A fixed inductor for surface induction hardening of high speed rail axle

Abstract

This invention relates to the field of metal surface heat treatment technology, and discloses a fixed induction heater for surface induction hardening of high-speed train axles, comprising a busbar, a fixing plate, a cooling water sprayer, and an effective geometric heating coil. The busbar is used to fix the effective geometric heating coil and forms an electrical and water passage with the hollow effective geometric heating coil. The effective geometric heating coil includes three straight induction tubes of different lengths and two arc-shaped induction rings. The straight induction tubes are arranged in lengths D1, D2, and D3, with the D1 straight tube segment transitioning to the D2 straight tube segment by an R1 arc, and the D2 straight tube segment transitioning to the D3 straight tube segment by an R2 arc. The three straight tube segments are parallel to each other and advance inward layer by layer. The arc of the two arc-shaped induction rings is 90°. This invention can perform one-time, full-area synchronous induction heating on multiple journals and transition R-angle areas with complex geometry and significant stress concentration at both ends of the axle.

Description

Technical Field

[0001] This invention relates to the field of metal surface heat treatment technology, and more specifically, to a fixed inductor for induction hardening of the surface of high-speed train axles. Background Technology

[0002] As a key load-bearing component of the locomotive and rolling stock, the performance of high-speed train axles directly affects the operational safety and service life of the train. During operation, axles primarily bear alternating bending stresses from the car body's own weight and the load itself, as well as impact loads from rail gaps and turnouts. Numerous failure analyses show that fatigue fractures in axles often originate on the surface or near-surface areas of stress concentration points such as the axle body, wheel seats, or gear seats. Therefore, strengthening the axle surface, introducing residual compressive stress, and improving its hardness, wear resistance, and fatigue strength are core methods for enhancing axle reliability. Compared to other thermal processes, surface induction hardening offers concentrated energy, extremely high thermal efficiency, low energy consumption, and rapid heating, preventing austenite grains from growing quickly enough to produce a fine martensitic structure. This results in a hardened layer with higher hardness, strength, and toughness, significantly improving the axle's fatigue limit and wear resistance. Simultaneously, the hardened layer also possesses extremely high residual compressive stress, which can inhibit the propagation of surface cracks and extend the remaining life of the axle.

[0003] Currently, traditional sensors used in long-shaft components such as high-speed train axles are mainly fixed single-turn or multi-turn scanning ring sensors. Their typical structure includes an induction coil wound from a copper tube, a magnetic conductor (usually ferrite or laminated silicon steel sheet) installed inside the induction coil to concentrate the magnetic field, and an integrated or independent water-cooling structure. The shape and heating position of traditional sensors are as follows: Figure 16 As shown. Conventional inductors can basically meet the requirements for induction hardening of railway axles, but they have the following problems: 1. The water spray cooling structure on traditional inductors has an unsatisfactory match between the spray angle and coverage area and the induction heating zone, which can easily lead to problems such as insufficient cooling and uneven cooling. This results in incomplete martensite transformation, affecting surface hardness and microstructure properties, and causing quenching cracks or insufficient hardness.

[0004] 2. Due to the angle problem, traditional sensors are only suitable for straight shaft sections. The heating layer is deeper at the corners of the R-angle transition, but the heating temperature is lower and the heating layer is shallower at the center of the R-angle. The temperature difference is large, the stress distribution is unreasonable, and quenching cracks are easily generated, which reduces the product life. Summary of the Invention

