Method for processing an elongated spring rod

Abstract

The application discloses a processing method of an elongated spring rod, and specific steps are as follows: ① blanking: preparing blanks and blanking according to the size of each part in the elongated spring rod; ② semi-finishing: semi-finishing the blank of each part to meet the assembly requirement; ③ assembly welding: assembling each part according to the drawing requirement and adopting laser deep penetration welding to perform assembly welding; ④ finishing: finishing the spring rod assembly; ⑤ quenching: performing laser surface quenching on the middle part of the spring rod assembly; and ⑥ final inspection: performing inspection on the spring rod assembly according to the drawing requirement. The application makes the deformation of the elongated spring rod small, shortens the processing period and reduces the production cost. Meanwhile, the application prolongs the service life, improves the processing efficiency and greatly improves the qualified rate of finished products.

Description

Technical Field

[0001] This invention relates to the field of spring bar processing, and particularly to a method for processing slender spring bars. Background Technology

[0002] The slender spring rod on the finishing mill shaft is welded from components of different materials, featuring a large length-to-diameter ratio and thin walls. Its middle section contacts the spring and undergoes sliding friction. Simultaneously, the slender spring rod requires stable movement, high shape and position tolerances, and wear-resistant outer surface of the shaft diameter, making its manufacturing process highly challenging. The existing manufacturing method for this slender spring rod is: blank—rough machining—assembly welding—annealing—semi-finish machining—quenching—correction—finish machining—final inspection. The disadvantages of this method are: 1. Assembly welding uses gas shielded welding, and quenching uses a pit-type heat treatment furnace. Gas shielded welding, preheating before welding, post-weld annealing, and overall furnace quenching of the semi-finished product all affect the deformation of the parts. Therefore, the overall deformation of the assembly is large, meaning the machining allowance for removing the deformation is large. Simultaneously, rough machining, annealing, and correction processes are needed to remove the deformation. The large machining allowance and long processes significantly extend the processing cycle, increase production costs, reduce processing efficiency, and greatly decrease the finished product qualification rate. 2. Welding between existing parts requires specially designed beveling, such as... Figure 3 As shown, welds are prone to defects such as porosity, cracks, and inclusions. Summary of the Invention

[0003] The problem this invention aims to solve is to provide a method for processing slender spring rods, which minimizes overall deformation, shortens the processing cycle, and reduces production costs. Simultaneously, it extends service life, improves processing efficiency, and significantly increases the yield rate of finished products.

[0004] The specific steps of the processing method for the slender spring rod of the present invention are as follows:

[0005] ① Blanking: Prepare blanks and cut them according to the dimensions of each part in the slender spring rod;

[0006] ② Semi-finishing: The blanks of each part are semi-finished to meet the assembly requirements;

[0007] ③ Assembly welding: Assemble the parts according to the drawing requirements and use laser deep penetration welding for assembly welding;

[0008] ④ Finishing: Perform finishing on the spring rod assembly;

[0009] ⑤ Quenching: Laser surface quenching is performed on the intermediate parts of the spring rod assembly;

[0010] ⑥ Final inspection: Inspect the spring rod assembly according to the drawing requirements.

[0011] The specific steps of step ③ assembly welding are as follows: Ⅰ. Clean and wash each part to remove surface impurities and oil stains from the weld joints; Ⅱ. Adjacent parts are assembled radially with small gaps and straight edges, and their end faces are in contact. The assembled components are mounted on a double-top clamping rotary table to ensure coaxial assembly; Ⅲ. Fiber laser welding is used with an output power of 6KW, a welding defocusing amount of -2mm, a welding speed of 1.5m / min-2.0m / min, and an inert gas atmosphere for protection.

[0012] In step III, the inert gas is a mixture of helium, nitrogen, and argon in a ratio of 1:10:20.

[0013] In step ③, the weld bead after group welding is a straight butt weld bead with a weld width of 1mm and a welding depth of 8mm.

