Manufacturing process of a rotor of an asynchronous traction motor with a phosphor copper bar

Abstract

The present invention discloses a manufacturing process for a rotor phosphor bronze bar of an asynchronous traction motor, belonging to the technical field of the preparation of phosphor bronze bars, and comprising: S1. Preparing an up-drawn phosphor bronze rod: preparing an up-drawn continuous casting phosphor bronze rod through an up-drawn continuous casting technology and coiling it to obtain a coiled copper rod; S2. Continuous extrusion: obtaining a phosphor bronze bar profile through a continuous extrusion technology; S3. Cold drawing: feeding the phosphor bronze bar profile obtained in step S2 into a cold drawing machine for cold drawing; S4. Fixed-length sawing: sizing the phosphor bronze bar obtained in step S3 and then sawing off the phosphor bronze bar by means of sawing; S5. Annealing heat treatment: performing annealing heat treatment on the sized copper bar obtained in step S4; S6. Machining: machining the heat-treated bar obtained in step S5; S7. Final product inspection: inspecting the standard phosphor bronze bar obtained in step S6; the present invention has excellent properties of the produced bars, continuous operation, and can achieve large-scale production.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of phosphor copper bars, and specifically relates to a manufacturing process of phosphor copper bars for the rotor of an asynchronous traction motor. Background Art

[0002] In recent years, rail transit has developed rapidly, and AC drive technology has developed rapidly. Asynchronous traction motors are more widely used. Asynchronous motors have the characteristics of simple structure, reliable components, and excellent electromagnetic performance, and are suitable for electric locomotives and EMUs. The rotor of the motor is the core component of the asynchronous traction motor, which converts electrical energy into kinetic energy through electromagnetic action to provide power for the entire locomotive. The rotor bar is an important part of the rotor of the asynchronous traction motor.

[0003] Because of the good electrical conductivity, thermal conductivity and welding performance of phosphor copper, it has become the main material for the bars of rail transit traction motors. Most existing manufacturers use general semi-continuous casting for raw material preparation, with low production efficiency and low material utilization rate; the profiles are obtained through hot extrusion process. Due to the uneven deformation during the hot extrusion process, the mechanical properties and metallographic structure of the manufactured bars have low consistency, and the energy consumption during the production process is large; the surface quality of the profiles after hot extrusion is unstable, with many defects such as surface inclusions, peeling, and extrusion lines, and the treatment process is complex and affects the product quality. In addition, the extrusion tail defect will inevitably occur at the tail of the profiles produced by the hot extrusion method, and this defect can only be minimized through the process and cannot be completely solved.

[0004] The existence of the extrusion tail defect destroys the density and continuity of the material, seriously affecting the performance of the material. Generally, it is detected and removed by visual inspection and ultrasonic flaw detection. However, due to the irregularity and instability of the defect, there are detection blind spots, and there is a risk of non-identification. Moreover, it cannot be pressed during subsequent processing, and there is a certain quality risk for the product, which may cause economic losses to subsequent enterprises. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a manufacturing process of phosphor copper bars for the rotor of an asynchronous traction motor, including the following steps:

[0006] S1. Prepare an up-drawn phosphor copper rod:

[0007] S1-1. Batching:

[0008] Mix an oxygen-free copper rod and a CuP15 master alloy according to the mass percentage of phosphorus element being 0.002 - 0.005% to obtain a mixed metal;

[0009] S1-2. Up-drawn continuous casting:

[0010] Put the mixed metals prepared in step S1-1 into a graphite crucible in an upward continuous casting furnace and heat to melt. The temperature of the molten metal in the upward continuous casting furnace is 1100-1300 °C, and upward continuous casting is carried out through an upward continuous casting crystallizer. The continuous casting speed is 300-500 mm / min to obtain an upward continuous casting phosphorus-containing copper rod.

[0011] S1-3. Coiling:

[0012] Coil the upward continuous casting phosphorus-containing copper rod obtained in step S1-2 through a coiling machine. The coiling diameter used is 1600-2400 mm to obtain a coiled copper rod.

[0013] S2. Continuous extrusion:

[0014] Uncoil the coiled copper rod obtained in step S1-3 through an uncoiling machine, feed the uncoiled copper rod into a continuous extruder for extrusion, cool it through a cooling water tank after extrusion, and wind it on a spool through a take-up machine to obtain a phosphorus-containing copper guide bar profile.

[0015] S3. Cold drawing:

[0016] Feed the phosphorus-containing copper guide bar profile obtained in step S2 into a cold drawing machine for cold drawing, and obtain a phosphorus-containing copper guide bar after cold drawing.

[0017] S4. Cut to length:

[0018] First, cut the phosphorus-containing copper guide bar obtained in step S3 to the specified length according to the guide bar length standard and cross-section standard designed for the traction motor, and then use a sawing processing method to saw off the phosphorus-containing copper guide bar to obtain a cut-to-length copper guide bar part.

[0019] S5. Annealing heat treatment:

[0020] Carry out annealing heat treatment on the cut-to-length copper guide bar part obtained in step S4, and obtain a heat-treated guide bar part after annealing heat treatment.

[0021] S6. Machining:

[0022] Machine the heat-treated guide bar part obtained in step S5 to obtain a standard phosphorus-containing copper guide bar.

