Bearing inner ring curved surface laser quenching strengthening process

Abstract

The invention provides a bearing inner ring curved surface laser quenching strengthening technology, and relates to the technical field of bearing machining, and the technology comprises the following steps: S1, workpiece pretreatment; s2, implementing laser quenching: dividing the outer side surface of the to-be-quenched bearing into a plurality of strengthening areas along the axis direction of the to-be-quenched bearing, dividing the inner side surface into a plurality of cooling areas, and sequentially carrying out laser quenching strengthening on the plurality of strengthening areas by utilizing laser equipment, and meanwhile, cooling equipment is used for continuously cooling corresponding cooling areas on the inner sides of the multiple strengthening areas, the cooling equipment comprises multiple hollow solid cooling blocks, cooling liquid continuously flows in the solid cooling blocks, and the surfaces of the solid cooling blocks are controlled to be attached to the cooling areas to achieve continuous cooling. According to the laser quenching device, efficient and accurate laser quenching and cooling of the bearing can be achieved, efficient control is achieved, and the laser quenching device is suitable for laser quenching strengthening of bearings wide in size and small in thickness.

Description

Technical Field

[0001] This invention relates to the field of bearing processing technology, and in particular to a laser hardening process for strengthening the inner ring curved surface of bearings. Background Technology

[0002] As a key load-bearing component, the inner ring of the crankshaft bearing must have high hardness and excellent wear resistance on its raceway surface that contacts the steel balls. Traditional quenching processes (integral quenching / induction quenching) have problems such as large deformation, uneven hardening layer, and severe stress concentration, which make it difficult to meet high precision requirements.

[0003] Laser hardening is considered an ideal alternative due to its rapid heating, rapid cooling, and minimal heat-affected zone. However, for some wide and thin inner ring curved surfaces of bearings, laser hardening over a wide distance on the bearing surface can lead to difficulty in quickly dissipating heat, affecting the quality of the hardening process. Furthermore, traditional cooling equipment and processes have relatively limited cooling methods and effects, failing to effectively and precisely cool the heat generated within the bearing, thus impacting the final hardened quality of the bearing. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a laser hardening process for the inner ring curved surface of bearings. This invention enables efficient and accurate laser hardening and cooling of bearings, achieving high-efficiency control and is suitable for laser hardening and strengthening of bearings with wide dimensions and thin thickness.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] The laser hardening process for the inner ring curved surface of a bearing includes the following steps: S1, workpiece pretreatment; S2, implementation of laser hardening: the outer surface of the bearing to be hardened is divided into multiple strengthening areas and the inner surface into multiple cooling areas along the axial direction of the bearing to be hardened. Laser equipment is used to perform laser hardening on multiple strengthening areas in sequence, while cooling equipment is used to continuously cool the corresponding cooling areas inside the multiple strengthening areas. The cooling equipment includes multiple hollow solid cooling blocks, and coolant flows continuously inside the solid cooling blocks. The surface of the solid cooling blocks is controlled to adhere to the cooling areas to achieve continuous cooling; S3, post-hardening inspection and verification: the hardness, size, and microstructure of the bearing hardened surface are inspected.

[0007] Preferably, the cooling device includes a cooling body and a position control body, wherein the position control body controls the cooling body to move along the axis of the bearing to be quenched.

[0008] Preferably, laser equipment is used to sequentially perform laser hardening on the alternating strengthening regions, and a cooling device is used to continuously cool the corresponding cooling regions inside the strengthening regions.

[0009] Preferably, multiple solid cooling blocks are arranged circumferentially, and the outer arc-shaped surfaces of the multiple solid cooling blocks are located on the same virtual cylindrical surface. The cooling body also includes multiple intermediate connecting pipes, which connect two adjacent solid cooling blocks. The intermediate connecting pipes are arc-shaped and slidably connected to the corresponding solid cooling blocks. The multiple intermediate connecting pipes and the interior of the multiple solid cooling blocks form a relatively sealed cooling control channel.

