inductor assembly, and a slot of the silicon steel sheet being located on a side of the inductor assembly facing the workpiece.

[0035] In some embodiments, a thickness of the silicon steel sheet is adapted to a case depth and / or an induction heating frequency.

[0036] In some embodiments,

[0037] a first distance between the first induction frame and the second induction frame is adapted to a case depth of the end portion of the workpiece; and / or

[0038] a second distance between the first induction frame and the third induction frame is adapted to the case depth of the end portion of the workpiece.

[0039] In some embodiments, the first distance is equal to the second distance.

[0040] In some embodiments, the first induction frame, the second induction frame and the third induction frame are each annular.

[0041] According to a second aspect of the present disclosure, an induction quenching system is provided, comprising:

[0042] the inductor assembly of the above embodiments; and

[0043] A water spraying device for spraying cooling water on a workpiece after induction heating.

[0044] According to a third aspect of the present disclosure, an induction heating method based on the induction heat treatment device of the above embodiments is provided, comprising:

[0045] rotating the workpiece around a preset center line;

[0046] moving the inductor assembly to the first end of the workpiece;

[0047] moving the inductor assembly along a preset path to be flush with the first end of the workpiece;

[0048] moving the inductor assembly along a preset path to be away from the second end of the workpiece.

[0049] In some embodiments, during the movement of the inductor assembly, the second induction frame is flush with the workpiece before the first induction frame, and moving the inductor assembly along the preset path to be flush with the first end of the workpiece comprises:

[0050] during the process of the second induction frame being flush with the first end of the workpiece, the inductor assembly does not heat the workpiece;

[0051] during the process of the first induction frame being flush with the first end of the workpiece, only the first induction frame heats the workpiece;

[0052] during the process of the third induction frame being flush with the first end of the workpiece, the first induction frame heats the workpiece, and the heating power of the second induction frame and the third induction frame gradually increases, and the maximum heating power of the second induction frame and the third induction frame is less than the heating power of the first induction frame.

[0053] In some embodiments, during the movement of the inductor assembly, the second induction frame is away from the workpiece before the first induction frame, and moving the inductor assembly along the preset path to be away from the second end of the workpiece comprises:

[0054] during the process of the second induction frame being away from the second end of the workpiece, the heating power of the third induction frame gradually decreases;

[0055] after the second induction frame is away from the second end of the workpiece, only the first induction frame heats the workpiece;

[0056] after the first induction frame is away from the second end of the workpiece, the inductor assembly stops heating.

[0057] Based on the above technical scheme, the induction heat treatment device provided by the embodiment of the present disclosure can automatically reduce the heating power of the inductor assembly during the movement of the inductor assembly through the end portion of the workpiece, thereby compensating for the rapid temperature rise of the end portion caused by the sharp corner effect, improving the uniformity of the induction heat treatment, and making the depth of the hardened layer of the end portion of the workpiece consistent with the depth of the hardened layer of the main body portion. The inductor assembly can achieve uniform heating effect of the workpiece in a single scanning, without reciprocating adjustment, thereby improving the efficiency of the induction heat treatment. BRIEF DESCRIPTION OF DRAWINGS

[0058] The accompanying drawings, which are included to provide a further understanding of the present disclosure and constitute a part of this application, illustrate certain illustrative embodiments of the present disclosure and are used to explain the present disclosure, but should not be construed as an improper limitation on the present disclosure. In the drawings:

[0059] FIG. 1 is a structural schematic diagram of some embodiments of the induction heat treatment device of the present disclosure.

[0060] FIG. 2 is a side view of some embodiments of the induction heat treatment device of the present disclosure.

[0061] FIG. 3 is a structural schematic diagram of some embodiments of the inductor assembly of the present disclosure for induction heating of a workpiece.

[0062] FIGS. 4a-g are schematic diagrams of the distribution of heating power density on the surface of a workpiece in multiple stages during the scanning induction heating process of the inductor assembly of the present disclosure.

[0063] BRIEF DESCRIPTION OF DRAWINGS

[0064] 1, inductor assembly; 2, first connecting beam; 3, second connecting beam; 4, cooling water joint; 5, bottom plate; 6, insulating plate; 7, fixing piece; 11, first induction frame; 111, first connecting section; 12, second induction frame; 122, second connecting section; 13, third induction frame; 133, third connecting section; 110, first transition section; 120, second transition section; 130, third transition section; 140, fourth transition section; 101, workpiece; x, first direction; y, second direction; z, third direction. DETAILED DESCRIPTION

[0065] The present disclosure is described in detail below. In the following paragraphs, different aspects of the embodiments are defined in more detail. Each aspect thus defined can be combined with any other aspect or aspects, unless explicitly stated otherwise. In particular, any feature described as preferred or advantageous can be combined with other feature or features described as preferred or advantageous.

[0066] The terms "first", "second", and the like appearing in the present disclosure are only for the convenience of description to distinguish different components with the same name, and do not represent a prior or a primary relationship.

[0067] In the description of the present disclosure, it should be understood that the orientation or position relationship indicated by the terms "upper", "lower", "inner" or "outer" is defined based on the inductor assembly, the induction frame or the workpiece as the reference, only for the convenience of describing the present disclosure, and does not indicate or imply that the device must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the protection scope of the present disclosure.

[0068] The inventors found in the research process that, in order to control the end hardening layer fluctuation problem, for products with relatively shallow hardening layer requirements, the industry often uses single-coil inductor structure or increases shielding flux guides to reduce the influence of alternating magnetic field on the end, and to alleviate the problem of uneven end hardening layer; for products with relatively deep hardening layer requirements, generally use inductor structures with multiple effective coils, and compensate for the uneven end heating by adjusting the heating position and controlling the end heating dwell time and other heat treatment methods. The above measures cannot avoid the inherent end sharp corner effect of induction heating, and the improvement effect on the uneven heating problem is not ideal, for example, manual intervention may cause insufficient end heating. Especially for workpieces with groove structure near the end position, it is more likely to cause local stress concentration problems due to uneven end hardening layer, resulting in cracking along the groove direction.

