Corrosion-resistant manufacturing method for secondary cylinder of super-large hydraulic support column

Abstract

The present invention provides a corrosion-resistant manufacturing method for a secondary cylinder of a super-large hydraulic support column, including blanking, upsetting, flattening the two end faces of the cylinder and the outer chamfers of the two ends of the cylinder, rough boring the inner hole, scraping and rolling the inner hole of the cylinder, turning the size of the sealing groove before copper melting, cladding the sealing groove with copper alloy, rough turning the sealing groove after cladding the copper alloy, turning the outer circle of the chrome-plated area of ​​the cylinder, turning the cylinder port thread, the sealing surface, the flat end face, turning the groove and the cylinder bottom matching surface, welding the cylinder and the cylinder bottom, obtaining the secondary cylinder, turning the end face of the plunger end, rough turning the outer circle close to the cylinder tail end, turning the plunger end sealing groove and the guide ring groove to the required size of the drawing, and fine turning the outer circle of the dynamic sealing area. The method can improve the corrosion resistance of the sealing groove of the secondary cylinder, shorten the process flow and processing time, and reduce the processing cost.

Description

Technical Field

[0001] The invention relates to the field of hydraulic supports, in particular to a corrosion-resistant manufacturing method for a secondary cylinder of a super-large hydraulic support column. Background Art

[0002] Hydraulic cylinders such as columns and jacks are widely used in the fields of coal mine hydraulic supports. Hydraulic supports are important supporting equipment for underground coal mining. Among them, columns and jacks are the power sources of hydraulic supports. Their reliability and stability will determine the reliability and service life of hydraulic supports. The corrosion of the sealing groove in the plunger area of ​​the traditional hydraulic support column is one of the reasons for the failure of the middle cylinder.

[0003] In order to solve the rust problem, electroplating or copper melting process is usually adopted. For example, the plunger of the hydraulic support column is usually electroplated with copper-tin alloy to improve the corrosion resistance. However, this process has the risk of thin electroplating thickness, low bonding strength, and easy plating shedding during use. In addition, in the production and manufacturing of super-large columns such as columns with an inner hole diameter greater than 500mm and a length greater than 2 meters, due to the limitation of the size of the electroplating equipment itself, the plunger of the cylinder of the super-large column cannot be electroplated. The copper melting technology refers to the technology of directly welding the copper alloy on the surface of the parent material and achieving the required size and roughness through processing. It has the advantages of high bonding force, good corrosion resistance, low dilution rate, and no limitation on the size of equipment and workpieces, which can significantly improve the reliability of the workpiece. However, there is currently no forming processing technology for the secondary cylinder body of the hydraulic support column using the sealing groove copper melting process. That is, the conventional processing steps of the existing hydraulic support column secondary cylinder body are to weld the middle cylinder barrel and the middle cylinder bottom, flatten the two end faces of the cylinder barrel, and determine the size of the sealing groove based on the cylinder bottom end face and process it. Since the inner hole has been processed to the size of the drawing at this time, if the copper melting process is performed directly after the sealing groove is processed according to the processing flow, the heat input caused by the full copper melting process will cause the inner hole to shrink, resulting in a low yield rate, and rework will further cause the inner hole to shrink and deform.

[0004] For example, the invention patent with the authorization announcement number CN113070638B discloses a method for processing the cylinder barrel of a highly corrosion-resistant hydraulic cylinder, which includes the following steps: (a) turning the two end surfaces of the cylinder barrel and the outer chamfers at both ends of the cylinder barrel; (b) boring and scraping the inner hole of the cylinder barrel, assuming that the target cylinder barrel inner hole diameter is Φd1, boring the inner hole diameter within a certain range of the cylinder tail end to no more than Φ(d1-0.5) mm as the non-melting copper zone, assuming that the length of the non-melting copper zone is h, and scraping and rolling the inner hole diameter of the remaining part to Φ(d1+1) mm as the melting copper zone; (c) turning the frame sockets and external cylindrical chucks at both ends of the cylinder barrel, and turning the front cylinder mouth of the melting copper; (d) cladding the melting copper zone in the inner hole of the cylinder barrel with copper alloy, and retaining the non-melting copper zone; (e) turning guide holes at both ends of the cylinder barrel respectively, and repairing the outer chamfers at both ends of the cylinder barrel; (f) scraping and rolling the inner hole of the cylinder barrel to the drawing size; (g) welding the cylinder barrel and the cylinder bottom. The processing method of the high corrosion-resistant hydraulic cylinder barrel has the advantages of scientific design, stronger corrosion resistance of the cylinder barrel inner hole, short production process and high cylinder body yield. However, this method only performs copper melting corrosion resistance treatment on the cylinder barrel inner hole, and the process cannot be directly applied to copper melting in the sealing groove. Summary of the invention