[0010] Preferably, one of the solid cooling blocks is connected to a coolant pumping pipe. Coolant is pumped into the cooling control channel through the coolant pumping pipe to increase the pressure in the coolant pumping channel, thereby controlling multiple solid cooling blocks to expand outward synchronously and abut against the inner wall of the bearing to be quenched. Coolant is extracted from the cooling control channel through the coolant pumping pipe to reduce the pressure, thereby controlling multiple solid cooling blocks to contract inward synchronously and detach from the inner wall of the bearing to be quenched.

[0011] Preferably, the coolant pumping pipeline includes a first pipeline and a second pipeline, the first pipeline and the second pipeline are arranged adjacent to each other and a partition plate is provided between the first pipeline and the second pipeline.

[0012] Preferably, the positioning control body includes a horizontal positioning plate, a horizontal positioning groove is formed in the horizontal positioning plate, a positioning rod is movably arranged inside the horizontal positioning groove, and the positioning rod is fixedly connected to the cooling body.

[0013] Preferably, in step S1, the inner ring of the crankshaft bearing is quenched and tempered to ensure that the hardness of the base material reaches 58-62 HRC; the inner ring surface is cleaned with a cleaning solution to remove surface oil and impurities, avoid oxidation defects during quenching, and ensure the uniformity of subsequent quenching effect.

[0014] Preferably, in step S2, the laser power is determined based on the inner diameter. For an inner diameter of 30mm, a laser power of 800-1000W is selected, resulting in a hardened layer depth of 0.7-0.82mm. Too low a power results in poor hardening, while too high a power increases the heat-affected zone. The scanning speed is 8-15mm / s, combined with the robotic arm's helical scanning trajectory. Too high a speed results in a shallow hardened layer, while too slow a speed can easily cause thermal deformation of the inner circle. The laser angle is 15-25° to reduce the tempering effect caused by direct laser radiation at the edges, improving the stability of the strengthened area. The overlap rate is 20-30%, precisely controlled by programming the robotic arm trajectory to minimize the overlap between adjacent laser spots. Too high an overlap rate reduces the density of the microstructure, while too low a rate can lead to unstrengthened gaps. The cooling rate is controlled at 10... 4 -10 5 ℃ / s, promotes the formation of martensite structure and increases the hardness of the quenched layer.

[0015] Preferably, step S3 is performed after quenching, where the inner ring is radially prepared using wire cutting, and tested according to the following standards to ensure product quality meets the requirements:

[0016] Hardness testing: The hardness of the matrix area, reinforced center area and edge area is measured radially along the sample using a Rockwell hardness tester. The hardness of the reinforced area should be 4-7 HRC higher than that of the matrix, and the hardness error within the same reinforced area should be ≤3 HRC. Microstructure observation: The microstructure of the quenched layer is observed using a metallographic microscope to ensure that it is a fine martensitic structure without obvious oxide layer, cracks or loose structure. Dimensional inspection: The key dimensions of the inner ring surface, such as diameter and roundness, are measured using a micrometer. The deformation should be ≤0.010 mm to meet the crankshaft bearing assembly clearance requirements.

[0017] The beneficial effects of this invention are as follows:

[0018] Compared with existing technologies, the above-mentioned process for layered and refined laser hardening and targeted cooling of bearings can quickly and accurately dissipate the heat generated by laser hardening, avoiding excessively high or low surface temperatures. It also prevents excessively rapid cooling from causing significant internal structural and thermal stresses, which could lead to surface microcracks, transgranular cracks, or even complete breakage. Furthermore, it avoids the problem of slow cooling allowing carbon atoms sufficient time to diffuse and aggregate, forming coarse network or granular carbides that prevent the formation of hard martensite. Simultaneous layered laser hardening and cooling enables highly efficient and accurate cooling of the bearings, achieving efficient control and making it suitable for laser hardening of wide-sized, thin-thick bearings. Attached Figure Description

[0019] Figure 1 This is a process flow diagram of the present invention.

