A sprocket wheel continuous induction quenching device

Abstract

This invention discloses a continuous induction hardening device for sprockets, belonging to the field of hardening technology. It includes a hardening frame filled with coolant; a hardening section installed inside the hardening frame for induction heating of the sprocket; and a loading section installed at the bottom of the hardening frame for picking up and feeding the sprocket. In this device, the induction coil is curved to match the arc-shaped tooth profile of the sprocket. The upper and lower effective heating sections correspond to the upper and lower tooth roots, respectively. The heat source preferentially acts on the thicker part of the tooth root, ensuring sufficient heat input. Simultaneously, a rotary motor drives the sprocket to rotate. For sprockets with greater thickness, a side coil can be added to assist in heating the tooth sides, avoiding the problem of overheating in the main heating zone and insufficient heating of the side walls. This improves upon existing circular induction coils where the tooth tip heating rate is much faster than the tooth root during hardening, effectively reducing the risk of hardening cracks caused by the significant difference in heating rates and improving the quality of the finished sprocket.

Description

Technical Field

[0001] This invention belongs to the field of quenching technology, and in particular to a continuous induction quenching device for sprockets. Background Technology

[0002] Sprockets are core components in mechanical transmission systems, widely used in industries such as chemical, textile machinery, escalators, construction machinery, food processing, and petroleum. When a chain engages and disengages from a sprocket, the tooth roots experience significant friction and torque. The meshing points are on the tooth surface and root, with the surface layer bearing higher stress than the core. Therefore, the sprocket surface layer requires high strength, high hardness, high wear resistance, and a high fatigue limit. Induction hardening, as a highly efficient and energy-saving heat treatment method, offers advantages such as energy saving, short production cycles, a good working environment, and the ability to be produced online, making it the preferred process for sprocket surface strengthening. During induction hardening of sprockets, a certain hardened layer must be present on both the tooth surface and root, distributed along the tooth profile, to ensure the sprocket's durability.

[0003] In existing technologies, circular induction coils are commonly used for induction hardening of sprockets. The sprocket workpiece is placed inside the circular induction coil, and when energized, the coil generates an alternating magnetic field, inducing eddy currents in the sprocket teeth for heating. However, circular induction coils struggle to achieve uniform heating of the tooth profile at a single current frequency, easily leading to uneven hardness distribution in the hardened layer. The fundamental reason lies in the geometrical characteristics of the sprocket tooth profile: the tooth tip bulges while the tooth root is concave. The gap between the circular induction coil and the tooth tip is small, while the gap with the tooth root is large. Magnetic lines of force are concentrated at the tooth tip and sparse at the tooth root, resulting in concentrated heat at the tooth tip and overheating, while the tooth root is underheated. Currently, sprocket induction hardening mainly employs two methods: synchronous dual-frequency induction heating and contour induction heating. Synchronous dual-frequency induction heating equipment is expensive and not suitable for widespread adoption; while traditional contour coils repeatedly heat the tooth tip, resulting in sparse magnetic lines of force and weak magnetic field strength at the tooth groove, leading to low heating efficiency and a large temperature difference in the tooth profile, resulting in poor heating effect. If the hardened layer at the tooth tip is too deep after quenching, it is prone to cracking. If the hardened layer at the tooth root is too shallow, it becomes a weak point in strength. Under alternating loads, fatigue cracks are very likely to initiate from the tooth root and propagate to fracture.

[0004] The aforementioned problems are particularly pronounced in sprockets with larger dimensions, diameters, or thicknesses. For large-diameter sprockets, the tip circle diameter is larger, and the distance from the tooth root to the tip is correspondingly larger. When using circular induction coil heating, the inner diameter of the coil needs to be determined by adding a safety clearance to the tip circle diameter, which further increases the distance from the coil to the tooth root, leading to more severe attenuation of the magnetic field lines. For example, in industrial sprockets with an outer diameter of over 300 mm, when using medium-frequency induction heating, due to the large size of the parts, the heat loss at the tooth root is much greater than that at the tooth tip. During pre-cooling, the temperature at the tooth root drops rapidly, resulting in the tooth root not being hardened. Meanwhile, the rapid heating rate at the tooth corners easily produces a sharp-corner effect, and quenching cracks are prone to appear at the tooth tip. For thicker sprockets, i.e., sprocket teeth with a larger axial width, during the heating process, the induced current generates a skin effect on the tooth sidewall, and the heat distribution on the tooth side is also uneven. Moreover, the heat dissipation conditions in the middle area of ​​the tooth side are different from those at the edge, which can easily lead to insufficient heating or overheating of the tooth side, resulting in uneven distribution of the hardened layer on the tooth side and affecting the overall contact fatigue life when the sprocket and chain mesh.

