A laser cladding repair method for a crusher cylinder

Abstract

The application relates to a crusher cylinder laser cladding repair method, and relates to the field of crushers, which comprises the following steps: cleaning the inner wall of a crusher cylinder to be repaired; supporting the crusher cylinder on a rotary support tool; placing a heating device and a laser cladding head provided with a range finder in the crusher cylinder, and arranging the laser cladding head downstream of the heating device; driving the crusher cylinder to rotate around its own axis, preheating or heat-preserving the area to be cladded by the heating device; driving the heating device and the laser cladding head to move along the axial direction of the crusher cylinder while the crusher cylinder is rotating, detecting the distance change between the inner wall and the laser cladding head in real time by the range finder, identifying the starting point and the ending point of the cladded area according to the distance change, and controlling the laser cladding head to start cladding at the starting point of the cladded area and stop cladding at the ending point of the cladded area; and the application can realize selective cladding of the local area of the inner wall of the crusher cylinder, avoid non-target surfaces from being cladded, and improve the repair quality.

Description

Technical Field

[0001] This application relates to the field of crushers, and in particular to a method for laser cladding repair of crusher cylinders. Background Technology

[0002] The crusher cylinder is a key load-bearing component in a hydraulic crusher, and its inner wall typically works in long-term contact with the piston, seals, or hydraulic oil. During the high-frequency impact and reciprocating friction of the crusher, the inner wall of the cylinder is prone to wear, scoring, localized spalling, or dimensional deviations. Directly scrapping a worn crusher cylinder would result in high maintenance and replacement costs; therefore, it is usually necessary to repair the inner wall to restore its dimensional accuracy and surface wear resistance.

[0003] In existing technologies, laser cladding is used to repair the inner walls of hydraulic cylinders, cylinder barrels, or other internal bore parts. This process typically involves using an internal bore laser cladding head to deliver a laser beam and cladding material to the inner wall of the workpiece. The cladding material melts and bonds with the workpiece substrate, forming a metallurgical bond and creating a wear-resistant or corrosion-resistant coating on the inner wall. For ordinary continuous inner cylindrical surfaces, the laser cladding head can usually rotate with the workpiece to perform continuous circumferential cladding.

[0004] However, the structure of the inner wall of a crusher cylinder differs from that of ordinary continuous inner bore parts. The areas to be repaired on the inner wall of some crusher cylinders are not complete, continuous inner circular surfaces, but rather distributed as multiple local arc surfaces or localized areas to be clad. If continuous processing is still performed using the ordinary method of cladding a complete circular inner wall, the cladding material easily accumulates in non-repair areas, leading to cladding of non-target surfaces, localized dimensional deviations, increased subsequent processing work, and even damage to the workpiece.

[0005] Therefore, how to selectively cladize the target area based on the structural characteristics of the local area to be repaired on the inner wall of the crusher cylinder, and avoid cladding the non-target surface, is a technical problem that needs to be solved in this field. Summary of the Invention

[0006] In order to achieve selective cladding of the target area and avoid cladding of non-target surfaces, this application provides a laser cladding repair method for crusher cylinders.

[0007] The laser cladding repair method for a breaker cylinder body provided in this application adopts the following technical solution: A method for laser cladding repair of a breaker cylinder includes the following steps: S1. Clean the inner wall of the crusher cylinder to be repaired to remove oil and impurities from the inner wall of the crusher cylinder. S2. Support the cleaned crusher cylinder on the rotating support fixture. S3. The heating device and the laser cladding head are placed inside the crusher cylinder. The laser cladding head is equipped with a rangefinder and is located downstream of the heating device along the moving direction of the heating device and the laser cladding head. S4. The crusher cylinder is driven to rotate around its own axis by the rotary support fixture. The heating device preheats or keeps the area to be clad on the inner wall of the crusher cylinder before and / or during the cladding process, so that the area to be clad is within a preset temperature range. S5. While the crusher cylinder is rotating, the heating device and the laser cladding head are driven to move along the axial direction of the crusher cylinder. The rangefinder detects the change in distance between the inner wall of the crusher cylinder and the laser cladding head in real time. When the laser cladding head is detected to be at the starting point of the cladding area based on the distance change, the laser cladding head is controlled to output a laser beam and deliver cladding powder to the laser cladding head to clad the cladding area. When the laser cladding head is detected to be at the ending point of the cladding area based on the distance change, the laser cladding head is controlled to stop outputting a laser beam and / or stop delivering cladding powder to the laser cladding head, so that the cladding layer is formed in the cladding area and the non-cladding area is avoided from being clad. S6. After the cladding is completed, the crusher cylinder is kept warm and cooled slowly. S7. Grind, polish and inspect the inner wall of the crusher cylinder after slow cooling.

