A cold welding device for repairing the surface of a hydraulic piston

Abstract

The present invention relates to the field of laser welding equipment, and in particular to a cold welding device for hydraulic piston surface repair, comprising a laser cladding nozzle, an axial motion module, and a composite slag removal system. The composite slag removal system comprises: a front dynamic suction unit comprising a first negative pressure generator and a suction pipe in fluid communication with the first negative pressure generator; a rear adsorption assembly comprising a second negative pressure generator, an adsorption pipe disposed behind the laser cladding nozzle in the direction of travel, and an adsorption block sleeved outside the adsorption pipe. The adsorption block comprises: a slag inlet facing the laser cladding nozzle; an exhaust gas inlet located at the bottom of the adsorption block; and a flow channel system connecting the slag inlet and the exhaust gas inlet to the second negative pressure generator. The present invention is effective in reducing the effects of smoke and small particles of slag formed by solder melt, oxidation, and sputtering on hydraulic piston surface repair.

Description

Technical Field

[0001] 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. Background Art

[0002] In the fields of industrial manufacturing and equipment maintenance, many key components inevitably suffer from wear, corrosion, and other damage over long-term use. As critical components in numerous mechanical devices, the stable performance of piston cylinders is crucial for their proper operation. With the continuous advancement of industrial technology, the demand for piston cylinder repair is growing, and efficient, high-quality repair technologies have become a focus of industry attention.

[0003] Laser cladding technology, with its unique advantages, such as high energy density and precise controllability, offers a new approach for repairing piston cylinder inner walls. Piston cylinders are used in various hydraulic systems, engines, and other equipment, and the integrity of their inner walls is directly related to the equipment's sealing, power transmission efficiency, and overall reliability. Effective piston cylinder inner wall repair technology not only extends the service life of piston cylinders and reduces equipment maintenance costs, but also improves operational stability and safety, significantly contributing to the development of related industries.

[0004] Refer to the Chinese patent document entitled "A Cladding Welding Auxiliary Device for Hydraulic Cylinder Body" with publication number CN211727904U and publication date October 23, 2020. The patent uses a detachably connected screw and a fixing plate provided at the end of the screw to press against one side of the hydraulic cylinder body to be repaired, and an L-shaped plate to elastically press against the other side of the hydraulic cylinder body to be repaired, thereby securing the hydraulic cylinder.

[0005] Although the above-mentioned existing patents can complete basic cladding operations, during the laser cladding process of the inner wall of the hydraulic cylinder, when the powdered solder is blown towards the welding point, part of the solder will melt, oxidize and sputter to form smoke and small particles of welding slag. These smoke and small particles of welding slag are easily deposited at the cladding interface, hindering the wetting of the molten metal and the substrate, resulting in a decrease in bonding strength. At the same time, the splashing welding slag rolls in the piston cylinder and mixes into the molten pool during the cladding process, causing pores to form on the repaired surface after welding, reducing the strength of the repaired surface and increasing the roughness, affecting the quality and performance of the repaired inner wall of the piston cylinder. This makes the repair layer have a potential risk of peeling, making it difficult to meet the stringent requirements of the hydraulic piston for surface integrity and durability. Summary of the Invention

[0006] In view of this, the present invention provides a cold welding device for hydraulic piston surface repair, which is used to solve the impact of smoke and small particles of welding slag formed by solder melting, oxidation and sputtering on the surface repair of hydraulic piston during laser cladding 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:

[0008] A cold welding device for repairing the surface of a hydraulic piston comprises a laser cladding nozzle, an axial motion module and a composite slag removal system, wherein the composite slag removal system comprises: a front dynamic suction unit, which comprises a first negative pressure generator and a suction pipe fluidically connected to the first negative pressure generator, the suction pipe extending along the axial processing direction of the laser cladding nozzle, and the air inlet end is arranged at the front side of the travel direction of the laser cladding nozzle and maintains a gap of 0.5-1.2mm with the inner wall of the piston cylinder; a rear adsorption assembly, comprising a second negative pressure generator, an adsorption pipe arranged at the rear side of the travel direction of the laser cladding nozzle and an adsorption block sleeved outside the adsorption pipe, the adsorption block having: a welding slag inlet facing the laser cladding nozzle; an exhaust gas inlet located at the bottom of the adsorption block; and a flow channel system connecting the welding slag inlet, the exhaust gas inlet and the second negative pressure generator.

