Shaft cooling structure and shaft laser cladding device

Abstract

This invention relates to the field of laser cladding technology, and more particularly to a shaft cooling structure and a shaft laser cladding device. A shaft laser cladding device includes a worktable, on which a positioner, a laser cladding head induction heating device, and a cooling device are mounted. The cooling device includes a shaft cooling structure and a cold source generating device. The shaft cooling structure includes a cooling substrate surrounding the outer circumference of the shaft. The cooling substrate includes a cooling block with fluid channels for coolant flow. Rolling elements are mounted on the cooling block to contact the shaft and rotate with it for heat transfer. A controller and a temperature sensor are also mounted on the worktable. The temperature sensor is connected to the controller and provides a temperature signal to adjust the induction heating device and the cooling device. The contact cooling between the rolling elements and the shaft improves the heat dissipation efficiency of the shaft.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser cladding, in particular to a shaft cooling structure and a shaft laser cladding device. BACKGROUND

[0002] Laser cladding is a surface modification technology, which adds cladding material on the surface of the substrate, and uses high-energy-density laser beam to melt the cladding material together with the thin layer of the substrate surface, forming a surface cladding layer on the substrate surface which is metallurgically combined with the substrate.

[0003] Since laser cladding processing is a process of rapid melting of powder, rapid cooling and solidification of molten pool, the larger temperature gradient will lead to larger thermal stress, which makes the material prone to crack initiation and expansion during additive manufacturing, and the residual stress after forming is large, and the larger residual stress will be detrimental to the mechanical properties such as fracture toughness and fatigue life of the material, and on the shaft parts, due to the serious heat accumulation phenomenon, the molten pool is enlarged, the cladding layer is excessively oxidized, and it is difficult to form a cladding layer, which seriously affects the macroscopic morphology of the cladding layer, so generally the workpiece is preheated by a heating furnace or a heating wire before laser cladding, so as to reduce the temperature difference of the cladding layer and thus reduce the crack rate, and the high-temperature environment in the laser cladding process will cause heat transfer to the workpiece beside the operation, resulting in excessive temperature, so a cooling device is needed to cool the workpiece, so as to ensure the appropriate temperature range of the workpiece.

[0004] At present, the traditional cooling method is generally liquid cooling or air cooling, liquid cooling is to cool the workpiece by applying cooling liquid or placing a cooling block at the bottom of the workpiece, but for the shaft in laser cladding, it needs to keep dry on the shaft, if there is liquid on the shaft, it is difficult to form a cladding layer, in addition, the shaft itself rotates and has a certain arc, and the liquid cooling with high cooling efficiency cannot be directly contacted, so the liquid cooling is difficult to achieve. The air cooling for cooling the shaft blows inert gas on the cladding layer during the cladding process, but this method easily affects the powder feeding gas flow, and the cooling efficiency of the air cooling method is low. SUMMARY

[0005] The purpose of the present application is to provide a shaft cooling structure, which solves the problems of the existing cooling structure that liquid cooling cannot be directly contacted and air cooling affects the powder feeding gas flow and has low cooling efficiency.

[0006] The shaft cooling structure of the present application adopts the following technical scheme: a shaft cooling structure, comprising a cooling assembly for being arranged around the outer periphery of the shaft, the cooling assembly comprising a cooling block, a fluid channel for cooling liquid flow is formed in the cooling block, and a rolling member for being attached to the shaft and rolling with the shaft to transfer heat is arranged on the cooling block.

[0007] The shaft cooling structure of this invention is a completely new design. In practical use, the cooling component is arranged around the outer surface of the shaft. The cooling block has a fluid channel for coolant to cool the cooling block. A rolling element is arranged between the cooling block and the shaft to facilitate heat exchange and cool the shaft. This reduces the adverse effects of heat accumulation on the cladding layer. The contact cooling between the rolling element and the shaft improves the heat dissipation efficiency of the shaft. Furthermore, the coolant does not come into contact with the shaft and affect the cladding effect. It also avoids the influence of air cooling on the powder feeding airflow.