[0008] By adopting the above technical solution, the crusher cylinder can rotate around its own axis on the rotating support fixture, and the laser cladding head and heating device can extend into the crusher cylinder and move along the axial direction of the crusher cylinder, thereby meeting the processing requirements of internal hole cladding repair. During the rotation of the crusher cylinder and the axial movement of the laser cladding head, the rangefinder can detect the change in distance between the inner wall of the crusher cylinder and the laser cladding head in real time, and identify the start and end points of the cladding area based on the distance change.

[0009] When the laser cladding head detects the starting point of the cladding area, it begins outputting a laser beam and conveying cladding powder. When it detects the ending point of the cladding area, it stops outputting the laser beam and / or stops conveying cladding powder. This ensures that the cladding layer forms only on the target cladding area on the inner wall of the crusher cylinder, avoiding continuous cladding along the entire inner surface which would cause cladding powder to deposit in non-cladding areas. This reduces the risk of cladding non-target surfaces, localized dimensional deviations, increased subsequent processing, or workpiece damage.

[0010] Preferably, in step S3, when the laser cladding head is in a vertical state, the laser cladding head is offset backward relative to the diameter direction of the crusher cylinder, and the laser cladding head is tilted around the X-axis to reduce the risk of reflected light from the inner wall of the crusher cylinder being reflected back to the laser cladding head.

[0011] By adopting the above technical solution, the laser cladding head extends into the crusher cylinder in an offset and tilted manner, so that the reflection path of the laser beam after irradiating the inner wall of the crusher cylinder deviates from the laser cladding head, thereby reducing the risk of reflected light returning to the laser cladding head and causing burns to the nozzle, protective lens or other accessories, and improving the stability of the laser cladding process.

[0012] Preferably, the laser cladding head is offset backward by 20mm to 50mm relative to the diameter direction of the crusher cylinder, and the laser cladding head is rotated 10° to 15° around the X-axis.

[0013] By adopting the above technical solution, the position and angle of the laser cladding head can be adjusted according to the inner diameter of the crusher cylinder, the size of the cladding head, and the laser incident direction, so that the laser cladding head can not only stably act on the cladding area of ​​the inner wall of the crusher cylinder, but also reduce the possibility of laser reflection causing damage to the laser cladding head.

[0014] Preferably, the heating device is an induction heating coil, and a temperature sensor is provided on the induction heating coil. The temperature sensor is used to detect the temperature of the inner wall of the crusher cylinder, and adjust the heating current of the induction heating coil according to the detection result of the temperature sensor so that the inner wall of the crusher cylinder is within the preset temperature range.

[0015] By adopting the above technical solution, the induction heating coil can preheat or maintain the temperature of the inner wall of the crusher cylinder before and / or during laser cladding. The temperature sensor can provide real-time feedback on the temperature of the inner wall of the crusher cylinder, and the heating current of the induction heating coil can be adjusted to maintain the cladding area within a preset temperature range. This reduces the temperature gradient between the cladding area and the surrounding substrate during laser cladding, reduces thermal stress caused by rapid local heating and cooling, and thus reduces the risk of cracking, peeling, or poor bonding of the cladding layer.

[0016] Preferably, the axis of the induction heating coil is collinear with the axis of the crusher cylinder, so that the induction heating coil can preheat or keep the circumferential area of ​​the inner wall of the crusher cylinder.

[0017] By adopting the above technical solution, the induction heating coil can maintain a relatively uniform heating distance with the inner wall of the crusher cylinder, making the circumferential area of ​​the inner wall of the crusher cylinder more uniformly heated, thereby improving the stability of the preheating or heat preservation effect.

[0018] Preferably, in step S4, the induction heating coil is first used to heat the cladding starting end of the cladding area to raise the temperature of the cladding starting end to 300°C. Then, the heating current of the induction heating coil is adjusted according to the detection result of the temperature sensor to keep the temperature of the inner wall of the crusher cylinder between 300°C and 400°C.

[0019] By adopting the above technical solution, the starting end of the cladding can be preheated to reduce the temperature change during the arc initiation or initial cladding stage; then the temperature of the inner wall of the crusher cylinder is maintained in the range of 300℃ to 400℃, so that the temperature change between the substrate and the cladding layer during the cladding process is more gradual, which helps to reduce the risk of crack generation and improve the bonding quality of the cladding layer.

[0020] Preferably, in step S5, the heating device and the laser cladding head move synchronously within the crusher cylinder while maintaining a preset axial distance, so that the heating device first preheats or keeps the cladding area warm, and then the laser cladding head performs laser cladding on the preheated or kept warm cladding area.

