A die-casting process for a small cover plate of a motor end cover

Abstract

The invention discloses a die-casting process for a small cover plate of a motor end cover, comprising the following steps: step one, raw material processing; step two, melting operation; step three, die-casting; step four, flushing the water outlet; step five, removing the burr; step six, pre-processing heat treatment; step seven, shape adjustment; step eight, CNC processing; step nine, cleaning treatment; and step ten, packaging and warehousing. According to the invention, the raw materials are mechanically cleaned and pickled before the aluminum casting is melted, thereby ensuring the raw material purity of the melt, avoiding the generation of bubbles during the melting process, and improving the quality of the prepared product; a modifier is added during the melting process to refine the grains, thereby improving the hardness and corrosion resistance of the prepared product; and a pre-processing heat treatment is performed after the die-casting to optimize the mechanical processing performance of the plate and reduce the process difficulty of the CNC processing. At the same time, the internal stress remaining in the plate is removed through the process of stress relief annealing, thereby preventing the internal stress from causing deformation of the product.

Description

Technical Field

[0001] The invention relates to the technical field of motor end cover preparation, in particular to a die-casting process for a small motor end cover. Background Art

[0002] The motor end cover is the shell at both ends of the motor, used to protect the core components inside the motor. It is usually installed at both ends of the motor and is generally made of metal. Common materials include cast iron, steel plate, aluminum alloy, etc. Some motor end covers are made of non-metallic materials such as plastic and bakelite, but they are relatively rare. The selection of these materials is usually based on factors such as the type of motor, the operating environment and cost. Its primary function is to protect the internal components of the motor from the influence of the external environment, such as dust, moisture, corrosion and physical damage. They can prevent these harmful substances from entering the motor, thereby extending the service life of the motor. At the same time, they also provide support and fixation for the rotor and bearings of the motor, so that the stator and rotor maintain a certain gap and enable them to Stable operation, the existing die-casting process for motor end cover plates can basically meet daily use needs, but there are still certain shortcomings. First, the existing small motor end cover plates are limited by the molten raw materials, which limits the corrosion resistance and physical properties of the cover plates after preparation; second, the preparation process of the existing small motor end cover plates is simple, and there is a lack of raw material processing operations. The oil and impurities remaining on the raw materials can easily produce bubbles or impurities in the molten material, thereby affecting the quality of the prepared product; third, the existing small motor end cover plates lack a heat treatment process in the preparation process to remove the stress accumulated in the plate during the die-casting process, and the product is easily deformed due to stress after preparation; therefore, it is necessary to design a die-casting process for small motor end cover plates. Summary of the Invention

[0003] The object of the present invention is to provide a die-casting process for a small cover plate of a motor end cover, so as to solve the problems raised in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solution: a die-casting process for a small cover plate of a motor end cap, comprising the following steps: step 1, raw material processing; step 2, molten material operation; step 3, die-casting; step 4, flushing the water outlet; step 5, removing the burr; step 6, pre-processing heat treatment; step 7, shape adjustment; step 8, CNC machining; step 9, cleaning treatment; step 10, packaging and storage;

[0005] In the above step 1, the cast aluminum raw material is first mechanically cleaned, and after the mechanical cleaning is completed, the cast aluminum is cut, and then the cut cast aluminum block is put into a pickling tank for pickling, and after the pickling treatment, it is taken out and continuously rinsed, and after continuous rinsing, the cast aluminum block is taken out and flattened in a dryer for drying, and after drying, the molten cast aluminum is obtained for standby use;

[0006] In the above step 2, the molten cast aluminum prepared in the above step 1 is put into a smelting furnace, and then a modifier composed of strontium and vanadium raw materials is added to the smelting furnace, and then the temperature of the smelting furnace is increased. After the solid is completely dissolved, the molten material is stirred in the smelting furnace to obtain a die casting stock solution for standby use;

[0007] In the above step 3, the designed mold is installed on the die-casting machine and preheated to ensure that the mold maintains a stable temperature during the die-casting process. Then, the die-casting stock solution prepared in the above step 2 is injected into the mold. After the injection is completed, the mold is cooled. After the cooling treatment, the die-cast sheet is demoulded and set aside.