[0023] S7: Final inspection:

[0024] Inspect the standard phosphorus-containing copper guide bar obtained in step S6, remove unqualified products, and obtain qualified phosphorus-containing copper guide bars.

[0025] Further, after the mixed metals in the graphite crucible are melted in step S1-2, the molten liquid in the graphite crucible is stirred at a stirring speed of 20-30 r / min for a stirring duration of 30-60 min. After the stirring is completed, upward continuous casting is carried out. The diameter of the upward continuous casting phosphorus-containing copper rod obtained through upward continuous casting is 20-25 mm.

[0026] Explanation: Stirring can make the phosphorus element and copper element in the graphite crucible fully mixed, so that the phosphorus element is more evenly distributed in the molten liquid.

[0027] Further, during the upward continuous casting in step S1-2, a furnace front sample is taken every 2 hours to detect the chemical composition, and samples are taken at the head and tail of the upward continuous casting phosphorus-containing copper rod at the beginning and end of the casting to detect the chemical composition. The chemical composition detection standard is: Cu≥99.95%, Bi≤0.0005%, P: 0.002-0.005%, Pb≤0.005, total impurities≤0.03.

[0028] Explanation: Detecting the chemical composition of the molten liquid and the rod head can make timely adjustments once the chemical composition is found to be incorrect. Detecting the chemical composition of the rod tail can ensure that the entire upward continuous casting phosphorus-containing copper rod meets the process requirements. Making timely adjustments to the upward continuous casting phosphorus-containing copper rod that does not meet the requirements can save unnecessary waste of human and financial resources in the follow-up.

[0029] Further, in step S3, the cold drawing pass is 1-2 times, the cold deformation amount of a single pass of cold drawing is 10%-15%, and the cumulative cold deformation amount is controlled within 15%-35%.

[0030] Explanation: Experiments have shown that when the cumulative cold deformation amount exceeds 35%, the internal structure of the phosphorus-containing copper bar will become uneven, so the cumulative cold deformation amount is controlled within 35%.

[0031] Further, in step S4, the cross-sectional shape of the copper bar sizing part is rectangular, trapezoidal or circular. During the sawing process, coolant cooling is carried out simultaneously to keep the process temperature of the copper bar at 20-25°C.

[0032] Explanation: Cooling with coolant during the sawing process can prevent the copper bar from being affected by the processing temperature rise and affecting the product quality.

[0033] Further, in step S5, the annealing heat treatment process is as follows: First, the heating furnace is heated at a heating rate of 5-10°C / min to 260-330°C, and then heat preservation treatment is carried out. The duration of the heat preservation treatment is 1-2 hours.

[0034] Explanation: Through the above annealing heat treatment, the residual stress of the copper bar sizing part can be reduced, the size can be stabilized, and the tendency of deformation and crack can be reduced; the grains can be refined, the structure can be adjusted, and the structure defects can be eliminated.

[0035] Further, the standard part of the phosphor copper bar obtained after machining in step S6 meets the final dimensional tolerance requirements of the product. During the machining process, coolant is used for cooling to ensure that the process temperature of the bar machining is between 20 - 25 °C.

[0036] Note: Cooling with coolant during the process can prevent the bar from being affected by the temperature rise during machining, thus affecting the product quality.

[0037] Further, the continuous extrusion method in step S2 is as follows: First, preheat the extrusion die at a preheating temperature of 200 - 400 °C. Then, install the preheated extrusion die into the die cavity, start the continuous extruder, and make the extrusion wheel continuously feed the phosphor copper rod into the extrusion cavity. After recrystallization, it is extruded from the extrusion die.

[0038] Note: The above continuous extrusion method can efficiently extrude the copper rod after uncoiling.

[0039] Further, for the heat-treated guide bar condition in step S5, the conductivity of the bar is detected at a sampling frequency of 100%, and the strength and hardness of the bar are detected at a sampling intensity of 1%.

[0040] Note: The guide bars that do not meet the design requirements are directly scrapped. Sampling inspection during the production process can promptly eliminate defective products and discover problems in a timely manner, which is beneficial to improving production efficiency and the qualified rate of products.

[0041] Further, the detection items for the finished product inspection in step S7 include: dimensional tolerance, appearance, chemical composition, conductivity, hardness, strength, elongation.

[0042] Note: The chemical composition of the standard part of the phosphor copper bar can be based on the chemical composition of the up-drawn continuous casting phosphor copper rod in steps S1 - 2. The conductivity and hardness can be based on the detection results after annealing heat treatment in step S5, so as to reduce the inspection efficiency of the finished product inspection.

[0043] Further, the water temperature in the cooling water tank in step S2 is 0 - 26 °C, and the cooling duration is 5 - 10 min.

[0044] Note: Maintaining the water temperature in the cooling water tank can effectively cool the copper rod with high cooling efficiency.

[0045] Further, the coolant is composed of the following components by weight: 2 - 8 parts of propylene carbonate, 10 - 12 parts of 1,3 - propanediol, 5 - 15 parts of tetraethylene glycol, 15 - 18 parts of butanediol, 3 - 5 parts of disodium ethylenediaminetetraacetate, 7 - 14 parts of methyl orthosilicate, 1 - 3 parts of stabilizer, and 50 - 80 parts of water.