[0069] In order to solve the problem of uneven end heating caused by sharp corner effect, first of all, the present disclosure proposes an induction heat treatment device for induction heating of a workpiece 101, as shown in FIGS. 1 to 4g, the induction heat treatment device includes an inductor assembly 1, the inductor assembly 1 is configured to surround the workpiece 101 and move relative to the workpiece 101 along a predetermined path for scanning, the inductor assembly 1 includes:

[0070] A first induction frame 11 connected to a power supply;

[0071] A second induction frame 12 spaced apart from the first induction frame 11 along a first direction x and arranged on a first side of the first induction frame 11, the second induction frame 12 being electrically connected to the first induction frame 11; and

[0072] A third induction frame 13 spaced apart from the first induction frame 11 along the first direction x on a second side of the first induction frame 11, the third induction frame 13 being electrically connected to the first induction frame 11, and the third induction frame 13 being connected in parallel with the second induction frame 12;

[0073] Among them, the current directions in the first induction frame 11, the second induction frame 12 and the third induction frame 13 are the same.

[0074] Specifically, the second induction frame 12 and the third induction frame 13 are connected in parallel and then connected in series to the first induction frame 11. Specifically, the first induction frame 11 is wound once and then divided into two winding loops. Specifically, the power supply provides alternating current, and the current passes through the middle first induction frame 11 and then returns to the power supply through the upper and lower second induction frames 12 and the third induction frame 13, or the current passes through the upper and lower second induction frames 12 and the third induction frame 13 and then returns to the power supply through the middle first induction frame 11. Specifically, the third induction frame 13 is arranged in the first direction x and is arranged on the second side of the first induction frame 11.

[0075] Specifically, during induction heating, the workpiece 101 rotates along the preset center line, and the inductor assembly 1 does not rotate, and the inductor assembly 1 moves along the preset path, so that the inductor assembly 1 and the workpiece 101 move relatively to realize uniform heating of the entire surface of the workpiece 101 by the inductor assembly 1.

[0076] Specifically, when the inductor assembly 1 heats to the end position of the workpiece 101, the second induction frame 12 or the third induction frame 13 exposes the end surface, and the current preferentially passes through the induction frame with the smallest resistance among the exposed induction frames, so that the other induction frame without exposure does not pass through the current, so that the eddy current depth of the workpiece that is flush with the inductor assembly 1 is reduced, thereby realizing the reduction of the overall induction heating power when the inductor assembly 1 heats to the end of the workpiece 101.

[0077] Specifically, when the inductor assembly 1 heats to the end position of the workpiece 101, due to the different current carrying densities of the three induction frames, the end surface area heating distribution can be controlled, and the end induction hardening layer distribution shape can be controlled. Specifically, the workpiece 101 after induction heating is rapidly cooled to form a hardening layer.

[0078] Specifically, when the inductor assembly 1 heats to the non-end position of the workpiece 101, if the resistances of the second induction frame 12 and the third induction frame 13 are the same, the three induction frames all wrap the workpiece 101, the middle first induction frame 11 is the main magnetic field generating area, and the induction heating power is the highest. The current value of the upper and lower branch induction frames is 1 / 2 of the first induction frame. Specifically, the effective wrapping area of the upper, middle, and lower three induction frames is increased compared with the conventional inductor structure, which is beneficial to control the surface temperature of the workpiece 101 and is not easy to appear overheated metallographic structure caused by high heating temperature.

[0079] Specifically, the induction heat treatment device adopts multiple induction frames to surround the workpiece 101, which can ensure that the inductor assembly 1 covers each part of the workpiece 101 during the heating process, reduce the end overheating phenomenon that may be caused by the traditional inductor, especially in the complex profile or edge area of the workpiece, greatly improve the uniformity of the heat treatment, and improve the consistency of the hardening layer depth of the end of the workpiece.

[0080] Specifically, the inductor assembly 1 can adapt to workpieces of different sizes and shapes by moving along a preset path, and can accurately control the heating area and eddy current depth by adjusting the moving path and speed, thereby meeting diversified heat treatment requirements and improving the versatility and flexibility of the equipment.

[0081] Specifically, the current directions of the three induction frames are consistent, which can optimize the distribution of the electromagnetic field, reduce energy loss, and enhance the electromagnetic induction heating efficiency.

[0082] Optionally, the induction heat treatment device is suitable for workpieces 101 of shaft type, plane type, inner hole type, or special-shaped thin-walled type, etc. that require induction treatment on the entire surface. Optionally, the preset path can be a straight line, a curve, or the like. Optionally, the second induction frame 12 can be flush with the workpiece 101 before the first induction frame 11, or the third induction frame 13 can be flush with the workpiece 101 before the first induction frame 11.

[0083] Optionally, one or more first induction frames 11, second induction frames 12, and third induction frames 13 can be provided. Optionally, the resistance values of the first induction frame 11, the second induction frame 12, and the third induction frame 13 can be the same or different. Optionally, the first induction frame 11, the second induction frame 12, and the third induction frame 13 can be made of rectangular copper pipes, such as hollow copper pipes, etc. The induction frame can also include one or more coils. Optionally, the first induction frame 11, the second induction frame 12, and the third induction frame 13 can be annular, rectangular, or other regular polygonal shapes, etc.

[0084] Optionally, the planes where the three induction frames are located can be parallel or at a certain angle, and the planes where the three induction frames are located can be perpendicular to the first direction x or at a certain angle with the first direction x. Optionally, the center axes of the three induction frames can coincide or not coincide.