[0021] By adopting the above technical solution, the heating device and the laser cladding head can form a continuous collaborative processing relationship. That is, the heating device is located upstream and preheats or keeps the area to be clad in the first place, while the laser cladding head is located downstream and then clads the area within the preset temperature range. This is beneficial to improving the stability of the cladding temperature field and the forming quality of the cladding layer.

[0022] Preferably, the rotary support fixture includes a rotary support drive wheel and a rotary support driven wheel, which together support the crusher cylinder. The rotary support drive wheel is used to drive the crusher cylinder to rotate around its own axis. Limiting devices are respectively provided on both axial sides of the crusher cylinder, which are used to limit the axial movement of the crusher cylinder during the cladding process.

[0023] By adopting the above technical solution, the rotary support drive wheel and the rotary support driven wheel can jointly support the crusher cylinder and drive the crusher cylinder to rotate stably. The limiting device can restrict the axial movement of the crusher cylinder during rotation and cladding, thereby improving the stability of the cladding position and reducing the risk of deviation in the cladding area caused by workpiece displacement.

[0024] Preferably, the cladding powder is an iron-based titanium carbide composite cladding powder, which is formed by mixing high-hardness iron-based powder and titanium carbide powder, and the mass fraction of titanium carbide powder in the iron-based titanium carbide composite cladding powder is 5%.

[0025] By adopting the above technical solution, iron-based powder can form a good metallurgical bond with the crusher cylinder matrix, and titanium carbide powder can improve the hardness and wear resistance of the cladding layer, thereby giving the repaired crusher cylinder inner wall good wear resistance and service life.

[0026] Preferably, in step S5, the laser power of the laser cladding head is 5000W to 6000W, the powder feeding speed is 50g / min to 60g / min, the rotation speed of the crusher cylinder is 3r / min to 6r / min, the cladding overlap rate is 60%, and a cladding layer is formed in the cladding area on the inner wall of the crusher cylinder after cladding. The hardness of the cladding layer is HRC58 to HRC62.

[0027] By adopting the above technical solution, the laser power, powder feeding speed, crusher cylinder rotation speed and cladding overlap rate are coordinated to enable the cladding powder to be stably melted and deposited in the cladding area on the inner wall of the crusher cylinder. While ensuring the continuity of the cladding layer formation, the cladding layer has the hardness to meet the wear-resistant repair requirements of the inner wall of the crusher cylinder.

[0028] In summary, this application includes at least one of the following beneficial technical effects: 1. This application uses a rangefinder installed on the laser cladding head to detect the distance change between the inner wall of the crusher cylinder and the laser cladding head in real time during the rotation of the crusher cylinder and the axial movement of the laser cladding head. The rangefinder identifies the start and end points of the cladding area based on the distance change, thereby controlling the laser cladding head to start cladding at the start point of the cladding area and stop cladding at the end point of the cladding area. This ensures that the cladding layer is formed only in the target cladding area, avoiding cladding of non-target surfaces and reducing the risks of non-target surfaces being clad, local dimensional deviations, increased subsequent processing, or workpiece damage. 2. This application places the heating device upstream of the laser cladding head, enabling the heating device to preheat or keep the area to be clad before and / or during cladding; at the same time, the temperature sensor detects the temperature of the inner wall of the crusher cylinder and adjusts the heating state of the heating device to keep the area to be clad within the preset temperature range, thereby reducing the temperature gradient and thermal stress during the cladding process and reducing the risk of cracking, peeling or poor bonding of the cladding layer. 3. By shifting the laser cladding head backward relative to the diameter of the crusher cylinder and tilting the laser cladding head around the X-axis, this application can change the reflection path of the laser beam after it irradiates the inner wall of the crusher cylinder, reduce the possibility of reflected light returning to the laser cladding head, thereby reducing the risk of burn-out of the nozzle, protective lens or other laser cladding head accessories, and improving the stability of the cladding process. 4. This application uses a rotary support fixture to stably support and drive the crusher cylinder to rotate, and uses a limiting device to restrict the axial movement of the crusher cylinder during the cladding process. At the same time, it uses iron-based titanium carbide composite cladding powder and heat preservation and slow cooling treatment to make the cladding layer have good forming stability, bonding quality and wear resistance, thereby improving the service life of the inner wall of the crusher cylinder after repair. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the installation of the crusher cylinder and its structure with the heating device, laser cladding head, and rangefinder in this embodiment.

[0030] Figure 2 It is used for display Figure 1 A side view of the structure.