[0046] Description: The above-mentioned coolant has good cooling effect and high cooling efficiency, reduces thermal deformation of workpieces and tools, and is beneficial to improving machining accuracy.

[0047] Furthermore, the phosphorus-containing copper conductor obtained in step S7 is further surface treated, and the surface treatment method is: polishing the phosphorus-containing copper conductor, and then placing the polished phosphorus-containing copper conductor in a copper alloy surface treatment agent for treatment for 1-2 hours, wherein the copper alloy surface treatment agent is composed of the following components in parts by weight: 5-8 parts of xanthine, 7-11 parts of sodium carbonate, 3-5 parts of potassium hydroxide, 5-8 parts of ammonium chloride, 1-3 parts of water-soluble mercaptobenzothiazole, 0.5-2 parts of OP active agent, and 60-80 parts of water.

[0048] Note: By further polishing the phosphorus-containing copper conductor bar, removing the barbs on the surface of the phosphorus-containing copper conductor bar, and then treating the phosphorus-containing copper conductor bar with a copper alloy surface treatment agent, the phosphorus-containing copper conductor bar can be effectively prevented from rusting, which facilitates the preservation of the phosphorus-containing copper conductor bar.

[0049] The beneficial effects of the present invention are:

[0050] (1) The present invention adopts continuous casting technology, which breaks through the difficult problem of low casting efficiency of phosphorus-containing copper conductor bars, enables the upward pulling of phosphorus-containing copper rods, realizes continuous production of phosphorus-containing copper conductor bars, improves production efficiency, and improves material utilization. The prepared phosphorus-containing copper conductor bar material has high purity and strong consistency.

[0051] (2) The present invention adopts continuous extrusion technology to obtain the required phosphorus-containing copper conductor bar profile, thereby realizing the continuous production of the phosphorus-containing copper conductor bar profile. The phosphorus-containing copper conductor bar profile prepared by this method has a smooth and bright surface without defects such as inclusions and peeling. The phosphorus-containing copper conductor bar profile will not produce tail shrinkage defects, thus completely solving the internal quality problem of the product.

[0052] (3) The mechanical properties, metallographic structure, material utilization rate, industrialization and other aspects of the phosphorus-containing copper conductor standard parts prepared by the present invention are further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a preparation flow chart of the present invention. DETAILED DESCRIPTION

[0054] Embodiment 1:

[0055] like Figure 1 As shown, a manufacturing process of phosphorus-containing copper bars of an asynchronous traction motor rotor comprises the following steps:

[0056] S1. Preparation of phosphorus-containing copper rod:

[0057] S1-1, Ingredients:

[0058] Mix the oxygen-free copper rod and CuP15 master alloy according to 0.002% by mass of phosphorus element to obtain a mixed metal;

[0059] S1-2. Upward continuous casting:

[0060] Put the mixed metal prepared in step S1-1 into a graphite crucible in an upward continuous casting furnace and heat it to melt. The temperature of the molten metal in the upward continuous casting furnace is 1100 °C. After the mixed metal in the graphite crucible melts, stir the molten solution in the graphite crucible. The stirring speed is 20 r / min, and the stirring duration is 30 min. After stirring, carry out upward continuous casting. The diameter of the upward continuous casting phosphorus-containing copper rod obtained by upward continuous casting is 20-25 mm. Stirring can make the phosphorus element and copper element in the graphite crucible fully mixed, so that the phosphorus element is more evenly distributed in the molten solution. Carry out upward continuous casting through the upward continuous casting mold. The continuous casting speed is 300 mm / min. Take a sample in front of the furnace to detect the chemical composition every 2 hours during upward continuous casting, and take samples at the head and tail of the upward continuous casting phosphorus-containing copper rod to detect the chemical composition at the beginning and end of casting. The chemical composition detection standard is: Cu≥99.95%, Bi≤0.0005%, P: 0.002-0.005%, Pb≤0.005, total impurities≤0.03, to obtain the upward continuous casting phosphorus-containing copper rod. Detect the chemical composition of the molten solution and the rod head. Once the chemical composition is found to be incorrect, adjustments can be made in time. Detect the chemical composition of the rod tail to ensure that the entire upward continuous casting phosphorus-containing copper rod meets the process requirements. Making timely adjustments to the upward continuous casting phosphorus-containing copper rod that does not meet the requirements can save unnecessary waste of manpower and financial resources in the follow-up;

[0061] S1-3. Coiling:

[0062] Coil the upward continuous casting phosphorus-containing copper rod obtained in step S1-2 through a coiling machine. The coiling diameter used is 1600 mm to obtain a coiled copper rod;

[0063] S2. Continuous extrusion:

[0064] Unroll the coiled copper rod obtained in steps S1 - 3 using an uncoiler, and feed the unrolled copper rod into a continuous extrusion machine for extrusion. The continuous extrusion method is as follows: First, preheat the extrusion die. The preheating temperature is 200°C. Then, install the preheated extrusion die into the die cavity, start the continuous extrusion machine, and let the extrusion wheel continuously feed the phosphor - containing copper rod into the extrusion cavity. After recrystallization, it is extruded from the extrusion die. Through the above - mentioned continuous extrusion method, the unrolled copper rod can be efficiently extruded. After extrusion, it is cooled in a cooling water tank. The water temperature in the cooling water tank is 0°C, and the cooling duration is 5 minutes. After cooling, it is wound up on an I - beam reel by a coiling machine to obtain a phosphor - containing copper guide bar profile. For the heat - treated guide bars after annealing treatment, the conductivity of the guide bars is detected at a sampling frequency of 100%, and the strength and hardness of the guide bars are detected at a sampling intensity of 1%. The guide bars that do not meet the design requirements are directly scrapped. Sampling during the production process can promptly eliminate defective products and discover problems in a timely manner, which is beneficial to improving production efficiency and the qualified rate of products;

[0065] S3. Cold drawing:

[0066] Feed the phosphor - containing copper guide bar profile obtained in step S2 into a cold drawing machine for cold drawing. The number of cold drawing passes is 1 time, the cold deformation amount in a single - pass cold drawing is 15%, and the cumulative cold deformation amount is controlled at 15%. Through experiments, it is proved that when the cumulative cold deformation amount exceeds 35%, the internal structure of the phosphor - containing copper guide bar will produce uneven phenomena. Therefore, the cumulative cold deformation amount is controlled within 35%. After cold drawing, a phosphor - containing copper guide bar is obtained;

[0067] S4. Cut to length:

[0068] First, size the phosphor - containing copper guide bar obtained in step S3 according to the guide bar length standard and cross - section standard designed by the traction motor, and then use a sawing processing method to cut the phosphor - containing copper guide bar to obtain a sized copper guide bar part. The cross - section shape of the sized copper guide bar part is rectangular, trapezoidal, or circular. During the sawing processing, coolant cooling is carried out simultaneously to keep the guide bar processing temperature at 20°C. Cooling during the sawing process can prevent the guide bar from being affected by processing temperature rise and affecting product quality;

[0069] S5. Annealing heat treatment:

[0070] Carry out annealing heat treatment on the sized copper guide bar part obtained in step S4. The annealing heat treatment process is as follows: First, heat the heating furnace at a heating rate of 5°C / min to 260°C, and then carry out heat preservation treatment. The heat preservation duration is 1 hour. After the annealing heat treatment, a heat - treated guide bar is obtained; Through the above annealing heat treatment, the residual stress of the sized copper guide bar part can be reduced, the size can be stabilized, and the tendency of deformation and crack can be reduced; The grain can be refined, the structure can be adjusted, and the structure defects can be eliminated;

[0071] S6. Machining:

[0072] The heat treatment guide conditions obtained in step S5 are machined to obtain a standard phosphor bronze conductor bar. The obtained standard phosphor bronze conductor bar meets the final dimensional tolerance requirements of the product. During the machining process, it is cooled with a coolant. The coolant is composed of the following components by weight: 2 parts of propylene carbonate, 10 parts of 1,3-propanediol, 5 parts of tetraethylene glycol, 15 parts of butanediol, 3 parts of disodium ethylenediaminetetraacetate, 7 parts of methyl orthosilicate, 1 part of stabilizer, and 50 parts of water, ensuring that the process temperature for conductor bar machining is 20°C. During the process, it is cooled with the coolant to prevent the conductor bar from affecting the product quality due to temperature rise during machining;

[0073] S7: Final product inspection:

[0074] The standard phosphor bronze conductor bar obtained in step S6 is inspected. The inspection items for final product inspection include: dimensional tolerance, appearance, chemical composition, conductivity, hardness, strength, and elongation. The chemical composition of the standard phosphor bronze conductor bar can be based on the chemical composition of the upward continuous casting phosphor bronze rod in steps S1-2. The conductivity and hardness can be based on the test results after annealing heat treatment in step S5, so as to improve the inspection efficiency of final product inspection, remove unqualified products, and obtain qualified phosphor bronze conductor bars.

[0075] Example 2:

[0076] As Figure 1 shown, a manufacturing process for a phosphor bronze conductor bar of an asynchronous traction motor rotor includes the following steps:

[0077] S1. Prepare an upward continuous casting phosphor bronze rod:

[0078] S1-1. Batching:

[0079] Mix an oxygen-free copper rod and a CuP15 master alloy according to the mass percentage of phosphorus element being 0.003% to obtain a mixed metal;

[0080] S1-2. Upward continuous casting:

[0081] Put the mixed metals prepared in step S1-1 into a graphite crucible in an upward continuous casting furnace and heat to melt. The temperature of the molten metal in the upward continuous casting furnace is 1200 °C. After the mixed metals in the graphite crucible are melted, stir the molten liquid in the graphite crucible. The stirring speed is 25 r / min and the stirring duration is 40 min. After stirring is completed, carry out upward continuous casting. The diameter of the upward continuous casting phosphorus-containing copper rod obtained through upward continuous casting is 23 mm. Stirring can make the phosphorus element and copper element in the graphite crucible fully mixed, and make the phosphorus element more evenly distributed in the molten liquid. Carry out upward continuous casting through the upward continuous casting crystallizer. The continuous casting speed is 400 mm / min. During upward continuous casting, take a sample in front of the furnace to detect the chemical composition every 2 hours, and take samples at the head and tail of the upward continuous casting phosphorus-containing copper rod at the beginning and end of casting to detect the chemical composition. The chemical composition detection standard is: Cu≥99.95%, Bi≤0.0005%, P: 0.002-0.005%, Pb≤0.005, total impurities≤0.03, to obtain the upward continuous casting phosphorus-containing copper rod. Detect the chemical composition of the molten liquid and the rod head. Once the chemical composition is found to be incorrect, adjustments can be made in a timely manner. Detect the chemical composition of the rod tail to ensure that the entire upward continuous casting phosphorus-containing copper rod meets the process requirements. Making timely adjustments to the upward continuous casting phosphorus-containing copper rod that does not meet the requirements can save unnecessary waste of manpower and financial resources in the follow-up;