[0014] The specific steps of step ⑤ quenching are as follows: the circumferential surface of the sliding motion section (i.e. the middle part) of the spring rod assembly is quenched using a semiconductor laser with an output power of 3KW, a surface quenching speed of 1.0m / min, and a surface quenching layer depth of 0.7-0.9mm.

[0015] In step ⑤, the surface hardness of the quenched layer of the sliding motion section of the spring rod assembly is HRC55-60.

[0016] The advantages of the processing method for the slender spring rod of this invention are as follows: 1. The components of the slender spring rod are welded together by laser deep penetration welding to form an assembly, and the sliding motion section of the spring rod assembly is quenched by a semiconductor laser, resulting in high processing energy density, a small heat field, fast processing speed, small heat-affected zone, and minimal heat deformation; 2. The tensile strength of the laser deep penetration weld area is superior to that of the original base material, while the deformation of the parts is minimal; 3. The surface hardness of the sliding motion section of the spring rod assembly is HRC55-60, which improves the working stability and service life of the slender spring rod in the overall equipment, while minimizing assembly deformation; 4. The overall deformation of the assembly is minimal, meaning that the machining allowance of the parts reserved to remove deformation is reduced. Therefore, the original processing steps such as rough machining, annealing, and correction are eliminated, shortening the processing cycle, reducing production costs, improving processing efficiency, and significantly increasing the finished product qualification rate. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the slender spring rod obtained by the processing method of the present invention;

[0018] Figure 2 This is a schematic diagram of the weld bead of the present invention;

[0019] Figure 3 This is a schematic diagram of the welding bevel in the existing method for making slender spring rods. Detailed Implementation

[0020] The method for the slender spring rod of the present invention will be described in further detail below.

[0021] Example 1

[0022] The processing method of the slender spring rod of the present invention is as follows:

[0023] ① Blanking: Prepare blanks and cut them according to the dimensions of each part in the slender spring rod;

[0024] ② Semi-finishing: The blanks of each part are semi-finished to meet the assembly requirements;

[0025] ③ Assembly welding: Assemble the parts according to the drawing requirements and use laser deep penetration welding for assembly welding;

[0026] ④ Finishing: Perform finishing on the spring rod assembly;

[0027] ⑤ Quenching: Laser surface quenching is performed on the intermediate parts of the spring rod assembly;

[0028] ⑥ Final inspection: Inspect the spring rod assembly according to the drawing requirements.

[0029] The slender spring rod of this invention is welded into components using laser deep penetration welding (e.g.) Figure 1 As shown, the sliding motion section of the spring rod assembly is laser surface hardened, which has high processing energy density, small heat range, fast processing speed, small heat-affected zone, and small deformation. Therefore, the machining allowance of the parts to be removed due to deformation is reduced, the processing cycle is shortened, the production cost is reduced, the processing efficiency is improved, and the finished product qualification rate is increased.

[0030] Example 2

[0031] The processing method of the slender spring rod of the present invention: The specific steps of step ③ assembly welding are as follows:

[0032] Ⅰ. Clean and wash each part to remove surface impurities and oil stains from the weld joints;

[0033] II. Adjacent parts are assembled radially with small gaps and straight edges, and their end faces are in contact. The assembled components are mounted on a double-top clamping rotary table to ensure that the components are assembled coaxially.

[0034] III. Fiber laser welding is used, with an output power of 6KW, a welding defocusing amount of -2mm, a welding speed of 1.5m / min-2.0m / min, and an inert gas atmosphere for protection.

[0035] When the slender spring rod of this invention is assembled and welded, the end faces of adjacent parts are in direct contact during assembly. The two adjacent end faces are directly fused into a whole by laser deep penetration welding, avoiding defects such as porosity, cracks, and inclusions in existing welds. Therefore, the tensile strength of the welded area is better than that of the original base material, and the deformation of the parts is smaller.

[0036] Example 3

[0037] The processing method of the slender spring rod of the present invention: In step III: the inert gas is a mixture of helium, nitrogen and argon, and the gas ratio is 1:10:20.

[0038] The setting and specific proportion of the mixed gas in step III can better ensure the quality of welding.

