Cold welding device for repairing surface of hydraulic piston

Abstract

The invention relates to the field of laser welding equipment, in particular to a cold welding device for repairing the surface of a hydraulic piston, which comprises a laser cladding nozzle, an axial movement module and a composite deslagging system, the air suction device comprises a first negative pressure generator and an air suction pipe in fluid communication with the first negative pressure generator; the rear adsorption assembly comprises a second negative pressure generator, an adsorption pipe arranged on the rear side of the advancing direction of the laser cladding spray head and an adsorption stop block arranged outside the adsorption pipe in a sleeving mode, and the adsorption stop block is provided with a welding slag inlet facing the laser cladding spray head; the waste gas inlet is positioned at the bottom of the adsorption baffle; and the runner system is used for communicating the welding slag inlet, the waste gas inlet and the second negative pressure generator. The method has the effect that the influence of smoke and small-particle welding slag formed by welding flux melting, oxidizing and sputtering on hydraulic piston surface repairing is reduced.

Description

Technical Field

[0001] The present invention relates to the field of laser welding equipment, and more particularly to a cold welding device for repairing the surface of a hydraulic piston. Background Art

[0002] In the fields of industrial manufacturing and equipment maintenance, many key components will inevitably suffer from damage problems such as wear and corrosion during long-term use. As an important component in many mechanical devices, the stable performance of the piston cylinder is crucial for the normal operation of the equipment. With the continuous development of industrial technology, the demand for repairing piston cylinders is increasing day by day, and efficient and high-quality repair technologies have become the focus of the industry.

[0003] Laser cladding technology, with its unique advantages such as high energy density and precise controllability, provides a new way for repairing the inner wall of the piston cylinder. The piston cylinder is applied to various hydraulic systems, engines and other equipment, and the integrity of its inner wall is directly related to the sealing performance, power transmission efficiency and overall reliability of the equipment. Effective inner wall repair technology of the piston cylinder can not only extend the service life of the piston cylinder, reduce the equipment maintenance cost, but also improve the stability and safety of equipment operation, which is of great significance for promoting the development of related industries.

[0004] Referring to the Chinese patent document with the publication number CN211727904U, the publication date of October 23, 2020, and the name of a cladding welding auxiliary device for a hydraulic cylinder block. This patent tightly presses one side of the hydraulic cylinder block to be repaired through a detachable screw and a fixing plate arranged at the end of the screw, and elastically presses the other side of the hydraulic cylinder block to be repaired through an L-shaped plate, thereby fixing the hydraulic cylinder.

[0005] Although the above-mentioned existing patent can complete the basic cladding operation, during the laser cladding process of the inner wall of the hydraulic cylinder, when the powder solder is blown towards the welding point, some of the solder will melt, oxidize and sputter to form smoke and small particle welding slag. These smoke and small particle welding slag are likely to deposit on the cladding interface, hinder the wetting of the molten metal and the substrate, and lead to a decrease in the bonding strength. At the same time, the splashed welding slag rolls in the piston cylinder and will be mixed into the molten pool during the cladding process, resulting in pores on the repaired surface after welding, reducing the strength of the repaired surface and increasing the roughness, affecting the quality and performance of the inner wall of the piston cylinder after repair. This makes the repair layer have a potential peeling risk and is difficult to meet the strict requirements for surface integrity and durability of the hydraulic piston. Summary of the Invention

[0006] In view of this, the present invention provides a cold welding device for repairing the surface of a hydraulic piston, which is used to solve the influence of the smoke and small particle welding slag formed by the melting and oxidation sputtering of the solder on the surface repair of the hydraulic piston during the laser cladding process of the inner wall of the hydraulic cylinder.

[0007] The cold welding device for repairing the surface of a hydraulic piston provided by the present invention adopts the following technical solution: A cold welding device for repairing the surface of a hydraulic piston, comprising a laser cladding spray head, an axial movement module and a composite slag discharging system. The composite slag discharging system includes: a front dynamic air suction unit, which includes a first negative pressure generator and an air suction pipe fluidly connected to the first negative pressure generator. The air suction pipe extends along the axial processing direction of the laser cladding spray head, and the air inlet end is arranged on the front side of the advancing direction of the laser cladding spray head and keeps a gap of 0.5-1.2 mm from the inner wall of the piston cylinder; a rear adsorption assembly, which includes a second negative pressure generator, an adsorption pipe arranged on the rear side of the advancing direction of the laser cladding spray head, and an adsorption baffle sleeved outside the adsorption pipe. The adsorption baffle has: a welding slag inlet facing the laser cladding spray head; an exhaust gas inlet located at the bottom of the adsorption baffle; and a flow channel system connecting the welding slag inlet, the exhaust gas inlet and the second negative pressure generator.