[0085] The induction heat treatment device of the embodiment is provided in parallel through the second induction frame 12 and the third induction frame 13, can automatically reduce the heating power of the inductor assembly 1 in the moving process through the end of the workpiece 101, and further compensate the too fast end temperature rise caused by the sharp corner effect, improve the uniformity of the induction heat treatment, make the end hardening layer depth of the workpiece 101 uniform and consistent with the hardening layer depth of the main body part; the inductor assembly 1 can realize the uniform heating effect of the workpiece 101 in a single scanning, without reciprocating adjustment, and can improve the efficiency of the induction heat treatment.

[0086] In some embodiments, the working principle of the inductor assembly 1 is further described in combination with FIGS. 4a to 4g, and the black area in the drawing represents the eddy current depth or the heating power or the heating power density, and the thin solid line is the hardening layer depth. Specifically, the second induction frame 12, the first induction frame 11 and the third induction frame 13 of the embodiment are arranged from top to bottom, the inductor assembly 1 moves from bottom to top, the workpiece 101 rotates around the preset center line, and the resistance values of the second induction frame 12 and the third induction frame 13 are equal.

[0087] In the first stage, as shown in FIG. 4a, in the moving process of the inductor assembly 1, the second induction frame 12 gradually aligns with the first end of the workpiece 101, the first induction frame 11 and the third induction frame 13 are located outside the end face of the workpiece 101, and there is no workpiece in the third induction frame 13. Therefore, the resistance in the third induction frame 13 is zero, the current directly returns to the power supply through the third induction frame 13 after passing through the first induction frame 11, and therefore there is no current in the second induction frame 12, which does not heat the workpiece 101. Therefore, in the process that the second induction frame 12 gradually aligns with the first end of the workpiece 101, the inductor assembly 1 does not heat the workpiece 101.

[0088] In the second stage, as shown in FIGS. 4a to 4b, in the process that the first induction frame 11 aligns with the first end of the workpiece 101, the third induction frame 13 is located outside the end face of the workpiece 101, and there is no workpiece 101 in the third induction frame 13. Therefore, the resistance in the third induction frame 13 is zero, the current directly returns to the power supply through the third induction frame 13 after passing through the first induction frame 11, and therefore there is no current in the second induction frame 12, which does not heat the workpiece 101. At this time, the first induction frame 11 has the workpiece 101, so only the first induction frame 11 aligning part heats the workpiece 101.

[0089] In the third stage, as shown in Fig. 4b to Fig. 4c, the third induction frame 13 passes the end face of the workpiece 101 until it completely surrounds the end of the workpiece 101 in the process of being flush with the first end of the workpiece 101, in which the current of the second induction frame 12 and the third induction frame 13 gradually increases from zero to half of the first induction frame 11, and the heating power of the second induction frame 12 and the third induction frame 13 gradually increases from zero to about one fourth of the first induction frame 11.

[0090] In the fourth stage, as shown in Fig. 4c to Fig. 4e, the inductor assembly 1 is flush with the workpiece 101 as a whole, and the three induction frames all wrap the workpiece 101, the current intensity in the first induction frame 11 is the largest, which is the main magnetic field generating area, the inductive heating power is the highest, the current intensity in the second induction frame 12 and the third induction frame 13 is half of the first induction frame 11, and the heating power is about one fourth of the first induction frame 11, the inductor assembly 1 provides the maximum inductive heating power in the fourth stage.

[0091] In the fifth stage, as shown in Fig. 4e to Fig. 4f, in the process of the second induction frame 12 leaving the second end of the workpiece 101, the resistance of the second induction frame 12 gradually decreases to zero, the heating power of the second induction frame 12 and the third induction frame 13 gradually decreases to zero, and the first induction frame 11 has not left the second end of the workpiece 101, so the first induction frame 11 normally heats.

[0092] In the sixth stage, as shown in Fig. 4f to Fig. 4g, after the second induction frame 12 leaves the second end of the workpiece 101, the second induction frame 12 is located outside the end face of the workpiece 101, and there is no workpiece 101 in the second induction frame 12, so the resistance in the second induction frame 12 is zero, the current directly returns to the power supply through the second induction frame 12 after passing through the first induction frame 11, so there is no current in the third induction frame 13, which does not heat the workpiece 101, and only the first induction frame 11 flush part heats the workpiece 101.

[0093] In the seventh stage, as shown in Fig. 4g, after the first induction frame 11 leaves the second end of the workpiece 101, the third induction frame 13 gradually leaves the workpiece 101 from being flush with the workpiece 101, at this time the first induction frame 11 and the second induction frame 12 are located outside the end face of the workpiece 101, and there is no workpiece in the second induction frame 12, so the resistance in the second induction frame 12 is zero, the current directly returns to the power supply through the second induction frame 12 after passing through the first induction frame 11, so there is no current in the third induction frame 13, which does not heat the workpiece 101, so after the first induction frame 11 leaves the second end of the workpiece 101, the inductor assembly 1 stops heating the workpiece 101.

[0094] In this embodiment, the heating power of the inductor assembly 1 on the first end of the workpiece 101 gradually increases from the first stage to the third stage, the inductor assembly 1 heats the non-end region of the workpiece in the fourth stage, the heating power remains unchanged, and the heating power of the inductor assembly 1 on the second end of the workpiece 101 gradually decreases from the fifth stage to the seventh stage. The low heating power of the inductor assembly 1 on the first end and the second end of the workpiece 101 can compensate for the rapid end temperature rise caused by the sharp corner effect, so that the end hardening layer depth of the workpiece 101 is uniform with the hardening layer depth of the main body part.

[0095] In some embodiments, as shown in FIGS. 1 to 4g, the planes where the first inductor frame 11, the second inductor frame 12 and the third inductor frame 13 are located are all perpendicular to the first direction x.