[0005] In order to improve the corrosion resistance of the secondary cylinder sealing groove, shorten the process flow and processing time, and reduce the processing cost, the technical solution adopted by the present invention is: a corrosion-resistant manufacturing method for the secondary cylinder of a super-large hydraulic support column, comprising the following steps:

[0006] (a) After the seamless steel pipe is cut and upset, the inner hole of the cylinder is used as the reference to flatten the two end surfaces of the cylinder and chamfer the two ends of the cylinder at 30°, and the inner hole of the top is roughly bored with 30° chamfers at both ends;

[0007] (b) The cylinder barrel after rough boring is subjected to a quenching and aging heat treatment process to give the cylinder barrel good mechanical properties and reduce residual stress;

[0008] (c) Support the inner holes at both ends, flatten the two end surfaces of the cylinder and repair the 30° chamfers at both ends of the cylinder, and roughly bore the inner holes of the cylinder with 30° chamfers at both ends of the top;

[0009] (d) Chamfer the outer edges of the two ends of the top cylinder, scrape the inner hole of the cylinder, set the target inner hole diameter of the cylinder to ΦD1mm, and scrape the inner hole of the cylinder to the size required by the process;

[0010] (e) The inner holes at both ends of the support are machined to the dimensions of the sealing groove before copper melting;

[0011] (f) Sealing groove cladding copper alloy;

[0012] (g) Support the inner holes at both ends and rough-machine the sealing groove to ensure that the distance between the center of the sealing groove and the left end surface of the cylinder is L1;

[0013] (h) Support the inner holes at both ends, set the target diameter of the outer circle dynamic sealing area of ​​the cylinder barrel to ΦD5mm, turn the outer circle of the dynamic sealing area of ​​the cylinder, turn the process frame sockets and clamps at the left and right ends of the cylinder barrel, and the outer circle of the frame sockets and clamps dynamic sealing areas is Φ(D5+5)mm. After turning, the center frame is close to the groove end frame socket, and the cylinder port thread and sealing surface are turned according to the process requirements;

[0014] (i) With the socket and the clamp as the reference, clamp the clamp close to the cylinder mouth, use the center stand to stand the socket at the bevel end, measure the distance between the center of the seal groove and the cylinder tail, flatten the end surface, ensure that the distance between the center of the seal groove and the cylinder tail end is L1 (+0.3mm, 0), ensure that the total length of the cylinder is L4+10mm, and turn the bevel and cylinder bottom matching surfaces to the process requirements;

[0015] (j) welding the cylinder barrel and the cylinder bottom to obtain a secondary cylinder body;

[0016] (k) Clamp the dynamic seal area of ​​the cylinder mouth, set up the center frame, and machine the end face of the plunger to ensure the total length L2 of the bottom valve hole on the end face of the plunger. Roughly machine the outer circle of the dynamic seal area near the cylinder tail end, clamp the dynamic seal area near the cylinder mouth, push the cylinder mouth, and machine the plunger end seal groove and guide ring groove to the process requirements.

[0017] (l) The soft claw clamps the dynamic seal area close to the cylinder tail end, the cylinder mouth, and precision-machines the dimensions of the outer circle of the dynamic seal area.

[0018] Based on the above, the thickness of the copper alloy cladding in the sealing groove is 0.3 mm to 3 mm.

[0019] Based on the above, in order to facilitate copper melting operation and improve bonding strength, slopes are provided on both side walls of the sealing groove, and the angle between the slope and the vertical line is 0 to 45 degrees. Sealing groove root arcs are provided on both sides of the bottom of the sealing groove.

[0020] Based on the above, CNC variable pressure low temperature cold melting equipment and aluminum bronze alloy welding wire are used to clad copper alloy in the sealing groove.

