Rapid strengthening device for differential case of drive axle

Abstract

The invention provides a rapid strengthening device for a differential case of a drive axle. The rapid strengthening device comprises a base body, a quenching inductor and a case mounting structure. The quenching inductor is connected with the base body, and induction coils are wound around the two ends, arranged at intervals in the first direction, of the quenching inductor. The shell installation structure is provided with an assembly position used for being connected with a drive axle differential case and has a starting state for driving the drive axle differential case to rotate around the central axis of the drive axle differential case, and when the drive axle differential case is connected to the assembly position, the inner spherical surface of the drive axle differential case is located on the outer sides of the two ends of the quenching inductor. And a preset spacing distance is formed between the inner spherical surface of the drive axle differential case and each induction coil. The inner spherical surface of the drive axle differential case is rapidly quenched and strengthened through the quenching inductor, and the problems that in the prior art, a drive axle differential case strengthening process is long in process time, high in cost and low in overall strength of parts are solved.

Description

Technical Field

[0001] The invention relates to the technical field of automobile manufacturing, and in particular to a rapid strengthening device for a drive axle differential case. Background Art

[0002] In the manufacturing process of the automobile industry, the differential is an important part of the automobile drive system. It is a device that distributes the power transmitted from the power transmission device to the left and right half-axles so that the left and right half-axles can rotate at different speeds. The rotation principle of the differential is to distribute the transmitted power to the left and right half-axles in a certain proportion, and then change the speed of the left and right half-axles according to the contact between the wheels and the ground, so that when the car turns, the outer wheels turn faster than the inner wheels to ensure that the vehicle turns smoothly. The differential housing is the main body of the differential. Its structure consists of an inner spherical area, an outer spherical area, a hole area, and a plane area. The inner spherical area contacts the half-axle gears and bears large impacts and alternating loads. It is a vulnerable part of the differential housing, so this part is required to have high fatigue strength and wear resistance. The drive axle differential housing plays an important role in carrying and transmitting power in the automobile transmission system, so it needs to have high strength and wear resistance. In order to improve the performance of the differential housing, a strengthening process scheme of quenching and tempering + nitriding is generally adopted.

[0003] The quenching and tempering treatment is to heat treat the material to obtain a certain hardness and strength while maintaining a certain toughness and machinability. Quenching and tempering can improve the overall hardness and strength of the differential case, increase its compression resistance, bending resistance and fatigue resistance, thereby improving its service life and durability. Nitriding treatment is to form a layer of nitride film on the surface of the material, so that it has high hardness and wear resistance. Nitriding can improve the surface hardness and wear resistance of the differential case, reduce the damage and failure of parts caused by friction and wear, and thus improve the reliability and stability of the transmission system. Therefore, the strengthening process scheme of quenching and tempering + nitriding can effectively improve the overall performance of the drive axle differential case, making it more suitable for working under high load, high speed and harsh working conditions, and ensuring the normal operation and long-term stability of the transmission system. However, the existing technology uses the strengthening process of quenching and tempering + nitriding to treat the drive axle differential case, which has the problems of long process time, high cost and low overall strength of parts.

[0004] To address the above problems, no effective solution has been proposed yet. Summary of the invention

[0005] The main purpose of the present invention is to provide a rapid strengthening device for a drive axle differential case to solve the problems of long process time, high cost and low overall strength of parts in the prior art strengthening process of the drive axle differential case.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a rapid strengthening device for a drive axle differential case is provided, comprising: a substrate; a quenching sensor, the quenching sensor is connected to the substrate, and both ends of the quenching sensor spaced apart along a first direction are wound with induction coils; a shell mounting structure, the shell mounting structure has an assembly position for connecting to the drive axle differential case, the shell mounting structure has a starting state for driving the drive axle differential case to rotate around its own central axis, when the drive axle differential case is connected to the assembly position, the inner spherical surface of the drive axle differential case is located on the outside of the two ends of the quenching sensor, and there is a preset spacing distance between the inner spherical surface of the drive axle differential case and each induction coil.