[0008] By adopting the above technical solution, the reasonable design of the front dynamic air suction unit enables the air suction pipe to keep a specific gap from the inner wall of the piston cylinder, which can efficiently suck the smoke generated by laser cladding, avoid the oxide particles in the smoke from adhering to the surface to be welded, maintain the surface cleanliness, greatly improve the wettability between the cladding material and the substrate, and enhance the bonding force. The rear adsorption assembly can accurately collect and discharge the splashed welding slag to prevent it from mixing into the molten pool, significantly reduce the porosity of the repaired surface after welding, improve the strength of the repaired surface, and the adsorption baffle can also reduce the intensity of the air flow directly passing through the laser welding point from the hydraulic piston, thereby improving the cold welding effect of the cold welding device at the welding site. The air flow cooperative control module monitors the pressure difference between the front dynamic air suction unit and the rear adsorption assembly in real time through a pressure sensor and dynamically adjusts the power of the two negative pressure generators, and can accurately form a directional air flow from the front dynamic air suction unit to the rear adsorption assembly. This design can effectively guide the smoke and welding slag generated during the laser cladding process to move along the air flow direction and be more efficiently processed by the front air suction and rear adsorption assemblies. The directional air flow not only enhances the slag discharging effect, reduces the residue of smoke and welding slag in the piston cylinder, but also reduces its interference with the laser cladding process, further improving the quality and stability of the repair of the inner wall of the piston cylinder.

[0009] When using this cold welding device to repair the inner surface of the hydraulic piston surface, first start the axial movement module to make the laser cladding spray head move axially along the inner wall of the piston cylinder at a constant speed for repair work. At the same time, turn on the composite slag discharging system, and the first negative pressure generator starts to work. Through the air suction pipe fluidly connected to it, while keeping the air inlet end 0.5-1.2 mm away from the inner wall of the piston cylinder, the smoke generated on the front side of the advancing direction of the laser cladding spray head is timely sucked.

[0010] Optionally, the following are formed inside the adsorption stopper: a receiving cavity that communicates with the welding area through a welding slag inlet; an air suction channel connected to the second negative pressure generator; and a diversion baffle disposed in the receiving cavity and having a tapered guiding surface facing the welding slag inlet.

[0011] By adopting the above technical solution, a receiving cavity is provided inside the adsorption stopper, and this receiving cavity communicates with the welding area through the welding slag inlet. This ingenious design enables it to efficiently and accurately collect the welding slag splashed from the welding area. At the same time, the air suction channel is closely connected to the second negative pressure generator, and the exhaust gas generated in the piston cylinder is discharged by means of the suction force of the second negative pressure generator, thereby maintaining the air in the piston cylinder fresh and clean. More importantly, when the air suction channel works in cooperation with the second negative pressure generator, a stable negative pressure environment can be formed in the receiving cavity. This negative pressure environment will change the gas flow direction at the welding slag inlet, effectively reducing the possibility of the welding slag rebounding out of the receiving cavity and ensuring that the welding slag is firmly "locked" in the receiving cavity.

[0012] A diversion baffle with a tapered guiding surface is specially designed in the receiving cavity. When the welding slag enters the receiving cavity, the tapered guiding surface of the diversion baffle can play an excellent guiding role for the welding slag. It guides the welding slag to enter the interior of the receiving cavity along a specific curved surface trajectory in an orderly manner, successfully avoiding the situation of the welding slag rebounding disorderly or scattering everywhere in the receiving cavity. Through such a design, the device's ability to collect and process the welding slag generated during the welding process is further improved, providing a strong guarantee for the high-quality development of the laser cladding repair work on the inner wall of the piston cylinder.

[0013] Optionally, the composite slag discharge system further includes an air flow cooperative control module. The air flow cooperative control module monitors the pressure difference between the front dynamic air suction unit and the rear adsorption component in real time through a pressure sensor, and dynamically adjusts the power of the first negative pressure generator and the second negative pressure generator, so as to form a directional air flow from the front dynamic air suction unit to the rear adsorption component at the laser cladding nozzle.

