Method for machining a cam in an unwinding machine

Abstract

The application discloses a processing method of a cam in an uncoiler, two cams are spliced together and blanked and forged, after once marking, rough machining, UT flaw detection, quenching and tempering treatment, semi-finish machining and twice marking, the workpiece is cut into two cams through wire cutting, and after stress relief, finish machining, clamp sequence, nitriding treatment and final inspection processes, the processing of the cam is completed. The method has the characteristics that the inclined surface tooth shapes of the two cams can be spliced together to form a cuboid forging material, the two cams are forged at the same time, the generation of waste material is reduced, the material utilization rate is improved, the machining efficiency is improved, and the processing cost of the cam is reduced.

Description

Technical Field

[0001] This invention belongs to the technical field of mechanical equipment manufacturing methods, and relates to a method for processing a wedge in an uncoiling machine. Background Technology

[0002] Uncoilers are essential auxiliary equipment on the main rolling mill line, primarily used to wind extra-long steel strips into coils for production, transportation, and storage. The drum surface in the uncoiler directly contacts the strip and bears the load, making it an extremely important component. In recent years, the expansion and contraction drums of coilers used in cold-rolled strip steel workshops have mostly adopted a four-sided pyramid structure due to its high spindle strength and relatively simple structure, making it widely used in high-tension coilers. However, in coilers or uncoilers with small diameters, low tension, and a large expansion and contraction range requirements, there is a trend towards using four-wedge type drums instead of four-sided pyramid drums. Wedges, being irregularly shaped workpieces with inclined surfaces, are more difficult to manufacture. Summary of the Invention

[0003] The purpose of this invention is to provide a method for processing wedges in an unwinding machine. This method processes two wedges simultaneously, thereby improving material utilization and processing efficiency.

[0004] The technical solution adopted in this invention is a processing method for wedges in an uncoiling machine. During forging, two wedges are joined together for forging. After one scribing, rough machining, UT flaw detection, heat treatment, semi-finishing, and a second scribing, the workpiece is cut into two wedges by wire cutting. After stress relief, finishing, clamping, nitriding, and final inspection, the processing of the wedges is completed.

[0005] The invention is further characterized by:

[0006] The dimensions of the blank material during forging are: the dimensions of the cuboid formed by splicing the inclined surfaces of two wedges together according to the tooth shape, with an allowance of more than 10mm on each side.

[0007] The roughing process is as follows: first, rough mill the two end faces, leaving a margin of 7mm to 8mm on each face in the total length direction; then, rough plan the faces in the length direction on a planer, leaving a margin of 7mm to 8mm on each face, with a roughness of ≤6.3.

[0008] Tempering and quenching processes include quenching and tempering;

[0009] The quenching process is as follows: heat to 350℃, hold for 1 to 3 hours, then heat to 640℃ to 660℃ at a heating rate of ≤70℃ / h, hold for 2 to 2.5 hours, then heat to 840℃ to 860℃ at a heating rate of ≤80℃ / h, hold for 1.5 to 2 hours, then oil cool to 200℃ to 250℃, and remove from oil.

[0010] The tempering process is as follows: heat to 350℃, hold for 1h to 3h, then heat to 540℃ to 560℃ at a heating rate of ≤70℃ / h, hold for 3h to 3.5h, then furnace cool to 350℃, and finally air cool after removal from the furnace.

[0011] Semi-finished to leave a 3mm allowance on each side.

[0012] The secondary scribing is performed by scribing and cutting the machining lines according to the sawtooth shape of the wedge's inclined surface, leaving a 3mm allowance on each side of the inclined surface.

[0013] The specific process for stress relief is as follows: the workpiece is placed in an aging furnace, heated to 530℃~550℃, held for 4~6 hours, cooled in the furnace to below 300℃, and then air-cooled. After stress relief, the flatness of the workpiece is required to be less than 1.5mm.

[0014] The finishing process is as follows: finish milling the two sides of the thickness, leaving a margin of 0.5mm to 0.6mm on each side, with a roughness of 6.3. Then, grind the thickness of multiple parts on the same side until they meet the drawing requirements. During the grinding process, turn the parts over multiple times and remove the margin evenly on each side. Then, finish mill the two ends of the length on the same side until they meet the drawing requirements. Finally, finish mill all the machined surfaces on the same side until they meet the drawing requirements.