[0009] By adopting the above technical solution, the rational design of the front dynamic suction unit maintains a specific gap between the suction pipe and the inner wall of the piston cylinder, effectively removing the smoke generated by laser cladding, preventing oxide particles in the smoke from adhering to the surface to be welded, maintaining surface cleanliness, significantly improving the wettability between the cladding material and the substrate, and strengthening the bonding strength. The rear suction assembly can accurately collect and discharge spattered welding slag, preventing it from mixing into the molten pool, significantly reducing the porosity of the repaired surface after welding and improving the strength of the repaired surface. The suction block also reduces the intensity of the airflow directly flowing through the laser weld point from the hydraulic piston, thereby improving the cold welding effect of the cold welding device at the welding point. The airflow coordination control module uses a pressure sensor to monitor the pressure difference between the front dynamic suction unit and the rear suction assembly in real time, and dynamically adjusts the power of the two negative pressure generators to accurately form a directional airflow from the front dynamic suction unit to the rear suction assembly. This design effectively guides the smoke and welding slag generated during the laser cladding process, causing them to move along the airflow direction and be more efficiently processed by the front suction and rear suction assemblies. The directional airflow not only enhances the slag removal effect and reduces the residual 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.

[0010] When using this cold welding device to repair the inner surface of a hydraulic piston, the axial motion module is first activated, causing the laser cladding nozzle to move at a constant speed along the inner wall of the piston cylinder to perform the repair. Simultaneously, the composite slag removal system is activated, and the first negative pressure generator begins operating. Through the suction pipe connected to it, while maintaining a 0.5-1.2mm gap between the air inlet and the inner wall of the piston cylinder, the smoke generated in front of the laser cladding nozzle in the direction of travel is promptly sucked out.

[0011] Optionally, the adsorption block is internally formed with: a accommodating cavity, which is connected to the welding area through the welding slag inlet; an air suction channel connected to the second negative pressure generator; and a guide baffle arranged in the accommodating cavity, which has a tapered guide surface facing the welding slag inlet.

[0012] By adopting the above-mentioned technical solution, a accommodating chamber is provided inside the adsorption block, which is connected to the welding area through the slag inlet. This ingenious design enables it to efficiently and accurately collect the slag splashed from the welding area. At the same time, the suction channel is tightly connected to the second negative pressure generator, and with the help of the suction force of the second negative pressure generator, the exhaust gas generated in the piston cylinder is discharged, thereby maintaining the freshness and cleanliness of the air in the piston cylinder. More importantly, when the suction channel works in conjunction with the second negative pressure generator, it can form a stable negative pressure environment in the accommodating chamber. This negative pressure environment will change the gas flow direction at the slag inlet, effectively reducing the possibility of the slag rebounding out of the accommodating chamber, ensuring that the slag is firmly "locked" in the accommodating chamber.

[0013] A specially designed guide baffle with a tapered guide surface is incorporated into the containment chamber. This tapered guide surface effectively guides the welding slag as it enters the containment chamber. This guides the slag along a specific curved path, allowing it to enter the containment chamber in an orderly manner, effectively preventing the slag from bouncing around or scattering randomly within the containment chamber. This design further enhances the device's ability to collect and process welding slag, ensuring high-quality laser cladding repairs on piston cylinder inner walls.

[0014] Optionally, 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.

[0015] 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 based on 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, this directional airflow can effectively guide the generated smoke and welding slag, causing them to move 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 about by the directional airflow are significant. On the one hand, it greatly enhances the slag removal effect of the device and significantly reduces the amount of smoke and welding slag remaining inside the piston cylinder. On the other hand, it effectively reduces the interference of smoke and welding slag on the laser cladding process, allowing the repair work on the inner wall of the piston cylinder to be carried out more stably and with high quality, effectively improving the repair quality and stability.

[0016] 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.

[0017] Optionally, the air intake pipe is a retractable bellows structure, and its front end is provided with an annular air intake hood that 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 0.5-1.2mm.

[0018] By adopting the above-mentioned technical solution, the suction pipe adopts a retractable bellows structure, which allows it to easily adapt to different locations and various complex working conditions within 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 operate stably and efficiently. The annular suction hood significantly improves suction efficiency by increasing the suction area. With this larger suction area, it can more effectively collect the smoke generated in front of the laser cladding nozzle, ensuring that the smoke is removed in a timely manner. In addition, a specific gap of 0.5-1.2mm is deliberately maintained between the air inlet end of the suction pipe and the inner wall of the piston cylinder. This cleverly avoids the suction pipe from colliding with the inner wall of the piston cylinder during operation, ensuring stable operation of the equipment, while also ensuring the perfect suction effect, effectively reducing the residual smoke in the piston cylinder. This creates a cleaner environment for laser cladding operations and significantly promotes the improvement of the quality of piston cylinder inner wall repair.