[0021] Based on the above, the material of the cylinder barrel is 27SiMn, 30CrMnSi or S890.

[0022] Based on the above, in step (e), a three-jaw self-centering chuck is used to support the inner holes at both ends of the secondary cylinder, and the dimensions of the cylinder sealing groove before copper melting are respectively turned. The distance between the center of the sealing groove and the groove end is the drawing dimension L1mm, the rough-cut sealing groove width is the drawing width L3+4mm, the groove depth is the drawing dimension D4-2 mm, the sealing groove groove is opened from the bottom of the groove to the top of the groove, and the arc of the root of the sealing groove is turned at the root of the groove bottom.

[0023] Based on the above, the step (f) specifically includes moving the welding gun under the action of the robotic arm; setting a working stroke, melting copper on the bottom and walls of the sealing groove, and filling the bottom of the sealing groove with a single layer. After the bottom of the sealing groove is filled, under the action of the robotic arm, multi-layer single-pass copper melting is performed on the walls of the sealing groove along both sides, and copper alloy is only deposited on the bottom of the entire sealing groove and the walls on both sides of the sealing groove.

[0024] Based on the above, the step (l) also includes plating the outer circle of the secondary cylinder with milky white chrome + hard chrome, copper + hard chrome or melting stainless steel powder, and copper plating or melting copper on the inner hole of the secondary cylinder. The relevant dimensions are matched and adjusted according to the selection of the surface treatment process.

[0025] Specifically, in the process of rough turning the sealing groove, the present invention measures the distance between the center of the sealing groove and the cylinder tail by placing a card near the outer circle of the cylinder mouth end and a rack near the rack nest at the cylinder tail end, and flattens the end surface to ensure the distance between the center of the sealing groove and the cylinder tail end, and determines the position of the sealing groove in advance during the processing of the cylinder barrel, and performs copper melting treatment. After copper melting in the sealing groove, the sealing groove is rough turned with the center of the sealing groove as a reference, and in the process of fine turning the plunger end of the secondary cylinder body, the plunger end surface is flattened with the center of the sealing groove as a reference to ensure the size required by the drawing, and the dimensions of the guide ring groove and other parts are machined with the center of the rough turning sealing groove as a reference.

[0026] The present invention has outstanding substantive features and significant progress compared to the prior art. Specifically, the corrosion-resistant manufacturing method of the secondary cylinder of the super-large hydraulic support column provided by the present invention determines the process sequence of copper melting in the sealing groove of the secondary cylinder, determines the processing dimensions before and after melting, melts copper on the secondary cylinder and roughly turns the sealing groove, and then finely turns the sealing groove after the cylinder welding process is completed, which has the following advantages:

[0027] The present invention arranges the copper melting process of the sealing groove before the thread and sealing surface of the cylinder port, beveling and welding process of the secondary cylinder body, thereby reducing the impact on the size of the inner hole of the cylinder body after fine processing when melting copper in the sealing groove. In addition, the copper melting of the sealing groove does not make the entire sealing groove fully melted, but adopts the method of bottoming and vertical multi-layer surfacing on both sides, thereby reducing the impact of heat input in the copper melting process on the size of the cylinder after fine processing, and improving the precision of the fine processing size of the cylinder and the product quality.

[0028] After copper is melted in the sealing groove, the sealing groove is roughly turned with the center of the sealing groove as the reference. In the process of fine turning the plunger end of the secondary cylinder body, the center of the sealing groove is used as the reference to level the plunger end face, thereby ensuring the size of the workpiece.

[0029] At the same time, the present invention makes the copper melting process before the cylinder barrel finishing process by rough-turning the sealing groove on the cylinder barrel, and takes the center of the rough-turned sealing groove as a reference to turn the dimensions of the sealing groove, the guide ring groove and other parts, thereby avoiding the traditional method of flattening the plunger end face on the secondary cylinder body and then determining the dimensions of the sealing groove and the guide ring groove based on the plunger end face, and further improving the precision of the finishing dimensions.

[0030] This method also avoids the traditional method of using the cylinder bottom end face to position the sealing groove after welding of the two-stage cylinder body, and the influence of melting copper on the inner hole finishing size on the two-stage cylinder body. It reduces the sealing groove before melting the cylinder body and the honing process on the two-stage cylinder body after melting copper. The overall processing reduces two processes, saving 150 minutes of processing time for each piece, shortening the process flow by 16%, and improving processing efficiency by 20%.