[0014] By adopting the above technical solution, the pressure sensor monitors the pressure difference between the front dynamic suction unit and the rear adsorption component in real time, and dynamically adjusts the power of the two negative pressure generators according to the monitoring data. Based on this, a directional airflow flowing from the front dynamic suction unit to the rear adsorption component can be accurately constructed. During the laser cladding process, the directional airflow can effectively guide the generated smoke and welding slag so that it moves smoothly along a specific airflow direction. In this way, the smoke and welding slag can be more efficiently processed by the front dynamic suction unit and the rear adsorption component respectively. The positive effects brought by the directional airflow are significant. On the one hand, it greatly enhances the slag removal effect of the device and significantly reduces the residual amount of smoke and welding slag inside the piston cylinder. On the other hand, it effectively reduces the interference of smoke and welding slag on the laser cladding process, so that the repair work of the inner wall of the piston cylinder can be carried out more stably and with high quality, which effectively improves the repair quality and stability.

[0015] Optionally, the pressure sensor is a piezoelectric dynamic pressure sensor with a response frequency ≥1kHz and a measurement accuracy error of ±0.5Pa, and at least three groups are arranged, respectively located at the air inlet of the suction pipe, the laser cladding nozzle and the inlet of the adsorption tube.

[0016] Optionally, the air intake pipe is a retractable bellows structure, and a front end thereof is provided with an annular air intake hood which radially expands and faces the inner wall of the piston cylinder, and the gap between the air inlet of the annular air intake hood and the inner wall of the piston cylinder is 0.5-1.2 mm.

[0017] By adopting the above technical solution, the suction pipe adopts a retractable bellows structure, so that it can easily adapt to the needs of different positions and various complex working conditions in the piston cylinder. In the complex environment inside the piston cylinder, the suction pipe with a retractable bellows structure can be arranged more conveniently and work stably and efficiently. The annular suction hood significantly improves the suction efficiency by increasing the suction area. With a larger suction area, it can more effectively collect the smoke generated in front of the laser cladding nozzle to ensure that the smoke is sucked out in time. In addition, the air inlet end of the suction pipe and the inner wall of the piston cylinder deliberately maintain a specific gap of 0.5-1.2mm, which not only cleverly avoids the collision of the suction pipe with the inner wall of the piston cylinder during operation, ensuring the stable operation of the equipment, but also just guarantees the suction effect, which can effectively reduce the residual smoke in the piston cylinder. It creates a cleaner environment for laser cladding operations and strongly promotes the improvement of the repair quality of the inner wall of the piston cylinder.

[0018] Optionally, the composite slag removal system also includes a cleaning component arranged on the side of the adsorption block away from the laser cladding nozzle for cleaning welding slag attached to the inner surface of the hydraulic piston, and the adsorption block is provided with a vent facing the cleaning component and connecting the accommodating cavity and the internal space of the hydraulic piston.

[0019] By adopting the above technical solution, the cleaning component can accurately and efficiently clean the welding slag attached to the inner surface of the hydraulic piston. The vent cleverly connects the internal space of the accommodating cavity and the piston. This design has significant advantages during the cleaning operation: the waste gas and small particles of welding slag generated during the cleaning process can be quickly sucked away by the second negative pressure generator with the help of the unique flow channel system of the adsorption block, thereby further enhancing the slag removal capacity of the entire device, so that the inside of the piston cylinder is always kept clean. The clean internal environment of the piston cylinder creates more favorable conditions for the surface repair of the hydraulic piston, which not only helps to improve the quality of the repair, but also plays a positive role in optimizing the overall performance of the piston.

[0020] Optionally, the cleaning assembly includes: a rotation source; a rotating roller, which is rotatably connected to the side of the adsorption block away from the laser cladding nozzle and can rotate under the drive of the rotation source, and the surface of the rotating roller abuts against the inner surface of the hydraulic piston.

[0021] By adopting the above technical solution, the rotating source drives the rotating roller to rotate, and the surface of the rotating roller is in close contact with the inner surface of the hydraulic piston. During the operation of the equipment, the rotating roller continuously cleans the inner surface of the piston. At the same time, the cleaned welding slag can be discharged from the piston cylinder in time through the composite slag removal system with the help of the vent. This efficient slag removal mechanism further improves the cleanliness of the inside of the piston cylinder, providing a solid guarantee for the smooth progress of the hydraulic piston surface repair work.