[0096] Specifically, the planes where the three inductor frames are located are all perpendicular to the first direction x, which can make the workpiece 101 always enter the inductor assembly 1 along the tangential direction. Optionally, the central axes of the first inductor frame 11, the second inductor frame 12 and the third inductor frame 13 can coincide or not coincide.

[0097] The planes where the three inductor frames of this embodiment are located are all perpendicular to the first direction x, which can improve the heating uniformity of the inductor assembly 1; and can make the workpiece 101 always cut the alternating magnetic field in the inductor frame along the same direction, so as to ensure that the entire workpiece 101 obtains consistent heat treatment effect and improve the quality and efficiency of heat treatment.

[0098] In some embodiments, as shown in FIGS. 1 to 4g, the central axes of the first inductor frame 11, the second inductor frame 12 and the third inductor frame 13 coincide.

[0099] Specifically, the first direction x is the axial direction of the inductor assembly 1.

[0100] The central axes of the three inductor frames of this embodiment coincide, which can further improve the heating uniformity of the inductor assembly 1; and can make the workpiece 101 always cut the alternating magnetic field in the inductor frame along the same direction, and the workpiece 101 is always located at the geometric center of the inductor assembly 1, which can improve the uniformity and efficiency of heat treatment.

[0101] In some embodiments, as shown in FIGS. 1 and 2, the inductive heat treatment device further comprises:

[0102] a first connecting beam 2 for connecting the first inductor frame 11 to the power supply, the first connecting beam 2 extending along a second direction y, and the second direction y being perpendicular to the first direction x; and

[0103] A second connecting beam 3 is configured to connect the second induction frame 12 and the third induction frame 13 to the power supply, at least a part of the second connecting beam 3 extends along the second direction y, the second connecting beam 3 and the first connecting beam 2 are spaced apart along a third direction z, and the third direction z is perpendicular to the first direction x and the second direction y.

[0104] Specifically, the inductor assembly 1 is connected to the power supply through the first connecting beam 2 and the second connecting beam 3, which can simplify the electrical wiring, make the current distribution safer and more orderly, and facilitate the disassembly, maintenance and troubleshooting of the induction frame. Specifically, the first connecting beam 2 and the second connecting beam 3 are spaced apart along the third direction z, which can avoid short circuit of the induction heat treatment device. Optionally, the first connecting beam 2 and the second connecting beam 3 can be provided with a tapered portion or an expanding portion according to the connection structure.

[0105] This embodiment can ensure the stable connection of each induction frame, enhance the structural stability of the induction heat treatment device, and avoid short circuit of the induction heat treatment device by optimizing the spatial layout of the first connecting beam 2 and the second connecting beam 3; can facilitate air circulation and promote heat dissipation; can improve the compactness of the induction heat treatment device and improve the space utilization.

[0106] In some embodiments, as shown in FIG. 1 and FIG. 2, the first induction frame 11, the second induction frame 12, the third induction frame 13, the first connecting beam 2 and the second connecting beam 3 are all hollow structures, and the induction heat treatment device further comprises:

[0107] Two cooling water joints 4 are respectively arranged at one end of the first connecting beam 2 and the second connecting beam 3 away from the inductor assembly 1, one of which is used for flowing in cooling water, and the other is used for flowing out cooling water.

[0108] Specifically, the hollow structure allows the cooling water to circulate inside the induction frame and the connecting beam, and the design of the hollow structure and the external cooling water joint facilitates regular inspection and maintenance, such as cleaning of scale. Specifically, the use of circulating cooling water can take away the heat generated during induction heating, reduce the accumulation of thermal stress, increase the overall stability and safety of the induction heat treatment device, especially in the working condition of long-time continuous work, good cooling can effectively prevent the deformation or failure of the induction frame due to overheating, and ensure the uniformity of the induction heating of the inductor assembly 1 to the workpiece 101.

[0109] This embodiment can improve the heat dissipation efficiency of the induction heat treatment device, prolong the service life, enhance the stability and safety, and improve the uniformity of the induction heating of the workpiece 101 by setting the hollow structure and circulating cooling water, which is easy to maintain.

[0110] In some embodiments, as shown in FIG. 1 and FIG. 2, the induction heat treatment device further comprises:

[0111] a bottom plate 5, which is perpendicular to the second direction y, is connected to the first connecting beam 2 and the second connecting beam 3 at an end away from the inductor assembly 1, and is connected to the power supply; and

[0112] an insulating plate 6, which is connected to the bottom plate 5 and is perpendicular to the third direction z, is arranged between the first connecting beam 2 and the second connecting beam 3.

[0113] Specifically, the first connecting beam 2 and the second connecting beam 3 can be provided with a bent portion at an end close to the power supply, the bent portion is connected to the bottom plate 5 and extends at least partially along the first direction x. Optionally, the bent portion can be bent away from the insulating plate 6, and the end of the bent portion away from the insulating plate 6 is provided with the cooling water joint 4. Optionally, the insulating plate 6 is provided with a fixing member 7, such as a fixing bolt.

[0114] Specifically, the bottom plate 5 serves as a support base of the induction heat treatment device, which is connected between the connecting beams and the power supply, can ensure stable installation of the connecting beams, and improve the reliability of current transmission. Specifically, the insulating plate 6 plays an electrical insulation role, which can prevent short circuit between the first connecting beam 2 and the second connecting beam 3, and improve the safety of the induction heat treatment device.

[0115] Optionally, the material of the insulating plate 6 can be polytetrafluoroethylene or the like.

[0116] The embodiment can enhance the structural stability and electrical safety by arranging the bottom plate 5 and the insulating plate 6, optimizes the layout and facilitates maintenance, and ensures efficient cooling and high-quality and efficient heat treatment process.