[0031] Therefore, the corrosion-resistant manufacturing method of the secondary cylinder of the super-large hydraulic support column provided by the present invention can improve the corrosion resistance of the secondary cylinder sealing groove, simplify the existing production process, shorten the process and processing time, and reduce processing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The present invention provides a schematic diagram of the structure of a secondary cylinder body produced by the corrosion-resistant manufacturing method of the secondary cylinder body of a super-large hydraulic support column.

[0033] Figure 2 The present invention provides a schematic diagram of the structure of a secondary cylinder barrel sealing groove before copper melting, which is manufactured by the corrosion-resistant manufacturing method of the secondary cylinder body of a super-large hydraulic support column provided by the present invention.

[0034] Figure 3 The present invention provides a schematic diagram of the secondary cylinder structure of the lathe process frame nest and the clamping head in the corrosion-resistant manufacturing method of the secondary cylinder body of the super-large hydraulic support column.

[0035] Figure 4 The present invention provides a schematic diagram of the structure of a secondary cylinder barrel produced by the corrosion-resistant manufacturing method of the secondary cylinder body of a super-large hydraulic support column.

[0036] Figure 5 and Figure 6 It is a schematic diagram of the sealing groove structure in the corrosion-resistant manufacturing method of the secondary cylinder body of the super-large hydraulic support column provided by the present invention.

[0037] In the figure: 1. Sealing groove; 2. Step; 3. Guide ring groove; 4. Secondary cylinder; 5. Dynamic sealing area; 6. Cylinder mouth thread; 7. Weld groove; 8. Inner hole; 9. Step hole outside cylinder mouth; 10. Step hole inside cylinder mouth; 11. Frame nest; 12. Chuck; 13. Processing reserved area; 14. Bottom valve hole; 15. Cylinder bottom; 16. Weld; 17. Sealing groove groove; 18. Arc at the root of sealing groove. DETAILED DESCRIPTION

[0038] The technical solution of the present invention is further described in detail below through specific implementation methods.

[0039] Example 1

[0040] This embodiment provides a corrosion-resistant manufacturing method for a secondary cylinder of a super-large hydraulic support column, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the processing method is illustrated by taking a two-stage cylinder body with an inner hole diameter ΦD1 = 460mm and a length of 3200mm as the target product.

[0041] In the finished product, L1=154.5mm, L2=38.5mm, L3=35mm, L4=3201mm, ΦD4=590mm, ΦD5=590mm.

[0042] The processing method is carried out according to the following steps:

[0043] Cutting: The raw material is S890 cylinder 1, and the flat ends of the cylinder are chamfered 30° to ensure the cylinder processing allowance.

[0044] Upsetting: After upsetting, the diameter of the upsetting end is Φ642mm, the length of the upsetting end is 318mm, and the total length of the live part L4 after upsetting is (3201+10)mm.

[0045] Flat end face: Turn the inner holes 8 at both end faces to ensure that the total length L4 of the secondary cylinder 4 is 3207mm, turn 4×30° chamfers at both ends, and the outer circle of the left end of the tool inspection is Φ638mm and 10mm long.

[0046] Rough boring: Clamp with 30° chamfers at both ends, rough bore the inner hole to Φ450mm, and remove burrs at both ends.

[0047] Heat treatment: pit gas furnace quenching, quenching temperature 920℃, water cooling, pit gas furnace tempering, tempering temperature 580℃, water cooling, quenching and tempering are completed, at this time the cylinder surface hardness is HBW260-300. Quenching and tempering hardness is generally HBW260-300.

[0048] Second leveling and chamfering: Use a three-jaw self-centering chuck to support the inner holes at both ends of the cylinder, respectively level the two end surfaces, and repair the 30° chamfers at both ends to ensure that the total length L4 of the secondary cylinder is 3205mm.

[0049] Rough boring: Clamp with 30° chamfers at both ends, bore the inner hole, and rough bore the inner hole to ΦD1=455mm. Remove burrs at both ends.

[0050] Three chamfers: Use a three-jaw self-centering chuck to support the inner holes at both ends of the cylinder, flatten the two end surfaces by 0.5mm respectively, and make the total length L4 3201+3mm. Repair the 30° chamfers at both ends and flatten the outer circles of the two end surfaces.