[0022] Optionally, the flow rate of the directional airflow is 0.5-1 m / s.

[0023] Optionally, the composite slag removal system further comprises an ultrasonic vibrator installed on the outside of the focusing lens group of the laser cladding nozzle, which is used to break the oxide film on the surface of the molten pool.

[0024] In summary, the present invention includes at least one of the following beneficial technical effects: 1. The reasonable design of the front dynamic suction unit keeps a specific gap between the suction pipe and the inner wall of the piston cylinder, which can effectively absorb the smoke generated by laser cladding, prevent the oxide particles in the smoke from adhering to the surface to be welded, maintain the surface cleanliness, greatly improve the wettability between the cladding material and the substrate, enhance the bonding force, and effectively improve the surface adhesion; 2. The post-adsorption component can accurately collect and discharge the splashing welding slag through a unique adsorption block and flow channel system to prevent it from mixing into the molten pool, significantly reducing the porosity of the repaired surface after welding, improving the strength of the repaired surface, reducing the roughness, and effectively improving the quality and performance of the repaired inner wall of the piston cylinder. The adsorption block can also reduce the strength of the gas added from the hydraulic piston directly passing through the laser welding point, thereby improving the cold welding effect of the cold welding device at the welding point; 3. The addition of the air flow collaborative control module further improves the performance of the cold welding device. By using a pressure sensor to continuously monitor the pressure difference between the front dynamic suction unit and the rear adsorption component, and dynamically adjusting the power of the two negative pressure generators, a directional air flow can be accurately formed from the front dynamic suction unit to the rear adsorption component. This design can effectively guide the smoke and welding slag generated during the laser cladding process, making them move along the air flow direction and be more efficiently processed by the front suction and rear adsorption components. The directional air flow not only enhances the slag removal effect, reduces the residue of smoke and welding slag in the piston cylinder, but also reduces its interference with the laser cladding process, further improving the quality and stability of the inner wall repair of the piston cylinder.

[0025] In addition, the cold welding device for repairing the surface of a hydraulic piston of the present invention also has the advantages of simple structure, easy assembly, safe and reliable use, and is convenient for implementation, popularization and application. Description of the Drawings

[0026] Figure 1 is a schematic structural diagram of the cold welding device according to the embodiment of the present invention; Figure 2 is a schematic structural diagram showing the installation state of the front dynamic suction unit and the rear adsorption component; Figure 3 is a schematic structural diagram showing the corresponding position relationship between the laser cladding nozzle and the welding slag inlet; Figure 4 is a schematic structural diagram showing the structure of the adsorption stopper; Figure 5 is a schematic structural diagram showing the gas flow direction at the laser cladding nozzle; Figure 6 is a schematic structural diagram showing the gas flow direction at the accommodation chamber; Figure 7 is a schematic structural diagram showing the gas and welding slag flow directions at the rear adsorption component.

[0027] Description of the Reference Numerals: 1. Front dynamic suction unit; 11. Suction pipe; 12. Annular suction hood; 2. Rear adsorption component; 21. Adsorption pipe; 22. Adsorption stopper; 221. Welding slag inlet; 222. Exhaust gas inlet; 223. Accommodation chamber; 224. Suction channel; 225. Deflector baffle; 226. Ventilation port; 3. Cleaning component; 31. Rotation source; 32. Rotating roller; 100. Cold welding device; 101. Laser cladding nozzle; 102. Axial movement module; 103. Composite slag removal system. Detailed Embodiments

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will describe the technical solutions of the embodiments of the present invention clearly and completely in conjunction with the accompanying drawings of the embodiments of the present invention. Figure 1 - Drawing Figure 7 , to clearly and completely describe the technical solutions of the embodiments of the present invention.

[0029] The embodiments of the present invention disclose a cold welding device for repairing the surface of a hydraulic piston.