[0007] Furthermore, the quenching sensor includes: a first side beam, there are two first side beams, the two first side beams are extended along the first direction, and the two first side beams are spaced apart along the second direction; a second side beam, there are two second side beams, the two second side beams are spaced apart along the first direction, and both ends of each second side beam are respectively connected to the two first side beams, so that the two first side beams and the two second side beams together form a quadrilateral frame structure, and the two second side beams form two end portions accordingly.

[0008] Furthermore, the two second side beams are both arc-shaped segments, and the curvature of the second side beams is the same as the curvature of the corresponding position of the inner spherical surface.

[0009] Furthermore, a geometric center line of the quenching inductor along the first direction is arranged at an inclination angle with a horizontal plane, so that the heights of the two ends are arranged at different levels, and the inclination angle is an acute angle or an obtuse angle.

[0010] Furthermore, when the drive axle differential case is connected to the assembly position, the drive axle differential case is in a horizontal position, and the drive axle differential case has a plurality of adjacent quenching height layers along its own height direction, and the two ends of the quenching sensor are respectively used for induction quenching of different quenching height layers.

[0011] Furthermore, the rapid strengthening device of the drive axle differential includes: a water spray structure, which is an annular structure, connected to a base or an installation base, and when the drive axle differential case is connected to the assembly position, the water spray structure is located on the inner side of the drive axle differential case.

[0012] Furthermore, the annular structure has a cavity inside, and part of the quenching sensor is located in the cavity. Two gap channels are opened on the side wall of the annular structure, and the two gap channels are symmetrically arranged along the central axis of the annular structure. The two ends of the quenching sensor extend to the outside of the annular structure through a gap channel respectively.

[0013] Furthermore, a plurality of water spray holes are arranged in an array on the side wall of the annular structure.

[0014] Furthermore, at least one of the two end surfaces in the height direction of the water spray structure is provided with at least one connecting column, and the water spray structure is connected to the installation base through the at least one connecting column.

[0015] Furthermore, the first direction is the length direction of the quenching inductor.

[0016] By applying the technical solution of the present invention, the rapid strengthening device realizes the rapid connection and strengthening of the drive axle differential case through the quenching sensor and the housing mounting structure. When the housing mounting structure is in the starting state, the drive axle differential case will rotate around its own central axis, thereby generating electromagnetic induction with the induction coil at the end of the quenching sensor, and realizing the rapid quenching strengthening of the inner spherical surface of the drive axle differential case, so as to solve the problems of long process time, high cost and low overall strength of the parts in the existing drive axle differential case strengthening process. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0018] Figure 1 A schematic structural diagram of a first embodiment of a rapid strengthening device for a drive axle differential case according to the present invention is shown;

[0019] Figure 2 A schematic structural diagram of a second embodiment of a rapid strengthening device for a drive axle differential case according to the present invention is shown;

[0020] Figure 3 A schematic structural diagram showing a third embodiment of a rapid strengthening device for a drive axle differential case according to the present invention;

[0021] Figure 4 A schematic structural diagram showing a fourth embodiment of a rapid strengthening device for a drive axle differential case according to the present invention;

[0022] Figure 5 A schematic structural diagram of a fifth embodiment of a rapid strengthening device for a drive axle differential case according to the present invention is shown.

[0023] The above drawings include the following reference numerals:

[0024] 10. Matrix;

[0025] 20. Quenching sensor;

[0026] 21. First side beam;

[0027] 22. Second side beam;

[0028] 23. Induction coil;

[0029] 30. Drive axle differential case;

[0030] 40. Water spraying structure;

[0031] 41. Gap channel;

[0032] 42. Connecting column. DETAILED DESCRIPTION

[0033] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0034] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0035] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0036] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in a variety of different forms and should not be construed as being limited to the embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of the present application thorough and complete, and to fully convey the concepts of these exemplary embodiments to those of ordinary skill in the art. In the accompanying drawings, for the sake of clarity, the thickness of the layers and regions may be enlarged, and the same reference numerals are used to represent the same devices, and thus their descriptions will be omitted.