[0008] Furthermore, the rolling element is a cooling ball, which is rotatably mounted on the cooling block. The cooling ball can rotate 360 ​​degrees and will not jam when rotating relative to the shaft. It is positioned between the cooling block and the shaft to provide good cooling and heat transfer for the shaft.

[0009] Furthermore, the cooling blocks are multiple and distributed around the outer periphery of the shaft, with an elastic connection structure connecting adjacent cooling blocks. For shafts of different diameters, the elastic connection structure allows adjustment of the distance between the cooling blocks and ensures that the cooling blocks are always tightly clamped to the shaft, making it convenient to use.

[0010] Furthermore, the cooling block includes a fixed cooling block and at least two movable cooling blocks. The fixed cooling block is used to fix it to the lower connecting structure on the worktable of the shaft laser cladding device, and the movable cooling blocks are used to surround the outer circumference of the shaft. The fixed cooling block facilitates fixation to the lower connecting structure and maintains the stability of the cooling assembly, while the movable cooling blocks surrounding the outer circumference of the shaft facilitate adjustment and clamping to the shaft.

[0011] Furthermore, the elastic connection structure is a tension spring. Tension springs have a simple structure, good elasticity, high elastic force, are suitable for certain high-temperature environments, and have a long service life.

[0012] Furthermore, the cooling block is provided with an air-cooling channel, and the air outlet of the air-cooling channel is located on the same side of the rolling element on the cooling block. The air-cooling channel on the cooling block changes the cooling method to liquid cooling plus air cooling, with air cooling improving the cooling effect on top of liquid cooling.

[0013] Furthermore, the opening of the air-cooling outlet of the air-cooling channel faces towards the shaft. This arrangement ensures that the air-cooling outlet blows only onto one side of the shaft. During installation, the air-cooling outlet is oriented away from the laser cladding operation direction, avoiding disturbance to the powder and gas on the shaft, allowing the operation to proceed normally and making more efficient use of gas cooling.

[0014] Further, the fluid channel is extended in the cooling block in a meandering manner. The fluid channel with meandering extension increases the volume of the fluid channel, so that the heat dissipation cooling effect of the cooling block is more rapid, and heat transfer of the rolling member is ensured.

[0015] The shaft laser cladding device of the present application is used to solve the problem that the cooling structure of the existing shaft laser cladding device cannot be directly contacted with the shaft in liquid cooling mode and is difficult to be implemented, and the air cooling mode affects the air flow and has low cooling efficiency.

[0016] The shaft laser cladding device of the present application adopts the following technical scheme: a workbench is provided, a positioner for fixing the position of the shaft and driving the rotation of the shaft is arranged on the workbench, a laser cladding head, an induction heating device for preheating the shaft, and a cooling device for cooling the shaft are arranged on the workbench, the cooling device comprises a shaft cooling structure and a cold source generating device for providing a cold source for the shaft cooling structure, the shaft cooling structure comprises a cooling assembly for being arranged around the outer periphery of the shaft, the cooling assembly comprises a cooling block, a fluid channel for the flow of cooling liquid is formed in the cooling block, a rolling member for being attached to the shaft and rolling with the shaft to transfer heat is arranged on the cooling block, a controller is further arranged on the workbench and is in control connection with the induction heating device and the cooling device, a temperature sensor is arranged on the workbench for monitoring the temperature of the shaft, and the temperature sensor is connected to the controller and provides a temperature signal to the controller to control the induction heating device and the cooling device.