[0019] 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.

[0020] By adopting the above technical solution, the cleaning assembly can accurately and efficiently remove welding slag attached to the inner surface of the hydraulic piston. The vent cleverly connects the accommodating cavity with the internal space of the piston. This design offers significant advantages during cleaning operations: 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 through the unique flow channel system of the adsorption block, further enhancing the slag removal capacity of the entire device and keeping the interior of the piston cylinder clean. The clean internal environment of the piston cylinder creates more favorable conditions for hydraulic piston surface repair work, 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.

[0021] 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 the inner surface of the hydraulic piston.

[0022] With this technical solution, a rotary source drives the rotating roller, whose surface contacts the inner surface of the hydraulic piston. During operation, the roller continuously cleans the inner surface of the piston. Simultaneously, removed weld slag is promptly discharged from the piston cylinder via a composite slag removal system through vents. This highly efficient slag removal mechanism further improves the cleanliness of the piston cylinder interior, ensuring smooth progress in hydraulic piston surface repair.

[0023] Optionally, the flow rate of the directional airflow is 0.5-1 m / s.

[0024] 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.

[0025] In summary, the present invention includes at least one of the following beneficial technical effects:

[0026] 1. The rational design of the front dynamic suction unit maintains 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 surface cleanliness, greatly improve the wettability between the cladding material and the substrate, enhance the bonding force, and effectively improve the surface adhesion;

[0027] 2. The post-adsorption component uses a unique adsorption block and flow channel system to accurately collect and discharge spattered welding slag, preventing it from mixing into the molten pool. This significantly reduces the porosity of the repaired surface after welding, improves the strength of the repaired surface, reduces roughness, and effectively improves the quality and performance of the repaired piston cylinder inner wall. The adsorption block can also reduce the intensity of the gas supplied 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.

[0028] 3. The addition of the airflow coordination control module further improves the performance of the cold welding device. By using a pressure sensor to monitor the pressure difference between the front dynamic suction unit and the rear adsorption component in real time and dynamically adjusting the power of the two negative pressure generators, a directional airflow 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, so that it moves along the direction of the airflow and is more efficiently processed by the front suction and rear adsorption components. The directional airflow not only enhances the slag removal effect and reduces the residual 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.

[0029] In addition, the cold welding device for repairing the surface of a hydraulic piston of the present invention has the advantages of simple structure, easy assembly, and safe and reliable use, and is easy to implement, promote and apply. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 2 is a schematic structural diagram of a cold welding device according to an embodiment of the present invention;

[0031] Figure 2 It is a structural diagram showing the installation status of the front dynamic suction unit and the rear adsorption component;

[0032] Figure 3 It is a structural diagram reflecting the corresponding position relationship between the laser cladding nozzle and the welding slag inlet;

[0033] Figure 4 It is a structural diagram reflecting the adsorption block;

[0034] Figure 5 It is a structural diagram reflecting the gas flow direction at the laser cladding nozzle;

[0035] Figure 6 It is a structural schematic diagram reflecting the gas flow direction in the accommodation cavity;

[0036] Figure 7 It is a structural diagram showing the flow of gas and welding slag at the post-adsorption component.

[0037] Description of reference numerals:

[0038] 1. Front dynamic suction unit; 11. Suction pipe; 12. Annular suction hood;

[0039] 2. Post-adsorption assembly; 21. Adsorption tube; 22. Adsorption block; 221. Welding slag inlet; 222. Exhaust gas inlet; 223. Accommodation chamber; 224. Intake channel; 225. Guide baffle; 226. Vent;

[0040] 3. Cleaning assembly; 31. Rotation source; 32. Rotation roller;

[0041] 100. Cold welding device; 101. Laser cladding nozzle; 102. Axial motion module; 103. Composite slag removal system. DETAILED DESCRIPTION

[0042] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the following will be combined with the appended drawings of the embodiments of the present invention. Figure 1 -Attached Figure 7 , clearly and completely describe the technical solutions of the embodiments of the present invention.

[0043] An embodiment of the present invention discloses a cold welding device for repairing the surface of a hydraulic piston.