[0037] In the prior art, a strengthening process of quenching and tempering + nitriding is used to treat the drive axle differential case. The drive axle differential case uses material 42CrMoH, whose chemical composition and mechanical properties meet the requirements of high strength and wear resistance. After quenching and tempering, the surface hardness of the parts is required to reach (287-323) HBW to ensure sufficient wear resistance and fatigue resistance. In the subsequent nitriding treatment, the depth of the compound layer formed needs to be controlled within (0.006-0.020) mm to ensure surface wear resistance while not excessively affecting the toughness of the material. The nitriding process specifically includes keeping warm at high temperature (usually 520-570°C) for 10 hours to allow nitrogen atoms to fully diffuse to the surface of the material to form the required compound layer. Subsequently, cooling is performed for 12 hours to reduce internal stress and prevent cracking of the workpiece. The following problems exist in the strengthening treatment using this process: nitriding treatment requires long-term heat preservation and cooling, which leads to an extension of the overall production cycle, and long-term heat treatment increases energy consumption and production costs.

[0038] The prior art discloses the following three technologies for local strengthening of the differential case:

[0039] (1) A differential case induction quenching heat treatment production line. The invention includes an independently set quenching double-station machine tool, an IGBT quenching power cabinet, an IGBT tempering power cabinet, an electrical control cabinet, an industrial computer, an industrial robot for loading and unloading materials, a visual recognition system, a machine tool cooling water circulation system, a quenching liquid cooling circulation system, and a through-type automatic induction tempering device. The automation of the quenching and tempering process is achieved through the industrial computer and the industrial robot for loading and unloading materials, which improves production efficiency and quality consistency, saves labor costs, and reduces labor intensity.

[0040] (2) A method for processing a differential case assembly, by separately processing the front half case of the differential and the rear half case of the differential, and induction hardening the outer surface of the small head of the two workpieces and the shoulder step within 25mm, and then assembling the differential case assembly. This method aims to solve the problem of fracture of the differential case assembly by separately processing the differential case, improve the static torque, and enhance the strength and life of the product.

[0041] (3) A method for processing a differential case between heavy-duty vehicles, belonging to the technical field of automotive parts. First, the front end face and the outer circle of the tooth profile are roughly turned by a lathe; then the rear end face and the outer circle are finely turned by a lathe; the face cone angle of the tooth profile and the front end face shape are finely turned; the assembly hole is processed; the tooth profile is processed; the tooth profile is heat treated on the workpiece, and the surface is subjected to high-frequency quenching treatment; the cross shaft holes C and G are roughly bored and two parallel planes M and K are roughly milled; the rear end face, the outer circle and the spherical surface are finely turned; the cross shaft holes C and G are finely bored and two parallel planes M and K are finely milled. The above method is used to improve the dimensional control of the differential case after local heat treatment, improve the connection performance and strength, while reducing fuel consumption and cost, and ensuring production efficiency and quality.

[0042] There are still some problems in processing and strengthening the drive axle differential case through the above methods and technologies:

[0043] (1) Affects the heating uniformity of the overall inner spherical structure of the drive axle differential case.

[0044] (2) No specific technical requirements are involved to ensure that the desired technical effects can be achieved, nor is a detailed description of the local strengthening process made.

[0045] (3) The technology for quick installation and removal of the sensor parts is not explained, and only the machining details and assembly of the differential case assembly are focused on.

[0046] Combination Figures 1 to 5 As shown, according to a specific embodiment of the present application, a rapid strengthening device for a drive axle differential case is provided.

[0047] Specifically, the rapid strengthening device includes: a base 10, a quenching sensor 20 and a shell mounting structure. The quenching sensor 20 is connected to the base 10, and the two ends of the quenching sensor 20 spaced apart along the first direction are both wound with induction coils 23; the shell mounting structure has an assembly position for connecting with the drive axle differential case 30, and the shell mounting structure has a starting state for driving the drive axle differential case 30 to rotate around its own central axis. When the drive axle differential case 30 is connected to the assembly position, the inner spherical surface of the drive axle differential case 30 is located outside the two ends of the quenching sensor 20, and there is a preset spacing distance between the inner spherical surface of the drive axle differential case 30 and each induction coil 23.

[0048] By applying the technical solution of the present invention, the rapid strengthening device realizes the rapid connection and strengthening of the drive axle differential case 30 through the quenching sensor 20 and the housing mounting structure. When the housing mounting structure is in the starting state, the drive axle differential case 30 will rotate around its own central axis, thereby generating electromagnetic induction with the induction coil 23 at the end of the quenching sensor 20, and realizing the rapid quenching strengthening of the inner spherical surface of the drive axle differential case 30, so as to solve the problems of long process time, high cost and low overall strength of the parts in the strengthening process of the drive axle differential case 30 in the prior art.