[0017] The shaft laser cladding device of the present application is an improvement on the existing shaft laser cladding device. In specific use, the induction heating device is used to heat the shaft. For the shaft, the short-distance laser cladding heat accumulation phenomenon is not obvious, and the preheating process can be used to reduce the temperature gradient between the shaft and the cladding layer, thereby reducing the cladding cracks caused by thermal stress. After the cladding layer of a certain distance is completed, the slow cooling process can be realized by adjusting the frequency and size of the induction current, so that the cladding layer slowly cools in the air. The cooling device is used to cool the shaft. For long-distance laser cladding, due to the serious heat accumulation phenomenon, the molten pool is enlarged, the cladding layer is excessively oxidized, and it is difficult to form a cladding layer. The cooling base is arranged around the outer surface of the shaft, the fluid channel with cooling liquid is arranged in the cooling block, the cooling block is cooled, the rolling member is arranged between the cooling block and the shaft to exchange heat between the cooling block and the shaft, the shaft is cooled and cooled, the adverse effects of heat accumulation on the cladding layer are reduced, the shaft is cooled by the contact cooling of the rolling member and the shaft, the heat dissipation efficiency of the shaft is improved, the cooling liquid does not contact the shaft to affect the cladding effect, the temperature sensor monitors the real-time temperature of the shaft, the controller controls the heating temperature of the induction heating device and the cold source generating device of the cooling device to achieve good cooling effect.

[0018] Furthermore, the rolling element is a cooling ball, which is rotatably mounted on the cooling block. The cooling ball can rotate 360 ​​degrees and will not jam when rotating relative to the shaft. It is positioned between the cooling block and the shaft to provide good cooling and heat transfer for the shaft.

[0019] Furthermore, the cooling blocks are multiple and distributed around the outer periphery of the shaft, with an elastic connection structure connecting adjacent cooling blocks. For shafts of different diameters, the elastic connection structure allows adjustment of the distance between the cooling blocks and ensures that the cooling blocks are always tightly clamped to the shaft, making it convenient to use.

[0020] Furthermore, the cooling block includes a fixed cooling block and at least two movable cooling blocks. The fixed cooling block is used to fix it to the lower connecting structure on the worktable of the shaft laser cladding device, and the movable cooling blocks are used to surround the outer circumference of the shaft. The fixed cooling block facilitates fixation to the lower connecting structure and maintains the stability of the cooling assembly, while the movable cooling blocks surrounding the outer circumference of the shaft facilitate adjustment and clamping to the shaft.

[0021] Furthermore, the elastic connection structure is a tension spring. Tension springs have a simple structure, good elasticity, high elastic force, are suitable for certain high-temperature environments, and have a long service life.

[0022] Furthermore, the cooling block is provided with an air-cooling channel, and the air outlet of the air-cooling channel is located on the same side of the rolling element on the cooling block. The air-cooling channel on the cooling block changes the cooling method to liquid cooling plus air cooling, with air cooling improving the cooling effect on top of liquid cooling.

[0023] Furthermore, the opening of the air-cooling outlet of the air-cooling channel faces towards the shaft. This arrangement ensures that the air-cooling outlet blows only onto one side of the shaft. During installation, the air-cooling outlet is oriented away from the laser cladding operation direction, avoiding disturbance to the powder and gas on the shaft, allowing the operation to proceed normally and making more efficient use of gas cooling.

[0024] Furthermore, the fluid channel extends and folds back within the cooling block. This folded-back extension increases the fluid channel volume, resulting in faster heat dissipation and cooling of the cooling block, thus ensuring heat transfer to the rolling components. Attached Figure Description

[0025] Figure 1 A schematic diagram of the structure of the shaft laser cladding device of the present invention in conjunction with a shaft, according to Embodiment 1;

[0026] Figure 2 for Figure 1 Side view of the cooling block in the middle;

[0027] Figure 3 for Figure 1 A cross-sectional view of the cooling block in the middle;

[0028] Figure 4 for Figure 1 A front view of the cooling block in the middle;

[0029] Figure 5 for Figure 1 A schematic diagram of the cooling structure and its fit with the shaft.