[0005] In view of this, the present invention proposes a fixed inductor for induction hardening of the surface of high-speed train axles, in order to solve the technical problems of uniform cooling of water sprayer in traditional inductors, as well as the uniform hardening of the axle plane and R-angle.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A fixed inductor for surface induction hardening of high-speed train axles includes a busbar, a fixing plate, a cooling sprayer, and an effective geometric heating coil. The busbar is used to fix the effective geometric heating coil and forms an electrical and water passage with the hollow effective geometric heating coil. The fixing plate is also provided at the connection between the busbar and the effective geometric heating coil. The effective geometric heating coil and the cooling sprayer located around the effective geometric heating coil are both connected to the bottom surface of the fixing plate. The inner sidewall of the cooling sprayer has an array of water outlet holes facing the effective geometric heating coil. The effective geometric heating coil includes three straight inductor sections of different lengths and two arc-shaped inductor rings. The inner area of ​​the tube body is the straight section sensing area, and the inner area of ​​the arc sensing ring body is the arc sensing area. The straight section sensing area and the arc sensing area are located on both sides below the fixed plate. The straight section sensing tube bodies are arranged in lengths D1, D2, and D3. The straight tube section D1 and the straight tube section D2 transition with an arc of R1, and the straight tube section D2 and the straight tube section D3 transition with an arc of R2. The three straight tube sections are parallel to each other and advance inward layer by layer. The two transition arc sections R1 and R2 fit the corresponding transition fillets of the axle being processed. The corresponding three straight section sensing surfaces on the three straight tube sections are parallel and face the arc sensing ring axis of the arc sensing ring body. The arc of the two arc sensing ring bodies is 90°, and the two arc sensing ring bodies are concentric and coaxial with the axle being processed.

[0007] Preferably, the manifold has a circulating water channel, a first water nozzle is installed at the inlet of the circulating water channel, the effective geometric heating coil has a heating coil inlet at the connection with the manifold that connects the hollow cavity of the heating coil with the circulating water channel, the tail of the effective geometric heating coil has a heating coil outlet, and a second water nozzle is installed at the heating coil outlet.

[0008] Preferably, there are two busbars connected to two electrodes respectively, an insulating plate is provided between the two busbars, the effective geometric heating coil has two heating coil inlets corresponding to the circulating water channel outlets of the two busbars respectively, and the tail of the effective geometric heating coil has two heating coil outlets.

[0009] Preferably, there are two cooling water sprayers distributed on both sides of the effective geometric heating coil. The spray surface of the cooling water sprayer is parallel to the straight sensing surface on the straight sensing tube. Several third water nozzles are provided on the cooling water sprayer as water inlets. The interior of the cooling water sprayer also includes a filter plate.

[0010] Preferably, the cross-sectional area of ​​the water passage at each point in the effective geometric heating coil is 200~400mm². 2 .

[0011] Preferably, the cross-sections of the two arc-shaped sensing rings are both racetrack-shaped hollow structures, and the plane of the racetrack-shaped cross-section forms a 45° angle with the axis of the arc-shaped sensing ring; the cross-sections of the three straight sections and the two transition arc sections in the straight sensing tube are all rectangular hollow structures.

[0012] Preferably, the cross-sectional thickness of the effective geometric heating coil is greater than or equal to 2 mm.

[0013] Preferably, the back of both arc-shaped sensing rings is provided with an arc-shaped induction coil magnetic conductor, and the back of the three straight sections of the straight sensing tube is provided with a straight sensing surface magnetic conductor. The cross-sectional shape of all the magnetic conductors is U-shaped. The two arc-shaped induction coil magnetic conductors are held in place on the corresponding two arc-shaped sensing rings by friction from the outside of the ring to the inside of the ring. The three straight sensing surface magnetic conductors are held in place on the corresponding three straight sections by friction from the outside of the straight section to the inside of the straight sensing surface.

[0014] Preferably, the inner bottom end of the arc-shaped induction coil magnetic conductor is curved; the two ends of the U-shape of the arc-shaped induction coil magnetic conductor are pointed, and the pointed ends point towards the sensing arc surface of the circular arc sensing ring; the inner bottom end of the straight section sensing surface magnetic conductor and the two ends of the U-shape are both flat, and the surface where the flat end is located is the same as the corresponding straight section sensing surface.

[0015] Preferably, the axle being processed is a multi-diameter cylinder with rounded corners at the diameter changes; the two arc-shaped sensing rings in the fixed sensor are used to process the transition R-angle area at the diameter change of the axle; and the three straight pipe sections are used to process the multiple sections of the axle body.

[0016] Compared with the prior art, the fixed inductor for surface induction hardening of high-speed train axles of the present invention has the following advantages: (1) The fixed inductor for surface induction hardening of high-speed train axles of the present invention can perform one-time, full-area synchronous induction heating on multiple journals and transition R-angle regions with complex geometry and significant stress concentration at both ends of the axle. The fixed inductor is designed based on the precise three-dimensional contour of the axle end to ensure that it maintains a constant and optimal electromagnetic coupling gap with the surface of each axle segment and the R-angle curved surface.