[0049] Furthermore, if Figure 4As shown, the quenching sensor 20 includes: a first side beam 21 and a second side beam 22. There are two first side beams 21, the two first side beams 21 are extended along the first direction, and the two first side beams 21 are spaced apart along the second direction; there are two second side beams 22, the two second side beams 22 are spaced apart along the first direction, and the two ends of each second side beam 22 are respectively connected to the two first side beams 21, so that the two first side beams 21 and the two second side beams 22 form a quadrilateral frame structure together, and the two second side beams 22 form two ends correspondingly. Designing the two first side beams 21 and the two second side beams 22 to form a quadrilateral frame structure together can enhance the stability and reliability of the quenching sensor 20. The quadrilateral frame structure can effectively support the entire quenching sensor 20 to prevent it from being deformed or damaged during operation. At the same time, the quadrilateral frame structure can also improve the structural strength of the quenching sensor 20, making it more durable and long-lasting. Through this design, the quenching sensor 20 can better adapt to various working environments and conditions to ensure its normal operation and accurate detection.

[0050] like Figure 1 , Figure 4 As shown, two first side beams 21 are arranged in parallel, the first side beam 21 at the upper end is composed of two parts of L-shaped beams, and the first side beam 21 at the lower end is a whole cross beam. The quenching sensor 20 is connected to the substrate through the first side beam 21 at the upper end, and the two ends of each second side beam 22 are respectively connected to the two first side beams 21, and the two second side beams 22 form two ends with induction coils 23 wound around them. The function of the induction coils wound around the two ends of the quenching sensor 20 is to detect the temperature of the metal material. When the drive axle differential case 30 is heated to a certain temperature, its magnetism will change, causing the induced current in the induction coil 23 to change. By detecting the current change in the induction coil 23, it can be determined whether the temperature of the drive axle differential case 30 has reached the quenching requirements, and corresponding treatment can be carried out in time. This design can realize real-time monitoring of the temperature of the drive axle differential case 30 to ensure the quality and effect of the quenching process. In this embodiment, there is a preset spacing distance between the inner spherical surface of the drive axle differential case 30 and each induction coil 23. Setting the spacing distance can prevent the induction coil 23 from directly contacting the inner spherical surface of the drive axle differential case 30 to avoid wear and friction. At the same time, it can also ensure the normal operation and stable performance of the induction coil 23, effectively protect the induction coil 23, and extend its service life.

[0051] Specifically, the two second side beams 22 are both arc segments, and the curvature of the second side beams 22 is the same as the curvature of the corresponding position of the inner spherical surface. If the two second side beams 22 are both arc segments, the shape of the quenching sensor 20 is a fan-shaped sensor, and the curvature of the second side beams 22 is the same as the curvature of the corresponding position of the inner spherical surface, the quenching sensor 20 can fit the inner spherical surface of the drive axle differential case 30 as much as possible, thereby improving the accuracy and reliability of detection.

[0052] Further, the quenching sensor 20 is arranged with an inclination angle with the horizontal plane along the geometric center line of the first direction, so that the heights of the two ends are set differently, and the inclination angle is an acute angle or an obtuse angle. The quenching sensor 20 is arranged with an inclination with the horizontal plane along the geometric center line of the first direction, so that there is a height difference between the two second side beams 22, so that the quenching sensor 20 has a wider temperature detection range, and the inner spherical surface of the drive axle differential case 30 can be monitored over a larger area.

[0053] like Figure 1 , Figure 2 As shown, in this embodiment, the inclination angle between the geometric center line of the quenching sensor 20 along the first direction and the horizontal plane is set to an acute angle, and the induction coils 23 at both ends of the quenching sensor 20 are made of 12×10×1.5 copper tubes to form an asymmetric sector with a diameter of Φ138.5mm and a height of 82mm, that is, the height difference between the two ends of the quenching sensor 20 is 82mm. The gap width between the asymmetric sector structure at both ends of the quenching sensor 20 and the inner spherical surface of the drive axle differential case 30 is 2.5mm. The asymmetric design can better fit the workpiece and reduce energy loss and workpiece deformation during heating. The design of the induction coil 23 of the quenching sensor 20 as an asymmetric sector can increase the induction area of ​​the induction coil 23, so that it can better capture the signal generated during the quenching process and improve the sensitivity of the quenching sensor 20; it can also reduce the interference between the induction coils 23, so that the quenching sensor 20 can more stably detect the signal generated during the quenching process, thereby making the quenching sensor 20 more effective and reliable during the quenching process.