[0020] Figure 2 This is a three-dimensional structural diagram of the cooling body and the position control body of the present invention.

[0021] Figure 3 For the present invention Figure 2 A top-view structural diagram.

[0022] Figure 4 This is a schematic diagram showing the cooling body and the position control body at different heights of the present invention.

[0023] Figure 5 This is a schematic diagram showing the expanded and contracted states of the solid cooling block of the present invention.

[0024] In the diagram: 100, bearing to be quenched; 200, cooling body; 210, solid cooling block; 211, partition plate; 220, intermediate connecting pipe; 231, first pipe; 232, second pipe; 300, positioning control body; 310, horizontal positioning plate; 311, horizontal positioning groove; 320, positioning rod; 330, guide rod; 340, lifting rod. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] See attached document Figure 1 - Appendix Figure 5 The laser hardening process for the inner ring curved surface of a bearing includes the following steps:

[0027] S1. Workpiece Pretreatment: During workpiece pretreatment, the inner ring of the crankshaft bearing is quenched and tempered to ensure that the matrix hardness reaches 58-62 HRC. The inner ring surface is cleaned with cleaning fluid to remove surface oil and impurities, avoid oxidation defects during quenching, and ensure the uniformity of subsequent quenching effect. The quenching and tempering treatment is to improve the matrix hardness and structural stability of the bearing inner ring, laying the foundation for subsequent laser quenching. The quenching and tempering process parameters are: quenching temperature 850-880℃, holding temperature 1-2h, oil cooling to room temperature; tempering temperature 180-200℃, holding temperature 2-3h, air cooling to room temperature, ensuring that the matrix hardness is stable at 58-62 HRC. The cleaning fluid is a neutral water-based cleaning agent with a pH value of 7-9, free of corrosive components to avoid damaging the bearing surface. The cleaning method is ultrasonic cleaning with a power of 300-500W and a cleaning time of 10-15 minutes, which can effectively remove surface oil, iron filings and other impurities. After cleaning, it is dried with compressed air, and the residual moisture on the surface is ≤0.1g / m², to prevent surface oxidation and cracking defects caused by impurities or moisture during quenching.

[0028] S2. Implementation of laser quenching: The outer surface of the bearing 100 to be quenched is divided into multiple strengthening areas and the inner surface is divided into multiple cooling areas along the axial direction of the bearing 100. Laser equipment is used to perform laser quenching strengthening on multiple strengthening areas in sequence. At the same time, cooling equipment is used to continuously cool the corresponding cooling areas inside the multiple strengthening areas. The cooling equipment includes multiple hollow solid cooling blocks 210. Cooling liquid flows continuously inside the solid cooling blocks 210. The surface of the solid cooling blocks 210 is controlled to adhere to the cooling area to achieve continuous cooling.

[0029] In step S2, the strengthening area and the cooling area are in a one-to-one correspondence and are evenly divided along the bearing axis. Each area is 5-10mm wide to ensure precise synchronization of quenching and cooling and avoid local overheating or uneven cooling. The solid cooling block 210 is made of copper with a thermal conductivity of ≥380W / (m・K), which can quickly conduct heat from the inside of the bearing. The gap between its surface and the cooling area inside the bearing is ≤0.1mm to ensure cooling efficiency.

[0030] The coolant is a 5% ethylene glycol aqueous solution, which has a high boiling point and stable cooling effect. The flow rate is controlled at 5-8 L / min to ensure that the internal temperature of the solid cooling block 210 is stable at 20-30℃.

[0031] S3. Post-quenching inspection and verification: The hardness, dimensions, and microstructure of the quenched bearing surface are tested. The inspection covers the three core indicators of hardness, microstructure, and dimensions to fully verify the quenching effect and prevent unqualified products from entering subsequent processes.

[0032] Post-quenching testing and verification are carried out after quenching. The inner ring is made into a sample radially using wire cutting and tested according to the following standards to ensure that the product quality meets the standards.