[0031] Explanation of reference numerals in the attached drawings: 1. Crusher cylinder; 11. Cladding area; 12. Non-cladding area; 2. Rotary support fixture; 21. Rotary support drive wheel; 22. Rotary support driven wheel; 23. Rotary support fixture ring; 24. Limiting device; 241. Limiting rotating wheel; 3. Heating device; 31. Induction heating coil; 4. Laser cladding head; 5. Rangefinder. Detailed Implementation

[0032] The following is in conjunction with the appendix Figure 1-2 This application will be described in further detail.

[0033] This application discloses a laser cladding repair method for a breaker cylinder body, used to repair locally worn areas on the inner wall of a breaker cylinder body 1. This method is particularly suitable for areas on the inner wall of the breaker cylinder body 1 that are not complete and continuous inner circular surfaces, where the inner wall includes a cladding area 11 and a non-cladding area 12 formed by grooves.

[0034] A laser cladding repair method for a breaker cylinder block in this embodiment includes the following steps: S1. Cleaning the inner wall of crusher cylinder 1 The crusher cylinder 1 to be repaired undergoes pretreatment. Specifically, the inner wall of the crusher cylinder 1 is first thoroughly cleaned with gasoline to remove residual hydraulic oil; then, the inner wall is cleaned again with acetone or anhydrous ethanol to further remove oil, impurities, and deposits. This cleaning process improves the bonding quality between the subsequent cladding layer and the crusher cylinder 1 substrate, and reduces the impact of oil or impurities on the cladding quality.

[0035] S2, Clamping and positioning of crusher cylinder 1 Reference Figure 1 , Figure 2The cleaned crusher cylinder 1 is placed on the rotary support fixture 2. Specifically, the rotary support fixture 2 includes a rotary support drive wheel 21 and a rotary support driven wheel 22. A rotary support fixture ring 23 is first set at each end of the crusher cylinder 1 by welding or bolting to serve as the connection carrier between the crusher cylinder 1 and the rotary support fixture 2. The inner diameter of the rotary support fixture ring 23 is approximately equal to the inner diameter of the crusher cylinder 1. There are two rotating support drive wheels 21 and two rotating support driven wheels 22, which are respectively set at both ends of the crusher cylinder 1. Each rotating support drive wheel 21 and rotating support driven wheel 22 is rotatably connected to the frame. The rotating support drive wheels 21 and rotating support driven wheels 22 have the same diameter. The rotating support drive wheels 21 and rotating support driven wheels 22 are spaced apart, and the distance between them is less than the diameter of the rotating support tooling ring 23. This allows the rotating support tooling ring 23 to be placed on the rotating support drive wheels 21 and rotating support driven wheels 22 simultaneously by gravity. The rotating support drive wheels 21 are connected to a rotating motor to achieve their own rotation, and drive the crusher cylinder 1 to rotate around its own axis through the rotating support tooling ring 23.

[0036] To prevent the crusher cylinder 1 from axially shifting and to improve the rotational stability of the crusher cylinder 1, a limiting device 24 is provided at the end of each rotating support tooling ring 23. Specifically, the limiting device 24 is a limiting rotating wheel 241. The limiting rotating wheel 241 is rotatably connected to the frame through a bracket, and the rotation axis of the limiting rotating wheel 241 is set along the radial direction of the rotating support tooling ring 23. The limiting rotating wheel 241 presses against the rotating support tooling ring 23 to limit the axial movement of the crusher cylinder 1. By setting the limiting rotating wheel 241, the obstruction effect of the limiting device 24 on the rotation of the crusher cylinder 1 can be reduced, thereby improving the rotational stability of the crusher cylinder 1.

[0037] During the clamping process of the crusher cylinder 1, the rotating support tooling rings 23 at both ends of the crusher cylinder 1 are first placed on the corresponding rotating support drive wheel 21 and rotating support driven wheel 22. By driving the rotating support drive wheel 21 to rotate, observe whether the rotation axis of the crusher cylinder 1 is stable. After the rotation axis of the crusher cylinder 1 is stable, press the limiting device 24 on the end face of the rotating support tooling 2 frame at both ends of the crusher cylinder 1 to limit the circumferential movement of the crusher cylinder 1.

[0038] S3, heating device 3 and laser cladding head 4 arrangement Reference Figure 1 , Figure 2A left robot for holding the heating device 3 is arranged on one side of the crusher cylinder 1, and a right robot for holding the laser cladding head 4 is arranged on the other side of the crusher cylinder 1. The left robot can drive the heating device 3 to be inserted into the crusher cylinder 1 from the left port, and the right robot can drive the laser cladding head 4 to be inserted into the crusher cylinder 1 from the right port. In this embodiment, the right port of the crusher cylinder 1 is taken as the starting point of the cladding process. Therefore, during the cladding process on the inner wall of the crusher cylinder 1, both the heating device 3 and the laser cladding head 4 move from right to left.