[0039] Example 4

[0040] The processing method of the slender spring rod of this invention: Step ③ The weld bead after assembly welding is a straight butt weld bead with a weld width of 1mm and a welding depth of 8mm, as shown below. Figure 2 As shown.

[0041] The width and depth of the weld bead can ensure the reliability of the welding between adjacent parts.

[0042] Example 5

[0043] The processing method of the slender spring rod of the present invention: The specific steps of step ⑤ quenching are as follows: the circumferential surface of the sliding motion section (i.e. the middle part) of the spring rod assembly is quenched with a semiconductor laser with an output power of 3KW, a surface quenching speed of 1.0m / min, and a surface quenching layer depth of 0.7-0.9mm.

[0044] After the circumferential surface of the sliding section of the spring rod assembly is quenched, its surface hardness is HRC55-60, which is sufficient to meet the requirements for sliding friction motion in contact with the spring.

[0045] The advantages of the processing method for the slender spring rod of this invention are: 1. The components of the slender spring rod are welded together by laser deep penetration welding to form an assembly, and the sliding movement section of the spring rod assembly is quenched by a semiconductor laser, resulting in high processing energy density, a small heat field, fast processing speed, small heat-affected zone, and minimal heat deformation; 2. Since the end faces of adjacent parts are in direct contact during assembly, laser deep penetration welding directly integrates the adjacent end faces into a single unit, avoiding defects such as porosity, cracks, and inclusions that may exist in the original weld. Therefore, the tensile strength of the weld area is superior to that of the original base material, and the deformation of the parts is minimal; 3. Only the spring rod is affected. The sliding section of the component is strengthened on its outer cylindrical surface through laser surface quenching. The strengthening method is a combination of phase transformation strengthening and fine grain strengthening, which improves the structural strength, mechanical properties, and wear resistance of the spring rod shaft diameter. The surface quenching layer hardness is HRC55-60, which improves the working stability and service life of the slender spring rod in the whole machine. At the same time, the component deformation is small. Fourth, because the overall deformation of the component is small, the machining allowance of the parts reserved to remove the deformation is reduced. Therefore, the original processing steps such as rough machining, annealing, and correction are eliminated, which shortens the processing cycle, reduces production costs, improves processing efficiency, and greatly improves the finished product qualification rate.

Claims

1. The machining method for slender spring rods, specifically the following steps: ① Blanking: Prepare blanks and cut them according to the dimensions of each part in the slender spring rod; ② Semi-finishing: Perform semi-finishing on the blanks of each part to meet assembly requirements; ③ Assembly and welding: Assemble the parts according to the drawings and perform laser deep penetration welding; ④ Finishing: Perform finishing on the spring rod assembly; ⑤ Quenching: Perform laser surface quenching on the intermediate parts of the spring rod assembly; ⑥ Final inspection: Inspect the spring rod assembly according to the drawings; among which, Step ③, the specific steps for assembly welding, are as follows: I. Clean and wash each part to remove surface impurities and oil stains from the weld joints; II. Adjacent parts are assembled radially with small gaps and straight edges, and their end faces are in contact. The assembled components are mounted on a double-top clamping rotary table to ensure coaxial assembly; III. Fiber laser welding is used with an output power of 6KW, a welding defocusing amount of -2mm, a welding speed of 1.5m / min-2.0m / min, and an inert gas atmosphere for protection; the weld bead after assembly welding is a straight butt weld bead with a weld width of 1mm and a welding depth of 8mm; Step ⑤, the specific steps for quenching, are as follows: The circumferential surface of the sliding section of the spring rod assembly, i.e., the middle part, is quenched using a semiconductor laser with an output power of 3KW, a surface quenching speed of 1.0m / min, and a surface quenching layer depth of 0.7-0.9mm.

2. The processing method according to claim 1, characterized in that: step III In the middle: the inert gas is a mixture of helium, nitrogen and argon in a ratio of 1:10:

20.

3. The processing method according to claim 1, characterized in that: Step 5: The surface hardness of the sliding motion section of the spring rod assembly after quenching is HRC55-60.

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