[0015] The specific process of nitriding is as follows: ammonia gas is introduced at 520℃ and kept at that temperature for 40h to 60h. After the furnace is cooled to below 200℃, the furnace is removed and air-cooled. After nitriding, the perpendicularity of the plane is required to be ≤0.01mm and the parallelism is required to be ≤0.05mm.

[0016] The beneficial effects of this invention are:

[0017] This invention involves simultaneously forging two wedges. After rough machining, tempering, and semi-finishing, the semi-finished material is cut into two wedges using wire cutting. Following stress relief, finishing, and nitriding, the finished wedges are obtained. This method utilizes the characteristic that the beveled teeth of the two wedges can be joined together to form a rectangular forging. Simultaneous forging of two wedges reduces waste, improves material utilization, increases machining efficiency, and lowers the processing cost of the wedges. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the workpiece wedge processed by the method of the present invention;

[0019] Figure 2 This is a side view of the workpiece wedge processed by the method of the present invention;

[0020] Figure 3 This is a schematic diagram of the structure after two wedges are spliced ​​together in the method of the present invention;

[0021] Figure 4 This is a schematic diagram of the cutting process line in the secondary scribing and wire cutting process of the method of the present invention. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0023] The present invention discloses a method for processing a wedge in an uncoiling machine, comprising the following steps: forging, primary scribing, rough machining, UT flaw detection, heat treatment, semi-finishing, secondary scribing, wire cutting, stress relief, finish machining, clamping, nitriding, and final inspection. The specific processes for each step are as follows:

[0024] (1) Blank forging

[0025] The structure of the wedge in the unwinding machine is as follows: Figure 1 and Figure 2 As shown, this part is forged from 42CrMo alloy steel, and its forging and quality acceptance are carried out according to the JB / T5000.8-2007 technical standard. Due to the part's irregular structure, the beveled surface is difficult to forge. Existing forging methods involve single-piece forging, where each piece is first forged into a rectangular steel block, and then the beveled surface is forged. This method suffers from low blank utilization, large processing workload, and low economic efficiency. The present invention combines two beveled wedges (one male and one female) together for forging, that is, splicing the beveled portions of the two wedges together to form a rectangular steel block, and then forging them together. Figure 3 The image shows the structure after two wedges are joined together in a toothed pattern. The blank material has a allowance of more than 10mm on each side to ensure sufficient machining allowance.

[0026] (2) One line drawing

[0027] Check whether the shape and size of the blank conform to the drawings and processing requirements, and determine the position and processing allowance of each processing surface of the workpiece.

[0028] (3) Rough processing

[0029] First, rough mill both ends, ensuring a margin of 7mm to 8mm on each side along the total length. Then, use a planer to rough plan each side along the length, again leaving a margin of 7mm to 8mm on each side, achieving a surface roughness of 6.3. Rough machining both parts together results in a simple blank structure, lower machining difficulty, and cost savings from planer machining.

[0030] (4) UT flaw detection

[0031] Ultrasonic testing shall be performed according to the drawings, and a testing report shall be issued. The next process shall proceed only after the test is passed. Ultrasonic testing shall be conducted according to JB / T5000.12-2007 Class II acceptance standards, and a report shall be issued. Its main function is to quickly, conveniently, non-destructively, and accurately detect, locate, evaluate, and diagnose various internal defects (such as cracks, porosity, air holes, inclusions, etc.) in workpieces.

[0032] (5) Conditioning

[0033] Tempering and quenching processes include quenching and tempering.

[0034] The quenching process is as follows: heat to 350℃, hold for 1h to 3h, then heat to 640℃ to 660℃ at a heating rate of ≤70℃ / h, hold for 2h to 2.5h, then heat to 840℃ to 860℃ at a heating rate of ≤80℃ / h, hold for 1.5h to 2h, then oil cool to 200℃ to 250℃, and then remove from the oil.

[0035] The tempering process is as follows: heat to 350℃, hold for 1h to 3h, then heat to 540℃ to 560℃ at a heating rate of ≤70℃ / h, hold for 3h to 3.5h, then furnace cool to 350℃, and finally air cool after removal from the furnace.