[0044] Reference Figure 1 , a cold welding device for repairing the surface of a hydraulic piston, comprising a laser cladding nozzle 101, an axial motion module 102 and a composite slag removal system 103. The laser cladding nozzle 101 and the axial motion module 102 in the cold welding device 100 play a vital and complementary role in the entire repair process. The laser cladding nozzle 101 is one of the core components of the cold welding device 100. It can accurately control the emission and focusing of the laser beam and the filler material, and accurately apply high-energy-density laser to the surface of the hydraulic piston to be repaired. By precisely controlling the parameters of the laser, such as power and pulse frequency, the nozzle can quickly melt and fuse the filler material with the piston surface to form a metallurgical bond, thereby generating a layer of excellent cladding layer on the piston surface, effectively repairing damage such as wear and corrosion, and improving the hardness, wear resistance and corrosion resistance of the piston surface.

[0045] The axial motion module 102 adopts a lathe structure design and includes two parts: a hydraulic piston fixing component and a laser cladding nozzle 101 driving component. Among them, the three-jaw chuck serves as the core unit of the fixing component. It stably clamps the hydraulic piston on the lathe spindle through adjustable jaws to ensure the axial positioning accuracy and rotational stability of the piston during the repair process, and avoids cladding deviations caused by vibration or offset. At the same time, the axial movement component drives the laser cladding nozzle 101 to move smoothly and accurately along the axis of the hydraulic piston through a precision screw, guide rail and servo drive system. This structure can not only achieve synchronous axial displacement of the nozzle and the piston surface, ensuring that the cladding trajectory accurately matches the piston contour, but also flexibly adjust the movement speed and stroke range according to the repair requirements, thereby ensuring the uniformity and continuity of the cladding layer, and significantly improving the integrity of the surface repair and process reliability.

[0046] Reference Figure 2 、 Figure 3 and Figure 4 The composite slag removal system 103 includes a front dynamic suction unit 1 and a rear adsorption assembly 2. The front dynamic suction unit 1 includes a first negative pressure generator and an air suction pipe 11 in fluid communication with the first negative pressure generator. The air suction pipe 11 extends along the axial processing direction of the laser cladding nozzle 101. The air inlet end is arranged at the front side of the laser cladding nozzle 101 in the direction of travel and maintains a gap of 0.5-1.2mm with the inner wall of the piston cylinder. The rear adsorption assembly 2 includes a second negative pressure generator, an adsorption pipe 21 arranged at the rear side of the laser cladding nozzle 101 in the direction of travel, and an adsorption block 22 sleeved on the outside of the adsorption pipe 21. The adsorption block 22 includes a slag inlet 221 facing the laser cladding nozzle 101, an exhaust gas inlet 222 located at the bottom of the adsorption block 22, and a flow channel system connecting the slag inlet 221 and the exhaust gas inlet 222 with the second negative pressure generator.

[0047] When using the cold welding device 100 to repair the inner surface of a hydraulic piston, the axial motion module 102 is first activated, causing the laser cladding nozzle 101 to move at a constant speed axially along the inner wall of the piston cylinder to perform the repair work. Simultaneously, the composite slag removal system 103 is activated, and the first negative pressure generator begins to operate. Through the suction pipe 11, which is fluidically connected to it, the smoke generated in front of the laser cladding nozzle 101 in the direction of travel is promptly sucked out while maintaining a gap of 0.5-1.2mm between the air inlet and the inner wall of the piston cylinder. At the rear of the laser cladding nozzle 101, the second negative pressure generator operates, using the adsorption tube 21 and the attached adsorption block 22 to collect the splashed slag using the slag inlet 221. The exhaust gas inlet 222 then transports the exhaust gas through the flow channel system to the second negative pressure generator for discharge, thereby continuously and effectively exhausting smoke and slag throughout the entire laser cladding repair process.

[0048] The rational design of the front dynamic suction unit 1 allows the suction pipe 11 to maintain a specific gap with the inner wall of the piston cylinder, which can effectively remove the smoke generated by laser cladding, prevent the oxide particles in the smoke from adhering to the surface to be welded, maintain 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, through its unique adsorption block 22 and flow channel system, can accurately collect and discharge the spattered welding slag, preventing 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. In addition, the adsorption block 22 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 100 at the welding point.