[0005] To address the aforementioned issues, CN205170921U discloses a novel induction coil for induction heating of heavy-duty, large-module sprockets. The induction coil is designed as a contoured induction coil with a V-shaped angle. A magnetic conductor is placed near the included angle of the heavy-duty sprocket, providing a magnetic focusing effect and increasing the magnetic field strength and heating efficiency at the tooth groove, thereby reducing the temperature difference on the tooth surface. CN205528937U discloses a device for targeted induction heating of sprocket tooth roots. Its induction coil is arranged circumferentially along each tooth of the sprocket. By hanging a magnetic conductor at the tooth root of the coil, with the opening of the magnetic conductor facing the tooth root, targeted heating of the tooth root area is achieved.

[0006] While the aforementioned existing technologies have improved the problem of insufficient heating at the tooth root to some extent, the improvements focus on the static optimization of the coil shape and have not fundamentally resolved the inherent contradiction that the tooth tip heating speed is much faster than the tooth root when using a circular induction coil. Furthermore, existing sprocket quenching devices are mostly specialized machines designed for single-specification sprockets. Changing production to different sprocket specifications requires replacing a large number of mechanical parts, resulting in long processing times and low efficiency. In addition, existing quenching devices generally rely on manual operation in the loading and unloading process, which is not only labor-intensive and inefficient, but also suffers from poor positioning consistency during manual clamping, further exacerbating quality fluctuations caused by uneven heating.

[0007] The purpose of this invention is to provide a continuous induction hardening device for sprockets to solve the problems mentioned in the background art. Summary of the Invention

[0008] The purpose of this invention is to provide a continuous induction hardening device for sprockets to solve the problems mentioned in the background art.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a sprocket continuous induction hardening device: including a hardening frame filled with coolant;

[0010] The quenching section, installed inside the quenching frame, is used for induction heating of the sprocket;

[0011] The feeding section is installed at the bottom of the quenching frame and is used to pick up and feed the sprocket;

[0012] The circulation section is used to circulate and cool the coolant and spray the sprocket for cooling.

[0013] The transport section is installed on one side of the top of the quenching frame and is used to feed the sprocket to be quenched into the loading section and to pick up the quenched sprocket from the loading section.

[0014] The quenching section includes an electric slide rail, a power supply box, and an induction coil. The electric slide rail is installed on the inner wall of the quenching frame. The power supply box is fixed on the movable slider of the electric slide rail. The induction coil is connected to the front end of the power supply box. The overall shape of the induction coil is a curved shape that matches the arc tooth profile of the sprocket. Its upper and lower effective heating sections are close to the upper tooth root and lower tooth root of the sprocket, respectively. The curvature of the induction coil fits the arc tooth profile of the sprocket. During heating, the heat source of the induction coil preferentially acts on the upper tooth root and lower tooth root areas of the sprocket.

[0015] The feeding section includes a drive motor, a rotary disk, and at least two sets of lifting structures. The rotary disk is mounted on the output shaft of the drive motor and can rotate in a horizontal plane. Multiple sets of lifting structures are evenly arranged on the top of the rotary disk. Each lifting structure includes a waterproof shell, a rotary motor, an electric push rod, and a locking block. The waterproof shell is fixed on the rotary disk, and the rotary motor is sealed and installed inside the waterproof shell. The electric push rod is connected to the output end of the rotary motor and has a built-in stroke sensor. The locking block is installed on the top of the telescopic rod of the electric push rod and is used to fix the sprocket.

[0016] Furthermore, the electric slide rail is used to drive the induction coil to reciprocate between the quenching station near the sprocket and the standby station away from the sprocket; the rotary motor has a built-in angle sensor to drive the sprocket to rotate at a constant speed during the heating process.

[0017] Furthermore, the waterproof housing is a sealed housing, and the output axis of the rotary motor passes through the top of the waterproof housing, with a skeleton oil seal provided at the perforation for rotary sealing.