[0033] Hardness testing uses a Rockwell hardness tester to measure the hardness of the matrix area, the reinforced center area (center of the laser scanning trajectory), and the edge area (0.1-1.5 mm from the reinforced center) along the radial direction of the sample. The hardness of the reinforced area should be 4-7 HRC higher than that of the matrix, and the hardness error within the same reinforced area should be ≤3 HRC.

[0034] The microstructure of the quenched layer was observed using a metallographic microscope to ensure that it was a fine martensitic structure with no obvious oxide layer, cracks or loose structure.

[0035] Dimensional inspection is performed using a micrometer to measure key dimensions of the inner ring surface, such as diameter and roundness, requiring deformation ≤0.010mm to meet crankshaft bearing assembly clearance requirements.

[0036] The detection in step S3 is carried out 24 hours after quenching is completed. After the inner ring of the bearing is completely cooled to room temperature and the internal stress is fully released, the detection results can be ensured to be accurate. During the hardness test, 3 different cross-sections are selected for each specimen, 5 points are measured for each cross-section, and the average value is taken as the final hardness value; during the microstructure observation, the specimen needs to be polished, ground, and corroded to ensure that the microstructure morphology of the quenched layer can be clearly observed. The thickness of the quenched layer needs to be within the range of 0.7 - 0.82 mm, and the transition with the matrix is smooth without obvious demarcation defects; for the dimensional inspection, a digital micrometer is used to measure multiple diameter values and roundness of the inner ring of the bearing, and the maximum deformation amount is calculated, and it is required not to exceed 0.010 mm to ensure that the bearing can meet the clearance requirements for subsequent assembly. All inspection items must meet the standards to be qualified products. If the hardness does not meet the standard, there are microstructure defects or dimensional tolerance exceeds the standard, the reasons need to be analyzed and the process parameters need to be adjusted before re-quenching.

[0037] In summary, through the above process of hierarchical refinement laser quenching strengthening and hierarchical targeted cooling of the bearing, the heat generated by laser quenching can be quickly and accurately conducted and removed, avoiding the surface temperature of the bearing being too high or too low, and avoiding the rapid cooling rate transformation that will cause huge microstructure stress and thermal stress inside the workpiece, resulting in surface microcracks, internal transgranular cracks, or even direct cracking; it also avoids slow cooling that allows carbon atoms to have enough time to diffuse and aggregate, forming coarse network-like or granular carbides, resulting in the inability to form hard martensite; at the same time, laser quenching and cooling are carried out synchronously in layers, which can achieve efficient and accurate cooling and temperature reduction of the bearing, achieving efficient control, and is suitable for laser quenching strengthening of bearings with a wide size and a relatively thin thickness.

[0038] Furthermore, the cooling device includes a cooling main body 200 and a position control main body 300. The position control main body 300 controls the cooling main body 200 to move along the axis direction of the bearing 100 to be quenched. The laser equipment is used to carry out laser quenching strengthening on the mutually spaced strengthening regions in sequence, and the cooling device is used to continuously cool the correspondingly spaced cooling regions inside the strengthening regions.

[0039] The cooling main body 200 is the core execution component of the cooling device, integrating structures such as a solid cooling block 210 and an intermediate connecting pipe 220; the position control main body 300 is a linear module driven by a servo motor, ensuring the movement synchronization between the cooling main body 200 and the laser equipment. That is, when the laser scans to a certain strengthening region, the cooling main body 200 drives the corresponding solid cooling block 210 to accurately fit the inner cooling region, realizing the synchronous follow-up of quenching-cooling. The stroke of the position control main body 300 is designed according to the length of the inner ring of the bearing, which is 20 - 30 mm longer than the length of the bearing, ensuring that both ends of the strengthening region can also be fully cooled and avoiding cooling blind spots.