[0030] In the diagram: 1. Servo motor; 2. Three-jaw chuck; 3. Shaft; 4. Water-cooled pipe; 5. Cooling block; 6. Laser cladding head; 7. Induction coil; 8. Tailstock center; 9. Spring; 10. Air-cooled pipe; 11. Temperature sensor; 12. Induction heater; 13. Slider; 14. Lead screw; 15. Water-cooled box; 16. Solenoid valve; 17. Air cooler; 18. Lead screw nut; 19. PLC control cabinet; 20. Communication line; 21. Machine bed; 22. Ball retainer; 23. Cooling balls; 24. Air-cooled outlet; 25. Serpentine water-cooling channel; 26. Fastening bolt. Detailed Implementation

[0031] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0032] Specific embodiment one of the laser cladding device for shafts of the present invention:

[0033] To more clearly illustrate the structure and application of the shaft laser cladding device, this embodiment focuses on the scenario where the shaft laser cladding device and the shaft are used together.

[0034] The laser cladding device for shaft components of the present invention, as shown in the figure Figures 1-5 As shown, a laser cladding device for shaft components includes a machine bed 21, which includes a horizontal worktable. A positioner for fixing the position of a shaft component 3 and driving its rotation is mounted on the worktable. A laser cladding head 6 is mounted on the worktable beside the shaft component 3. The laser cladding head 6 is used to perform operations on the surface of the shaft component 3. The laser cladding head 6 is wrapped with heat insulation cotton and has a certain working distance from the shaft component 3. An induction heating device for preheating the shaft component 3 and a cooling device for cooling the shaft component 3 are also mounted on the worktable. A drive mechanism for driving the induction heating device and the cooling device to slide on the worktable is also mounted on the worktable. A controller is also mounted on the worktable and is connected to the induction heating device and the cooling device. A temperature sensor 11 is mounted on the worktable to monitor the temperature of the shaft component 3. The temperature sensor 11 is connected to the controller and provides a temperature signal to the controller to adjust the induction heating device and the cooling device.

[0035] The positioner includes a three-jaw chuck 2 and a positioner tailstock. The three-jaw chuck 2 clamps one end of the shaft 3, and the other end of the shaft 3 is fixed by the center point 8 of the positioner tailstock. The positioner tailstock can slide on the worktable. The lower part of the machine bed 21 has a hollow structure. A lead screw and nut mechanism is arranged in the hollow structure under the machine bed 21. The two ends of the lead screw 14 of the lead screw and nut mechanism are embedded inside the machine bed 21, and one end of the lead screw 14 extends out of the machine bed 21 and is connected to the servo motor 1. A slide rail is provided on the machine bed 21 below the shaft 3, along the direction of the shaft 3. A slider 13 is provided on the slide rail. The slider 13 passes through the machine bed 21 from top to bottom and is connected to the lead screw and nut 18 of the lead screw and nut mechanism.

[0036] The slider 13 is equipped with a cooling device, a temperature sensor 11, and an induction heating device. Specifically, the cooling device includes a cooling structure, which includes a cooling assembly for fitting onto the outer circumference of the shaft 3. The cooling assembly includes cooling blocks 5, four of which are evenly distributed along the outer wall of the shaft 3. The two lower cooling blocks 5 are fixed cooling blocks, and the two upper cooling blocks 5 are movable cooling blocks. A spring 9 connects adjacent fixed and movable cooling blocks, and another spring 9 connects adjacent movable cooling blocks. At least one spring 9 is detachable, and its extension length can be adjusted for different shaft diameters, making it convenient to use. The cooling blocks 5 are equipped with cooling balls 23 that fit against the shaft 3 and roll with the shaft 3 for heat transfer. Each cooling block 5 has four cooling balls 23. A ball retainer 22 is provided on the cooling blocks 5 to keep the cooling balls 23 rolling stably within it, ensuring the stability of the cooling balls 23 and the shaft 3 during rolling contact. A structure similar to a bullseye wheel can be used in implementation. The cooling block 5 is equipped with a serpentine water cooling channel 25 to increase the cooling area of ​​the coolant in the cooling block 5.