[0008] In the above step 4, a punch is used to remove the gate of the die-casting sheet prepared in the above step 3, and the gate-removed sheet is obtained after the gate is removed for later use;

[0009] In the above step 5, a vibrating grinding and polishing machine is used to perform a burr removal process on the drain plate prepared in the above step 4, and after the burr removal, the plate to be processed is obtained and set aside;

[0010] In the above step 6, the sheet material to be processed obtained in the above step 5 is placed in a melting furnace for stress relief tempering to obtain a heat-treated sheet for standby use;

[0011] In the above step 7, a hydraulic press or a press is used to perform a calibration operation on the heat-treated plate prepared in the above step 6, and a calibration plate is obtained after the calibration operation and is used for standby;

[0012] In the above step eight, it is necessary to use computer-aided design software to carry out detailed design of the product according to the final requirements of the product and the design drawings. Then, CAM software is used to convert the design file into a processing program that can be recognized by the CNC machine tool. The prepared processing program is then input into the controller of the CNC machine tool, and the correction plate prepared in the above step seven is CNC-machined in the CNC machine tool. After the CNC processing operation, the processed cover plate is obtained and set aside.

[0013] In the above step nine, the dirt and possible oxide layer on the surface of the tempered cover plate are removed by mechanical force by rotating, spraying or brushing, and then the plate is placed in an ultrasonic cleaning tank for ultrasonic cleaning. After ultrasonic cleaning, the plate is shot peened to obtain a small cover plate for the motor end cover;

[0014] In the above step 10, the motor end cover small cover in the above step 9 is inspected for size, shape, surface quality, etc. to ensure that it meets the design requirements, and then the qualified small cover is packaged for transportation and storage.

[0015] As a further technical solution of the present invention, in step one, mechanical cleaning uses mechanical equipment such as a shot blasting machine and a grinding wheel machine to clean the casting to remove impurities such as metal slag, molding sand, sticky sand, and oil sludge on the surface; and cutting processing cuts the cast aluminum into cubic blocks with a specification of 50 to 80 mm.

[0016] As a further technical solution of the present invention, in step one, when pickling treatment is carried out in the pickling tank, the pickling liquid used is a nitric acid solution with a molar concentration of 10 to 15 mol / L, and the concentration of the pickling liquid is continuously adjusted and replenished during the pickling treatment to maintain the molar concentration of the nitric acid solution in the pickling tank at 10 to 15 mol / L, and the pickling treatment time is 20 to 30 minutes; after the pickling treatment, deionized water is used for continuous rinsing, and the continuous rinsing time is 3 to 4 minutes; when drying treatment is performed after the pickling treatment, the temperature in the dryer is 65 to 75°C, and the drying treatment time is 30 to 45 minutes.

[0017] As a further technical solution of the present invention, in the step 2, the amount of the modifier added is 0.05% to 0.1% by mass of the molten cast aluminum; to increase the temperature of the smelting furnace, the temperature in the smelting furnace needs to be increased to 740 to 780°C, and the stirring speed of the stirring rod in the smelting furnace when stirring the molten material is 30 to 60 r / min, and the stirring time of the molten material is 8 to 10 minutes.