[0040] Alternating reinforcement zones refer to quenching the reinforcement zones in a sequence of 1-3-5, 2-4-6, etc. This intermittent quenching method avoids heat accumulation caused by continuous heating of adjacent areas, reducing the risk of thermal deformation of the bearing inner ring. For example, the outer side of the bearing can be divided into 6 reinforcement zones. Zones 1, 3, and 5 are quenched first, while the corresponding inner zones 1, 3, and 5 are cooled simultaneously. After the temperature of these zones drops below 200℃, zones 2, 4, and 6 are then quenched, with the corresponding inner zones cooled synchronously. The time interval between intermittent quenching is adjusted according to the bearing size, typically 30-60 seconds, to ensure that the previously quenched zones are fully cooled before proceeding with the subsequent zones. This results in a more uniform temperature distribution throughout the bearing inner ring, with deformation controlled within 0.010mm.

[0041] Furthermore, multiple solid cooling blocks 210 are arranged circumferentially, and the outer arc-shaped surfaces of the multiple solid cooling blocks 210 are located on the same virtual cylindrical surface. The cooling body 200 also includes multiple intermediate connecting pipes 220, which connect two adjacent solid cooling blocks 210 through the intermediate connecting pipes 220. The intermediate connecting pipes 220 are arc-shaped and slidably connected to the corresponding solid cooling blocks 210. The multiple intermediate connecting pipes 220 and the interior of the multiple solid cooling blocks 210 form a relatively sealed cooling control channel.

[0042] The number of solid cooling blocks 210 is determined according to the inner ring diameter of the bearing. 4-6 blocks are set for bearings with a diameter of 30-50mm, and 6-8 blocks are set for bearings with a diameter of 50-100mm. They are evenly arranged circumferentially to ensure uniform cooling on the inner side. The virtual cylindrical surface on the outer arc surface of multiple solid cooling blocks 210 has the same curvature as the inner curved surface of the bearing to ensure the fit between the solid cooling blocks 210 and the inner wall of the bearing.

[0043] The intermediate connecting pipe 220 is made of corrosion-resistant material, and its arc curvature is adapted to the movement trajectory of the solid cooling block 210. A sealing ring is set at the sliding connection between it and the solid cooling block 210 to ensure the sealing of the cooling control channel and prevent coolant leakage. The volume of the cooling control channel is designed according to the number of solid cooling blocks 210 to ensure that the coolant can quickly fill the entire channel and achieve synchronous cooling.

[0044] One of the solid cooling blocks 210 is connected to a coolant pumping pipe. Coolant is pumped into the cooling control channel through the coolant pumping pipe to increase the pressure in the coolant pumping channel, thereby controlling multiple solid cooling blocks 210 to expand outward synchronously and abut against the inner wall of the bearing 100 to be quenched. Coolant is extracted from the cooling control channel through the coolant pumping pipe to reduce the pressure, thereby controlling multiple solid cooling blocks 210 to contract inward synchronously and detach from the inner wall of the bearing 100 to be quenched.

[0045] The coolant pumping pipeline connects to an external high-pressure pump, with the pumping pressure controlled at 0.3-0.5 MPa. Pressure changes drive the expansion and contraction of the solid cooling blocks 210, replacing the traditional mechanical drive structure, simplifying equipment design and providing more precise control. When the pumped coolant increases the channel pressure, the pressure acts on the inner end face of the solid cooling blocks 210, pushing multiple blocks to expand outwards synchronously until they are tightly pressed against the inner wall of the bearing. The pressing pressure is 0.1-0.2 MPa, ensuring a tight fit while preventing excessive pressure from deforming the bearing. When the coolant is withdrawn to reduce the pressure, the solid cooling blocks 210, with their own elastic reset structure, can synchronously contract inwards under the action of an internal spring, disengaging from the inner wall of the bearing. The contraction stroke is 5-10 mm, facilitating the removal and placement of the bearing. This pressure-driven telescopic structure can adapt to bearing inner rings of different inner diameters, improving the equipment's versatility.

[0046] It should also be noted that the bearing 100 to be quenched is placed horizontally during the processing. At this time, the cooling body 200 in the middle only plays a positioning role for the outer bearing 100 to be quenched. The bearing 100 to be quenched will not exert lateral pressure on the cooling body 200, thus ensuring the stability of the overall structure during the laser quenching process.