[0049] The interior of the adsorption block 22 is formed with a receiving chamber 223 connected to the welding area through the welding slag inlet 221, an air suction channel 224 connected to the second negative pressure generator, and a flow channel system provided in the receiving chamber 223. Among them, the guide baffle 225 has a tapered guide surface facing the welding slag inlet 221. The receiving chamber 223 inside the adsorption block 22 is connected to the welding area through the welding slag inlet 221, and can effectively collect the flying welding slag. The air suction channel 224 is connected to the second negative pressure generator, which can quickly discharge the exhaust gas and keep the air in the piston cylinder fresh. At the same time, it can form a negative pressure in the receiving chamber 223, thereby changing the gas flow direction at the welding slag inlet and reducing the probability of the welding slag rebounding out of the receiving chamber 223. The guide baffle 225 with a tapered guide surface in the accommodating cavity 223 can play a good guiding role for the incoming welding slag, so that the welding slag enters the accommodating cavity 223 in an orderly manner along the guide surface, avoiding the welding slag from rebounding disorderly in the cavity or scattering everywhere, thereby more efficiently collecting the welding slag, further improving the device's ability to handle the welding slag generated during the welding process, and effectively ensuring the quality of the laser cladding repair of the inner wall of the piston cylinder.

[0050] Reference Figure 5The composite slag removal system 103 also includes an airflow coordination control module, which monitors the pressure difference between the front dynamic 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 that a directional airflow is formed from the front dynamic suction unit 1 to the rear adsorption component 2 at the laser cladding nozzle 101. As an embodiment, the flow rate of the directional airflow is preferably 0.5-1m / s. This flow rate range can not only effectively drive the smoke and welding slag generated during the laser cladding process, so that it flows smoothly from the front dynamic suction unit 1 to the rear adsorption component 2, ensuring the slag removal efficiency, but also will not interfere with the normal operation of the laser cladding nozzle 101 due to excessive flow rate, thereby ensuring the stability of laser cladding. The appropriate flow rate also helps to maintain the stability of the airflow in the piston cylinder, avoids the disordered dispersion of smoke and welding slag in the cylinder due to airflow turbulence, thereby creating a more favorable environment for the repair of the inner wall of the piston cylinder and improving the repair quality.

[0051] The addition of the airflow coordination control module further improves the performance of the cold welding device 100. By using a pressure sensor to monitor the pressure difference between the front dynamic suction unit 1 and the rear adsorption component 2 in real time and dynamically adjusting the power of the two negative pressure generators, a directional airflow can be accurately formed from the front dynamic suction unit 1 to the rear adsorption component 2. This design can effectively guide the smoke and welding slag generated during the laser cladding process, so that it moves along the direction of the airflow and is more efficiently processed by the front suction and rear adsorption components 2. The directional airflow not only enhances the slag removal effect and reduces the residual 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.

[0052] As an embodiment, 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 located at the air inlet of the suction pipe 11, the laser cladding nozzle 101, and the inlet 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 collaborative 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.

[0053] The suction pipe 11 is a retractable bellows structure, and its front end is provided with an annular suction hood 12 that expands radially 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 expanding 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 repair quality of the inner wall of the piston cylinder.

[0054] Reference Figure 6 and Figure 7 The composite slag removal system 103 also includes a cleaning component 3 arranged on the side of the adsorption block 22 away from the laser cladding nozzle 101 for cleaning the welding slag attached to the inner surface of the hydraulic piston. The adsorption block 22 is provided with an air vent 226 facing the cleaning component 3 and connecting the accommodating cavity 223 and the internal space of the hydraulic piston.

[0055] Cleaning assembly 3 effectively removes welding slag adhering to the inner surface of the hydraulic piston, preventing its long-term accumulation from affecting piston performance. Vent 226 connects chamber 223 with the piston's interior, allowing waste gas and small particles of welding slag generated during the cleaning process to be drawn away by the second negative pressure generator through the flow channel system of adsorption block 22. This further enhances slag removal capabilities, maintains the cleanliness of the piston cylinder, and provides more favorable conditions for hydraulic piston surface repair, helping to improve repair quality and overall piston performance.

[0056] The cleaning assembly 3 includes a rotating source 31 and a rotating roller 32, wherein the rotating roller 32 is rotatably connected to the side of the adsorption block 22 facing away from the laser cladding nozzle 101, and can be rotated and contacted with the inner surface of the hydraulic piston under the drive of the rotating source 31. The rotating source 31 drives the rotating roller 32 to rotate, and the surface of the rotating roller 32 abuts the inner surface of the hydraulic piston. This design brings significant results. The rotating rotating roller 32 can continuously clean the inner surface of the piston, effectively removing attached welding slag and preventing welding slag accumulation from affecting the normal operation of the piston. During the rotation process, the dynamic contact with the inner surface of the piston ensures comprehensive and uniform cleaning, leaving no welding slag residue. At the same time, in conjunction with the vent 226 on the adsorption block 22, the cleaned welding slag can be discharged in time through the composite slag removal system 103, further improving the cleanliness of the interior of the piston cylinder, effectively ensuring the smooth progress of the hydraulic piston surface repair work and the long-term stable operation of the piston.