[0037] The cooling device also includes a cold source generating device, which includes a water-cooled box 15 and a cold air blower 17. The water-cooled box 15 is connected to the cooling block 5 via a water-cooling pipe 4, and the cold air blower 17 is connected to the cooling block 5 via an air-cooling pipe 10. The cooling block 5 is provided with an air-cooled outlet 24, and the outlet of the air-cooled outlet 24 faces away from the laser cladding head 6, so that the air-cooled outlet 24 cools the shaft 3 through a single-sided outlet, avoiding disturbance to the laser cladding powder and gas on the right side, and making more efficient use of gas cooling. A fastening bolt 26 is provided between the two fixed cooling blocks at the lower end. A column for mounting the cooling component on the slider 13 is provided below the fastening bolt 26. The column constitutes the lower connection structure of the fixed cooling block. A handle is also provided below the fastening bolt 26. The cooling component is fixed to the column by tightening the fastening bolt 26.

[0038] The induction heating device includes an induction coil 7 and an induction heater 12. The induction coil 7 is fitted onto the shaft 3 and fixed to the induction heater 12. The controller is a PLC control cabinet 19. A temperature sensor 11 detects the local temperature of the shaft 3. The temperature sensor 11 is connected to the PLC control cabinet 19 via a communication line 20, transmitting the real-time temperature to the PLC control cabinet 19. A solenoid valve 16 is installed on the water-cooling pipe 4 at the top of the water-cooled tank 15, and the water pressure is controlled by the PLC control cabinet 19. A cooler 17 is connected to the PLC control cabinet 19, and the air cooling output is adjusted by the PLC control cabinet 19. The PLC control cabinet 19 maintains communication with the water-cooled tank 15 and the cooler 17 via the communication line 20.

[0039] In practical use, the laser cladding device for shaft components of the present invention uses a servo motor 1 to drive the lead screw 14 to rotate, and the lead screw nut 18 to drive the slider 13 to slide linearly. There is a slide rail between the slider 13 and the machine tool bed 21. The slider 13 and the laser cladding head 6 are controlled by the motor. The three-jaw chuck 2 of the positioner clamps the shaft component 3. The cooling block 5 is sleeved on the shaft component 3. The shaft component 3 is preheated by the induction coil 7. The temperature sensor 11 detects the local temperature of the shaft component 3 and transmits the real-time temperature to the PLC control cabinet 19 through the communication line 20. The solenoid valve 16 of the water cooling tube 4 on the top of the water cooling box 15 controls the water flow pressure through the PLC control cabinet 19. The air cooler 17 adjusts the exhaust volume through the PLC control cabinet 19. The temperature of the cooling block 5 decreases under the action of water cooling. The cooling ball 23 on the cooling block 5 cools the shaft 3 through contact cooling with the shaft 3. The cooling block 5 dissipates heat to the left side of the shaft 3 through the air cooling outlet 24, avoiding disturbance to the laser cladding powder and gas on the right side, so that the laser cladding operation can be carried out normally.

[0040] Through the above description of a specific embodiment of the laser cladding device for shafts of the present invention, it can be seen that the laser cladding device for shafts of the present invention cools the shafts by means of contact cooling balls with the shafts, thereby improving the heat dissipation efficiency of the shafts. Moreover, the coolant does not come into contact with the shafts and affect the cladding effect, thus avoiding disturbance to the laser cladding powder and gas on the right side. The temperature sensor monitors the real-time temperature of the shafts, and the controller controls the heating temperature of the induction heating device and the cold source generating device of the cooling device, resulting in a good cooling effect.

[0041] Of course, the laser cladding apparatus for shafts of the present invention is not limited to the embodiments described above. Several other embodiments of the laser cladding apparatus for shafts based on the design concept of the present invention are also listed below.

[0042] For example, in other embodiments, unlike the first embodiment described above, the rolling element is configured as a cylindrical roller that rotates with the shaft.

[0043] For example, in other embodiments, unlike the first embodiment described above, the cooling block includes a semi-circular fixed cooling block and a semi-circular movable cooling block, with a tension spring connecting the fixed cooling block and the movable cooling block.