[0082] S1-3, Coiling:

[0083] Coil the upward continuous casting phosphorus-containing copper rod obtained in step S1-2 through a coiling machine. The coiling diameter used is 2000 mm to obtain a coiled copper rod;

[0084] S2, Continuous Extrusion:

[0085] Uncoil the coiled copper rod obtained in step S1-3 through an uncoiling machine, and feed the uncoiled copper rod into a continuous extruder for extrusion. The continuous extrusion method is as follows: First, preheat the extrusion die. The preheating temperature is 300 °C, then install the preheated extrusion die into the die cavity, start the continuous extruder, and make the extrusion wheel continuously feed the phosphorus-containing copper rod into the extrusion cavity. After recrystallization, it is extruded from the extrusion die. Through the above continuous extrusion method, the uncoiled copper rod can be efficiently extruded. After extrusion, it is cooled through a cooling water tank. The water temperature in the cooling water tank is 10 °C and the cooling duration is 8 min. After cooling, it is wound up on a spool through a take-up machine to obtain a phosphorus-containing copper guide bar profile. The conductivity of the heat-treated guide bar after annealing heat treatment is detected at a 100% sampling frequency, and the strength and hardness of the guide bar are detected at a 1% sampling intensity. The guide bars that do not meet the design requirements are directly scrapped. Sampling during the production process can promptly eliminate defective products and detect problems in a timely manner, which is beneficial to improving production efficiency and product qualification rate;

[0086] S3, Cold Drawing:

[0087] Feed the phosphorus-containing copper bar profiles obtained in step S2 into a cold drawing machine for cold drawing. The number of cold drawing passes is 2, the cold deformation per single pass is 15%, and the cumulative cold deformation is controlled at 30%. Experiments have shown that when the cumulative cold deformation exceeds 35%, the internal structure of the phosphorus-containing copper bar will become uneven. Therefore, the cumulative cold deformation is controlled within 35%. After cold drawing, phosphorus-containing copper bars are obtained.

[0088] S4. Cut to specified length:

[0089] First, size the phosphorus-containing copper bars obtained in step S3 according to the bar length standard and cross-section standard designed for the traction motor, and then use a sawing process to cut the phosphorus-containing copper bars to obtain sized copper bar parts. The cross-sectional shape of the sized copper bar parts is rectangular, trapezoidal, or circular. During the sawing process, coolant cooling is carried out simultaneously to maintain the process temperature of the bar at 23°C. Cooling through the coolant during the sawing process can prevent the bars from being affected by processing temperature rise and thus affect product quality.

[0090] S5. Annealing heat treatment:

[0091] Carry out annealing heat treatment on the sized copper bar parts obtained in step S4. The process of annealing heat treatment is as follows: First, heat the furnace to 300°C at a heating rate of 8°C / min, and then carry out heat preservation treatment for 1.5 hours. After the annealing heat treatment, heat-treated bar parts are obtained. Through the above annealing heat treatment, the residual stress of the sized copper bar parts can be reduced, the size can be stabilized, and the tendency of deformation and cracks can be reduced; the grains can be refined, the structure can be adjusted, and the structural defects can be eliminated.

[0092] S6. Machining:

[0093] Machine the heat-treated bar parts obtained in step S5 to obtain standard parts of phosphorus-containing copper bars that meet the final dimensional tolerance requirements of the product. During the machining process, coolant cooling is used. The coolant is composed of the following components by weight: 5 parts of propylene carbonate, 11 parts of 1,3-propanediol, 13 parts of tetraethylene glycol, 16 parts of butanediol, 4 parts of disodium ethylenediaminetetraacetate, 10 parts of methyl orthosilicate, 2 parts of stabilizer, and 60 parts of water. Ensure that the process temperature during bar machining is 23°C. Cooling through the coolant during the process can prevent the bars from being affected by processing temperature rise and thus affect product quality.

[0094] S7: Final product inspection:

[0095] Inspect the standard phosphorus-containing copper busbar obtained in step S6. The inspection items for finished product inspection include: dimensional tolerance, appearance, chemical composition, conductivity, hardness, strength, elongation. Among them, the chemical composition of the standard phosphorus-containing copper busbar can be based on the chemical composition of the upward continuous casting phosphorus-containing copper rod in step S1-2, and the conductivity and hardness can be based on the test results after annealing heat treatment in step S5, so as to reduce the inspection efficiency of finished product inspection, remove unqualified products, and obtain qualified phosphorus-containing copper busbars.