[0030] Referring to Figure 1 , a cold welding device for repairing the surface of a hydraulic piston includes a laser cladding spray head 101, an axial movement module 102, and a composite slag removal system 103. In this cold welding device 100, the laser cladding spray head 101 and the axial movement module 102 play crucial and complementary roles throughout the repair process. The laser cladding spray head 101 is one of the core components of the cold welding device 100. It can precisely control the emission and focusing of the laser beam and the filler material, and accurately apply the high-energy-density laser to the surface of the hydraulic piston to be repaired. By precisely adjusting the parameters of the laser, such as power, pulse frequency, etc., the spray head can quickly melt and fuse the filler material with the piston surface to form a metallurgical bond, thereby generating a cladding layer with excellent performance on the piston surface, effectively repairing damages such as wear and corrosion, and improving the properties of the piston surface such as hardness, wear resistance, and corrosion resistance.

[0031] The axial movement module 102 adopts a lathe structure design and includes two parts: a hydraulic piston fixing component and a driving component for the laser cladding spray head 101. Among them, the three-jaw chuck is the core unit of the fixing component. It stably clamps the hydraulic piston on the lathe spindle through adjustable jaws, ensuring the axial positioning accuracy and rotational stability of the piston during the repair process, and avoiding cladding deviation caused by vibration or offset. At the same time, the axial movement component drives the laser cladding spray head 101 to perform smooth and precise linear movement along the axis of the hydraulic piston through a precision lead screw, guide rail, and servo drive system. This structure can not only achieve the synchronous axial displacement of the spray head and the piston surface, ensuring that the cladding trajectory precisely matches the piston contour, but also flexibly adjust the moving speed and stroke range according to the repair requirements, thereby ensuring the uniformity and continuity of the cladding layer, and significantly improving the integrity and process reliability of the surface repair.

[0032] Referring to Figure 2 , Figure 3 and Figure 4, the composite slag removal system 103 includes a front dynamic air suction unit 1 and a rear adsorption component 2. The front dynamic air suction unit 1 includes a first negative pressure generator and an air suction pipe 11 fluidly connected to the first negative pressure generator. The air suction pipe 11 extends along the axial processing direction of the laser cladding nozzle 101, and the air inlet end is arranged on the front side of the advancing direction of the laser cladding nozzle 101 and maintains a gap of 0.5 - 1.2 mm from the inner wall of the piston cylinder. The rear adsorption component 2 includes a second negative pressure generator, an adsorption pipe 21 arranged on the rear side of the advancing direction of the laser cladding nozzle 101, and an adsorption baffle 22 sleeved outside the adsorption pipe 21. The adsorption baffle 22 includes a welding slag inlet 221 facing the laser cladding nozzle 101, an exhaust gas inlet 222 located at the bottom of the adsorption baffle 22, and a flow channel system that connects the welding slag inlet 221, the exhaust gas inlet 222 to the second negative pressure generator.

[0033] When using the cold welding device 100 to repair the inner surface of the hydraulic piston, first start the axial movement module 102 to make the laser cladding nozzle 101 move axially along the inner wall of the piston cylinder at a constant speed for the repair work. At the same time, turn on the composite slag removal system 103, and the first negative pressure generator starts to work. Through the air suction pipe 11 fluidly connected to it, while maintaining a gap of 0.5 - 1.2 mm between the air inlet end and the inner wall of the piston cylinder, the smoke generated on the front side of the advancing direction of the laser cladding nozzle 101 is timely sucked. At the rear side of the laser cladding nozzle 101, the second negative pressure generator operates. Through the adsorption pipe 21 and the sleeved adsorption baffle 22, the welding slag splashed is collected by the welding slag inlet 221, and the exhaust gas inlet 222 conveys the exhaust gas to the second negative pressure generator through the flow channel system for discharge, so as to continuously and effectively discharge the smoke and welding slag during the entire laser cladding repair process.

[0034] The reasonable design of the front dynamic air suction unit 1 enables the air suction pipe 11 to maintain a specific gap with the inner wall of the piston cylinder, which can efficiently suck the smoke generated by laser cladding, avoid the oxide particles in the smoke from adhering to the surface to be welded, maintain the surface cleanliness, greatly improve the wettability between the cladding material and the substrate, enhance the bonding force, and effectively improve the surface adhesion. The rear adsorption component 2 can accurately collect and discharge the splashed welding slag through the unique adsorption baffle 22 and the flow channel system, prevent it from mixing into the molten pool, significantly reduce the porosity of the repaired surface after welding, improve the strength of the repaired surface, reduce the roughness, effectively improve the quality and performance of the inner wall of the piston cylinder after repair, and the adsorption baffle 22 can also reduce the intensity of the gas supplemented from the hydraulic piston directly passing through the laser welding point position, thereby improving the cold welding effect of the cold welding device 100 at the welding site.