[0047] The coolant pumping pipeline includes a first pipeline 231 and a second pipeline 232. The first pipeline 231 and the second pipeline 232 are arranged adjacent to each other and a partition plate 211 is provided between the first pipeline 231 and the second pipeline 232. The partition plate 211 is located on the side closer to the two pipelines, which can ensure the unidirectional orderly flow of coolant.

[0048] The first pipe 231 is the coolant inlet pipe, and the second pipe 232 is the coolant outlet pipe. Both are stainless steel pipes, and their adjacent arrangement reduces the space occupied by the pipes, making the structure more compact. The partition plate 211 is made of stainless steel plate with a thickness of 3-5mm and is fixed inside the solid cooling block 210, completely isolating the inlet and outlet channels to prevent coolant short circuits and ensure that the coolant can flow through the internal cooling channels of each solid cooling block 210 to achieve uniform cooling. The inlet direction of the first pipe 231 is consistent with the tangential direction of the cooling control channel, which can promote the formation of swirling flow of coolant in the channel and improve heat exchange efficiency. The outlet direction of the second pipe 232 is perpendicular to the inlet direction, ensuring that the high-temperature coolant in the channel can be discharged quickly and maintaining a stable cooling effect.

[0049] Furthermore, the position control body 300 includes a horizontal positioning plate 310, a horizontal positioning groove 311 is opened in the horizontal positioning plate 310, a positioning rod 320 is movably arranged inside the horizontal positioning groove 311, and the positioning rod 320 is fixedly connected to the cooling body 200.

[0050] The horizontal positioning plate 310 is fixed on the equipment frame to provide a stable positioning reference; the horizontal positioning groove 311 is a rectangular groove, and the positioning rod 320 is a cylindrical structure, which is fixedly connected to the cooling body 200 by threads. The fit clearance between the rod and the horizontal positioning groove 311 is 0.05-0.1mm, which can ensure smooth movement and limit the radial sway of the cooling body 200, and ensure the fitting accuracy between the solid cooling block 210 and the inner side of the bearing.

[0051] The upper end of the lifting rod 340 is connected to a lifting control structure, which can control the cooling body 200 and the position control body 300 according to the attached... Figure 4 The mechanism moves up and down in a manner that allows for adaptive cooling of different areas of the inner wall of the bearing 100 to be quenched; during the lifting and lowering process, multiple solid cooling blocks 210 are controlled according to the attached... Figure 5 The mechanism allows for expansion and contraction, either offset from or fitted to the inner wall of the bearing 100 to be quenched, ensuring efficient movement or cooling.

[0052] It should also be noted that the laser power in step S2 is determined based on the inner diameter. For an inner diameter of 30mm, a laser power of 800-1000W is selected, with a quenching layer depth of 0.7-0.82mm. Too low a power results in poor quenching, while too high a power increases the heat-affected zone. The scanning speed is 8-15mm / s, combined with the robotic arm's helical scanning trajectory. Too high a speed results in a shallow quenching layer, while too slow a speed can easily cause thermal deformation of the inner circle. The laser angle is selected as 15-25°, which reduces the tempering effect caused by direct laser radiation at the edges and improves the stability of the strengthened area. The overlap rate is selected as 20-30%, precisely controlled by programming the robotic arm trajectory to ensure the overlap between adjacent laser spots. Too high an overlap rate reduces the density of the microstructure, while too low a rate can lead to unstrengthened gaps. The cooling rate is controlled at 10... 4 -10 5 ℃ / s, promotes the formation of martensite structure and increases the hardness of the quenched layer.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A laser hardening process for the curved surface of the bearing inner ring, characterized in that, Includes the following steps: S1. Workpiece pretreatment; S2. Implementation of laser quenching: The outer surface of the bearing (100) to be quenched (100) is divided into multiple strengthening areas and the inner surface is divided into multiple cooling areas along the axial direction of the bearing (100). Laser equipment is used to perform laser quenching strengthening on multiple strengthening areas in sequence. At the same time, cooling equipment is used to continuously cool the corresponding cooling areas inside the multiple strengthening areas. The cooling equipment includes multiple hollow solid cooling blocks (210). Cooling liquid flows continuously inside the solid cooling blocks (210). The surface of the solid cooling blocks (210) is controlled to be in contact with the cooling areas to achieve continuous cooling. S3. Post-quenching inspection and verification: The hardness, dimensions and microstructure of the quenched bearing surface are inspected.