[0096] Example 3:

[0097] As Figure 1 shown, a manufacturing process for a phosphorus-containing copper busbar of an asynchronous traction motor rotor includes the following steps:

[0098] S1. Prepare an upward continuous casting phosphorus-containing copper rod:

[0099] S1-1. Batching:

[0100] Mix the oxygen-free copper rod and CuP15 master alloy according to the mass percentage of phosphorus element being 0.005% to obtain a mixed metal;

[0101] S1-2. Upward continuous casting:

[0102] Put the mixed metal prepared in step S1-1 into a graphite crucible in an upward continuous casting furnace and heat it to melt. The temperature of the furnace liquid in the upward continuous casting furnace is 1300°C. After the mixed metal in the graphite crucible melts, stir the melt in the graphite crucible. The stirring speed is 30 r / min, and the stirring duration is 60 min. After stirring is completed, perform upward continuous casting. The diameter of the upward continuous casting phosphorus-containing copper rod obtained through upward continuous casting is 25 mm. Stirring can make the phosphorus element and copper element in the graphite crucible fully mixed, so that the phosphorus element is more evenly distributed in the melt. Perform upward continuous casting through the upward continuous casting crystallizer. The continuous casting speed is 500 mm / min. Take a sample in front of the furnace to detect the chemical composition every 2 hours during upward continuous casting, and take samples at the head and tail of the upward continuous casting phosphorus-containing copper rod to detect the chemical composition at the beginning and end of casting. The chemical composition detection standard is: Cu≥99.95%, Bi≤0.0005%, P: 0.002-0.005%, Pb≤0.005, total impurities≤0.03, to obtain the upward continuous casting phosphorus-containing copper rod. Detect the chemical composition of the melt and the rod head. Once the chemical composition is found to be incorrect, adjustments can be made in time. Detect the chemical composition of the rod tail to ensure that the entire upward continuous casting phosphorus-containing copper rod meets the process requirements. Making timely adjustments to the upward continuous casting phosphorus-containing copper rod that does not meet the requirements can save unnecessary waste of manpower and financial resources in the follow-up;

[0103] S1-3. Reeling:

[0104] The up-drawing continuous casting phosphor copper rod obtained in step S1-2 is coiled by a coiling machine, and the coiling diameter used is 2400 mm to obtain a coiled copper rod;

[0105] S2. Continuous extrusion:

[0106] The coiled copper rod obtained in step S1-3 is uncoiled by an uncoiling machine, and the uncoiled copper rod is fed into a continuous extruder for extrusion. The continuous extrusion method is as follows: First, preheat the extrusion die. The preheating temperature is 400 °C. Then, install the preheated extrusion die into the die cavity, start the continuous extruder, and make the extrusion wheel continuously feed the phosphor copper rod into the extrusion cavity. After recrystallization, it is extruded from the extrusion die. Through the above continuous extrusion method, the uncoiled copper rod can be efficiently extruded. After extrusion, it is cooled by a cooling water tank. The water temperature in the cooling water tank is 26 °C, and the cooling time is 10 min. After cooling, it is wound on a spool by a rewinding machine to obtain a phosphor copper guide bar profile. The conductivity of the heat-treated guide bar after annealing heat treatment is detected at a sampling frequency of 100%, and the strength and hardness of the guide bar are detected at a sampling intensity of 1%. The guide bars that do not meet the design requirements are directly scrapped. Sampling during the production process can timely eliminate defective products and discover problems in a timely manner, which is conducive to improving production efficiency and the qualified rate of products;

[0107] S3. Cold drawing:

[0108] The phosphor copper guide bar profile obtained in step S2 is fed into a cold drawing machine for cold drawing. The number of cold drawing passes is 2 times, and the cold deformation amount per single pass of cold drawing is 10%. The cumulative cold deformation amount is controlled at 20%. Through experiments, it is proved that when the cumulative cold deformation amount exceeds 35%, the internal structure of the phosphor copper guide bar will produce uneven phenomena. Therefore, the cumulative cold deformation amount is controlled within 35%. After cold drawing, a phosphor copper guide bar is obtained;

[0109] S4. Fixed-length sawing:

[0110] First, size the phosphor copper guide bar obtained in step S3 according to the guide bar length standard and cross-section standard designed by the traction motor, and then use a sawing processing method to saw off the phosphor copper guide bar to obtain a fixed-length part of the copper guide bar. The cross-section shape of the fixed-length part of the copper guide bar is rectangular, trapezoidal or circular. During the sawing processing, coolant cooling is carried out simultaneously to keep the guide bar processing temperature at 25 °C. Cooling by the coolant during the sawing process can prevent the guide bar from being affected by processing temperature rise and affecting product quality;

[0111] S5. Annealing heat treatment:

[0112] The copper bar sizing parts obtained in step S4 are subjected to annealing heat treatment. The process of annealing heat treatment is as follows: First, the heating furnace is heated to 330°C at a heating rate of 10°C / min, and then heat preservation treatment is carried out. The duration of heat preservation treatment is 2 hours. After the annealing heat treatment is completed, heat-treated bar conditions are obtained; through the above annealing heat treatment, the residual stress of the copper bar sizing parts can be reduced, the size can be stabilized, and the tendency of deformation and cracks can be reduced; the grains can be refined, the structure can be adjusted, and the structure defects can be eliminated;