[0117] In some embodiments, as shown in FIGS. 1 and 2, the inductor assembly 1 further comprises:

[0118] a first connecting section 111 extending along the second direction y, which is connected to the first induction frame 11 and is arranged apart from the first connecting beam 2 along the third direction z;

[0119] two second connecting sections 122 each extending along the second direction y, which are connected to the second induction frame 12 and are arranged apart along the third direction z; and

[0120] two third connecting sections 133 each extending along the second direction y, which are connected to the third induction frame 13 and are arranged apart along the third direction z.

[0121] Specifically, the first induction frame 11, the second induction frame 12 and the third induction frame 13 each have a first opening, a second opening and a third opening, the first connecting segment 111 and the first connecting beam 2 are connected to the first end and the second end of the first opening respectively, two second connecting segments 122 are connected to the first end and the second end of the second opening respectively, and two third connecting segments 133 are connected to the first end and the second end of the third opening respectively.

[0122] Specifically, by arranging the first connecting segment 111, the second connecting segment 122 and the third connecting segment 133 extending along the second direction y, the second induction frame 12 and the third induction frame 13 can be connected in parallel. Specifically, the first connecting segment 111, the second connecting segment 122 and the third connecting segment 133 are located outside the area enclosed by the induction frame, which can reduce the influence on the induction magnetic field and avoid the damage of the connecting structure to the induction magnetic field.

[0123] The embodiment can allocate current as required, compensate for the defects of the sharp corner effect, and improve the uniformity of induction heat treatment by arranging multiple connecting segments in parallel. The layout of multiple connecting segments can enhance the rigidity and stability of the induction heat treatment device. The multiple connecting segments extend along the second direction y and are located outside the area enclosed by the induction frame, which can avoid the damage of the connecting structure to the induction magnetic field. By arranging the multiple connecting segments at intervals along the third direction z, more contact area can be provided for the cooling water while avoiding short circuit, thereby improving the cooling efficiency.

[0124] In some embodiments, as shown in FIGS. 1 and 2, the inductor assembly 1 further comprises:

[0125] a first transition segment 110 connected between the first connecting segment 111 and the second connecting segment 122 close to the first connecting beam 2, the first transition segment 110 extending along the first direction x; and / or

[0126] a second transition segment 120 connected between the first connecting segment 111 and the third connecting segment 133 close to the first connecting beam 2, the second transition segment 120 extending along the first direction x; and / or

[0127] a third transition segment 130 connected between the second connecting segment 122 and the second connecting segment 122 away from the first connecting beam 2, the third transition segment 130 extending along the first direction x; and / or

[0128] a fourth transition segment 140 connected between the third connecting segment 133 and the second connecting segment 122 away from the first connecting beam 2, the fourth transition segment 140 extending along the first direction x.

[0129] Specifically, the plurality of transition sections are located outside the area enclosed by the induction frame. Specifically, in one transmission direction of the alternating current, when the inductor assembly 1 is flush with the non-end position of the workpiece 101 (as shown in FIG. 3), the current from the power source flows through the bottom plate 5, the first connecting beam 2 to the first induction frame 11, and then splits into two branch currents after flowing around the first induction frame 11.

[0130] Specifically, the first branch current flows through the first transition section 110 to the second connecting section 122 close to the first connecting beam 2, and then flows away from the second connecting section 122 of the first connecting beam 2 after flowing around the second induction frame 12, and then flows through the third transition section 130 to the second connecting beam 3.

[0131] Specifically, the second branch current flows through the second transition section 120 to the third connecting section 133 close to the first connecting beam, and then flows away from the third connecting section 133 of the first connecting beam 2 after flowing around the third induction frame 13, and then flows through the fourth transition section 140 to the second connecting beam 3. After the first branch current and the second branch current converge, they flow to the bottom plate 5 and the power source. Correspondingly, in the other transmission direction of the alternating current, the transmission direction of the current is reversed.

[0132] This embodiment can allocate current as needed, compensate for the defects of the sharp corner effect, and improve the uniformity of induction heat treatment by designing a parallel structure with multiple transition sections. The layout of the multiple transition sections can enhance the rigidity and stability of the induction heat treatment device. The multiple transition sections extending along the first direction x and the multiple connecting sections extending along the second direction y form a stepped right-angle connection, which can avoid the destruction of the induction magnetic field caused by the structural changes of the connecting part.

[0133] In some embodiments, as shown in FIGS. 1 and 2, the inductor assembly 1 further comprises:

[0134] A magnetic conductor is provided on at least one of the first induction frame 11, the second induction frame 12, and the third induction frame 13.

[0135] Specifically, the magnetic conductor can guide and concentrate the magnetic field generated by the induction frame, improve the coupling heating efficiency, and improve the accuracy of controlling the thickness of the hardened layer. Specifically, the magnetic conductor can narrow the magnetic field line escape area of the induction frame, prevent the escape of the magnetic field lines, make the magnetic field distribution more uniform, narrow the influence range of induction heating, reduce the local high temperature caused by the inherent sharp corner effect of the end of the workpiece 101, and further improve the uniformity of the end hardened layer.

[0136] Specifically, by concentrating the magnetic field lines, the energy loss can be reduced, more electric energy can be effectively converted into heat required for workpiece heating, the energy efficiency ratio of the induction heat treatment device can be improved, and the operation cost of the device can be reduced.

[0137] The embodiment can improve the heating efficiency, save energy consumption, and enhance the accuracy of heat treatment by arranging the magnetic conductors on the induction frame. The embodiment can reduce the adverse effects of inherent sharp corner effects and improve the uniformity of the hardened layer at the end.

[0138] In some embodiments, as shown in FIGS. 1 and 2, the magnetic conductors include a plurality of silicon steel sheets, which are arranged adjacently along the circumference of the inductor assembly 1, and the notches of the silicon steel sheets are located on the side of the inductor assembly 1 facing the workpiece 101.