[0017] (2) The multi-hole structure cooling water sprayer with fixed sensor on both sides of the present invention has the advantages of wide coverage and uniform water spray, which can effectively ensure the cooling rate of the treated part, thereby forming a uniform quenching layer.

[0018] (3) The fixed sensor of the present invention can also be used in conjunction with the scanning sensor disclosed in CN119082410A for partitioned collaborative quenching. This division of labor mode can achieve precise strengthening of the axle by partition and strategy, and overcome the problems of shallow hardened layer of the axle R angle, easy overheating and cracking, uneven distribution of quenched layer, etc., significantly improve processing efficiency and product qualification rate, and enable the axle to obtain a reinforced layer with uniform depth and reasonable stress distribution, thereby greatly improving the fatigue strength, wear resistance and service life of the axle. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 A schematic diagram of typical geometric elements of the axle being processed.

[0021] Figure 2 This is a schematic diagram of the assembly of a fixed inductor for surface induction hardening of high-speed train axles in an embodiment of the present invention.

[0022] Figure 3 This is a front view of the assembly drawing of a fixed inductor for surface induction hardening of high-speed train axles in an embodiment of the present invention.

[0023] Figure 4 This is a diagram showing the structural distribution of a fixed inductor used for surface induction hardening of high-speed train axles in an embodiment of the present invention.

[0024] Figure 5 This is a schematic diagram of the bus structure in an embodiment of the present invention.

[0025] Figure 6 This is a schematic diagram of the structure of the effective geometric heating coil in an embodiment of the present invention.

[0026] Figure 7 This is a schematic diagram of the cooling water sprayer in an embodiment of the present invention.

[0027] Figure 8 This is a schematic diagram of the structure of the fixing plate in an embodiment of the present invention.

[0028] Figure 9 This is a cross-sectional view of the arc-shaped induction coil magnetic conductor in an embodiment of the present invention.

[0029] Figure 10 This is a cross-sectional view of the straight section of the magnetic conductor in an embodiment of the present invention.

[0030] Figure 11This is a cross-sectional view of the arc-shaped sensing ring in an embodiment of the present invention.

[0031] Figure 12 This is a cross-sectional view of the straight section of the induction tube in an embodiment of the present invention.

[0032] Figure 13 This is a schematic diagram of the assembly of the effective geometric heating coil and the corresponding magnetic conductor in an embodiment of the present invention.

[0033] Figure 14 This is a schematic diagram of a fixed inductor used for surface induction hardening of high-speed train axles to process the axle ends in an embodiment of the present invention.

[0034] Figure 15 This is a schematic diagram illustrating the process of using a fixed sensor in conjunction with a scanning sensor (for induction hardening of railway axle surfaces) to process the axle in an embodiment of the present invention.

[0035] Figure 16 This is a schematic diagram of a traditional sensor.

[0036] In the diagram: 1-Busbar, 2-Fixing plate, 3-Cooling water sprayer, 4-Effective geometric heating coil, 5-Water outlet, 6-Straight section induction tube, 7-Circular arc induction ring, 8-First water nozzle, 9-Second water nozzle, 10-Insulating plate, 11-Heating coil outlet, 12-Third water nozzle, 13-Arc-shaped induction coil magnetic conductor, 14-Straight section induction surface magnetic conductor. Detailed Implementation

[0037] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0038] Example: like Figures 2-8 As shown, this embodiment provides a fixed inductor for surface induction hardening of high-speed train axles, including a busbar 1, a fixing plate 2, a cooling water sprayer 3, and an effective geometric heating coil 4.

[0039] Among them, the busbar 1 is used to fix the effective geometric heating coil 4, and forms an electric passage and a water passage with the hollow effective geometric heating coil 4.

[0040] A fixing plate 2 is also provided at the connection between the busbar 1 and the effective geometry heating coil 4. The effective geometry heating coil 4 and the cooling water sprayer 3 located around the effective geometry heating coil are both connected to the bottom surface of the fixing plate 2. The inner side wall of the cooling water sprayer 3 has an array of water outlet holes 5 facing the effective geometry heating coil, which are used to spray water to cool the sensor and improve the sensor life.