[0113] S6. Machining:

[0114] The heat-treated bar conditions obtained in step S5 are machined to obtain standard parts of phosphor-containing copper bars. The obtained standard parts of phosphor-containing copper bars meet the requirements of the final dimensional tolerance of the product. During the machining process, coolant cooling is used. The coolant is composed of the following components by weight: 8 parts of propylene carbonate, 12 parts of 1,3-propanediol, 15 parts of tetraethylene glycol, 18 parts of butanediol, 5 parts of disodium ethylenediaminetetraacetate, 14 parts of methyl orthosilicate, 3 parts of stabilizer, and 80 parts of water. Ensure that the process temperature of bar processing is 25°C. During the process, cooling is carried out through the coolant to prevent the bars from affecting the product quality due to processing temperature rise;

[0115] S7: Final product inspection:

[0116] The standard parts of phosphor-containing copper bars obtained in step S6 are inspected. The inspection items for final product inspection include: dimensional tolerance, appearance, chemical composition, conductivity, hardness, strength, and elongation. Among them, the chemical composition of the standard parts of phosphor-containing copper bars can be based on the chemical composition of the up-drawing continuous casting phosphor-containing copper rod in steps S1-2. The conductivity and hardness can be based on the test results after annealing heat treatment in step S5 to reduce the inspection efficiency of final product inspection, remove unqualified products, and obtain qualified phosphor-containing copper bars.

[0117] The final product test results of Example 1 are shown in Tables 1-3:

[0118] Table 1: Dimensional specifications:

[0119]

[0120]

[0121] Table 2: Chemical composition test results %

[0122]

[0123] Table 3. Electrical and mechanical properties

[0124]

[0125] The final product test results of Example 2 are shown in Tables 4-6:

[0126] Table 4. Dimension Specifications:

[0127]

[0128]

[0129] Table 5. Chemical Composition Test Results %

[0130]

[0131] Table 6. Electrical and Mechanical Properties

[0132]

[0133] The finished product test results of Example 3 are shown in Tables 7 - 9:

[0134] Table 7. Dimension Specifications:

[0135]

[0136]

[0137] Table 8. Chemical Composition Test Results %

[0138]

[0139] Table 9. Electrical and Mechanical Properties

[0140]

[0141] By comparing Tables 1, 4, and 7, it can be found that Example 3 has the highest machining accuracy and the smallest error. By comparing Tables 2, 5, and 8, it can be found that Examples 1 - 3 all meet the process standard requirements. By comparing Tables 3, 6, and 9, it can be found that Example 3 has the best performance in all aspects. Therefore, Example 3 is the best example.

[0142] Example 4:

[0143] On the basis of Example 3, in Example 4, the phosphor - copper busbar obtained in step S7 is further subjected to surface treatment. The surface treatment method is as follows: polish the phosphor - copper busbar, and then put the polished phosphor - copper busbar into a copper alloy surface treatment agent for 1 h. The copper alloy surface treatment agent is composed of the following components in parts by weight: 5 parts of xanthine, 7 parts of sodium carbonate, 3 parts of potassium hydroxide, 5 parts of ammonium chloride, 1 part of water - soluble mercaptobenzothiazole, 0.5 part of OP surfactant, and 60 parts of water.

[0144] Example 5:

[0145] On the basis of Example 3, in Example 5, the phosphorus-containing copper busbar obtained in step S7 is further subjected to surface treatment. The method of surface treatment is as follows: The phosphorus-containing copper busbar is polished, and then the polished phosphorus-containing copper busbar is placed in a copper alloy surface treatment agent for 1.5 h. The copper alloy surface treatment agent is composed of the following components in parts by weight: 6 parts of xanthine, 10 parts of sodium carbonate, 4 parts of potassium hydroxide, 6 parts of ammonium chloride, 2 parts of water-soluble mercaptobenzothiazole, 1 part of OP surfactant, and 70 parts of water.

[0146] Example 6:

[0147] On the basis of Example 3, in Example 6, the phosphorus-containing copper busbar obtained in step S7 is further subjected to surface treatment. The method of surface treatment is as follows: The phosphorus-containing copper busbar is polished, and then the polished phosphorus-containing copper busbar is placed in a copper alloy surface treatment agent for 2 h. The copper alloy surface treatment agent is composed of the following components in parts by weight: 8 parts of xanthine, 11 parts of sodium carbonate, 5 parts of potassium hydroxide, 8 parts of ammonium chloride, 3 parts of water-soluble mercaptobenzothiazole, 2 parts of OP surfactant, and 80 parts of water.

[0148] Comparing Comparative Example 4 - Example 6, the effect of further treating the phosphorus-containing copper busbar in Example 6 is the best. Therefore, Example 6 is the best example.