[0036] (6) Semi-finishing

[0037] After tempering, semi-finishing is carried out, with a 3mm allowance left on each side.

[0038] (7) Secondary line drawing

[0039] According to the shape of the wedge saw teeth, scribing and cutting the machining lines, such as... Figure 4 The dashed line indicates the cutting line, ensuring a 3mm allowance on each side of the workpiece's bevel.

[0040] (8) Wire EDM

[0041] Following the marking process described above, wire EDM cuts the workpiece in two, resulting in two rough-machined wedge-shaped workpieces. Wire EDM offers high cutting speed and precision, and is convenient for machining irregularly shaped parts.

[0042] (9) Stress relief treatment

[0043] The workpiece is placed in a heat treatment furnace for heat treatment to gradually relieve stress. The workpiece is loaded into the furnace, heated to 530℃~550℃, held for 4~6 hours, and then cooled in the furnace to below 300℃ before being air-cooled. After stress relief, it is inspected on a platform. Figure 1 If the flatness of the two sides A and B of the wedge shown is greater than 1.5mm, heat treatment should be performed first to straighten it so that the flatness is less than 1.5mm before proceeding to the next process.

[0044] (10) Finishing

[0045] Finish mill both sides of the thickness, leaving an allowance of 0.5mm to 0.6mm on each side, achieving a surface roughness of 6.3. Then, grind multiple parts on the same thickness surface until they meet the drawing requirements, ensuring consistent thickness dimensions. During the grinding process, turn the parts over multiple times, removing allowance evenly on each side. Next, finish mill both ends of the length until they meet the drawing requirements, and then finish mill all machined surfaces until they meet the drawing requirements.

[0046] Note: such as Figure 1 , Figure 2 As shown, with the thickness A reference surface as the mounting reference, finish mill the B surface, with the B surface as the mounting reference and the A surface as the alignment reference, finish mill the inclined surfaces and related surfaces to meet the drawing requirements. When finishing milling each inclined surface, return the reference dimension from one end face in the length direction, strictly control the dimensions of each position, and ensure that the dimensions of each wedge are consistent.

[0047] (11) Clamping sequence

[0048] Perform the cleaning of burrs, rough edges, and blunting operations, and grind the inclined wedges with related parts to ensure uniform contact and a contact fit greater than 80%, and mark them.

[0049] (12) Nitriding treatment

[0050] Ammonia gas is introduced at 520℃ and held for 40-60 hours. After furnace cooling to below 200℃, the parts are removed and air-cooled. The hardness of the nitrided parts is between 600-650 HV5, with a depth of 0.4-0.6 mm, meeting the workpiece's technical requirements. After nitriding, the flatness and hardness are checked, requiring perpendicularity of the AB surfaces to be ≤0.01 mm and parallelism to be ≤0.05 mm. As the final process, nitriding requires strict control of deformation because the workpiece has already undergone finishing; therefore, the requirements for deformation during nitriding are relatively high.

[0051] (13) Final inspection

[0052] Check the workpiece dimensions, roughness, hardness, and various shapes and dimensions.

[0053] Example 1

[0054] The dimensions of the wedges to be processed in this embodiment are 1500×80×80mm. Two wedges are forged together. The dimensions of the blank are 1600×180×100mm, and the dimensions after rough machining are 1570×170×90mm. After passing UT flaw detection, they undergo quenching and tempering treatment. The quenching process is as follows: heat to 350℃, hold for 2 hours, then heat to 650℃ at a rate of 70℃ / h, hold for 2 hours, then heat to 850℃ at a rate of 80℃ / h, hold for 2 hours, then oil cool to 200℃~250℃, and remove from the oil. The tempering process is as follows: heat to 350℃, hold for 2 hours, then heat to 550℃ at a rate of 70℃ / h, hold for 3.5 hours, then furnace cool to 350℃, and finally air cool. After semi-finishing and secondary scribing, wire cutting is performed to divide the workpiece in two, creating two wedges, each with a 3mm allowance on the bevel surface. The workpieces are then placed in an aging furnace, heated to 540℃, held for 5 hours, and then furnace-cooled to below 300℃ before air cooling. Finishing is then performed until each surface meets the drawing requirements. After clamping, nitriding is performed using the following process: ammonia gas is introduced at 520℃, held for 40 hours, and then furnace-cooled to below 200℃ before air cooling. After nitriding, the workpiece dimensions, roughness, hardness, and all geometric dimensions are checked. The hardness is 630HV5, the perpendicularity of surfaces A and B is 0.01mm, the parallelism is 0.05mm, the roughness is 3.2, and the dimensions meet the drawing requirements.