[0039] Specifically, the left robot drives the heating device 3 to move to the cladding start end of the crusher cylinder 1, and the right robot drives the laser cladding head 4 to move to the same cladding start end of the crusher cylinder 1. The heating device 3 is located to the left of the laser cladding head 4, that is, the laser cladding head 4 is located downstream of the heating device 3, so that during the cladding process, the heating device 3 first heats the crusher cylinder 1 in front of the laser cladding head 4 to a preset temperature range.

[0040] In this embodiment, the heating device 3 is an induction heating coil 31. The induction heating coil 31 is circular, and its axis can be collinear or substantially collinear with the axis of the crusher cylinder 1. This allows the induction heating coil 31 to preheat or maintain the temperature of the circumferential area of ​​the inner wall of the crusher cylinder 1 more uniformly. The outer diameter of the induction heating coil 31 is slightly smaller than the minimum diameter of the inner wall of the cylinder to reduce the distance between the induction heating coil 31 and the inner wall of the crusher cylinder 1, thereby improving the heating effect of the induction heating coil 31 on the crusher cylinder 1.

[0041] A temperature sensor is installed on the induction heating coil 31. The temperature sensor is used to detect the temperature of the inner wall of the crusher cylinder 1 and adjust the heating current of the induction heating coil 31 according to the detection result, so that the inner wall of the crusher cylinder 1 is kept within the preset temperature range.

[0042] A rangefinder 5 is provided on the laser cladding head 4. In this embodiment, the rangefinder 5 is a laser rangefinder 5, which is fixedly mounted on the laser cladding head 4 and moves synchronously with the laser cladding head 4. The detection direction of the rangefinder 5 is towards the inner wall of the cylinder, and its detection point is located in front of or near the cladding point of the laser cladding head 4. It is used to identify the start and end points of the cladding area 11 before the laser cladding head 4 reaches the cladding area 11, thereby controlling the start and stop of the laser cladding head 4's light emission and powder feeding.

[0043] Specifically, since the area 11 to be clad on the inner wall of the crusher cylinder 1 is a local arc surface or a local area to be repaired, there are boundaries, steps, curvature changes, or distance changes between the area 11 to be clad and the adjacent non-clad area 12. Therefore, when the rangefinder 5 moves with the laser cladding head 4 and passes through the boundary between the area 11 to be clad and the non-clad area 12, the distance detected by the rangefinder 5 changes.

[0044] The control system determines whether the laser cladding head 4 corresponds to the cladding area 11 based on whether the distance detected by the rangefinder 5 is within a preset distance range, or based on the trend of the detected distance change. When the detected distance changes from the distance state corresponding to the non-cladding area 12 to the distance state corresponding to the cladding area 11, the control system determines that the laser cladding head 4 corresponds to the starting point of the cladding area 11 and controls the laser cladding head 4 to output a laser beam and transport cladding powder; when the detected distance changes from the distance state corresponding to the cladding area 11 to the distance state corresponding to the non-cladding area 12, the control system determines that the laser cladding head 4 corresponds to the ending point of the cladding area 11 and controls the laser cladding head 4 to stop outputting a laser beam and / or stop transporting cladding powder.

[0045] When the right robot moves the laser cladding head 4 to the cladding starting point, it rotates the laser cladding head 4 around the X-axis by a certain angle, forming an angle α between the orientation of the laser cladding head 4 and the vertical direction. The laser cladding head 4 rotates around the X-axis by 10° to 15°, meaning the value of α ranges from 10° to 15°. This embodiment uses 10° as an example. The laser cladding head 4 is offset backward by 20mm to 50mm relative to the diameter of the crusher cylinder 1. This embodiment uses an offset of 20mm relative to the diameter of the crusher cylinder 1 as an example. The above offset and rotation angle can be adjusted according to the inner diameter of the crusher cylinder 1, the size of the laser cladding head 4, the laser incident direction, and the reflection path.

[0046] By offsetting the laser cladding head 4 backward relative to the diameter of the crusher cylinder 1 and tilting the laser cladding head 4 around the X-axis, the reflection path of the laser beam after irradiating the inner wall of the crusher cylinder 1 can be changed, causing the reflected light to deviate from the laser cladding head 4, thereby reducing the risk of nozzles, protective lenses or other accessories being burned by reflected light.

[0047] S4. The rotating support fixture 2 drives the crusher cylinder 1 to rotate around its own axis. The induction heating coil 31 preheats the starting end of the cladding area 11 to be clad, raising the temperature of the starting end to approximately 300°C. Subsequently, the heating current of the induction heating coil 31 is adjusted according to the detection results of the temperature sensor to maintain the inner wall temperature of the crusher cylinder 1 between 300°C and 400°C. This preheating and heat preservation method can reduce the temperature gradient between the cladding area 11 and the surrounding substrate during laser cladding, reduce the thermal stress caused by rapid local heating and cooling, and thus reduce the risk of cracking, peeling, or poor bonding of the cladding layer.