Claims

1. A manufacturing process for a rotor of an asynchronous traction motor with a phosphor-containing copper bar, characterized in that It includes the following steps: S1. Prepare the up-drawing phosphorus-containing copper rod: S1-1. Batching: Mix the oxygen-free copper rod and the CuP15 master alloy according to the mass percentage of phosphorus element being 0.002 - 0.005% to obtain the mixed metal. S1-2. Up-drawing continuous casting: Put the mixed metal proportioned in step S1-1 into the graphite crucible in the up-drawing continuous casting furnace to heat and melt it. The temperature of the molten metal in the up-drawing continuous casting furnace is 1100 - 1300 °C. Conduct up-drawing continuous casting through the up-drawing continuous casting mold, and the continuous casting speed is 300 - 500 mm / min to obtain the up-drawing continuous casting phosphorus-containing copper rod. S1-3. Coiling: Coil the up-drawing continuous casting phosphorus-containing copper rod obtained in step S1-2 through a coiling machine. The coiling diameter used is 1600 - 2400 mm to obtain the coiled copper rod. S2. Continuous extrusion: Uncoil the coiled copper rod obtained in step S1-3 through an uncoiling machine, send the uncoiled copper rod into a continuous extruder for extrusion, cool it through a cooling water tank after extrusion, and wind it on a spool through a winding machine to obtain the phosphorus-containing copper guide bar profile. S3. Cold drawing: Send the phosphorus-containing copper guide bar profile obtained in step S2 into a cold drawing machine for cold drawing, and obtain the phosphorus-containing copper guide bar after cold drawing. S4. Cut to length: First, size the phosphorus-containing copper guide bar obtained in step S3 according to the guide bar length standard and cross-section standard designed by the traction motor, and then saw off the phosphorus-containing copper guide bar by means of sawing to obtain the sized copper guide bar part. S5. Annealing heat treatment: Conduct annealing heat treatment on the sized copper guide bar part obtained in step S4, and obtain the heat-treated guide bar part after annealing heat treatment. S6. Machining: Machine the heat-treated guide bar part obtained in step S5 to obtain the standard part of the phosphorus-containing copper guide bar; the standard part of the phosphorus-containing copper guide bar obtained after machining meets the product's final dimensional tolerance requirements. Cool it with a coolant during the machining process to ensure that the process temperature of the guide bar machining is 20 - 25 °C; the coolant is composed of the following components in parts by weight: 2 - 8 parts of propylene carbonate, 10 - 12 parts of 1,3-propanediol, 5 - 15 parts of tetraethylene glycol, 15 - 18 parts of butanediol, 3 - 5 parts of disodium ethylenediaminetetraacetate, 7 - 14 parts of methyl orthosilicate, 1 - 3 parts of stabilizer, and 50 - 80 parts of water. S7: Final product inspection: Inspect the standard part of the phosphorus-containing copper guide bar obtained in step S6, remove the unqualified products to obtain the qualified phosphorus-containing copper guide bar; further conduct surface treatment on the obtained phosphorus-containing copper guide bar. The method of the surface treatment is: polish the phosphorus-containing copper guide bar, and then put the polished phosphorus-containing copper guide bar into a copper alloy surface treatment agent for 1 - 2 h. The copper alloy surface treatment agent is composed of the following components in parts by weight: 5 - 8 parts of xanthine, 7 - 11 parts of sodium carbonate, 3 - 5 parts of potassium hydroxide, 5 - 8 parts of ammonium chloride, 1 - 3 parts of water-soluble mercaptobenzothiazole, 0.5 - 2 parts of OP surfactant, and 60 - 80 parts of water.

2. The manufacturing process of a rotor of an asynchronous traction motor with a phosphor-containing copper bar, as described in claim 1, is characterized in that, After the molten metal in the graphite crucible melts in step S1-2, stir the melt in the graphite crucible at a stirring speed of 20-30 r / min for 30-60 min. After stirring, perform upward continuous casting. The diameter of the upward continuous casting phosphorus-containing copper rod obtained by upward continuous casting is 20-25 mm.

3. The manufacturing process of a rotor with a phosphorus-containing copper bar for an asynchronous traction motor according to claim 1, characterized in that, The water temperature in the cooling water tank in step S2 is 0-26 °C, and the cooling duration is 5-10 min.

4. The manufacturing process of a rotor of an asynchronous traction motor with a phosphor-containing copper bar, as described in claim 1, is characterized in that, In step S3, the number of cold drawing passes is 1-2 times, the cold deformation amount of a single-pass cold drawing is 10%-15%, and the cumulative cold deformation amount is controlled within 15%-35%.

5. The manufacturing process of a rotor with a phosphor-containing copper bar for an asynchronous traction motor according to claim 1, characterized in that, In step S4, the cross-sectional shape of the copper bar sizing part is rectangular, trapezoidal or circular. During the sawing process, coolant cooling is carried out simultaneously to keep the process temperature of the copper bar at 20-25 °C.

6. The manufacturing process of a rotor of an asynchronous traction motor with a phosphor-containing copper bar, as described in claim 1, is characterized in that In step S5, the annealing heat treatment process is as follows: first, heat the heating furnace at a heating rate of 5-10 °C / min to 260-330 °C, and then perform heat preservation treatment for 1-2 hours.

7. The manufacturing process of a rotor of an asynchronous traction motor with a phosphor-containing copper bar as claimed in claim 1, wherein The continuous extrusion method in step S2 is as follows: first preheat the extrusion die at a preheating temperature of 200-400 °C, then install the preheated extrusion die into the die cavity, start the continuous extruder, and let the extrusion wheel continuously feed the phosphorus-containing copper rod into the extrusion cavity. After recrystallization, it is extruded from the extrusion die.

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