[0035] An accommodation cavity 223 communicating with the welding area through a welding slag inlet 221, an air suction channel 224 connected to a second negative pressure generator, and a flow channel system disposed in the accommodation cavity 223 are formed inside the adsorption stopper 22. Among them, the diversion baffle 225 has a tapered guiding surface facing the welding slag inlet 221. The accommodation cavity 223 inside the adsorption stopper 22 communicates with the welding area through the welding slag inlet 221, and can effectively collect the splashed welding slag. The air suction channel 224 is connected to the second negative pressure generator, and can quickly discharge the waste gas, keep the air in the piston cylinder fresh, and at the same time can form a negative pressure in the accommodation cavity 223, thereby changing the gas flow direction at the welding slag inlet and reducing the probability of the welding slag rebounding out of the accommodation cavity 223. The diversion baffle 225 with a tapered guiding surface in the accommodation cavity 223 can play a good guiding role for the incoming welding slag, so that the welding slag enters the accommodation cavity 223 orderly along the guiding surface, avoiding the disorderly rebound or scattering of the welding slag in the cavity, so as to more efficiently realize the collection of welding slag, further improving the device's processing ability for the welding slag generated during the welding process, and effectively ensuring the quality of laser cladding repair of the inner wall of the piston cylinder.

[0036] Referring to Figure 5 , the composite slag discharge system 103 further includes an air flow collaborative control module. The air flow collaborative control module monitors the pressure difference between the front dynamic air suction unit 1 and the rear adsorption component 2 in real time through a pressure sensor, and dynamically adjusts the power of the first negative pressure generator and the second negative pressure generator, so as to form a directional air flow from the front dynamic air suction unit 1 to the rear adsorption component 2 at the laser cladding nozzle 101. As an implementation manner, the flow rate of the directional air flow is preferably 0.5-1 m / s. This flow rate range can effectively drive the smoke and welding slag generated during the laser cladding process, making them flow smoothly from the front dynamic air suction unit 1 to the rear adsorption component 2, ensuring the slag discharge efficiency, and will not interfere with the normal operation of the laser cladding nozzle 101 due to too fast flow rate, ensuring the stability of the laser cladding. The appropriate flow rate also helps to maintain the air flow stability in the piston cylinder, avoiding the disorderly dispersion of smoke and welding slag in the cylinder due to air flow disorder, thereby creating a more favorable environment for the repair of the inner wall of the piston cylinder and improving the repair quality.

[0037] The addition of the air flow collaborative control module further improves the performance of the cold welding device 100. By monitoring the pressure difference between the front dynamic air suction unit 1 and the rear adsorption component 2 in real time through a pressure sensor and dynamically adjusting the power of the two negative pressure generators, a directional air flow from the front dynamic air suction unit 1 to the rear adsorption component 2 can be accurately formed. This design can effectively guide the smoke and welding slag generated during the laser cladding process, making them move along the air flow direction and being more efficiently processed by the front air suction and rear adsorption component 2. The directional air flow not only enhances the slag discharge effect, reduces the residue of smoke and welding slag in the piston cylinder, but also reduces its interference with the laser cladding process, further improving the quality and stability of the repair of the inner wall of the piston cylinder.

[0038] As an implementation method, the pressure sensor is a piezoelectric dynamic pressure sensor with a response frequency ≥1kHz and a measurement accuracy error of ±0.5Pa. At least three groups are arranged, respectively at the air inlet of the suction pipe 11, the laser cladding nozzle 101, and the entrance of the adsorption tube 21. The three groups of sensors work together to comprehensively monitor the pressure conditions at different key positions of the composite slag removal system 103. This provides accurate data support for the airflow coordination control module, enabling it to more accurately and dynamically adjust the power of the first and second negative pressure generators according to real-time pressure changes, thereby better maintaining the stability of the directional airflow from the front dynamic suction unit 1 to the rear adsorption component 2, and further improving the slag removal efficiency and laser cladding repair quality.