[0139] Specifically, the plurality of silicon steel sheets are arranged adjacently along the circumference of the first induction frame 11, and / or the plurality of silicon steel sheets are arranged adjacently along the circumference of the second induction frame 12, and / or the plurality of silicon steel sheets are arranged adjacently along the circumference of the third induction frame 13. Optionally, the silicon steel sheets can be π-shaped silicon steel sheets, etc.

[0140] Specifically, the silicon steel sheets have high magnetic permeability and low loss characteristics, and the combination of a plurality of silicon steel sheets enhances the magnetic field guidance, which can improve the efficiency of induction heating. Specifically, the notches are designed to face the workpiece 101, which can optimize the coupling of the electromagnetic field and the surface of the workpiece, and ensure more accurate induction heating. Specifically, the adjacent arrangement of the silicon steel sheets can enhance the structural stability of the induction frame.

[0141] The embodiment can achieve precise heating control, improve heating stability, and improve the quality of heat treatment by arranging a plurality of silicon steel sheets adjacently on the induction frame.

[0142] In some embodiments, as shown in FIGS. 1 and 2, the thickness of the silicon steel sheets is adapted to the depth of the hardened layer and / or the induction heating frequency.

[0143] Specifically, the thickness of the silicon steel sheets can be selected according to the depth of the hardened layer or the induction heating frequency. Specifically, thinner silicon steel sheets are suitable for situations where the thickness of the hardened layer needs to be accurately controlled.

[0144] The embodiment can balance the heating efficiency and the quality of heat treatment, while taking into account the economy and process feasibility, to ensure accurate and efficient induction heat treatment by adapting the thickness of the silicon steel sheets to the depth of the hardened layer and / or the induction heating frequency.

[0145] In some embodiments, as shown in FIGS. 1 and 2,

[0146] The first distance between the first induction frame 11 and the second induction frame 12 is adapted to the depth of the hardened layer at the end of the workpiece 101; and / or

[0147] The second distance between the first induction frame 11 and the third induction frame 13 is adapted to the depth of the hardened layer at the end of the workpiece 101.

[0148] Specifically, the first distance and the second distance are both distances along the first direction x. Specifically, if the first distance increases, the second induction frame 12 will leave the second end of the workpiece 101 earlier in the fifth stage of the above embodiment, the heating power of the third induction frame 13 is reduced to zero earlier, and the inductor assembly 1 can reduce the inductive heating power on the second end; on the contrary, if the first distance decreases, the second induction frame 12 will leave the second end of the workpiece 101 later in the fifth stage of the above embodiment, the heating power of the third induction frame 13 is reduced to zero later, and the inductive heating power on the second end of the workpiece 101 can be increased.

[0149] Correspondingly, if the second distance increases, the third induction frame 13 will delay the time of being flush with the first end of the workpiece 101 in the third stage of the above embodiment, so that the time of inductive heating by only the first induction frame 11 is prolonged, and the maximum inductive heating power of the inductor assembly 1 on the first end is delayed; on the contrary, if the second distance decreases, the third induction frame 13 will be flush with the first end of the workpiece 101 earlier in the third stage of the above embodiment, so that the time of inductive heating by only the first induction frame 11 is shortened, and the maximum inductive heating power of the inductor assembly 1 on the first end is advanced.

[0150] This embodiment can control the depth of the end hardening layer by adjusting the first distance and / or the second distance; by adjusting the first distance and / or the second distance to adapt to the depth of the hardening layer at the end of the workpiece 101, the depth of the hardening layer at the end of the workpiece can be accurately controlled, the uniformity of the induction heat treatment of the end of the workpiece can be improved, the processing quality can be improved, and high-precision customization of heat treatment of workpieces with different structures and shapes can be realized.

[0151] In some embodiments, as shown in FIGS. 1 and 2, the first distance is equal to the second distance.

[0152] Specifically, the first distance equal to the second distance can simplify the structure configuration and process parameter setting, which is conducive to standardized production and reduces the complexity of manufacturing and operation. Specifically, the first distance equal to the second distance can ensure that the two ends of the workpiece are subjected to the same degree of heating treatment, which helps to achieve the consistency of the depth of the hardening layer at the two ends of the workpiece, for example, for workpieces with high symmetry or the same heat treatment requirements at both ends.

[0153] This embodiment can facilitate standardized production by making the first distance equal to the second distance, simplify the structure configuration and process parameter setting, ensure the consistency of the depth of the hardening layer at the two ends of the workpiece, be suitable for symmetric workpiece processing, and improve the uniformity of heat treatment.

[0154] In some embodiments, as shown in FIGS. 1 and 2, the first induction frame 11, the second induction frame 12, and the third induction frame 13 are all annular.

[0155] Specifically, the annular induction frame is adapted to the columnar workpiece 101 extending along the first direction x.

[0156] This example can effectively concentrate the magnetic field by setting the induction frame as annular, ensuring the overall uniform hardening of the workpiece 101, and is particularly suitable for processing tubular or columnar workpieces; the annular frame can reduce energy loss during heat treatment and improve heating efficiency, which is conducive to energy saving.

[0157] Secondly, the present disclosure also provides a quenching system, comprising:

[0158] The induction heat treatment device of the above-mentioned embodiment; and

[0159] The water spraying device is used for spraying cooling water on the workpiece 101 after induction heating.

[0160] The quenching system of this embodiment sprays cooling water on the workpiece 101 after heating by the induction heat treatment device, and the induction heat treatment device can automatically reduce the heating power of the inductor assembly 1 during the movement through the end of the workpiece 101, thereby compensating for the rapid end temperature rise caused by the sharp corner effect, making the end hardening layer depth of the workpiece 101 uniform with the main body hardening layer depth, and improving the uniformity of quenching treatment; the inductor assembly 1 can achieve uniform heating effect of the workpiece 101 in a single scan, without reciprocating adjustment, which can improve the efficiency of quenching treatment.