[0048] S5, Selective Laser Cladding Before cladding the crusher cylinder 1, it is necessary to prepare the cladding powder, which can be iron-based titanium carbide composite cladding powder. The iron-based titanium carbide composite cladding powder is formed by mixing high-hardness iron-based powder and titanium carbide powder, wherein the mass fraction of titanium carbide powder in the iron-based titanium carbide composite cladding powder can be 5%.

[0049] The iron-based titanium carbide composite cladding powder comprises the following components by mass percentage: Ni 0.46%, Cr 13.86%, V 0.12%, Si 1.35%, C 0.97%, Mn 0.33%, Zr 0.19%, Ti 4.16%, Fe 74.4%, with the balance being unavoidable impurities.

[0050] Before cladding, the iron-based titanium carbide composite cladding powder is placed in an oven for drying at 120°C for 45 minutes. This drying process reduces the moisture content of the cladding powder, thereby minimizing defects such as porosity, inclusions, or cracks during the cladding process.

[0051] The parameters for the laser cladding process are set as follows: laser power can be 5000W to 6000W, powder feeding speed can be 50g / min to 60g / min, crusher cylinder 1 rotation speed can be 3r / min to 6r / min, and cladding overlap rate can be 60%. Under the above process parameters, a cladding layer can be formed in the cladding area 11 on the inner wall of the crusher cylinder 1. The single-sided thickness of the cladding layer can be 1.5mm, and the hardness of the cladding layer can be HRC58 to HRC62.

[0052] The relationship between the hardness of the cladding layer, the temperature of the inner wall of the crusher cylinder 1, and the laser power can be expressed as: H = 71.1 + 0.1133*T - 14.9*P - 0.000542*T² + 0.0507T*P, where H is the hardness of the cladding layer, T is the temperature of the inner wall of the crusher cylinder 1 (ranging from 300℃ to 400℃), and P is the laser power (ranging from 5kW to 6kW). This formula can serve as a reference for selecting the preheating temperature and laser power to ensure that the hardness of the cladding layer meets the wear resistance requirements of the repaired inner wall of the crusher cylinder 1.

[0053] During the cladding process, the rotating support fixture 2 drives the crusher cylinder 1 to rotate around its own axis, while the heating device 3 and the laser cladding head 4 move synchronously along the axial direction of the crusher cylinder 1. As the laser cladding head 4 moves, the rangefinder 5 mounted on it moves synchronously with it and monitors the distance between the inner wall of the crusher cylinder 1 and the laser cladding head 4 in real time. Since the cladding area 11 on the inner wall of the crusher cylinder 1 is not a complete continuous inner circular surface, but may include multiple local arc cladding areas 11 and non-cladding areas 12, the distance detected by the rangefinder 5 will change as the laser cladding head 4 moves axially and rotates with the crusher cylinder 1 through different areas. The control system determines whether the laser cladding head 4 corresponds to the start or end point of the cladding area 11 based on this distance change.

[0054] When the rangefinder 5 detects that the laser cladding head 4 corresponds to the starting point of a certain local cladding area 11, the control system controls the laser cladding head 4 to output a laser beam and controls the powder feeding system to deliver cladding powder to the laser cladding head 4. The laser beam irradiates the inner wall surface of the crusher cylinder 1, causing micro-melting on the surface layer of the inner wall of the crusher cylinder 1. At the same time, the cladding powder melts under the action of the laser and enters the molten pool. As the crusher cylinder 1 continues to rotate and the laser cladding head 4 continues to move axially, the molten pool moves along the local cladding area 11, and the molten metal behind the molten pool solidifies to form a cladding layer.

[0055] When the rangefinder 5 detects that the laser cladding head 4 has reached the end point of the local cladding area 11, the control system controls the laser cladding head 4 to stop outputting the laser beam and / or stop feeding cladding powder to the laser cladding head 4. At this time, although the crusher cylinder 1 continues to rotate, the laser cladding head 4 and the induction heating coil 31 can continue to move axially, but the laser cladding head 4 no longer clads the non-cladding area 12, thereby avoiding the deposition of cladding material into the non-target area.

[0056] As the laser cladding head 4 continues to move and passes the starting point of the next local cladding area 11 again, the rangefinder 5 detects the corresponding distance change again, and the control system controls the laser cladding head 4 to output a laser beam and start feeding powder. When it passes the end point of the local cladding area 11, it stops emitting light and / or stops feeding powder. Thus, during the process of the induction heating coil 31 and the laser cladding head 4 moving from the starting end to the other end of the crusher cylinder 1 along the axial direction, multiple local cladding areas 11 can be intermittently and selectively clad sequentially.