[0054] It should be further explained that, since the two ends of the quenching sensor 20 are set as asymmetric fan-shaped structures and there is a gap between the asymmetric fan-shaped structures at both ends and the inner spherical surface of the drive axle differential case 30, the workpiece can be easily removed from one side without moving the quenching sensor 20, which greatly improves the efficiency of loading and unloading. The quenching sensor 20 does not need to be moved for loading and unloading, and the entire production process can achieve continuous operation, which greatly improves production efficiency.

[0055] In an exemplary embodiment, when the drive axle differential case 30 is connected to the assembly position, the drive axle differential case 30 is in a horizontal position, and the drive axle differential case 30 has a plurality of adjacent quenching height layers along its own height direction, and the two ends of the quenching sensor 20 are respectively used for induction quenching of different quenching height layers, that is, the drive axle differential case 30 is heated in sections using the asymmetric sectors at both ends. The drive axle differential case 30 has a plurality of adjacent quenching height layers along its own height direction, so that parts of different heights can be quenched, so that the strength and wear resistance of the entire drive axle differential case 30 are more uniform and stable. By induction quenching different quenching height layers, it can be ensured that the drive axle differential case 30 is not easily deformed and damaged when it is subjected to high loads and rotates around its own central axis, thereby improving its service life and reliability. At the same time, this arrangement can also effectively reduce production costs, improve production efficiency and product quality.

[0056] like Figure 1 As shown, the drive axle differential case 30 is a cylindrical metal shell with a certain thickness, and the height between the two ends of the quenching sensor 20 is greater than or equal to the height of the drive axle differential case itself to ensure that each quenching height layer can be completely covered. Performing quenching detection on each quenching height layer can ensure the accuracy of the detection.

[0057] Furthermore, if Figure 5 As shown, the rapid strengthening device for the drive axle differential includes: a water spray structure 40, which is an annular structure, connected to the base 10 or the installation base, and when the drive axle differential case 30 is connected to the assembly position, the water spray structure 40 is located inside the drive axle differential case 30. When the temperature of the drive axle differential case 30 is high during the strengthening process, the water spray structure 40 is located inside the drive axle differential case 30, and the water spray structure 40 can spray water to the inner spherical surface of the drive axle differential case 30 to cool it down.

[0058] When the drive axle differential is running, the water spray structure sprays water into the differential through the water spray hole, which effectively reduces the temperature of the differential, thereby improving its working efficiency and extending its service life. At the same time, the quenching sensor in the cavity can monitor the temperature change of the differential and adjust the water flow of the water spray structure in time to ensure that the differential always remains within the appropriate operating temperature range. Such a rapid strengthening device can effectively protect the drive axle differential and improve its performance and reliability.

[0059] Specifically, Figure 2As shown, the annular structure has a cavity inside, part of the quenching sensor 20 is located in the cavity, and two gap channels 41 are opened on the side wall of the annular structure. The two gap channels 41 are symmetrically arranged along the central axis of the annular structure, and the two ends of the quenching sensor 20 extend to the outside of the annular structure through a gap channel 41 respectively. In this embodiment, the two gap channels 41 divide the annular structure into two parts, and the two ends of the quenching sensor 20 extend to the outside of the annular structure through a gap channel 41 respectively. The internal frame of the quenching sensor 20 can be hidden in the cavity inside the annular structure, which optimizes the space and does not affect the electromagnetic induction generated by the induction coils 23 at the two ends and the inner spherical surface of the drive axle differential case 30.