[0039] The suction pipe 11 is a retractable bellows structure, and its front end is provided with an annular suction hood 12 that is radially expanded and faces the inner wall of the piston cylinder. The gap between the air inlet of the annular suction hood 12 and the inner wall of the piston cylinder is 0.5-1.2mm. The suction pipe 11 adopts a retractable bellows structure, so that the suction pipe 11 can flexibly adapt to the different positions and working conditions of the piston cylinder, and can be better arranged and work in the complex environment inside the piston cylinder. The radially expanded annular suction hood 12 increases the suction area, improves the suction efficiency, and can more effectively collect the smoke generated in front of the laser cladding nozzle 101. The specific 0.5-1.2mm gap not only avoids collision with the inner wall of the piston cylinder, but also ensures the suction effect, reduces the residual smoke in the piston cylinder, creates a cleaner environment for laser cladding, and helps to improve the quality of the repair of the inner wall of the piston cylinder.

[0040] Reference Figure 6 and Figure 7 The composite slag removal system 103 also includes a cleaning component 3 which is arranged on the side of the adsorption block 22 away from the laser cladding nozzle 101 and is used to clean the welding slag attached to the inner surface of the hydraulic piston. The adsorption block 22 is provided with an air vent 226 which is opposite to the cleaning component 3 and connects the accommodating cavity 223 and the internal space of the hydraulic piston.

[0041] The cleaning assembly 3 can effectively clean the welding slag attached to the inner surface of the hydraulic piston to prevent the long-term accumulation of welding slag from affecting the piston performance. The vent 226 connects the accommodating chamber 223 and the internal space of the piston, so that the waste gas and small particles of welding slag generated during the cleaning process can be sucked away by the second negative pressure generator through the flow channel system of the adsorption block 22, further enhancing the slag removal ability, keeping the inside of the piston cylinder clean, providing more favorable conditions for the surface repair of the hydraulic piston, and helping to improve the repair quality and the overall performance of the piston.

[0042] The cleaning component 3 includes a rotation source 31 and a rotating roller 32. The rotating roller 32 is rotatably connected to the side of the adsorption stopper 22 away from the laser cladding nozzle 101 and can rotate driven by the rotation source 31 and contact the inner surface of the hydraulic piston. The rotation source 31 drives the rotating roller 32 to rotate, and the surface of the rotating roller 32 abuts against the inner surface of the hydraulic piston. This design brings remarkable effects. The rotating rotating roller 32 can continuously clean the inner surface of the piston, effectively removing the attached welding slag and preventing the accumulation of welding slag from affecting the normal operation of the piston. During the rotation process, the dynamic contact with the inner surface of the piston can ensure comprehensive and uniform cleaning without missing any welding slag residue. At the same time, in cooperation with the vent hole 226 on the adsorption stopper 22, the cleaning welding slag can be discharged in time through the composite slag discharge system 103, further improving the cleanliness inside the piston cylinder, strongly ensuring the smooth progress of the surface repair work of the hydraulic piston and the long-term stable operation of the piston.

[0043] The composite slag discharge system 103 further includes an ultrasonic vibrator installed outside the focusing lens group of the laser cladding nozzle 101, which is used to break the oxide film on the surface of the molten pool. The ultrasonic vibrator installed outside the focusing lens group of the laser cladding nozzle 101 in the composite slag discharge system 103 plays a key role. The ultrasonic vibrator can effectively break the oxide film on the surface of the molten pool, which makes the contact between the cladding material and the piston cylinder matrix better, enhancing the wettability and bonding force between the two. The breaking of the oxide film reduces the interference of impurities on the cladding process, helps to reduce the porosity of the cladding layer, and improves the density and strength of the repaired surface. At the same time, the good cladding effect also reduces the surface roughness, thus comprehensively improving the quality of the laser cladding repair of the inner wall of the piston cylinder and extending the service life of the piston cylinder.

