Die-casting forming method for aluminum alloy shell die casting

Abstract

The invention discloses a die-casting forming method of an aluminum alloy shell die casting, which relates to the technical field of forming processing of metal parts and comprises the following steps: selecting materials, melting and refining, carrying out die-casting forming, shaping and trimming, refining and machining, cleaning and decontaminating, and assembling. Through fine polishing treatment and preheating measures, the problem of film sticking at a sprue is remarkably relieved, effective feeding, slow injection and rapid injection are achieved, the speed of an injection punch of rapid injection is larger than 6 m / s so that the density and quality of a final casting can be guaranteed, a cavity is divided into different temperature zones in the injection direction, staged cooling is conducted, and the casting quality is improved. The mold is opened 19-21 seconds after the cavity is filled with the raw materials, it is ensured that the casting has enough strength, deformation or damage is avoided, the high-performance requirement of the aluminum alloy shell of the automobile air conditioner compressor can be met, the production efficiency and the product quality can be improved, and meanwhile the influence on the environment is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of forming and processing of metal parts, and in particular to a die-casting method for an aluminum alloy shell die-casting. Background Art

[0002] The automotive air-conditioning compressor is the core component of the automotive air-conditioning refrigeration system. It is responsible for compressing the refrigerant to a high temperature and high pressure state, releasing heat through the condenser to achieve the refrigeration effect of the automotive air-conditioning. The automotive air-conditioning compressor plays a vital role in the automotive air-conditioning system. It inhales low-pressure refrigerant, compresses it into a high-temperature and high-pressure gas, and then discharges it into the condenser, dissipates heat through the radiator, and condenses the refrigerant into liquid. This process is one of the key steps in the automotive air-conditioning refrigeration cycle, providing power for the refrigeration cycle. When the automotive air-conditioning compressor is in use, its surface will be equipped with an aluminum alloy shell to protect it and prevent it from being damaged. The following problems exist in the prior art:

[0003] The existing die-casting molding method of aluminum alloy shell die-casting parts has high mold design and manufacturing costs: in order to achieve high density and excellent surface quality, the design and manufacture of the mold require high-precision technology and complex processes, which directly leads to an increase in mold costs. Parameters such as temperature, pressure and speed cannot be accurately controlled during the die-casting process. Improper operation may lead to casting defects. Some harmful metal vapor and dust may be generated during the die-casting process, and effective ventilation and purification facilities are required to reduce the impact on the environment. Summary of the invention

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A die-casting method for an aluminum alloy housing die-casting comprises the following steps:

[0006] Step 1: Select materials and melt and refine;

[0007] Step 2: die casting;

[0008] Step 3: shaping and cutting edges;

[0009] Step 4: Refining machining;

[0010] Step 5: Cleaning and decontamination;

[0011] Step 6: Assembly.

[0012] The further improvement of the technical solution of the present invention is that: the step 1 is to carefully select a suitable aluminum alloy grade according to the performance requirements of the aluminum alloy shell of the automobile compressor, generally A7075 aluminum alloy is selected, which is an aluminum alloy that can be strengthened by heat treatment and has excellent strength and good low-temperature strength. The selected A7075 aluminum alloy material is placed in a special aluminum alloy melting furnace, and its melting temperature is controlled between 650 degrees Celsius and 710 degrees Celsius to avoid overburning and underburning. During the refining process, 3.5-4.5% copper, 0.4-0.8% magnesium and 15-18% silicon need to be added to the melting furnace, and the mixture is stirred and heated to make the alloy homogenized. The stirring and heating time only takes 20 minutes, and necessary degassing and slag removal treatments need to be performed during this process.

[0013] A further improvement of the technical solution of the present invention is that the second step of die-casting includes the following steps:

[0014] Q1: Mold preparation;

[0015] Q2: Die casting machine adjustment;

[0016] Q3: Injection;

[0017] Q4: Take out the die casting and conduct preliminary inspection.

[0018] A further improvement of the technical solution of the present invention is that the Q1 mold preparation specifically refers to the mold structure design according to the design requirements of the aluminum alloy shell of the automobile air-conditioning compressor, including the cavity, core, gate and exhaust port, and the mold design is carried out using professional CAD software to ensure the accuracy and reliability of the design. The mold is manufactured according to the design drawings, and high-speed milling and electrospark machining precision processing technology are usually used to heat treat the mold surface to improve its hardness and wear resistance, adjust the mold gap, and ensure the dimensional accuracy and surface quality of the die-casting.

[0019] A further improvement of the technical solution of the present invention is that the Q2 die-casting machine is adjusted by selecting a suitable die-casting machine model and tonnage according to the size and weight of the aluminum alloy shell, setting the injection pressure, speed and time parameters according to the characteristics of the mold and the aluminum alloy, and adjusting the clamping force of the die-casting machine to ensure that the mold will not be displaced or deformed during the high-pressure injection process.

[0020] A further improvement of the technical solution of the present invention is that the Q3 injection is to pour the aluminum alloy melted in step one into the injection chamber, and the temperature of the aluminum alloy needs to be controlled at 400-450 degrees Celsius, and the liquid level needs to be lower than two-thirds of the injection chamber. After pouring, the injection chamber needs to be preheated to avoid cold shut and bubbles in the aluminum alloy during the injection process, and then the die-casting machine is started for high-pressure injection to inject the aluminum alloy into the mold cavity. Slow injection is required at the beginning, and the injection speed is 0.3-0.6m / s. When the stroke of the injection punch is 80-100mm, fast injection filling is started, and the speed needs to be greater than 6m / s. After the injection is completed, the mold with aluminum alloy liquid is quickly placed in a refrigerator so that it can quickly cool and solidify, thereby forming the desired shell shape. When the aluminum alloy reaches an appropriate degree of solidification, the die-casting machine automatically opens the mold and ejects the die-casting from the mold.