[0041] In this embodiment, the fixing plate 2 is specifically a resin plate. The cooling water sprayer 3 and the effective geometry heating ring 4 are both connected to the fixing plate 2 through corresponding bolt and nut assemblies. The effective geometry heating ring 4 has a connecting plate for bolts to pass through.

[0042] The effective geometric heating coil 4 includes three straight induction tubes 6 of different lengths and two circular arc induction rings 7. The inner area of ​​the straight induction tube 6 is the straight induction area, and the inner area of ​​the circular arc induction ring 7 is the circular arc induction area. The straight induction area and the circular arc induction area are located on both sides below the fixed plate.

[0043] The straight-section sensing tubes 6 are arranged in lengths D1, D2, and D3. The straight tubes D1 and D2 are transitioned by an arc of R1, and the straight tubes D2 and D3 are transitioned by an arc of R2. The three straight tubes are parallel to each other and advance inward layer by layer. The two transition arcs R1 and R2 fit the corresponding transition fillets of the axle being processed. The corresponding sensing surfaces of the three straight tubes are parallel and face the arc sensing ring axis of the arc sensing ring body 7.

[0044] The two arc-shaped sensing rings 7 each have an arc of 90° and radii of R3 and R4 respectively. The two arc-shaped sensing rings 7 are concentric and coaxial with the axle being processed.

[0045] In this embodiment, by making the two arc-shaped sensing rings 7 concentric and coaxial with the axle being processed, and by making the three straight sensing surfaces parallel and facing the arc-shaped sensing ring axis of the arc-shaped sensing rings 7, the sensor in this embodiment can simultaneously process the straight section at the end of the axle and its transition arc, and ensure that the quenching layer is uniform.

[0046] Meanwhile, this embodiment also ensures the distance between the three straight sensing surfaces and the axle by having the two transition arc segments R1 and R2 fit into the corresponding transition fillets of the axle being treated. This ensures that the surface of the axle after treatment obtains a uniformly distributed and reasonable residual compressive stress layer, ultimately greatly extending the service life of the axle.

[0047] In a further specific embodiment, such as Figures 2 to 6 As shown, a circulating water channel is provided inside the manifold 1. A first water nozzle 8 (i.e., a cooling water inlet) is installed at the inlet of the circulating water channel. The effective geometric heating coil 4 has a heating coil inlet at the connection point with the manifold 1, which connects the hollow cavity of the heating coil with the circulating water channel. The tail of the effective geometric heating coil 4 has a heating coil outlet 11, and a second water nozzle 9 (i.e., a cooling water outlet) is installed at the heating coil outlet 11. The circulating water channel and the hollow cavity of the heating coil are connected to form a water passage, and the entire effective geometric heating coil 4 is connected in a closed loop for water flow.

[0048] In this embodiment, the circulating water flow path for cooling the effective geometric heating coil 4 is as follows: the circulating water in the external water supply mechanism flows into the circulating water channel in the manifold 1 through the first water nozzle 8, and then flows into the hollow cavity of the heating coil through the heating coil inlet to cool the entire water-closed effective geometric heating coil 4. Finally, the circulating water flows out from the second water nozzle 9 through the heating coil outlet 11 and enters the next cycle after being cooled by the outside environment.

[0049] Furthermore, in this embodiment, there are two busbars 1 connected to two electrodes respectively, an insulating plate 10 is provided between the two busbars 1, and two heating coil inlets are provided on the effective geometric heating coil 4, which are respectively corresponding to the circulating water channel outlets of the two busbars 1. Two heating coil outlets 11 are provided at the tail of the effective geometric heating coil 4.

[0050] In this embodiment, the busbar 1 is directly welded to the effective geometric heating coil 4. Both busbars 1 are L-shaped structures, with the upper horizontal plates of the two L-shaped structures used to connect the two electrodes respectively, and the vertical plates of the two L-shaped structures are arranged in parallel; the insulating plate 10 is located between the two vertical plates and is secured by bolts screwed onto the two vertical plates on both sides; the bottom of the vertical plates is provided with a circulating water channel outlet, which is directly opposite to the heating coil inlet.

[0051] In a further specific embodiment, there are two cooling water sprayers 3, which are distributed on both sides of the effective geometric heating coil 4. The spray surface of the cooling water sprayer 3 is parallel to the straight sensing surface on the straight section sensing tube body 6. Several third water nozzles 12 are provided on the cooling water sprayer 3 as water inlets. At the same time, the interior of the cooling water sprayer 3 also contains a filter plate.