[0018] Furthermore, the circulation section includes a circulation pipe, a circulation pump, a fan, a gooseneck tube, and a spray nozzle. The circulation pipe is an S-shaped U-shaped pipe, with its inlet connected to the bottom of the quenching frame. The circulation pump is installed on the pipe. The fan is installed corresponding to the circulation pipe and is used to provide forced air cooling for the coolant circulating in the pipe. One end of the gooseneck tube is connected to the outlet of the circulation pipe, and the other end is fixedly installed with the spray nozzle. The spray nozzle can be adjusted in direction via the gooseneck tube, facing the sprocket in the quenching completion area.

[0019] Furthermore, the transport section includes two sets of transport tracks, a telescopic structure, a crossbeam, a clamping rod, and elastic locking points. The two sets of transport tracks are used to feed in and feed out sprockets, respectively. The telescopic structure is installed between the two sets of transport tracks to adjust the track spacing to accommodate sprockets of different diameters. The crossbeam is a telescopic crossbeam installed at the top of the transport tracks and can be adjusted vertically to accommodate sprockets of different thicknesses. The clamping rod is located on both sides of the bottom of the crossbeam and has a buffer spring inside to press the sprocket from above. The elastic locking points are installed on the inner wall of the transport tracks to limit the movement of the sprockets during transport.

[0020] Furthermore, both the telescopic structure and the crossbeam are adjustable structures, so that the spacing between the transport tracks and the height of the clamping rod can be adapted to sprockets of different diameters.

[0021] Furthermore, the locking block is a replaceable locking block, which can be adapted to different specifications of sprockets by replacing the locking block with different specifications and adjusting the lifting stroke of the electric push rod and the feed stroke of the induction coil.

[0022] Furthermore, when the thickness of the sprocket to be quenched exceeds a preset value, a side coil is added to the induction coil. The side coil is installed at the front end of the power supply box and located outside the induction coil. Its effective heating section corresponds to the side wall of the sprocket teeth, and the input power of the side coil is less than the main heating power of the induction coil.

[0023] Furthermore, the coolant in the quenching frame is water or quenching oil; for thin and small-diameter sprockets, after heating, the electric push rod retracts directly to submerge the entire sprocket in the coolant for immersion quenching; for large-diameter and thick sprockets, the rotary motor drives the sprocket to rotate slowly, and the spray nozzle sprays cooling water onto the heated sprocket area, so that the thick-section teeth are quenched and cooled.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) In this device, the induction coil adopts a curved shape that is compatible with the arc tooth profile of the sprocket. The upper and lower effective heating sections correspond to the upper tooth root and the lower tooth root respectively. The heat source is preferentially applied to the thicker part of the tooth root, so that the tooth root can obtain sufficient heat input. At the same time, it is coordinated with the rotary motor to drive the sprocket to rotate. For sprockets with larger thickness, a side coil can be added to assist in heating the tooth side, avoiding the problem of overheating of the main heating area and insufficient heating of the side wall. This improves the existing circular induction coil, where the tooth tip heating speed is much faster than the tooth root during quenching, thus effectively reducing the risk of quenching cracking caused by the large difference in heating speed between the two, and improving the quality of the finished sprocket.

[0026] (2) This device uses two sets of transport tracks in the transport section to carry out the feeding and receiving functions respectively. Combined with the cyclic transfer of the multi-station lifting structure on the rotary table, the five processes of picking up materials, heating, quenching, cooling and feeding are integrated into the same rotary cycle to form a complete automated operation process. The loading and unloading process does not require manual intervention, avoiding the problems of high labor intensity, low efficiency and poor positioning consistency caused by manual loading and unloading. In turn, it solves the problems of difficulty in manual clamping and positioning, uneven heating and sprocket cracking, and realizes continuous automated production of sprocket quenching process.

[0027] (3) The telescopic structure between the transport tracks of this device can adjust the distance between the two sets of tracks and adapt to sprockets of different diameters. The telescopic crossbar can adjust the height of the clamping rod in the vertical direction and adapt to sprockets of different thicknesses. At the same time, by replacing the clamps of different specifications and adjusting the lifting stroke parameters of the electric push rod and the feed stroke of the induction coil, the device can be compatible with the production of sprockets of various specifications within a certain size range, reducing the amount of hardware modification required for model change, shortening the model change time, and facilitating the automated production of multiple varieties and small batches. Attached Figure Description

[0028] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0030] Figure 2 This is a side view of the overall structure of the present invention;

[0031] Figure 3 This is a schematic diagram of the lifting structure in this invention;

[0032] Figure 4This is a schematic diagram of the quenching section structure in this invention;

[0033] Figure 5 This is a schematic diagram of the transportation section structure in this invention;

[0034] Figure 6 This is a schematic diagram of the circulation section structure in this invention;

[0035] Figure 7 This is a schematic diagram of an induction coil structure according to another embodiment of the present invention.