[0018] As a further technical solution of the present invention, in the step three, the injection of the die-casting liquid into the mold includes a slow pressure stage, a fast pressure stage, a pressurization stage and a pressure holding stage. The pressure range of the slow pressure stage is 5 to 10 MPa. During the slow pressure process, the die-casting liquid enters the mold cavity at a slower speed to ensure that the die-casting liquid fills the mold smoothly and avoids turbulence and gas entanglement; the pressure range of the fast pressure stage is 70 to 100 MPa, and after the die-casting liquid begins to fill the mold in the fast pressure stage, the pressure increases rapidly, pushing the molten metal to fill the mold cavity at a faster speed; the pressure range of the pressurization stage is 70 to 100 MPa, and after the molten metal fills the mold cavity, the pressure is further increased by the pressurization mechanism, so that the molten metal is further densified under pressure, reducing defects such as porosity and shrinkage; the pressure holding stage is the solidification process of the molten metal, and the pressure range is maintained at 80 to 100 MPa during the process to ensure that the casting obtains a dense structure and good performance during the solidification process.

[0019] As a further technical solution of the present invention, in step six, the temperature of the smelting furnace is increased to 550-580°C at a rate of 10-12°C / min, and then the smelting furnace is kept at 550-580°C for 50-60 minutes. The cooling rate after standing and keeping warm is 8-9°C / min, and the temperature of the plate needs to be reduced to 35-55°C for cooling.

[0020] As a further technical solution of the present invention, in step seven, the force should be controlled to be moderate during the correction process to avoid deformation or damage of the casting caused by excessive correction. At the same time, during the correction process, care should be taken to protect the surface of the casting from damage to avoid new defects and unevenness. After the correction is completed, the casting should be quality inspected to ensure that its shape, size and performance meet the design requirements.

[0021] As a further technical solution of the present invention, in step eight, after processing is completed, the size, shape and surface roughness of the workpiece are inspected using measuring tools and equipment to verify whether the workpiece meets the design requirements. If processing defects or areas that do not meet the requirements are found, subsequent processing such as trimming, grinding or polishing is required to improve the accuracy and surface quality of the workpiece.

[0022] As a further technical solution of the present invention, in step nine, the operating frequency of the ultrasonic cleaning machine during ultrasonic cleaning is 5 to 13 kHz, and the time of the ultrasonic cleaning machine is 3 to 7 minutes.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: in the die-casting process for the small cover plate of the motor end cover, the raw material is mechanically cleaned to remove the surface oxide layer and impurities before the aluminum casting operation is carried out, and then the raw material is cut and pickled to eliminate oil stains in the raw material, thereby ensuring the raw material purity of the melt, avoiding the residual oil stains and impurities on the raw material to generate bubbles during the melting process, thereby improving the quality of the prepared product; adding a modifier composed of strontium and vanadium raw materials during the melting process can refine the grains and improve the hardness and corrosion resistance of the prepared product; after die-casting, pre-heat treatment is carried out to optimize the mechanical processing performance of the plate, reduce the process difficulty of CNC processing, and at the same time remove the internal stress remaining in the plate to prevent the internal stress from causing deformation of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] Please see the attached Figure 1 The present invention provides an embodiment of a die-casting process for a small cover plate of a motor end cap, comprising the following steps: step 1, raw material processing; step 2, molten material operation; step 3, die-casting; step 4, flushing the water outlet; step 5, removing the burr; step 6, pre-processing heat treatment; step 7, shape adjustment; step 8, CNC machining; step 9, cleaning treatment; step 10, packaging and storage;

[0027] Among them, in the above step 1, the cast aluminum raw material is first mechanically cleaned, and the cast aluminum is cut after the mechanical cleaning is completed. Then, the cast aluminum block after the cutting process is put into the pickling tank for pickling treatment, and after pickling treatment, it is taken out and continuously rinsed. After continuous rinsing, the cast aluminum block is taken out and flattened in a dryer for drying treatment. After drying, molten cast aluminum is obtained for standby use; mechanical cleaning uses mechanical equipment such as shot blasting machines and grinding wheels to clean the castings to remove impurities such as metal slag, molding sand, sticky sand, and oil sludge on the surface; cutting treatment cuts the cast aluminum into vertical pieces with a specification of 50 to 80 mm. Block; when pickling in the pickling tank, the pickling liquid used is a nitric acid solution with a molar concentration of 10 to 15 mol / L, and the concentration of the pickling liquid is continuously adjusted and replenished during the pickling treatment to maintain the molar concentration of the nitric acid solution in the pickling tank at 10 to 15 mol / L, and the pickling treatment time is 20 to 30 minutes; after the pickling treatment, deionized water is used for continuous rinsing, and the continuous rinsing time is 3 to 4 minutes; when drying after the pickling treatment, the temperature in the dryer is 65 to 75° C., and the drying time is 30 to 45 minutes;