[0052] In this embodiment, the cooling water sprayer 3 is connected to another external water supply mechanism, that is, the cooling water sprayer 3 and the effective geometric heating coil 4 are supplied with water by their respective independent water supply systems.

[0053] In fact, the medium flowing inside the cooling water sprayer 3 is the induction hardening medium, which is sprayed out from the water outlet 5 after being pressurized.

[0054] Furthermore, in this embodiment, each cooling sprayer is a cuboid structure with six third water nozzles as water inlets. The inner wall of the cooling sprayer has 750 water outlets arranged in an array, each with a diameter of 1.8 mm. In this way, when the fixed sensor is operating, the cooling sprayers on both sides continuously spray water, ensuring sufficient and uniform cooling of the axle, thereby achieving complete martensitic transformation and uniform axle hardness.

[0055] In a further specific embodiment, the cross-sectional area of ​​the water passage at each point in the effective geometric heating coil 4 is 200~400mm². 2 This specification can better ensure the cooling effect of the effective geometric heating coil 4 and improve the service life of the sensor.

[0056] In a further specific embodiment, such as Figure 11 , Figure 12 As shown, the cross-sections of the two arc-shaped sensing rings 7 are both racetrack-shaped hollow structures, and the plane of the racetrack-shaped cross-section forms a 45° angle with the axis of the arc-shaped sensing ring; the cross-sections of the three straight sections and the two transition arc sections in the straight sensing tube 6 are all rectangular hollow structures.

[0057] In this embodiment, the effective geometric heating coil 4 is specifically a thin-walled hollow structure, and in practice, the cross-sectional thickness of the effective geometric heating coil 4 must be greater than or equal to 2mm.

[0058] Furthermore, such as Figure 9 , Figure 10 , Figure 13 As shown, each of the two arc-shaped induction rings 7 has an arc-shaped induction coil magnetic conductor 13 on its back, and each of the three straight sections of the straight induction tube 6 has a straight induction surface magnetic conductor 14 on its back. All magnetic conductors have a U-shaped cross-section. The two arc-shaped induction coil magnetic conductors 13 wrap around the corresponding two arc-shaped induction rings 7 from the outside inwards, relying on friction. The three straight induction surface magnetic conductors 14 wrap around the corresponding three straight sections from the outside inwards, relying on friction. This method of magnetic conductor assembly facilitates disassembly, assembly, and component maintenance.

[0059] In this embodiment, the lengths of the two U-shapes inside the arc-shaped induction coil magnet 13 are equal to the radius of the annular portion of the track-shaped cross-section of the arc-shaped induction ring 7 plus the length of the straight portion, so as to facilitate assembly; the lengths of the two U-shapes inside the straight section induction surface magnet 14 are consistent with the length of the rectangular cross-section of the straight pipe section.

[0060] Meanwhile, the inner bottom of the arc-shaped induction coil magnetic conductor 13 is curved, and the two ends of the U-shape of the arc-shaped induction coil magnetic conductor 13 are pointed, with the pointed ends pointing to the induction arc surface of the circular induction ring body 7; the inner bottom of the straight section induction surface magnetic conductor 14 and the two ends of the U-shape are both flat, and the surface where the flat end is located is the same as the corresponding straight section induction surface.

[0061] By utilizing the slot effect of the magnetic conductor, the current can be driven to the position closest to the workpiece. In this embodiment, the wall thickness of the heating coil can be increased to more than 3mm at this position (2mm at other positions). After thickening, the resistance of the current flowing through this position is smaller, which is more conducive to the passage of more current. At the same time, the total current density is reduced, the Joule heating of the inductor is reduced, and thus the energy utilization rate and thermal fatigue life of the inductor are maximized.