[0051] Scrape and roll: Clamp with 30° chamfers at both ends, scrape and roll the inner hole, scrape and roll the inner hole to ΦD1=460H8, and the roughness is required to be 0.4.

[0052] Turning the outer circle: the inner holes at both ends of the soft claw support are 480mm, the outer circle near the tail end of the cylinder is turned to Φ634±0.5, and the sharp edges are dried to R0.3.

[0053] Roughly turn the sealing groove: soft claws support the inner holes at both ends, flatten the left end surface to make the total length L4 3202mm, turn the sealing groove ΦD4 to 587mm × L3 to 39mm, and pay attention to ensure that the dimension L1 is 154.5+0.3mm.

[0054] Seal the trough with molten copper.

[0055] The inner holes of Φ460 at both ends of the soft claw support are roughly turned into the sealing groove with the center of the sealing groove as the reference. L3 is made into 33mm and the diameter ΦD4 is made into Φ593mm. Check whether there are air holes on the side and bottom of the sealing groove, and repair it until it is qualified.

[0056] Honing inner hole to Φ460H8 requirement as per drawing.

[0057] Set up the center frame near the cylinder mouth, remove the tailstock chuck, and machine the cylinder mouth thread, sealing surface, and chamfer.

[0058] A narrow gap annular welder is used, with a current of 200A to 240A and a voltage of 22V to 26V for base welding, and a current of 240A to 280A and a voltage of 25V to 29V for filling and cover welding to weld the secondary cylinder barrel and the cylinder bottom to obtain a secondary cylinder body.

[0059] Clamp the outer circle of the secondary cylinder body near the cylinder mouth, set up the center frame, turn the plunger end, ensure that L2 is 38.5mm in size, roughly turn the outer circle near the cylinder tail end, clamp the outer circle near the cylinder mouth, push the cylinder mouth, and turn all dimensions of the plunger end;

[0060] The soft claw clamp is close to the outer circle of the cylinder tail end, the cylinder mouth, and the size of each part of the outer circle welding area is ΦD5 590mm;

[0061] Grind the outer circle and polish it after grinding.

[0062] Specifically, in order to facilitate the clamping and processing, the processing steps after the sealing groove is molten copper are as follows: Figure 3As shown, it specifically includes: the inner holes at both ends of the support, the rough machining of the sealing groove after the copper alloy is clad, and the distance between the center of the sealing groove and the groove at the end face of the cylinder barrel is ensured; the inner holes at both ends of the support, the target cylinder barrel outer circle dynamic sealing area diameter, the outer circle of the cylinder chrome plating area, the frame nests 11 and the clamping head 12 at the left and right ends of the cylinder barrel are set. The processing reserved area 13 is between the frame nest 11 and the clamping head 12. After the frame nest is machined, the center frame is close to the frame nest at the groove end, and the cylinder mouth thread and sealing surface are machined according to the drawing. With the frame nest and the clamping head as the reference, the clamping head at the right end and the frame nest at the groove end of the center frame are clamped, and the distance between the center of the sealing groove and the cylinder tail is measured, and the end face is flat, and the groove and the matching surface of the cylinder bottom are machined. Welding the cylinder barrel and the cylinder bottom to obtain the secondary cylinder body. It can be seen that the corrosion-resistant manufacturing method for the secondary cylinder body of the super-large hydraulic support column provided by the present invention determines the processing dimensions before and after melting, and after melting copper on the secondary cylinder barrel and rough machining of the sealing groove, the sealing groove is finely machined after the cylinder body welding process is completed.

[0063] That is, the present invention arranges the copper melting process of the sealing groove before the process of turning the cylinder port thread and sealing surface, turning the groove and welding of the secondary cylinder, so that when the copper is melted in the sealing groove, the size of the inner hole of the cylinder body after fine processing will not be affected. Moreover, the copper melting of the sealing groove does not make the entire sealing groove fully melted, but adopts the method of base welding and vertical multi-layer surfacing on both sides, thereby reducing the influence of heat input in the copper melting process on the size of the finely processed cylinder, and improving the precision of the fine processing size of the cylinder and the product quality.