[0044] In other embodiments, unlike the first embodiment described above, the air-cooling outlet faces the shaft directly or away from the tangent of the laser cladding head to cool the shaft.

[0045] Alternatively, in other embodiments, unlike the first embodiment described above, the elastic connection structure may be a rubber band or other elastic element.

[0046] Alternatively, in other embodiments, unlike the first embodiment described above, the cooling block includes an inlet and an outlet, and the interior of the cooling block has a hollow structure, in which cooling water is contained.

[0047] The embodiments of the shaft cooling structure of the present invention are the same as the embodiments of the cooling structure in the above-described shaft laser cladding device, and therefore will not be described again.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. A shaft cooling structure, characterized in that, The system includes a cooling assembly surrounding the outer circumference of a shaft. The cooling assembly includes a cooling block with a fluid channel for coolant circulation. The cooling block has rolling elements, which are cooling balls, that fit against the shaft and rotate with it to transfer heat. The cooling balls are rotatably mounted on the cooling block. The cooling block is cooled by water cooling. The shaft is cooled by contact cooling between the cooling balls and the shaft to prevent coolant from contacting the shaft. The cooling block has an air-cooling channel with its air outlet located on the side where the rolling elements are located. The opening of the air outlet faces the side of the shaft away from the laser cladding head.

2. The shaft cooling structure according to claim 1, characterized in that, The cooling blocks are multiple and distributed around the outer periphery of the shaft, with an elastic connection structure connecting adjacent cooling blocks.

3. The shaft cooling structure according to claim 2, characterized in that, The cooling block includes a fixed cooling block and at least two movable cooling blocks. The fixed cooling block is used to fix it to the connecting structure below, and the movable cooling blocks are used to surround the outer periphery of the shaft.

4. The shaft cooling structure according to claim 2, characterized in that, The elastic connection structure is a tension spring.

5. The shaft cooling structure according to any one of claims 1-4, characterized in that, The fluid channel extends and folds back within the cooling block.

6. A laser cladding device for shaft components, comprising a worktable, a positioner for fixing the position of the shaft component and driving its rotation, a laser cladding head, an induction heating device for preheating the shaft component, and a cooling device for cooling the shaft component, the cooling device comprising a cooling structure and a cold source generating device for providing a cold source to the cooling structure, characterized in that... The cooling structure includes a cooling assembly surrounding the outer circumference of the shaft. The cooling assembly includes a cooling block with a fluid channel for coolant circulation. Rolling elements, specifically cooling balls, are mounted on the cooling block to contact the shaft and rotate with it for heat transfer. The cooling balls are rotatably mounted on the cooling block. The cooling block's temperature decreases under water cooling. The shaft is cooled through contact cooling between the cooling balls and the shaft, preventing coolant from contacting the shaft. A controller is also mounted on the worktable, connected to both the induction heating and cooling devices. A temperature sensor is mounted on the worktable to monitor the shaft temperature. The temperature sensor is connected to the controller and provides a temperature signal to control the induction heating and cooling devices. An air-cooling channel is provided on the cooling block, with its outlet located on the side where the rolling elements are located. The outlet of the air-cooling channel faces the side of the shaft away from the laser cladding head.

7. The shaft laser cladding device according to claim 6, characterized in that, The cooling blocks are multiple and distributed around the outer periphery of the shaft, with an elastic connection structure connecting adjacent cooling blocks.

8. The laser cladding device for shafts according to claim 7, characterized in that, The cooling block includes a fixed cooling block and at least two movable cooling blocks. The fixed cooling block is used to fix it to the connecting structure below, and the movable cooling blocks are used to surround the outer periphery of the shaft.

9. The laser cladding device for shafts according to claim 7, characterized in that, The elastic connection structure is a tension spring.

10. The laser cladding apparatus for shafts according to any one of claims 6-9, characterized in that, The fluid channel extends and folds back within the cooling block.

Images