[0060] Specifically, a plurality of water spray holes are arranged in an array on the side wall of the annular structure. The water spray structure 40 sprays water into the inside of the drive axle differential case 30 through the water spray holes, so that the temperature of the drive axle differential case 30 is effectively reduced, thereby improving its working efficiency and extending its service life. At the same time, the quenching sensor in the cavity can monitor the temperature change of the differential, and timely adjust the water flow of the water spray structure to ensure that the drive axle differential case 30 is always kept within a suitable working temperature range.

[0061] like Figure 1 As shown, in this embodiment, the annular structure of the water spray structure 40 is made of a rectangular metal material of 22×10×1.5, and is made into a ring with staggered water spray holes inside. The diameter of the water spray holes is Φ1.8, and the minimum inner diameter of the annular structure is 80mm, and the height is about 210mm. The water spray holes on the side wall of the annular structure are designed to be staggered inside and outside, which can ensure uniform cooling of the quenching area and avoid uneven hardness or thermal stress cracks caused by uneven cooling.

[0062] Specifically, at least one of the two end surfaces in the height direction of the water spray structure 40 is provided with at least one connecting column 42, and the water spray structure 40 is connected to the installation base through the at least one connecting column 42. Figure 1 As shown, two connection columns 42 are respectively arranged on the two end faces in the height direction of the water spray structure 40, and the two connection columns on each end face are symmetrically arranged. The water spray structure 40 is connected to the installation base through the connection columns 42 to ensure the stability of the installation.

[0063] Furthermore, if Figure 4As shown, the first direction is the length direction of the quenching sensor 20. The first direction is inclined at a certain angle to the horizontal plane, and the first side beam 21 of the quenching sensor 20 is extended along the first direction, and the length is less than the inner diameter of the drive axle differential case 30, so that the quenching sensor 20 can be completely installed inside the drive axle differential case 30. The length of the first side beam 21 is much larger than the inclined diameter of the annular structure, ensuring that the two ends of the quenching sensor 20 extend to the outside of the annular structure through a gap channel 41 respectively, and such a setting can effectively improve the efficiency and uniformity of the quenching process.

[0064] Taking a 42CrMoH differential case as a specific embodiment, the drive axle differential case is strengthened using the above-mentioned rapid strengthening device for the drive axle differential case 30, and the steps are as follows:

[0065] S1. Place the drive axle differential case 30 workpiece to be strengthened on the fixture of the machine tool in the assembly position, ensure that the workpiece is firmly fixed, and align the positions of the quenching sensor 20 and the workpiece so that the induction coil 23 of the quenching sensor 20 can accurately cover the entire inner spherical area of ​​the drive axle differential case 30 to be heated.

[0066] S2. After the workpiece is fixed and aligned, the drive axle differential case 30 is driven to rotate around its own central axis (rotation speed: 100r / min) and the quenching sensor 20 starts heating. The parameters are set according to the workpiece material and size: heating time 0.8~1.2s, heating power 100~110kW, medium frequency transformer turns ratio: 9:1, resonant capacitor: 35μF, DC voltage: 310~320V, DC current: 330~340A, medium frequency voltage: 375~380V, current frequency 2.6kHz.

[0067] S3. After the heating is completed, the water spraying structure 40 starts to spray water for cooling after a delay of 20 seconds. The delay ensures that the surface of the workpiece reaches a temperature that can be quenched, and avoids premature cooling that leads to poor hardening effect. After the cooling is completed, the operator or automated equipment can quickly remove the drive axle differential case 30 workpiece from the fixture.

[0068] S4. After quenching and strengthening, the drive axle differential case 30 is tested to ensure that the corresponding technical requirements are met: surface hardness (0.2 mm from the tooth root surface): 56-62 HRC, effective hardened layer depth: 1.0-3.0 mm, metallographic structure: fine martensite + a small amount of residual austenite on the surface, and tempered troostite in the core.

[0069] S5. After removing the first part, the next drive axle differential case 30 workpiece can be placed immediately, and the above steps S1-S4 are repeated.

[0070] It should be noted that the turns ratio of the medium frequency transformer is adjusted to meet the heating requirements of the spherical area inside the differential case. Reasonable adjustment of the turns ratio of the transformer can effectively improve the heating efficiency, reduce energy consumption, and is suitable for large-scale production environments, improving production efficiency and reducing costs.