[0057] During the aforementioned continuous movement, the induction heating coil 31 remains upstream of the laser cladding head 4, preheating or maintaining the temperature of the inner wall area to be laser-clad; the laser cladding head 4 is downstream, cladding the preheated or maintained target area; the rangefinder 5 monitors the changes in distance to the inner wall in real time along with the laser cladding head 4, and participates in controlling the laser output and powder feeding start / stop. With the cooperation of these three components, a continuous repair process of "upstream preheating and maintenance—real-time distance measurement and identification—downstream selective cladding" can be formed.

[0058] When the induction heating coil 31 and the laser cladding head 4 move to the other end of the crusher cylinder 1 and complete the cladding of all target cladding areas 11, the laser output, powder feeding and heating are stopped.

[0059] S6, Insulation and Slow Cooling After the cladding is completed, the crusher cylinder 1 is kept warm and cooled slowly. Specifically, asbestos or other insulation materials can be used to wrap the crusher cylinder 1, so that the crusher cylinder 1 and the cladding layer can be cooled slowly.

[0060] By using heat preservation and slow cooling treatment, the residual stress generated during the cooling stage can be reduced, the risk of cracking of the cladding layer can be reduced, and the bonding stability between the cladding layer and the crusher cylinder 1 substrate can be improved.

[0061] S7, Grinding, Polishing and Inspection After the crusher cylinder 1 has cooled to room temperature, the inner wall of the crusher cylinder 1 is ground and polished to ensure that the inner wall of the crusher cylinder 1 after cladding meets the requirements for dimensional accuracy and surface quality.

[0062] After grinding and polishing, the inner wall dimensions, surface quality of the cladding layer, and hardness of the cladding layer of the crusher cylinder 1 are inspected. Once the inspection is passed, the repaired crusher cylinder 1 can be sent to the subsequent assembly process.

[0063] The implementation principle of the laser cladding repair method for a crusher cylinder body according to an embodiment of this application is as follows: First, the inner wall of the crusher cylinder body 1 is cleaned, and the crusher cylinder body 1 is supported on the rotating support fixture 2 so that the crusher cylinder body 1 can rotate stably around its own axis. Then, the heating device 3 and the laser cladding head 4 are inserted into the crusher cylinder body 1, with the heating device 3 located upstream of the laser cladding head 4. Before the laser cladding head 4 performs cladding, the area 11 to be clad is preheated or kept warm to reduce the temperature gradient and thermal stress during the cladding process.

[0064] During the cladding process, the crusher cylinder 1 continues to rotate, while the heating device 3 and the laser cladding head 4 move axially along the crusher cylinder 1. The rangefinder 5 on the laser cladding head 4 detects the change in distance between the inner wall of the crusher cylinder 1 and the laser cladding head 4 in real time, and determines whether the laser cladding head 4 corresponds to the start or end point of the cladding area 11 based on this distance change. When the start point of the cladding area 11 is detected, the laser cladding head 4 is controlled to output a laser beam and deliver cladding powder, so that the cladding powder melts under the action of the laser and is deposited on the inner wall of the crusher cylinder 1; when the end point of the cladding area 11 is detected, the laser cladding head 4 is controlled to stop outputting the laser beam and / or stop delivering the cladding powder, so that the cladding layer is formed only in the target cladding area 11, avoiding cladding of the non-cladding area 12.

[0065] After the cladding is completed, the crusher cylinder 1 is kept warm and cooled slowly to reduce the residual stress generated during the cooling stage and reduce the risk of cracking of the cladding layer. Subsequently, the inner wall of the crusher cylinder 1 is ground, polished and inspected to ensure that the repaired inner wall of the crusher cylinder 1 meets the requirements for dimensional accuracy, surface quality and wear resistance.