[0036] Explanation of reference numerals in the attached figures:

[0037] In the picture:

[0038] 1. Quenching frame; 2. Quenching section; 21. Electric slide rail; 22. Power supply box; 23. Induction coil; 231. Side coil; 3. Circulation section; 31. Spray nozzle; 32. Gooseneck tube; 33. Circulation pipe; 34. Circulation pump; 35. Fan; 4. Loading section; 41. Lifting structure; 411. Clamping block; 412. Electric push rod; 413. Rotary motor; 414. Waterproof shell; 42. Rotary disk; 43. Drive motor; 5. Transportation section; 51. Transportation track; 52. Cross frame; 53. Clamping rod; 54. Elastic locking point; 55. Telescopic structure. Detailed Implementation

[0039] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid obscuring the invention.

[0040] Unless otherwise defined, the directions mentioned herein, such as up, down, left, right, front, back, inside, and outside, are based on the directions shown in the figures of this invention, and are explained here together.

[0041] The connection method can be any existing method, such as bonding, welding, or bolting, depending on the actual needs.

[0042] Please see Figures 1 to 7 As shown, a continuous induction hardening device for sprockets includes a hardening frame 1, a hardening section 2, a feeding section 4, a circulation section 3, and a transport section 5.

[0043] The quenching frame 1 is filled with coolant, which can be water or quenching oil. A loading section 4 is installed at the bottom of the quenching frame 1, and a transport section 5 is installed on one side of the top of the quenching frame 1. The transport section 5 is used to feed and receive the sprockets, and the loading section 4 is used to pick up the sprockets from the transport section 5 and send them to the quenching section 2 for quenching, and then send them back to the transport section 5.

[0044] The quenching section 2 includes an electric slide rail 21, a power supply box 22, and an induction coil 23. The electric slide rail 21 is mounted on the inner wall of the quenching frame 1, the power supply box 22 is fixed to the movable slider of the electric slide rail 21, and the induction coil 23 is connected to the front end of the power supply box 22. The overall shape of the induction coil 23 is curved to match the arc-shaped tooth profile of the sprocket, with its upper and lower effective heating sections located near the upper and lower tooth roots of the sprocket, respectively. During heating, the heat source generated by the induction coil 23 preferentially acts on the upper and lower tooth root areas of the sprocket, allowing the thicker tooth roots to receive more sufficient heat input and avoiding the problem of excessive heat concentration at the tooth tip in traditional circular coils. The electric slide rail 21 is used to drive the induction coil 23 to reciprocate between the quenching station near the sprocket and the standby station away from the sprocket.

[0045] The loading section 4 includes a drive motor 43, a rotating disk 42, and at least two sets of lifting structures 41. The drive motor 43 is installed at the bottom of the quenching frame 1, and its output shaft is connected to the rotating disk 42, driving the rotating disk 42 to rotate horizontally. Multiple workstations are evenly arranged on the top of the rotating disk 42, and a set of lifting structures 41 is installed at each workstation. The lifting structure 41 includes a waterproof shell 414, a rotary motor 413, an electric push rod 412, and a locking block 411. The waterproof shell 414 is a sealed shell fixed to the rotating disk 42, and the rotary motor 413 is installed inside it. The output shaft of the rotary motor 413 passes upward through the top of the waterproof shell 414, and a skeleton oil seal is provided at the perforation for rotational sealing. The top of the rotary motor 413 is connected to the electric push rod 412, and a locking block 411 for clamping and fixing the sprocket is installed at the top of its telescopic rod.

[0046] The rotary motor 413 incorporates an angle sensor, and the electric push rod 412 incorporates a stroke sensor, enabling precise control of the sprocket's lifting height and rotation angle. During operation, the drive motor 43 rotates the lifting structure 41 at one station to a receiving position near the transport section 5 via the rotary disk 42. The electric push rod 412 is activated, causing the locking block 411 to engage the sprocket. The drive motor 43 continues to rotate, delivering the sprocket to the front of the quenching section 2. Subsequently, the electric push rod 412 lifts the sprocket to a predetermined height according to a preset stroke, aligning the sprocket teeth to be quenched with the induction coil 23. At this point, the electric slide rail 21 activates, moving the induction coil 23 towards the sprocket to the quenching station, bringing the induction coil 23 close to the sprocket tooth root area for induction heating. During heating, the rotary motor 413 drives the sprocket to rotate at a uniform speed, ensuring that all sprocket teeth are heated evenly.