[0062] This invention can also be used in combination with an inductor for surface induction hardening of railway axles (hereinafter referred to as a scanning sensor) disclosed in patent application CN119082410A, and provides a zoned collaborative hardening solution. Figure 1 Taking the axle shown as an example, its induction hardening process is as follows: During quenching, the axle is laid flat and clamped by the quenching machine. The corresponding position of the sensor is as follows: Figure 15 As shown; The entire quenching process is divided into two stages. The first stage involves induction quenching using a scanning sensor, with the quenching direction from left to right. The third arc of the scanning sensor is used to quench section A3 of the axle, starting approximately 30mm from the end of this section. When quenching reaches section C1, the scanning sensor is moved to use the second arc to process the axle transition radius C1. Next, the scanning sensor is moved again to use the third arc to process section A4, followed by the first arc to process the axle transition radius B3. Similarly, this process is repeated for sections A5, C2, and A6. The axle section was induction hardened using the third, second, and third arcs of the scanning sensor in sequence. The second half of the high-speed rail axle was treated in the same way as above, in a symmetrical manner, until the scanning ended about 30mm from the beginning of section A9. Throughout the scanning process, the straight axle section of type A was treated with the third arc of the scanning sensor, the upward arc of type B was treated with the first arc of the scanning sensor, and the downward arc of type C was treated with the second arc of the scanning sensor. The position and movement speed of the scanning sensor were controlled by an XYZ three-axis servo motor CNC program. The second stage involves processing the remaining portion using the fixed sensors of this invention. First, the scanning sensors are removed. This invention uses two fixed sensors, symmetrically mounted at both ends of the axle. The mounting position of the fixed sensor on the left end is as follows: Figure 14 As shown, switching the power supply activates the fixed inductor. Simultaneously, straight pipe sections D1, D2, and D3 perform induction hardening on a portion of three adjacent straight sections of railway axles A1, A2, and A3. The end 40mm of section A1 remains untreated, while only the first 60mm of section A3 is treated. Figure 14 The assembly position shown is about 20mm away from the scanning start position and is not processed. At the same time, the two arc-shaped sensing rings of the fixed sensor also process the transition arcs at the end of the axle. After the processing is completed, the power is switched and the fixed sensor at the right end is started. The processing position is symmetrical to the left end, and the processing time and method are the same.

[0063] The fixed inductor in this invention can efficiently and uniformly complete the quenching of multiple shaft segments and their critical R-angle regions at both ends of the axle in one go, ensuring the heating consistency and quenching quality of these geometrically complex and stress-concentrated areas, and fundamentally solving the industry pain point of insufficient R-angle strengthening.

[0064] Meanwhile, the scanning sensor disclosed in CN119082410A, with its numerically controlled programmed movement trajectory, speed and position, accurately completes the scanning quenching of the middle long straight shaft section and transition zone, ensuring the extreme uniformity of the depth and flatness of the hardened layer in this area.

[0065] Furthermore, both of these sensors are paired with water sprayers that provide wide coverage and uniform cooling, ensuring efficient and comprehensive cooling for quenching in different areas. This effectively eliminates the risk of quenching soft bands and cracking, and together they can achieve efficient and precise strengthening of the entire axle.

[0066] Therefore, by using scanning sensors and fixed sensors in this invention for zoned collaborative quenching, this division of labor can achieve precise strengthening of axles by zone and strategy. It overcomes the technical bottlenecks of existing single scanning sensors, such as low processing efficiency, difficulty in ensuring quenching quality in geometric transition zones such as R-angles and steps, and poor process flexibility. It overcomes the problems of shallow hardened layers, easy overheating and cracking, and uneven distribution of quenched stress layers in axles, significantly improving axle processing efficiency and product qualification rate. It enables axles to obtain a reinforced layer with uniform depth and reasonable stress distribution, thereby greatly improving their fatigue strength, wear resistance and service life, exhibiting excellent comprehensive performance, and achieving a unified leap in quality, efficiency and flexibility.