[0044] The implementation principle of the cold welding device for repairing the surface of a hydraulic piston in an embodiment of the present invention is as follows: First, the hydraulic piston is stably clamped on the lathe spindle by the three-jaw chuck of the axial movement module 102, and the axial movement component is started to drive the laser cladding nozzle 101 to move uniformly along the piston axis for cladding repair. At the same time, the composite slag discharge system 103 is turned on. The suction pipe 11 of the front dynamic suction unit 1 (adopting a telescopic bellows structure, with a radially expanded annular suction hood 12 at the front end, maintaining a gap of 0.5 - 1.2 mm from the inner wall of the piston cylinder) efficiently sucks the smoke in front of the laser cladding nozzle 101 through the first negative pressure generator, and the rear adsorption component 2 collects the splashed welding slag and the rear smoke through the welding slag inlet 221 of the adsorption stopper 22. The airflow cooperative control module monitors the pressure difference in real time through three groups of piezoelectric dynamic pressure sensors (response frequency ≥ 1 kHz, error ± 0.5 Pa) arranged at the air inlet of the suction pipe 11, at the laser cladding nozzle 101, and at the inlet of the adsorption pipe 21, and dynamically adjusts the power of the first and second negative pressure generators to form a directional airflow of 0.5 - 1 m / s from the front dynamic suction unit 1 to the rear adsorption component 2, improving the slag discharge efficiency and reducing the residue.

[0045] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "vertical" and "horizontal" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

Claims

1. A cold welding device for repairing the surface of a hydraulic piston, comprising a laser cladding spray head, an axial movement module and a composite slag discharging system, characterized in that, The composite slag removal system comprises: A front dynamic air suction unit, comprising a first negative pressure generator and an air suction pipe in fluid communication with the first negative pressure generator, wherein the air suction pipe extends along the axial processing direction of the laser cladding nozzle, and an air inlet end is arranged at the front side of the laser cladding nozzle in the traveling direction and maintains a gap of 0.5-1.2 mm with the inner wall of the piston cylinder; The rear adsorption assembly comprises a second negative pressure generator, an adsorption tube arranged at the rear side of the laser cladding nozzle in the direction of travel, and an adsorption block sleeved outside the adsorption tube, wherein the adsorption block has: A slag inlet toward the laser cladding nozzle; an exhaust gas inlet at the bottom of the adsorption block; and A flow channel system connects the welding slag inlet, the exhaust gas inlet and the second negative pressure generator.

2. The cold welding device according to claim 1, wherein: The adsorption block is internally formed with: The accommodating cavity is connected with the welding area through the welding slag inlet; an inhalation channel connected to a second negative pressure generator; and The guide baffle plate arranged in the accommodating cavity has a tapered guide curved surface facing the welding slag inlet.

3. The cold welding device according to claim 1, characterized in that: The composite slag removal system also includes an airflow coordination control module, which monitors the pressure difference between the front dynamic suction unit and the rear adsorption component in real time through a pressure sensor, and dynamically adjusts the power of the first negative pressure generator and the second negative pressure generator, so that a directional airflow is formed from the front dynamic suction unit to the rear adsorption component at the laser cladding nozzle.

4. The cold welding device according to claim 3, characterized in that, The pressure sensor is a piezoelectric dynamic pressure sensor with a response frequency of ≥1kHz and a measurement accuracy error of ±0.5Pa. At least three groups are arranged, respectively located at the air inlet of the suction pipe, the laser cladding nozzle and the entrance of the adsorption tube.

5. The cold welding device according to claim 1, characterized in that, The air suction pipe is a retractable bellows structure, and its front end is provided with an annular air suction hood which is radially expanded and faces the inner wall of the piston cylinder. The gap between the air inlet of the annular air suction hood and the inner wall of the piston cylinder is 0.5-1.2mm.

6. The cold welding device according to claim 2, characterized in that, The composite slag removal system also includes a cleaning component arranged on the side of the adsorption block away from the laser cladding nozzle for cleaning welding slag attached to the inner surface of the hydraulic piston. The adsorption block is provided with an air vent facing the cleaning component and connecting the accommodating cavity and the internal space of the hydraulic piston.

7. The cold welding device according to claim 6, characterized in that, The cleaning component includes: Rotation source; A rotating roller is rotatably connected to the side of the adsorption block away from the laser cladding nozzle and can be rotated under the drive of the rotation source, and the surface of the rotating roller abuts against the inner surface of the hydraulic piston.

8. The cold welding device according to claim 4, characterized in that: The flow rate of the directional airflow is 0.5-1 m / s.

9. The cold welding device according to any one of claims 1-8, characterized in that, The axial motion module includes a hydraulic piston fixing assembly and a laser cladding nozzle driving assembly.

10. The cold welding device according to any one of claims 1-8, characterized in that: The composite slag removal system also includes an ultrasonic vibrator installed outside the focusing lens group of the laser cladding nozzle, which is used to break the oxide film on the surface of the molten pool.

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