[0047] The circulation section 3 includes a circulation pipe 33, a circulation pump 34, a fan 35, a gooseneck pipe 32, and a spray nozzle 31. The circulation pipe 33 is an S-shaped U-shaped pipe, arranged outside the quenching frame 1, with its inlet connected to the bottom of the quenching frame 1. The circulation pump 34 is installed on the pipe. A fan 35 is installed corresponding to the circulation pipe 33 for forced air cooling of the circulating coolant. One end of the gooseneck pipe 32 is connected to the outlet of the circulation pipe 33, and the other end is fixedly equipped with a spray nozzle 31. The spray nozzle 31 can be adjusted in direction via the gooseneck pipe 32, facing the sprocket that has detached from the quenching section 2.

[0048] This device automatically matches the cooling method according to the sprocket specifications. For sprockets with thinner thickness and smaller diameter, after heating, the electric slide rail 21 drives the induction coil 23 to return to the standby position, and the electric push rod 412 directly retracts to lower the sprocket and immerse it entirely in the coolant in the quenching frame 1. At the same time, the rotary motor 413 drives the sprocket to rotate slowly, using the coolant for uniform immersion quenching. For sprockets with larger diameter and thicker thickness, the rotary motor 413 drives the sprocket to rotate slowly and continuously, and the spray nozzle 31 sprays cooling onto the heated part of the sprocket, so that the thick-section teeth are quenched and cooled. After the sprocket has been completely quenched, the electric push rod 412 continues to lower, immersing the sprocket entirely in the coolant in the quenching frame 1 for uniform final cooling. After cooling is complete, the electric push rod 412 rises and resets, and the drive motor 43 sends the sprocket to the transport unit 5 via the rotating disk 42.

[0049] The transport section 5 includes two sets of transport tracks 51, a telescopic structure 55, a crossbeam 52, a clamping rod 53, and elastic locking points 54. The two sets of transport tracks 51 are respectively arranged on both sides of the top of the quenching frame 1. One set is used to feed the sprockets to be quenched into the device, and the other set is used to send out the quenched sprockets. A telescopic structure 55 is installed between the two sets of transport tracks 51. The telescopic structure 55 is used to adjust the distance between the two sets of transport tracks 51 to accommodate sprockets of different diameters. A telescopic crossbeam 52 is installed on the top of the transport tracks 51. The telescopic crossbeam 52 can be adjusted vertically. It includes a fixed sleeve and a sliding rod. The bottom end of the fixed sleeve is fixed to the side support of the transport track 51. The sliding rod is inserted into the fixed sleeve and can slide freely up and down. The top end of the sliding rod is fixedly connected to a horizontal beam. The side wall of the fixed sleeve has a threaded hole and a set screw. During adjustment, the sliding rod is manually pulled out or pushed in to the target height, and then the set screw is tightened to lock the sliding rod in place. Abutment rods 53 are installed on both sides of the bottom of the horizontal beam, and buffer springs are installed inside the abutment rods 53. During material removal, the abutment rods 53 apply flexible pressure to the sprocket from above, and the electric push rod 412 rises to align the locking block 411 with the center hole of the sprocket. The locking block 411 overcomes the spring force of the abutment rods 53 during the rising process to complete the locking and material removal. The inner wall of the transport track 51 is equipped with elastic locking points 54 to limit the sprocket during the transport process and prevent it from leaving the track. After the locking block 411 and the sprocket are engaged, the drive motor 43 drives the rotating disk 42 to rotate, and then the sprocket disengages from the restriction of the elastic locking points 54 and leaves the transport track.

[0050] During operation, the sprocket to be quenched is transported to the designated position along the receiving transport track 51, and the clamping rod 53 flexibly presses the sprocket from above. The drive motor 43 rotates a set of lifting structures 41 to this position via the rotating disk 42, and the electric push rod 412 rises to align the locking block 411 with the center hole of the sprocket, overcoming the spring force of the clamping rod 53 to complete the locking and material removal. The rotating disk 42 rotates the sprocket to the quenching section 2, and performs the corresponding heating and cooling procedures according to the sprocket specifications. After completing all quenching and cooling processes, it continues to rotate to the feeding transport track 51. The electric push rod 412 descends to place the sprocket on the track. As the electric push rod 412 continues to descend, the sprocket is restricted by the elastic locking point 54 on the inner wall of the transport track 51, and the locking block 411 disengages from the inner hole of the sprocket. The quenched sprocket is then sent out by the feeding transport track 51.