[0071] The capacity of the resonant capacitor is adjusted to match the power frequency and the heating power. In this embodiment, the capacity of the resonant capacitor is set to 35μF, which can achieve the best match between the power supply and the sensor, improve the heating uniformity and depth control, and is suitable for strengthening treatment with high-precision requirements on the spherical area inside the differential case, ensuring the consistency and reliability of the strengthening effect.

[0072] The control of medium frequency voltage is the key to achieve efficient heating. It is suitable for the spherical area inside the differential case that needs to be heated quickly, improving production efficiency and reducing waiting time.

[0073] By adjusting the heating power, the heating speed can be controlled while ensuring the strengthening effect. This is suitable for production environments where strengthening treatment needs to be completed in a short time, improving production flexibility and response speed.

[0074] Precisely controlling the heating time can avoid degradation of material properties caused by overheating. It is suitable for the spherical area inside the differential case that requires rapid heating and cooling, and improves the efficiency and effect of heat treatment.

[0075] The rapid strengthening device for the drive axle differential case 30 described in this embodiment can significantly improve the hardness and wear resistance of the spherical area inside the differential case by accurately controlling the heating and cooling process, thereby enhancing the mechanical properties and service life of the entire drive axle. This method can not only effectively avoid the material performance degradation and deformation problems that may be caused by overall heat treatment, but also ensure the uniformity and comprehensiveness of the heating area through the design of the fan-shaped inductor with an asymmetric structure, further improving the consistency of the strengthening effect. In addition, by setting various parameters such as heating time, heating power, frequency transformer turns ratio, resonant capacitor, DC voltage, DC current, medium frequency voltage, current frequency, etc., this method has good adaptability and flexibility, can meet the strengthening requirements of commercial vehicle drive axle differential cases of different models and sizes, and provides strong technical support for improving the driving stability and safety of commercial vehicles.

[0076] It should be known to those skilled in the art that in this solution, the hardness value is required to be between 56 and 62 within a depth of 0.2 mm from the tooth root surface. This parameter is crucial to ensure the wear resistance of the drive axle differential case 30, and the hardness value is determined by measuring the depth of the indenter (usually a diamond cone or a hardened steel ball) pressed into the material surface under a certain load. The effective hardened layer depth refers to the depth to which the material surface reaches a predetermined hardness after heat treatment (such as induction hardening). Within this range, the hardness and mechanical properties of the material are significantly improved, thereby enhancing the strength and durability of the parts.

[0077] The effective hardened layer depth is required to be between 1.0 and 3.0 mm. This depth range is set to balance the surface hardness and core toughness of the drive axle differential case 30 to prevent the core brittleness from increasing due to the increase in surface hardness, thereby affecting the overall performance.

[0078] The metallographic structure of the surface is required to be fine martensite + a small amount of residual austenite, which usually means that the surface has been rapidly cooled to form a hard and wear-resistant martensite phase, while retaining a certain proportion of incompletely transformed austenite, which helps to improve the toughness of the surface. The metallographic structure of the core is required to be tempered troostite, which usually means that the core material has been tempered after heat treatment, thereby obtaining higher strength and good toughness. Troostite is a structural phase characterized by a good balance between strength and toughness. This metallographic structure requirement for the surface and the core is to ensure that the drive axle differential case 30 has high wear resistance and can withstand high-intensity loads and friction while maintaining sufficient strength and toughness.

[0079] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0080] 1. This solution directly strengthens the overall inner spherical structure of the drive axle differential case by induction heat treatment. By designing the two ends of the quenching sensor to be asymmetric fan-shaped structures that fit closely with the inner spherical surface of the differential case, there is a height difference between the asymmetric fan-shaped structures at both ends of the quenching sensor, and different quenching height layers can be induction quenched, that is, the drive axle differential case 30 is heated in sections, which can further achieve rapid and uniform heating of the overall inner spherical surface, reduce thermal deformation of the workpiece during the heating process, ensure the dimensional accuracy of the parts, reduce the need for subsequent processing, and further improve production efficiency and reduce costs.