[0055] As can be seen from this embodiment, the method of the present invention can be used to prepare wedge workpieces that meet the requirements, and the method of the present invention can complete the processing of two wedges at one time, saving time, materials and labor.

[0056] Example 2

[0057] In this embodiment, the processing method of the wedge in the uncoiling machine involves forging two wedges together, cutting them into two pieces, and then performing a scribing, roughing, UT inspection, heat treatment, semi-finishing, and a second scribing. The workpiece is then cut into two wedges by wire cutting. After stress relief, finishing, clamping, nitriding, and final inspection, the processing of the wedges is completed.

[0058] Example 3

[0059] Based on Example 2, the dimensions of the blank material during forging are: the dimensions of the cuboid formed by splicing the inclined surfaces of two wedges together in a toothed shape, with an allowance of more than 10mm on each side.

[0060] The roughing process is as follows: first, rough mill the two end faces, leaving a margin of 7mm to 8mm on each face in the total length direction; then, rough plan the faces in the length direction on a planer, leaving a margin of 7mm to 8mm on each face, with a roughness of ≤6.3.

Claims

1. A method for processing a wedge in an unwinding machine, characterized in that, During forging, two wedges are joined together and forged. After scribing, rough machining, UT flaw detection, quenching and tempering, semi-finishing and scribing, the workpiece is cut into two wedges by wire cutting. After stress relief, finishing, clamping, nitriding and final inspection, the wedge processing is completed. The dimensions of the blank material during forging are: the dimensions of the cuboid formed by splicing the inclined surfaces of two wedges together according to the tooth shape, with an allowance of more than 10mm on each side; The roughing process is as follows: first, rough mill the two end faces, leaving a margin of 7mm~8mm on each face in the total length direction; then, rough plan the faces in the length direction on a planer, leaving a margin of 7mm~8mm on each face, with a roughness of ≤6.

3. Tempering and quenching processes include quenching and tempering; The quenching process is as follows: heat to 350℃, hold for 1h~3h, then heat to 640℃~660℃ at a heating rate of ≤70℃ / h, hold for 2h~2.5h, then heat to 840℃~860℃ at a heating rate of ≤80℃ / h, hold for 1.5h~2h, then oil cool to 200℃~250℃, and remove from oil. The tempering process is as follows: heat to 350℃, hold for 1h~3h, then heat to 540℃~560℃ at a heating rate of ≤70℃ / h, hold for 3h~3.5h, then furnace cool to 350℃, and then air cool after being taken out of the furnace. Semi-finished to leave a 3mm allowance on each side; The second scribing is to scribing and cutting the machining lines according to the sawtooth shape of the wedge's inclined surface, leaving a 3mm allowance on each side of the inclined surface; The specific process for stress relief is as follows: the workpiece is placed in an aging furnace, heated to 530℃~550℃, held for 4~6 hours, cooled in the furnace to below 300℃, and then air-cooled. After stress relief, the flatness of the workpiece is required to be less than 1.5mm. The finishing process is as follows: finish milling the two sides of the thickness, leaving a margin of 0.5mm~0.6mm on each side, with a roughness of 6.

3. Then, grind the thickness of multiple parts on the same side until they meet the drawing requirements. During the grinding process, turn the parts over multiple times and remove the margin evenly on each side. Then, finish mill the two ends of the length on the same side until they meet the drawing requirements. Finally, finish mill all the machined surfaces on the same side until they meet the drawing requirements. The specific process of nitriding is as follows: ammonia gas is introduced at 520℃ and kept at that temperature for 40h~60h. After the furnace is cooled to below 200℃, the furnace is removed and air-cooled. After nitriding, the perpendicularity of the plane is required to be ≤0.01mm and the parallelism is required to be ≤0.05mm.

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