[0051] The telescopic structure 55 and the telescopic crossbar 52 enable the device to accommodate sprockets of different diameters and thicknesses. Furthermore, by replacing the locking blocks 411 with different specifications and adjusting the stroke parameters of the electric push rod 412 driving the sprocket to rise and fall, as well as the feed stroke of the induction coil 23, the device can adapt to the production of sprockets of different specifications within a certain range, which is beneficial for flexible production lines.

[0052] As another preferred embodiment, when the thickness of the sprocket to be quenched is relatively thick, a side coil 231 is added to the induction coil 23. The side coil 231 is installed at the front end of the power supply box 22, located inside or outside the induction coil 23, and its effective heating section corresponds to the side wall surface of the sprocket teeth, used to provide auxiliary heating to the side part of the sprocket teeth. The input power of the side coil 231 is less than the main heating power of the induction coil 23 to ensure that the tooth side receives adequate heat and avoid overheating of the main heating area at the tooth tip and root or insufficient heating of the side wall.

[0053] The following are some issues that may arise during actual operation:

[0054] Technical Issue: The lifting structure 41 of the feeding section 4 needs to operate continuously inside the quenching frame 1, directly exposed to coolant splashes and steam. The lifting structures 41 at multiple stations on the rotating disk 42 periodically pass through the heating zone, spray zone, and immersion zone as they rotate, and contain electrical components such as a rotary motor 413 and an electric push rod 412. If coolant seeps into the waterproof shell 414 or enters the interior through the gaps in the telescopic rod of the electric push rod 412, it will cause malfunctions such as motor short circuits, bearing corrosion, and sensor failure, severely affecting the long-term reliability of the equipment.

[0055] Solution: The waterproof housing 414 adopts a fully sealed welded structure. The output shaft of the rotary motor 413 passes through the perforation at the top of the waterproof housing 414, and a radial rotary seal is formed by a double-layer skeleton oil seal, with high-temperature resistant waterproof grease filled between the two oil seals. The electric actuator 412 is an IP67 waterproof model.

[0056] Technical Issue: The proposed solution automatically matches the cooling method based on the sprocket specifications, but it doesn't explain how the device obtains the current sprocket specification information. Relying on manual parameter input each time a new sprocket is changed poses a risk of input errors and reduces the level of automation.

[0057] Solution: A set of through-beam photoelectric sensors or laser rangefinders can be installed at the entrance of transport track 51. When the sprocket passes by, its outer diameter and thickness can be quickly measured, and the measurement data can be fed back to the controller. The controller automatically identifies the sprocket model based on a preset specification parameter library and calls up the corresponding process parameters such as heating time, lifting stroke, and cooling method.

[0058] Technical Issue: The heating effect of the induction coil 23 is closely related to its distance from the sprocket tooth root. The electric slide rail 21 drives the induction coil 23 to feed, and the sprocket is lifted to the heating height by the electric push rod 412; both are open-loop controlled. If assembly errors, thermal deformation, or increased mechanical clearance after long-term use cause the gap between the induction coil 23 and the sprocket tooth root to deviate from the preset value, it will directly affect the heating uniformity and may even cause the induction coil 23 to collide with the sprocket, damaging the equipment.

[0059] Solution: A miniature proximity switch or laser displacement sensor can be installed in the non-heated area of ​​the induction coil 23. Before heating each sprocket, the electric slide rail 21 is fed at a low speed. The sensor detects the distance from the induction coil 23 to the top of the sprocket teeth in real time and feeds it back to the controller for position verification. Power is then turned on for heating only after the gap is confirmed to be within the tolerance range.

[0060] Technical problem: Multiple lifting structures 41 on the rotary table 42 perform different processes such as material picking, heating, cooling, and unloading simultaneously, with varying time consumption for each process. If the timing of the actions at each station is not properly coordinated, the rotary table 42 may wait or process interference may occur, reducing overall production efficiency.

[0061] The controller adopts a multi-task parallel scheduling algorithm, sets independent action triggering conditions for each workstation, and uses the longest heating process time as the basic cycle time of the rotary table 42. The remaining processes are completed in parallel within this cycle, ensuring that the actions of each workstation do not wait for each other and maximizing equipment utilization.