[0081] 2. The two ends of the quenching sensor are set as asymmetric fan-shaped structures, and there is a gap between the asymmetric fan-shaped structures at both ends and the inner spherical surface of the drive axle differential case 30. The workpiece can be easily removed from one side without moving the quenching sensor, which greatly improves the efficiency of loading and unloading. The quenching sensor 20 does not need to be moved for loading and unloading, and the entire production process can achieve continuous operation, which greatly improves production efficiency.

[0082] 3. To stipulate the technical requirements for induction hardening of the overall inner spherical surface of the drive axle differential case to improve the wear resistance and strength of the differential case while maintaining good core toughness to meet the high load requirements of heavy-duty vehicle drive axles.

[0083] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0084] In addition to the above, it should be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this specification refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of the present invention.

[0085] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0086] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A rapid strengthening device for a drive axle differential case, characterized in that: include: A substrate (10); A quenching inductor (20), the quenching inductor (20) being connected to the substrate (10), and both ends of the quenching inductor (20) spaced apart along a first direction are wound with an induction coil (23); A housing mounting structure, wherein the housing mounting structure has an assembly position for connecting to a drive axle differential case (30), and the housing mounting structure has a start state for driving the drive axle differential case (30) to rotate around its own central axis. When the drive axle differential case (30) is connected to the assembly position, the inner spherical surface of the drive axle differential case (30) is located outside the two ends of the quenching sensor (20), and there is a preset spacing distance between the inner spherical surface of the drive axle differential case (30) and each of the induction coils (23).

2. The rapid strengthening device for the drive axle differential case according to claim 1, characterized in that: The quenching sensor (20) comprises: a first side beam (21), wherein the number of the first side beams (21) is two, the two first side beams (21) are extended along the first direction, and the two first side beams (21) are spaced apart along the second direction; and a second side beam (22), wherein the number of the second side beams (22) is two, the two second side beams (22) are spaced apart along the first direction, and the two ends of each second side beam (22) are respectively connected to the two first side beams (21) so that the two first side beams (21) and the two second side beams (22) together form a quadrilateral frame structure, and the two second side beams (22) form the two end portions accordingly.

3. The rapid strengthening device for the drive axle differential case according to claim 2, characterized in that: The two second side beams (22) are both arc-shaped segments, and the curvature of the second side beams (22) is the same as the curvature of the corresponding position of the inner spherical surface.

4. The rapid strengthening device for a drive axle differential case according to any one of claims 2 to 3, characterized in that: The geometric center line of the quenching inductor (20) along the first direction is arranged at an inclined angle with the horizontal plane, so that the heights of the two ends are arranged at different levels, and the inclined angle is an acute angle or an obtuse angle.

5. The rapid strengthening device for the drive axle differential case according to claim 4, characterized in that: When the drive axle differential case (30) is connected to the assembly position, the drive axle differential case (30) is in a horizontally placed state, the drive axle differential case (30) has a plurality of adjacently arranged quenching height layers along its own height direction, and the two ends of the quenching sensor (20) are respectively used for induction quenching of different quenching height layers.

6. The rapid strengthening device for a drive axle differential case according to any one of claims 1 to 3, characterized in that: The rapid strengthening device of the drive axle differential case comprises: A water spray structure (40), the water spray structure (40) is an annular structure, the water spray structure (40) is connected to the base (10) or the installation base, and when the drive axle differential case (30) is connected to the assembly position, the water spray structure (40) is located on the inner side of the drive axle differential case (30).

7. The rapid strengthening device for a drive axle differential case according to claim 6, characterized in that: The annular structure has a cavity inside, and part of the quenching sensor (20) is located in the cavity. Two gap channels (41) are opened on the side wall of the annular structure. The two gap channels (41) are symmetrically arranged along the central axis of the annular structure. The two ends of the quenching sensor (20) extend to the outside of the annular structure through one of the gap channels (41).

8. The rapid strengthening device for a drive axle differential case according to claim 6, characterized in that: A plurality of water spray holes are arranged in an array on the side wall of the annular structure.

9. The rapid strengthening device for a drive axle differential case according to claim 6, characterized in that: At least one of the two end faces of the water spray structure (40) in the height direction is provided with at least one connecting column (42), and the water spray structure (40) is connected to the installation base via the at least one connecting column (42).

10. The rapid strengthening device for a drive axle differential case according to claim 2, characterized in that: The first direction is the length direction of the quenching inductor (20).

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