[0028] In the above step 2, the molten cast aluminum prepared in the above step 1 is put into a smelting furnace, and then a modifier composed of strontium and vanadium raw materials is added to the smelting furnace, and then the temperature of the smelting furnace is increased. After the solid is completely dissolved, the molten material is stirred in the smelting furnace, and the molten material is stirred to obtain a die-casting stock solution for standby use; the amount of the modifier added is 0.05% to 0.1% by mass of the molten cast aluminum; to increase the temperature of the smelting furnace, the temperature in the smelting furnace needs to be increased to 740 to 780°C, and the stirring speed of the stirring rod in the smelting furnace during the molten material stirring is 30 to 60 r / min, and the molten material stirring time is 8 to 10 minutes;

[0029] In the above step three, the designed mold is installed on the die-casting machine and preheated to ensure that the mold maintains a stable temperature during the die-casting process. Subsequently, the die-casting stock solution prepared in the above step two is injected into the mold, and after the injection is completed, the mold is cooled. After the cooling treatment, the die-casting sheet is demolded and set aside. The injection of the die-casting stock solution into the mold includes a slow pressure stage, a fast pressure stage, a pressurization stage and a pressure maintenance stage. The pressure range of the slow pressure stage is 5 to 10 MPa. During the slow pressure process, the die-casting stock solution enters the mold cavity at a slower speed to ensure that the die-casting stock solution fills the mold smoothly and avoids turbulence. The pressure range of the rapid pressure stage is 70-100MPa, and in the rapid pressure stage, after the die casting liquid begins to fill the mold, the pressure increases rapidly, pushing the molten metal to fill the mold cavity at a faster speed; the pressure range of the boosting stage is 70-100MPa, and after the molten metal fills the mold cavity, the pressure is further increased by the boosting mechanism to further densify the molten metal under pressure and reduce defects such as porosity and shrinkage; the pressure holding stage is the solidification process of the molten metal, and the pressure is maintained in the range of 80-100MPa during the process to ensure that the casting obtains a dense structure and good performance during the solidification process;

[0030] In the above step 4, a punch is used to remove the gate of the die-casting sheet prepared in the above step 3, and the gate-removed sheet is obtained after the gate is removed for later use;

[0031] In the above step 5, a vibrating grinding and polishing machine is used to perform a burr removal process on the drain plate prepared in the above step 4, and after the burr removal, the plate to be processed is obtained and set aside;

[0032] In the above step 6, the sheet material to be processed obtained in the above step 5 is placed in a melting furnace for stress relief tempering to obtain a heat-treated sheet material for standby use; the temperature of the melting furnace is increased to 550-580°C at a rate of 10-12°C / min, and then the sheet material is kept at 550-580°C in the melting furnace for 50-60 minutes. After the sheet material is kept at this temperature, the cooling rate is 8-9°C / min, and the temperature of the sheet material needs to be reduced to 35-55°C for cooling;

[0033] In the above step 7, a correction operation is performed on the heat-treated plate prepared in the above step 6 using mechanical equipment such as a hydraulic press or a press. After the correction operation, a corrected plate is obtained and set aside. During the correction process, the force should be controlled to be moderate to avoid deformation or damage of the casting caused by excessive correction. At the same time, during the correction process, care should be taken to protect the surface of the casting from damage to avoid the generation of new defects and unevenness. After the correction is completed, the casting should be quality inspected to ensure that its shape, size and performance meet the design requirements.