[0062] Working principle: Through the coordinated operation of the transportation section 5, the loading section 4, the quenching section 2 and the circulation section 3, the entire process of automatic loading and unloading, induction heating quenching and cooling of the sprocket is realized.

[0063] During the loading stage, the sprocket to be quenched is transported to the unloading station along the receiving transport track 51. The clamping rod 53 flexibly presses the sprocket from above to achieve positioning. The drive motor 43 rotates a set of lifting structures 41 to directly below the station via the rotary disk 42. The electric push rod 412 extends upward, and the locking block 411 aligns with the center hole of the sprocket and overcomes the buffer spring force inside the clamping rod 53 to complete the locking and unloading. After locking is completed, the electric push rod 412 descends slightly to disengage the sprocket from the clamping rod 53, and the drive motor 43 continues to drive the rotary disk 42 to transfer the sprocket to the quenching section 2 station.

[0064] During the heating stage, the electric push rod 412 lifts the sprocket to a preset height according to its specifications, allowing the teeth of the sprocket to be quenched to enter the working area of ​​the induction coil 23. The electric slide rail 21 is activated, pushing the induction coil 23 from the standby position to the quenching position, with the upper and lower effective heating sections of the induction coil 23 close to the upper and lower tooth roots of the sprocket, respectively. After being energized, the alternating magnetic field generated by the induction coil 23 induces eddy currents in the tooth root region of the sprocket, preferentially heating the thicker parts of the tooth roots. At the same time, the rotary motor 413 drives the sprocket to rotate at a uniform speed, allowing each tooth to pass through the heating zone in sequence, ensuring that the entire circumference of the teeth is heated evenly.

[0065] During the cooling phase, after heating is complete, the electric slide rail 21 drives the induction coil 23 to return to the standby position. The system executes differentiated cooling procedures according to the sprocket specifications: For thinner, smaller diameter sprockets, the electric push rod 412 retracts directly, immersing the entire sprocket in the coolant within the quenching frame 1, while the rotary motor 413 drives the sprocket to rotate slowly for uniform immersion quenching. For larger diameter, thicker sprockets, the electric push rod 412 first retracts, lowering the sprocket to the corresponding height of the spray nozzle 31. The rotary motor 413 then drives the sprocket to rotate, and the spray nozzle 31 sprays coolant onto the rotating sprocket for quenching and cooling. After spray cooling is complete, the electric push rod 412 continues to descend, immersing the entire sprocket in the coolant within the quenching frame 1 for uniform final cooling. After cooling is complete, the electric push rod 412 rises to its original position.

[0066] During the feeding stage, the drive motor 43 transfers the quenched sprocket to the top of the feeding conveyor track 51 via the rotary disk 42. The electric push rod 412 descends and places the sprocket on the track. During the continued descent, the sprocket is restrained by the elastic locking point 54 on the inner wall of the conveyor track 51, and the locking block 411 disengages from the inner hole of the sprocket. The sprocket remains on the track and is conveyed to the next process by the feeding conveyor track 51. At this point, one sprocket has completed all the quenching processes, and each station of the device returns to its initial state, entering the next cycle.

[0067] It should be noted that, in this document, relational terms such as "one" and "two" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, the phrase "comprising an element defined as..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0068] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A continuous induction hardening device for sprockets, characterized in that: Includes a quenching frame (1), which is filled with coolant; The quenching section (2) is installed inside the quenching frame (1) and is used to induction heat the sprocket; The feeding part (4) is installed at the bottom of the quenching frame (1) and is used to pick up and feed the sprocket; The circulation section (3) is used to circulate and cool the coolant and spray the sprocket for cooling. The transport section (5) is installed on one side of the top of the quenching frame (1) and is used to feed the sprocket to be quenched into the loading section (4) and to pick up the quenched sprocket from the loading section (4). The quenching section (2) is characterized in that it includes an electric slide rail (21), a power supply box (22) and an induction coil (23). The electric slide rail (21) is installed on the inner wall of the quenching frame (1). The power supply box (22) is fixed on the movable slider of the electric slide rail (21). The induction coil (23) is connected to the front end of the power supply box (22). The overall shape of the induction coil (23) is a curved shape that matches the arc tooth profile of the sprocket. Its upper and lower effective heating sections are close to the upper tooth root and lower tooth root of the sprocket, respectively. The curvature of the induction coil (23) fits the arc tooth profile of the sprocket. When heating, the heat source of the induction coil (23) preferentially acts on the upper tooth root and lower tooth root areas of the sprocket. The feeding section (4) includes a drive motor (43), a rotating disk (42), and at least two sets of lifting structures (41). The rotating disk (42) is mounted on the output shaft of the drive motor (43) and can rotate in the horizontal plane. Multiple sets of lifting structures (41) are evenly arranged on the top of the rotating disk (42). The lifting structure (41) includes a waterproof shell (414), a rotating motor (413), an electric push rod (412), and a locking block (411). The waterproof shell (414) is fixed on the rotating disk (42). The rotating motor (413) is sealed and installed inside the waterproof shell (414). The electric push rod (412) is connected to the output end of the rotating motor (413) and has a built-in stroke sensor. The locking block (411) is installed on the top of the telescopic rod of the electric push rod (412) and is used to fix the sprocket.