[0161] In addition, the present disclosure also provides an induction heating method based on the induction heat treatment device of the above-mentioned embodiment, comprising:

[0162] Rotating the workpiece 101 around the preset center line;

[0163] Moving the inductor assembly 1 to the first end of the workpiece 101;

[0164] Moving the inductor assembly 1 along the preset path to be flush with the first end of the workpiece 101;

[0165] Moving the inductor assembly 1 along the preset path from the first end of the workpiece 101 to the second end of the workpiece 101;

[0166] Moving the inductor assembly 1 along the preset path to be away from the second end of the workpiece 101.

[0167] Optionally, the inductor assembly 1 can move at a preset speed.

[0168] The induction heating method of the embodiment can realize uniform heating of the workpiece 101 in the whole circumferential direction by the combination of the rotation of the workpiece 101 and the movement of the inductor assembly 1, and improve the uniformity of heat treatment and the heating efficiency; the induction heating method can automatically reduce the heating power of the inductor assembly 1 in the movement process of the inductor assembly 1 passing through the end of the workpiece 101, thereby solving the problem of too fast temperature rise of the end caused by the sharp corner effect, and making the hardening layer depth of the end of the workpiece 101 uniform with the hardening layer depth of the main body part.

[0169] In some embodiments, during the movement of the inductor assembly 1, the second induction frame 12 is flush with the workpiece 101 before the first induction frame 11, so that the inductor assembly 1 moves along the preset path to be flush with the first end of the workpiece 101, which includes:

[0170] During the process that the second induction frame 12 is flush with the first end of the workpiece 101, the inductor assembly 1 does not heat the workpiece 101;

[0171] During the process that the first induction frame 11 is flush with the first end of the workpiece 101, only the first induction frame 11 heats the workpiece 101;

[0172] During the process that the third induction frame 13 is flush with the first end of the workpiece 101, the first induction frame 11 heats the workpiece 101, and the heating power of the second induction frame 12 and the third induction frame 13 gradually increases, and the maximum heating power of the second induction frame 12 and the third induction frame 13 is less than the heating power of the first induction frame 11.

[0173] The induction heating method of the embodiment automatically gradually increases the induction heating power during the process that the inductor assembly 1 moves along the preset path to be flush with the first end of the workpiece 101, which can heat the first end of the workpiece 101 with lower heating power, thereby solving the problem of too fast temperature rise of the end caused by the sharp corner effect, and making the hardening layer depth of the first end of the workpiece 101 uniform with the hardening layer depth of the main body part.

[0174] In some embodiments, during the movement of the inductor assembly 1, the second induction frame 12 is away from the workpiece 101 before the first induction frame 11, so that the inductor assembly 1 moves along the preset path to be away from the second end of the workpiece 101, which includes:

[0175] During the process that the second induction frame 12 is away from the second end of the workpiece 101, the heating power of the third induction frame 13 gradually decreases;

[0176] After the second induction frame 12 is away from the second end of the workpiece 101, only the first induction frame 11 heats the workpiece 101;

[0177] After the first induction frame 11 leaves the second end of the workpiece 101, the inductor assembly 1 stops heating.

[0178] The induction heating method of this embodiment automatically gradually reduces the induction heating power during the movement of the inductor assembly 1 along the preset path to leave the second end of the workpiece 101, which can heat the second end of the workpiece 101 with a lower heating power, thereby solving the problem of too fast end temperature rise caused by the sharp corner effect, and making the hardening layer depth of the second end of the workpiece 101 uniform with the hardening layer depth of the main body part.

[0179] The induction heat treatment device, quenching system and induction heat treatment method provided by the present disclosure are described in detail above. The principles and implementation manners of the present disclosure are described by applying specific embodiments, and the above embodiment descriptions are only used to help understand the method of the present disclosure and its core idea. It should be pointed out that, for those skilled in the art, without departing from the principles of the present disclosure, the present disclosure can be improved and modified in several ways, and these improvements and modifications also fall within the protection scope of the claims of the present disclosure.

Claims

1. An induction heat treatment device for inductively heating a workpiece (101), the induction heat treatment device comprising an inductor assembly (1) configured to encircle the workpiece (101) and to move relative to the workpiece (101) along a predetermined path for scanning, the inductor assembly (1) comprising: a first induction frame (11) connected to a power source; a second induction frame (12) spaced apart from the first induction frame (11) along a first direction (x) and arranged at a first side of the first induction frame (11), the second induction frame (12) being electrically connected to the first induction frame (11); and a third induction frame (13) spaced apart from the first induction frame (11) along the first direction (x) at a second side of the first induction frame (11), the third induction frame (13) being electrically connected to the first induction frame (11) and the third induction frame (13) being connected in parallel with the second induction frame (12); wherein the current directions in the first induction frame (11), the second induction frame (12) and the third induction frame (13) are the same.

2. The induction heat treatment device according to claim 1, wherein the planes in which the first induction frame (11), the second induction frame (12) and the third induction frame (13) are arranged are perpendicular to the first direction (x).

3. The induction heat treatment device according to claim 1 or 2, wherein the central axes of the first induction frame (11), the second induction frame (12) and the third induction frame (13) coincide.

4. The induction heat treatment device according to claim 3, further comprising: a first connecting beam (2) for connecting the first induction frame (11) to the power source, the first connecting beam (2) extending along a second direction (y) perpendicular to the first direction (x); and a second connecting beam (3) for connecting the second induction frame (12) and the third induction frame (13) to the power source, at least a part of the second connecting beam (3) extending along the second direction (y), the second connecting beam (3) and the first connecting beam (2) being spaced apart along a third direction (z) perpendicular to the first direction (x) and the second direction (y).