[0064] At the same time, the present invention makes the copper melting process before the cylinder barrel finishing process by rough-turning the sealing groove on the cylinder barrel, and takes the center of the rough-turned sealing groove as a reference to turn the dimensions of the sealing groove, the guide ring groove and other parts, thereby avoiding the traditional method of flattening the plunger end face on the secondary cylinder body and then determining the dimensions of the sealing groove and the guide ring groove based on the plunger end face, and further improving the precision of the finishing dimensions.

[0065] This method avoids the traditional method of positioning the sealing groove on the cylinder bottom end face after welding of the two-stage cylinder body, and the influence of melting copper on the inner hole finishing size on the two-stage cylinder barrel. It reduces the sealing groove before melting the cylinder body and the honing process on the two-stage cylinder body after melting copper. The overall processing reduces two processes, saves 150 minutes of processing time for each piece, shortens the process flow by 16%, and improves the processing efficiency by 20%.

[0066] Example 2

[0067] The present embodiment provides a method for melting copper in a secondary cylinder sealing groove of a super-large hydraulic support column, and the specific steps include: the welding gun moves under the action of a robotic arm, and a working stroke is set to melt copper on the bottom and the wall of the sealing groove. The bottom of the sealing groove is filled with a single layer of melting copper. After the bottom of the sealing groove is filled, under the action of the robotic arm, the sealing groove wall is melted with multiple layers of single copper along both sides. Only the bottom of the entire sealing groove and the groove walls on both sides of the sealing groove are melted with copper alloy.

[0068] Example 3

[0069] This embodiment provides a super-large hydraulic support column secondary cylinder body made by the corrosion-resistant manufacturing method described in Example 1. The specific finished product structure is as follows Figure 1 , Figure 5 and Figure 6 It includes a sealing groove 1, a step 2, a guide ring groove 3, a secondary cylinder 4, a dynamic sealing area 5, a cylinder port thread 6, a weld groove 7, an inner hole 8, a cylinder port outer step hole 9, a cylinder port inner step hole 10, a bottom valve hole 14, a cylinder bottom 15, a weld 16, a sealing groove groove 17, and a sealing groove root arc 18.

[0070] The cylinder bottom 15 is welded to the left side of the secondary cylinder barrel 4, and a bottom valve hole 14 is provided at the center of the cylinder bottom 15. A weld groove 7 is provided at the left end of the secondary cylinder barrel 4, and a weld 16 is formed in the weld groove 7.

[0071] The left outer circle of the secondary cylinder 4 is provided with a step 2. The step is provided with a guide ring groove 3 and a sealing groove 1. The top of the sealing groove 1 is provided with sealing groove grooves 17 on both sides, and the root of the sealing groove 1 is provided with sealing groove root arcs 18 on both sides. The inside of the sealing groove 1 is clad with a copper alloy layer.