[0066] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for laser cladding repair of a crusher cylinder, characterized in that: Includes the following steps: S1. Clean the inner wall of the crusher cylinder (1) to be repaired to remove oil and impurities from the inner wall of the crusher cylinder (1); S2. Support the cleaned crusher cylinder (1) on the rotating support fixture (2); S3. The heating device (3) and the laser cladding head (4) are placed inside the crusher cylinder (1). The laser cladding head (4) is equipped with a rangefinder (5), and along the moving direction of the heating device (3) and the laser cladding head (4), the laser cladding head (4) is located downstream of the heating device (3). S4. The crusher cylinder (1) is driven to rotate around its own axis by the rotating support fixture (2). The heating device (3) preheats or keeps the area (11) to be clad on the inner wall of the crusher cylinder (1) before and / or during the cladding process, so that the area (11) to be clad is within the preset temperature range. S5. While the crusher cylinder (1) is rotating, the heating device (3) and the laser cladding head (4) are driven to move along the axial direction of the crusher cylinder (1). The rangefinder (5) detects the change in distance between the inner wall of the crusher cylinder (1) and the laser cladding head (4) in real time. When the laser cladding head (4) is identified as being at the starting point of the cladding area (11) according to the change in distance, the laser cladding head (4) is controlled to output a laser beam and deliver cladding powder to the laser cladding head (4) to clad the cladding area (11). When the laser cladding head (4) is identified as being at the ending point of the cladding area (11) according to the change in distance, the laser cladding head (4) is controlled to stop outputting a laser beam and / or stop delivering cladding powder to the laser cladding head (4) so ​​that the cladding layer is formed in the cladding area (11) and the non-cladding area (12) is avoided from being clad. S6. After the cladding is completed, the crusher cylinder (1) is kept warm and cooled slowly. S7. Grind, polish and inspect the inner wall of the crusher cylinder (1) after slow cooling.

2. The laser cladding repair method for a crusher cylinder according to claim 1, characterized in that: In step S3, when the laser cladding head (4) is in a vertical state, the laser cladding head (4) is offset backward relative to the diameter direction of the crusher cylinder (1), and the laser cladding head (4) is tilted around the X-axis direction to reduce the risk of reflected light from the inner wall of the crusher cylinder (1) being reflected back to the laser cladding head (4).

3. The laser cladding repair method for a crusher cylinder according to claim 2, characterized in that: The laser cladding head (4) is offset backward by 20mm to 50mm relative to the diameter direction of the crusher cylinder (1), and the laser cladding head (4) is rotated 10° to 15° around the X-axis.

4. The laser cladding repair method for a crusher cylinder according to claim 1, characterized in that: The heating device (3) is an induction heating coil (31). A temperature sensor is provided on the induction heating coil (31). The temperature sensor is used to detect the temperature of the inner wall of the crusher cylinder (1) and adjust the heating current of the induction heating coil (31) according to the detection result of the temperature sensor so that the inner wall of the crusher cylinder (1) is within the preset temperature range.

5. The laser cladding repair method for a crusher cylinder according to claim 4, characterized in that: The axis of the induction heating coil (31) is collinear with the axis of the crusher cylinder (1) so that the induction heating coil (31) can preheat or keep the circumferential area of ​​the inner wall of the crusher cylinder (1).

6. The laser cladding repair method for a crusher cylinder according to claim 4, characterized in that: In step S4, the induction heating coil (31) is used to heat the cladding start end of the cladding area (11) to raise the temperature of the cladding start end to 300°C. Then, the heating current of the induction heating coil (31) is adjusted according to the detection result of the temperature sensor to keep the temperature of the inner wall of the crusher cylinder (1) between 300°C and 400°C.

7. The laser cladding repair method for a crusher cylinder body according to claim 1, characterized in that: In step S5, the heating device (3) and the laser cladding head (4) move synchronously within the crusher cylinder (1) while maintaining a preset axial distance, so that the heating device (3) first preheats or keeps the cladding area (11) warm, and then the laser cladding head (4) performs laser cladding on the preheated or kept warm cladding area (11).

8. The laser cladding repair method for a crusher cylinder according to claim 1, characterized in that: The rotating support fixture (2) includes a rotating support drive wheel (21) and a rotating support driven wheel (22). The rotating support drive wheel (21) and the rotating support driven wheel (22) jointly support the crusher cylinder (1). The rotating support drive wheel (21) is used to drive the crusher cylinder (1) to rotate around its own axis. Limiting devices (24) are respectively provided on both sides of the axial direction of the crusher cylinder (1). The limiting devices (24) are used to limit the axial movement of the crusher cylinder (1) during the cladding process.

9. The laser cladding repair method for a crusher cylinder according to claim 1, characterized in that: The cladding powder is an iron-based titanium carbide composite cladding powder, which is formed by mixing high-hardness iron-based powder and titanium carbide powder. The mass fraction of titanium carbide powder in the iron-based titanium carbide composite cladding powder is 5%.

10. The laser cladding repair method for a crusher cylinder according to claim 1, characterized in that: In step S5, the laser power of the laser cladding head (4) is 5000W to 6000W, the powder feeding speed is 50g / min to 60g / min, the rotation speed of the crusher cylinder (1) is 3r / min to 6r / min, the cladding overlap rate is 60%, and after cladding, a cladding layer is formed in the cladding area (11) on the inner wall of the crusher cylinder (1), and the hardness of the cladding layer is HRC58 to HRC62.

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