5. The induction heat treatment device according to claim 4, wherein the first induction frame (11), the second induction frame (12), the third induction frame (13), the first connecting beam (2) and the second connecting beam (3) are all hollow structures, the induction heat treatment device further comprising: two cooling water joints (4) respectively arranged at the ends of the first connecting beam (2) and the second connecting beam (3) away from the inductor assembly (1), one of the cooling water joints (4) being used for flowing in cooling water and the other of the cooling water joints (4) being used for flowing out cooling water.

6. The induction heat treatment device according to claim 4 or 5, further comprising: ​ ​ ​ ​ ​ ​ ​ ​ a bottom plate (5) connected to the first connecting beam (2) and the second connecting beam (3) at an end away from the inductor assembly (1), the bottom plate (5) being connected to a power supply; and an insulation plate (6) connected to the bottom plate (5) and perpendicular to the third direction (z), the insulation plate (6) being arranged between the first connecting beam (2) and the second connecting beam (3).

7. The induction heat treatment device according to any one of claims 4-6, wherein the inductor assembly (1) further comprises: a first connecting section (111) extending along the second direction (y), the first connecting section (111) being connected to the first induction frame (11), and the first connecting section (111) being spaced apart from the first connecting beam (2) along the third direction (z); two second connecting sections (122) each extending along the second direction (y), the two second connecting sections (122) each being connected to the second induction frame (12), and the two second connecting sections (122) being spaced apart along the third direction (z); and two third connecting sections (133) each extending along the second direction (y), the two third connecting sections (133) each being connected to the third induction frame (13), and the two third connecting sections (133) being spaced apart along the third direction (z).

8. The induction heat treatment device according to claim 7, wherein the inductor assembly (1) further comprises: a first transition section (110) connected between the first connecting section (111) and the second connecting section (122) close to the first connecting beam (2), the first transition section (110) extending along the first direction (x); and / or a second transition section (120) connected between the first connecting section (111) and the third connecting section (133) close to the first connecting beam (2), the second transition section (120) extending along the first direction (x); and / or a third transition section (130) connected between the second connecting section (122) and the second connecting section (122) away from the first connecting beam (2), the third transition section (130) extending along the first direction (x); and / or a fourth transition section (140) connected between the third connecting section (133) and the second connecting section (122) away from the first connecting beam (2), the fourth transition section (140) extending along the first direction (x).

9. The induction heat treatment device according to any one of claims 1-8, wherein the inductor assembly (1) further comprises: a magnetic conductor arranged on at least one of the first induction frame (11), the second induction frame (12), and the third induction frame (13).

10. The induction heat treatment device according to claim 9, wherein the magnetic conductor comprises a plurality of silicon steel sheets, the plurality of silicon steel sheets being adjacently arranged along a circumferential direction of the inductor assembly (1), and a notch of the silicon steel sheet being located at a side of the inductor assembly (1) facing the workpiece (101).

11. The induction heat treatment device according to claim 10, wherein a thickness of the silicon steel sheet is adapted to a hardened layer depth and / or an induction heating frequency.

12. The induction heat treatment device according to any one of claims 1 to 11, wherein a first distance between the first induction frame (11) and the second induction frame (12) is adapted to a hardened layer depth of an end portion of the workpiece (101); and / or a second distance between the first induction frame (11) and the third induction frame (13) is adapted to a hardened layer depth of the end portion of the workpiece (101).

13. The induction heat treatment device according to claim 12, wherein the first distance is equal to the second distance.

14. The induction heat treatment device according to any one of claims 1 to 13, wherein the first induction frame (11), the second induction frame (12) and the third induction frame (13) are each annular.

15. A quenching system, comprising: the induction heat treatment device according to any one of claims 1 to 14; and a water spraying device for spraying cooling water on the workpiece (101) after induction heating.

16. An induction heating method based on the induction heat treatment device according to any one of claims 1 to 14, comprising: rotating the workpiece (101) around a preset center line; moving the inductor assembly (1) to a first end of the workpiece (101); moving the inductor assembly (1) along the preset path to be flush with the first end of the workpiece (101); moving the inductor assembly (1) along the preset path from the first end of the workpiece (101) to a second end of the workpiece (101); and moving the inductor assembly (1) along the preset path to be away from the second end of the workpiece (101).

17. The induction heating method according to claim 16, wherein during the moving of the inductor assembly (1), the second induction frame (12) is flush with the workpiece (101) before the first induction frame (11), and the moving of the inductor assembly (1) along the preset path to be flush with the first end of the workpiece (101) comprises: during the second induction frame (12) being flush with the first end of the workpiece (101), not heating the workpiece (101) by the inductor assembly (1); and during the first induction frame (11) being flush with the first end of the workpiece (101), heating the workpiece (101) only by the first induction frame (11). ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ In the process that the third induction frame (13) is flush with the first end of the workpiece (101), the first induction frame (11) heats the workpiece (101), the heating power of the second induction frame (12) and the third induction frame (13) is gradually increased, and the maximum heating power of the second induction frame (12) and the third induction frame (13) is less than the heating power of the first induction frame (11).

18. The induction heating method of claim 16 or 17, wherein in the process that the inductor assembly (1) moves, the second induction frame (12) leaves the workpiece (101) before the first induction frame (11), and the inductor assembly (1) moves along the preset path to the second end away from the workpiece (101) comprises: In the process that the second induction frame (12) leaves the second end of the workpiece (101), the heating power of the third induction frame (13) is gradually reduced; After the second induction frame (12) leaves the second end of the workpiece (101), only the first induction frame (11) heats the workpiece (101); After the first induction frame (11) leaves the second end of the workpiece (101), the inductor assembly (1) stops heating.

Images