[0067] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0068] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fixed inductor for surface induction hardening of a high speed steel axle, characterized in that, The system includes a manifold, a fixing plate, a cooling spray nozzle, and an effective geometric heating coil. The manifold is used to fix the effective geometric heating coil and forms an electrical and water passage with the hollow effective geometric heating coil. The fixing plate is also provided at the connection between the manifold and the effective geometric heating coil. The effective geometric heating coil and the cooling spray nozzle located around the effective geometric heating coil are both connected to the bottom surface of the fixing plate. The inner wall of the cooling spray nozzle has an array of water outlet holes facing the effective geometric heating coil. The effective geometric heating coil includes three straight induction tubes of different lengths and two arc-shaped induction rings. The inner area of ​​the straight induction tubes is a straight-section induction ring. The inner area of ​​the arc-shaped sensing ring is the arc sensing area, and the straight section sensing area and the arc sensing area are located on both sides below the fixed plate. The straight section sensing tubes are arranged in lengths D1, D2, and D3. The straight section D1 and the straight section D2 are transitioned by an arc of R1, and the straight section D2 and the straight section D3 are transitioned by an arc of R2. The three straight sections are parallel to each other and advance inward layer by layer. The two transition arc sections R1 and R2 fit the corresponding transition fillets of the axle being processed. The corresponding three straight section sensing surfaces on the three straight sections are parallel and face the arc sensing ring axis of the arc-shaped sensing ring. The arc of both arc sensing rings is 90°, and the two arc sensing rings are concentric and coaxial with the axle being processed.

2. The fixed inductor for surface induction hardening of a high speed steel axle according to claim 1, wherein The manifold is provided with a circulating water channel. A first water nozzle is installed at the inlet of the circulating water channel. The effective geometric heating coil is provided with a heating coil inlet at the connection with the manifold, which connects the hollow cavity of the heating coil with the circulating water channel. The tail of the effective geometric heating coil is provided with a heating coil outlet, and a second water nozzle is installed at the heating coil outlet.

3. A fixed inductor for surface induction hardening of high-speed train axles according to claim 2, characterized in that, There are two busbars, each connected to one of the two electrodes. An insulating plate is provided between the two busbars. The effective geometric heating coil has two heating coil inlets that correspond to the circulating water channel outlets of the two busbars. The tail of the effective geometric heating coil has two heating coil outlets.

4. The fixed inductor for surface induction hardening of a high speed steel axle according to claim 1, wherein There are two cooling water sprayers distributed on both sides of the effective geometric heating coil. The spray surface of the cooling water sprayer is parallel to the straight sensing surface on the straight sensing tube. Several third water nozzles are provided on the cooling water sprayer as water inlets. The interior of the cooling water sprayer also contains a filter plate.

5. The fixed inductor for surface induction hardening of a high speed steel axle according to claim 1, wherein The cross-sectional area of ​​water flow at all points within the effective geometric heating coil is 200~400 mm². 2 .

6. The fixed inductor for surface induction hardening of a high speed steel axle according to claim 1, wherein Both of the arc-shaped sensing rings have a racetrack-shaped hollow cross-section, and the plane of the racetrack-shaped cross-section forms a 45° angle with the axis of the arc-shaped sensing ring; the three straight sections and two transition arc sections in the straight sensing tube have a rectangular hollow cross-section.

7. The fixed inductor for surface induction hardening of a high speed steel axle according to claim 6, wherein The cross-sectional thickness of the effective geometric heating coil is greater than or equal to 2 mm.

8. The fixed inductor for surface induction hardening of a high speed steel axle according to claim 6, wherein Both of the arc-shaped sensing rings have arc-shaped induction coil magnetic conductors on their back sides, and the three straight sections of the straight sensing tube have straight induction surface magnetic conductors on their back sides. All the magnetic conductors have a U-shaped cross-section. The two arc-shaped induction coil magnetic conductors are held in place by friction from the outside of the ring towards the inside of the ring. The three straight induction surface magnetic conductors are held in place by friction from the outside of the straight section towards the inside of the straight induction surface of the straight section.

9. The fixed inductor for surface induction hardening of a high speed steel axle according to claim 8, wherein The inner bottom of the arc-shaped induction coil magnetic conductor is curved; the two ends of the arc-shaped induction coil magnetic conductor are pointed, and the pointed ends point to the sensing arc surface of the circular arc sensing ring; the inner bottom of the straight section sensing surface magnetic conductor and the two ends of the U-shape are both flat, and the surface where the flat end is located is the same as the corresponding straight section sensing surface.

10. The fixed inductor for surface induction hardening of a high speed steel axle according to claim 1, wherein The axle being processed is a multi-diameter cylinder with rounded corners at the diameter changes; the two arc-shaped sensing rings in the fixed sensor are used to process the transition R-angle area at the diameter change of the axle; the three straight pipe sections are used to process the multiple sections of the axle body.

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