[0057] The composite slag removal system 103 also includes an ultrasonic vibrator installed on the outside of 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 on the outside of the focusing lens group of the laser cladding nozzle 101 in the composite slag removal 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 substrate better, and enhances the wettability and bonding between the two. The breakage 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, a good cladding effect also reduces the surface roughness, thereby 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.

[0058] The cold welding device for repairing the surface of a hydraulic piston according to an embodiment of the present invention operates as follows: First, the hydraulic piston is stably clamped to the lathe spindle using the three-jaw chuck of the axial motion module 102. The axial motion assembly is then activated to move the laser cladding nozzle 101 at a uniform speed along the piston axis for cladding repair. Simultaneously, the composite slag removal system 103 is activated. The suction pipe 11 of the front dynamic suction unit 1 (which utilizes a retractable bellows structure with a radially expanding annular suction hood 12 at the front, maintaining a 0.5-1.2mm gap with the inner wall of the piston cylinder) efficiently draws smoke from the front of the laser cladding nozzle 101 via a first negative pressure generator. The rear suction assembly 2 collects spattering slag and rear smoke via the slag inlet 221 of the suction block 22. The airflow coordination control module monitors the pressure difference in real time through three groups of piezoelectric dynamic pressure sensors (response frequency ≥ 1kHz, error ±0.5Pa) arranged at the air inlet of the suction pipe 11, the laser cladding nozzle 101 and the inlet of the adsorption tube 21, dynamically adjusts the power of the first and second negative pressure generators, and forms a directional airflow of 0.5-1m / s from the front dynamic suction unit 1 to the rear adsorption component 2, thereby improving slag removal efficiency and reducing residue.

[0059] In the description of the present invention, it should be understood that the terms "vertical", "horizontal", etc. indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are 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 cannot be understood as a limitation on the present invention.

Claims

1. A cold welding device for repairing the surface of a hydraulic piston, comprising a laser cladding nozzle, an axial motion module and a composite slag removal system, characterized in that: The composite slag discharge system includes: A front dynamic suction unit includes a first negative pressure generator and a suction pipe in fluid communication with the first negative pressure generator. The suction pipe extends along the axial processing direction of the laser cladding nozzle. The air inlet end is arranged at the front side of the laser cladding nozzle in the direction of travel and maintains a gap of 0.5-1.2 mm with the inner wall of the piston cylinder. The rear adsorption assembly includes 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; the adsorption block has: a slag inlet facing the laser cladding nozzle, an exhaust gas inlet located at the bottom of the adsorption block, and a flow channel system connecting the slag inlet and the exhaust gas inlet with the second negative pressure generator; The adsorption block is internally formed with: a receiving cavity connected to the welding area through the welding slag inlet; an air suction channel connected to the second negative pressure generator; and a guide baffle provided in the receiving cavity, which has a tapered guide surface facing the welding slag inlet; The composite slag removal system also includes an airflow coordination control module and a cleaning component arranged on the side of the adsorption block away from the laser cladding nozzle for cleaning the welding slag attached to the inner surface of the hydraulic piston; The airflow coordination control module 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 to form a directional airflow from the front dynamic suction unit to the rear adsorption component at the laser cladding nozzle; The adsorption block is provided with a vent facing the cleaning component and communicating with the accommodating cavity and the inner space of the hydraulic piston; The cleaning component includes: a rotating 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 rotating source, and the surface of the rotating roller abuts the inner surface of the hydraulic piston.

2. The cold welding device according to claim 1, characterized in that: 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 located at the air inlet of the suction pipe, the laser cladding nozzle and the inlet of the adsorption tube.

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

4. The cold welding device according to claim 2, characterized in that: The flow rate of the directional airflow is 0.5-1 m / s.

5. The cold welding device according to any one of claims 1 to 4, characterized in that: The axial motion module includes a hydraulic piston fixing assembly and a laser cladding nozzle driving assembly.

6. The cold welding device according to any one of claims 1 to 4, characterized in that: The composite slag removal system further comprises 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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