[0034] In the above step eight, it is necessary to use computer-aided design software to carry out detailed design of the product according to the final requirements and design drawings of the product, and then use CAM software to convert the design file into a processing program that can be recognized by the CNC machine tool. The compiled processing program is then input into the controller of the CNC machine tool, and the correction plate prepared in the above step seven is CNC-machined in the CNC machine tool. After the CNC processing operation, the processed cover plate is obtained and set aside; after the processing is completed, the size, shape and surface roughness of the processed part are inspected using measuring tools and equipment to verify whether the processed part meets the design requirements. If processing defects or non-compliance are found, subsequent processing such as trimming, grinding or polishing is required to improve the accuracy and surface quality of the processed part;

[0035] In the above step nine, the dirt and possible oxide layer on the surface of the tempered cover plate are removed by mechanical force by rotating, spraying or brushing, and then the plate is placed in an ultrasonic cleaning tank for ultrasonic cleaning. After ultrasonic cleaning, the plate is shot peened to obtain a small cover plate for the motor end cover; the operating frequency of the ultrasonic cleaning machine during ultrasonic cleaning is 5 to 13 kHz, and the ultrasonic cleaning time is 3 to 7 minutes;

[0036] In the above step 10, the motor end cover small cover in the above step 9 is inspected for size, shape, surface quality, etc. to ensure that it meets the design requirements, and then the qualified small cover is packaged for transportation and storage.

[0037] Based on the above, the advantage of the present invention is that, when the present invention is used, the raw material is mechanically cleaned to remove the surface oxide layer and impurities before the aluminum casting operation is carried out, and then the raw material is cut and pickled to eliminate the oil stains in the raw material, thereby ensuring the raw material purity of the melt, avoiding the residual oil stains and impurities on the raw material to generate bubbles during the melting process, thereby improving the quality of the prepared product; adding a modifier composed of strontium and vanadium raw materials during the melting process can refine the grains and improve the hardness and corrosion resistance of the prepared product; after die-casting, pre-heat treatment is performed to optimize the mechanical processing performance of the plate, reduce the process difficulty of CNC processing, and at the same time remove the internal stress remaining in the plate to prevent the internal stress from causing deformation of the product.

[0038] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A die-casting process for a small cover plate of a motor end cover, comprising the following steps: Step 1: Raw material processing; Step 2: Melt operation; Step 3: Die casting; Step 4: Flushing the water outlet; Step 5: Deburring; Step 6: Pre-processing heat treatment; Step 7: Shape adjustment; Step 8: CNC processing; Step 9: Cleaning; Step 10: Packing and storage; It is characterized by: In the above step 1, the cast aluminum raw material is first mechanically cleaned, and after the mechanical cleaning is completed, the cast aluminum is cut, and then the cut cast aluminum block is put into a pickling tank for pickling, and after the pickling treatment, it is taken out and continuously rinsed, and after continuous rinsing, the cast aluminum block is taken out and flattened in a dryer for drying, and after drying, the molten cast aluminum is obtained for standby use; In the above step 2, the molten cast aluminum prepared in the above step 1 is put into a smelting furnace, and then a modifier composed of strontium and vanadium raw materials is added to the smelting furnace, and then the temperature of the smelting furnace is increased. After the solid is completely dissolved, the molten material is stirred in the smelting furnace to obtain a die casting stock solution for standby use; In the above step 3, the designed mold is installed on the die-casting machine and preheated to ensure that the mold maintains a stable temperature during the die-casting process. Subsequently, the die-casting stock solution prepared in the above step 2 is injected into the mold, and after the injection is completed, the mold is cooled. After the cooling treatment, the die-casting sheet is demolded to obtain a standby material; the injection of the die-casting stock solution into the mold includes a slow pressure stage, a fast pressure stage, a pressurization stage and a pressure holding stage. The pressure range of the slow pressure stage is 5-10MPa; the pressure range of the fast pressure stage is 70-100MPa; the pressure range of the pressurization stage is 70-100MPa; the pressure holding stage is the solidification process of the molten metal, and the pressure range is maintained at 80-100MPa during the process; In the above step 4, a punch press is used to perform a nozzle removal process on the die-casting sheet prepared in the above step 3, and after the nozzle is removed, a nozzle-removed sheet is obtained for standby use; In the above step 5, a vibrating grinding and polishing machine is used to perform a burr removal process on the drain plate prepared in the above step 4, and after the burr removal, the plate to be processed is obtained and set aside; In the above step 6, the sheet material to be processed obtained in the above step 5 is placed in a melting furnace for stress relief tempering to obtain a heat-treated sheet for standby use; In the above step 7, a hydraulic press is used to perform a calibration operation on the heat-treated plate prepared in the above step 6, and a calibrated plate is obtained after the calibration operation and is ready for use; In the above step eight, it is necessary to use computer-aided design software to carry out detailed design of the product according to the final requirements of the product and the design drawings. Then, CAM software is used to convert the design file into a processing program that can be recognized by the CNC machine tool. The prepared processing program is then input into the controller of the CNC machine tool, and the correction plate prepared in the above step seven is CNC-machined in the CNC machine tool. After the CNC processing operation, the processed cover plate is obtained and set aside. In the above step nine, the dirt and the existing oxide layer on the surface of the processed cover plate are removed by spraying, and then the cover plate is placed in an ultrasonic cleaning tank for ultrasonic cleaning. After ultrasonic cleaning, the cover plate is shot peened to obtain a small cover plate for the motor end cover; In the above step 10, the motor end cover small cover in the above step 9 is inspected for size, shape and surface quality to ensure that it meets the design requirements, and then the qualified small cover is packaged for transportation and storage.