[0072] The outer circle of the right side of the secondary cylinder barrel 4 forms a dynamic sealing area 5. An inner hole 8 is provided inside the secondary cylinder barrel 4, and the right end of the inner hole 8 is respectively provided with a cylinder port outer step hole 9 and a cylinder port inner step hole 10. A cylinder port thread 6 is provided on the inner wall of the cylinder port inner step hole 10.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A corrosion-resistant manufacturing method for a secondary cylinder of a super-large hydraulic support column, comprising the following steps: (a) After the seamless steel pipe is cut and upset, the inner hole of the cylinder is used as the reference to flatten the two end surfaces of the cylinder and chamfer the outer ends of the cylinder, and the outer chamfers of the two ends of the top are roughly bored; (b) Performing quenching and aging heat treatment on the cylinder barrel after rough boring of the inner hole; (c) Support the inner holes at both ends, flatten the two end surfaces of the cylinder and repair the outer chamfers at both ends of the cylinder, top the outer chamfers at both ends and rough bore the inner hole of the cylinder again; (d) Chamfer the outer corners of the top cylinder and scrape the inner hole of the cylinder. Set the target inner hole diameter of the cylinder to ΦD1mm, and scrape the inner hole of the cylinder to the required size; (e) The inner holes at both ends of the support and the dimensions of the sealing groove before copper melting; (f) Sealing groove cladding with copper alloy; (g) Support the inner holes at both ends and rough-machine the sealing groove after copper alloy cladding to ensure that the distance between the center of the sealing groove and the left end surface of the cylinder is L1; (h) Support the inner holes at both ends, set the target diameter of the outer circle dynamic sealing area of ​​the cylinder barrel to ΦD5mm, turn the outer circle of the dynamic sealing area of ​​the cylinder in the middle, turn the process frame nests and clamps at the left and right ends of the cylinder barrel, and process the outer circle of the dynamic sealing area at the frame nests and clamps into Φ (D5+5) mm, turn the rear center frame, and the frame nest near the groove end, and turn the cylinder port thread and sealing surface according to the process requirements; (i) With the socket and the clamp as the reference, clamp the clamp close to the cylinder mouth, use the center stand to stand the socket at the bevel end, measure the distance between the center of the seal groove and the cylinder tail, flatten the end surface, ensure that the distance between the center of the seal groove and the cylinder tail end is L1 (+0.3mm, 0), ensure that the total length of the cylinder is L4+10 mm, and turn the bevel and cylinder bottom mating surfaces to the process requirements; (j) welding the cylinder barrel and the cylinder bottom to obtain a secondary cylinder body; (k) Clamp the dynamic seal area of ​​the cylinder mouth, set up the center frame, turn the end face of the plunger to ensure the total length L2 of the bottom valve hole on the end face of the plunger, roughly turn the outer circle of the dynamic seal area near the cylinder tail end, clamp the dynamic seal area near the cylinder mouth, push the cylinder mouth, and turn the plunger end seal groove and guide ring groove to the process requirements; (l) The soft claw clamps the dynamic seal area near the rear end of the cylinder, presses the cylinder mouth, and fine-turns the dimensions of the outer circle of the dynamic seal area.

2. The corrosion-resistant manufacturing method for the secondary cylinder of the super-large hydraulic support column according to claim 1 is characterized in that: The thickness of the copper alloy cladding in the sealing groove is 0.3 mm to 3 mm.

3. The corrosion-resistant manufacturing method for the secondary cylinder of the super-large hydraulic support column according to claim 2 is characterized in that: Slopes are provided on both side walls of the sealing groove, and the angle between the slope and the vertical line is 0 to 45 degrees. Sealing groove root arcs are provided on both sides of the bottom of the sealing groove.

4. The corrosion-resistant manufacturing method for the secondary cylinder of the super-large hydraulic support column according to claim 1, 2 or 3, characterized in that: Aluminum bronze alloy welding wire is used to clad the copper alloy in the sealing groove.

5. The corrosion-resistant manufacturing method for the secondary cylinder of the super-large hydraulic support column according to claim 1, 2 or 3, characterized in that: The material of the cylinder is 27SiMn, 30CrMnSi or S890.

6. The corrosion-resistant manufacturing method for the secondary cylinder of the super-large hydraulic support column according to claim 1 is characterized in that: In the step (e), a three-jaw self-centering chuck is used to support the inner holes at both ends of the cylinder barrel, and the dimensions of the cylinder barrel sealing groove before copper melting are respectively machined. The distance between the center of the sealing groove and the groove end is the drawing dimension L1 mm. The width of the rough-cut sealing groove is the drawing width L3+4 mm, and the groove depth is the drawing dimension D4-2 mm. A sealing groove groove is opened from the bottom of the groove to the top of the groove, and the arc of the root of the sealing groove is machined at the root of the groove bottom.

7. The corrosion-resistant manufacturing method for the secondary cylinder of a super-large hydraulic support column according to claim 1, 2 or 6, characterized in that: The step (f) specifically includes moving the welding gun under the action of the robot arm, setting the working stroke, melting copper on the bottom and the wall of the sealing groove, and filling the bottom of the sealing groove with a single layer. After the bottom of the sealing groove is filled, under the action of the robot arm, melting copper on the wall of the sealing groove in multiple layers and in a single pass along both sides, and only the bottom of the entire sealing groove and the groove walls on both sides of the sealing groove are fused with copper alloy.

8. The corrosion-resistant manufacturing method for the secondary cylinder of the super-large hydraulic support column according to claim 7 is characterized in that: After step (1), the outer circle of the secondary cylinder is plated with milky white chrome + hard chrome, copper + hard chrome, or stainless steel powder is melted, and the inner hole of the secondary cylinder is copper plated or melted.

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