2. The laser hardening and strengthening process for the inner ring curved surface of the bearing according to claim 1, characterized in that, The cooling device includes a cooling body (200) and a position control body (300), and the position control body (300) controls the cooling body (200) to move along the axis of the bearing (100) to be quenched.

3. The laser hardening and strengthening process for the curved surface of the bearing inner ring according to claim 2, characterized in that, Laser equipment is used to sequentially perform laser hardening on alternating strengthening regions, and cooling equipment is used to continuously cool the corresponding cooling regions inside the strengthening regions.

4. The laser hardening and strengthening process for the curved surface of the bearing inner ring according to claim 2, characterized in that, Multiple solid cooling blocks (210) are arranged circumferentially. The outer arc-shaped surfaces of the multiple solid cooling blocks (210) are located on the same virtual cylindrical surface. The cooling body (200) also includes multiple intermediate connecting pipes (220), which connect two adjacent solid cooling blocks (210) through the intermediate connecting pipes (220). The intermediate connecting pipes (220) are arc-shaped and slidably connected to the corresponding solid cooling blocks (210). The multiple intermediate connecting pipes (220) and the interior of the multiple solid cooling blocks (210) form a relatively sealed cooling control channel.

5. The laser hardening and strengthening process for the curved surface of the bearing inner ring according to claim 4, characterized in that, One of the solid cooling blocks (210) is connected to a coolant pumping pipe. Coolant is pumped into the cooling control channel through the coolant pumping pipe to increase the pressure in the coolant pumping channel, thereby controlling multiple solid cooling blocks (210) to expand outward synchronously and abut against the inner wall of the bearing (100) to be quenched. Coolant is extracted from the cooling control channel through the coolant pumping pipe to reduce the pressure, thereby controlling multiple solid cooling blocks (210) to contract inward synchronously and detach from the inner wall of the bearing (100) to be quenched.

6. The laser hardening and strengthening process for the curved surface of the bearing inner ring according to claim 5, characterized in that, The coolant pumping pipeline includes a first pipeline (231) and a second pipeline (232), which are arranged adjacent to each other and a partition plate (211) is provided between the first pipeline (231) and the second pipeline (232).

7. The laser hardening and strengthening process for the curved surface of the bearing inner ring according to claim 2, characterized in that, The position control body (300) includes a horizontal positioning plate (310), a horizontal positioning groove (311) is opened in the horizontal positioning plate (310), a positioning rod (320) is movably arranged inside the horizontal positioning groove (311), and the positioning rod (320) is fixedly connected to the cooling body (200).

8. The laser hardening and strengthening process for the curved surface of the bearing inner ring according to claim 1, characterized in that, In step S1, the inner ring of the crankshaft bearing is quenched and tempered to ensure that the hardness of the base material reaches 58-62HRC; the inner ring surface is cleaned with cleaning fluid to remove surface oil and impurities.

9. The laser hardening and strengthening process for the curved surface of the bearing inner ring according to claim 1, characterized in that, In step S2, the scanning speed is 8-15 mm / s; the laser angle is 15-25°; and the overlap rate is 20-30%.

10. The laser hardening and strengthening process for the curved surface of the bearing inner ring according to claim 1, characterized in that, Step S3 is performed after quenching. The inner ring is made into a sample radially by wire cutting, and then the hardness, size and microstructure of the quenched surface of the bearing are tested.

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