2. The die-casting process for a small cover plate of a motor end cap according to claim 1, characterized in that: In the step 1, the casting is cleaned mechanically using a shot blasting machine or a grinding wheel machine to remove metal slag, molding sand, sticky sand, and oil sludge on the surface; and the cast aluminum is cut into cubic blocks with a specification of 50 to 80 mm.

3. The die-casting process for a small cover plate of a motor end cap according to claim 1, characterized in that: In the step 1, when the pickling treatment is performed in the pickling tank, the pickling liquid used is a nitric acid solution with a molar concentration of 10 to 15 mol / L, and the concentration of the pickling liquid is continuously adjusted and replenished during the pickling treatment to maintain the molar concentration of the nitric acid solution in the pickling tank at 10 to 15 mol / L. The pickling treatment time is 20 to 30 minutes; after the pickling treatment, deionized water is used for continuous rinsing, and the continuous rinsing time is 3 to 4 minutes; when the drying treatment is performed after the pickling treatment, the temperature in the dryer is 65 to 75° C., and the drying treatment time is 30 to 45 minutes.

4. The die-casting process for a small cover plate of a motor end cap according to claim 1, characterized in that: In the step 2, the amount of the modifier added is 0.05% to 0.1% by mass of the molten cast aluminum; to increase the temperature of the smelting furnace, the temperature in the smelting furnace needs to be increased to 740 to 780°C, the stirring speed of the stirring rod in the smelting furnace when stirring the molten material is 30 to 60 r / min, and the stirring time of the molten material is 8 to 10 minutes.

5. The die-casting process for a small cover plate of a motor end cap according to claim 1, characterized in that: In step six, the stress relief tempering process is to first slowly heat the melting furnace at a heating rate of 3 to 5°C / min, raise the temperature of the melting furnace to 240 to 280°C, place the sheet material to be processed in the furnace and keep it warm for 240 to 300 minutes, and then lower the furnace temperature to 100°C before taking out the sheet material to be processed.

6. The die-casting process for a small cover plate of a motor end cap according to claim 1, characterized in that: In the step nine, the operating frequency of the ultrasonic cleaning machine during ultrasonic cleaning is 5 to 13 kHz, and the ultrasonic cleaning time is 3 to 7 minutes.

Images