2. The continuous induction hardening device for sprockets according to claim 1, characterized in that: The electric slide rail (21) is used to drive the induction coil (23) to move back and forth between the quenching station near the sprocket and the standby station away from the sprocket; the rotary motor (413) has a built-in angle sensor to drive the sprocket to rotate at a constant speed during the heating process.

3. The continuous induction hardening device for sprockets according to claim 1, characterized in that: The waterproof shell (414) is a sealed shell. The output axis of the rotary motor (413) passes through the top of the waterproof shell (414) and a skeleton oil seal is provided at the perforation for rotational sealing.

4. The continuous induction hardening device for sprockets according to claim 1, characterized in that: The circulation section (3) includes a circulation pipe (33), a circulation pump (34), a fan (35), a gooseneck pipe (32), and a spray nozzle (31). The circulation pipe (33) is an S-shaped pipe with its inlet connected to the bottom of the quenching frame (1). The circulation pump (34) is installed on the pipe. The fan (35) is installed corresponding to the circulation pipe (33) and is used to provide forced air cooling for the coolant circulating in the pipe. One end of the gooseneck pipe (32) is connected to the outlet of the circulation pipe (33), and the other end is fixedly installed with the spray nozzle (31). The spray nozzle (31) can be adjusted in direction through the gooseneck pipe (32) and is directly facing the sprocket in the quenching completion area.

5. The continuous induction hardening device for sprockets according to claim 1, characterized in that: The transport section (5) includes two sets of transport tracks (51), a telescopic structure (55), a crossbar (52), a clamping rod (53), and an elastic locking point (54). The two sets of transport tracks (51) are used to feed in and feed out sprockets, respectively. The telescopic structure (55) is installed between the two sets of transport tracks (51) to adjust the track spacing to accommodate sprockets of different diameters. The crossbar (52) is a telescopic crossbar (52) installed on the top of the transport track (51) and can be extended and retracted vertically to accommodate sprockets of different thicknesses. The clamping rod (53) is located on both sides of the bottom of the crossbar (52) and has a buffer spring inside to press the sprocket from above. The elastic locking point (54) is installed on the inner wall of the transport track (51) to limit the sprocket during transport.

6. The continuous induction hardening device for sprockets according to claim 5, characterized in that: Both the telescopic structure (55) and the crossbeam (52) are adjustable structures, so that the spacing between the transport tracks (51) and the height of the clamping rod (53) can be adapted to sprockets of different diameters.

7. The continuous induction hardening device for sprockets according to claim 1, characterized in that: The locking block (411) is a replaceable locking block (411). By replacing the locking block (411) with different specifications and adjusting the lifting stroke of the electric push rod (412) and the feed stroke of the induction coil (23), it can be adapted to different specifications of sprockets.

8. The continuous induction hardening device for sprockets according to claim 1, characterized in that: When the thickness of the sprocket to be quenched exceeds the preset value, a side coil (231) is added on the basis of the induction coil (23). The side coil (231) is installed at the front end of the power supply box (22) and located outside the induction coil (23). Its effective heating section corresponds to the side wall of the sprocket teeth, and the input power of the side coil (231) is less than the main heating power of the induction coil (23).

9. A continuous induction hardening device for sprockets according to claim 4, characterized in that: The coolant in the quenching frame (1) is water or quenching oil. For sprockets with thin thickness and small diameter, after heating, the electric push rod (412) retracts directly to immerse the sprocket in the coolant for immersion quenching. For sprockets with large diameter and thick thickness, the rotary motor (413) drives the sprocket to rotate slowly, and the spray nozzle (31) sprays and cools the heated part of the sprocket, so that the thick section teeth are quenched and cooled.

Images