[0021] A further improvement of the technical solution of the present invention is that: Q4 refers to taking the aluminum alloy mold obtained in Q3 out of the die-casting machine with pliers, and it is not easy to use excessive force during the removal process. After the die-casting is taken out, it is necessary to conduct a preliminary inspection to observe whether its shape, size and surface quality meet the design requirements.

[0022] A further improvement of the technical solution of the present invention is that: Step three is to remove the flash and burrs on the die-casting of the formed aluminum alloy shell with a special deburring tool, and to cut off the edge parts that exceed the design size with a cutting machine to ensure the dimensional accuracy and appearance quality of the shell.

[0023] A further improvement of the technical solution of the present invention is that: the step four is to process the required holes on the aluminum alloy shell and perform tapping according to the size of the automobile air-conditioning compressor, so as to facilitate its subsequent assembly on the automobile air-conditioning compressor. After the tapping, the shell surface needs to be fine-milled using a milling machine to improve its flatness and smoothness. If needed, the aluminum alloy shell is heat treated to improve its mechanical properties and stability.

[0024] A further improvement of the technical solution of the present invention is that: step five is to rinse the aluminum alloy shell treated in step four with clean water, and after rinsing, it is dried to ensure that the surface of the shell is clean and free of water stains. Step six is ​​to inspect the quality of the aluminum alloy shell cleaned in step five to ensure its composite requirements, and install it on the automobile air-conditioning compressor, and then apply sealant to the connection to ensure its sealing performance.

[0025] Due to the adoption of the above technical solution, the present invention has the following technical advances compared with the prior art:

[0026] The invention provides a die-casting method for an aluminum alloy shell die-casting. Through fine polishing and preheating measures, the sticking film problem at the gate is significantly alleviated, the shrinkage is effectively compensated, the qualified rate of the aluminum alloy shell is increased from the original 60% to more than 90%, the filling speed and filling time of the mold are reduced, and the service life of the mold is extended. The temperature of the mold temperature field is controlled to 400-450°C to improve the fluidity and filling performance of the molten metal. The method includes two stages of slow injection and fast injection, wherein the injection punch speed of the fast injection is greater than 6m / s to ensure the density and quality of the final casting. The cavity is divided into different temperature zones along the injection direction, and the temperature is lowered in stages to control the solidification shrinkage of the casting to avoid deformation or damage. The mold is opened 19-21s after the raw material fills the cavity, so as to ensure that the casting has sufficient strength to avoid deformation or damage. The method can not only meet the high performance requirements of the aluminum alloy shell of the automobile air-conditioning compressor, but also effectively solve various problems in the die-casting process, improve production efficiency and product quality, and reduce the impact on the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a flow chart of the die-casting method of the aluminum alloy housing die-casting of the present invention;

[0028] Figure 2 It is a flow chart of the die casting process of the present invention. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with embodiments:

[0030] Example 1

[0031] like Figure 1-2 As shown, the present invention provides a die-casting method for an aluminum alloy housing die-casting, comprising the following steps:

[0032] Step 1: Select materials and melt and refine;

[0033] Step 2: die casting;

[0034] Step 3: shaping and cutting edges;

[0035] Step 4: Refining machining;

[0036] Step 5: Cleaning and decontamination;

[0037] Step 6: Assembly.

[0038] Example 2

[0039] like Figure 1-2As shown, on the basis of Example 1, the present invention provides a technical solution: preferably, step 1 is to carefully select a suitable aluminum alloy grade according to the performance requirements of the aluminum alloy shell of the automobile compressor, generally select A7075 aluminum alloy, which is an aluminum alloy that can be strengthened by heat treatment, and has excellent strength and good low-temperature strength. The selected A7075 aluminum alloy material is placed in a special aluminum alloy melting furnace, and its melting temperature is controlled between 650 degrees Celsius and 710 degrees Celsius to avoid overburning and underburning. During the refining process, 3.5-4.5% copper, 0.4-0.8% magnesium and 15-18% silicon need to be added to the melting furnace, and the mixture is stirred and heated to make the alloy homogenized. The stirring and heating time only takes 20 minutes, and necessary degassing and slag removal treatments need to be performed during this process.

[0040] In this embodiment, the addition of copper helps to improve the strength and wear resistance of the material, the addition of magnesium can enhance the strength and corrosion resistance of the aluminum alloy, and the high content of silicon helps to increase the hardness of the material, reduce the coefficient of thermal expansion, and maintain the dimensional accuracy of parts. The addition of these elements can significantly improve the performance of the aluminum alloy, making it more suitable for manufacturing compressor housings. The smelting time is controlled at 20 minutes in order to reduce oxidation and air absorption and avoid cracks in the ingot forming fine structure.

[0041] Example 3

[0042] like Figure 1-2 As shown, based on Example 1, the present invention provides a technical solution: preferably, step 2, die-casting, comprises the following steps:

[0043] Q1: Mold preparation;

[0044] Q2: Die casting machine adjustment;

[0045] Q3: Injection;

[0046] Q4: Take out the die casting and conduct preliminary inspection;

[0047] Q1 Mold preparation specifically refers to the design of the mold structure, including the cavity, core, gate and exhaust port, according to the design requirements of the aluminum alloy shell of the automobile air-conditioning compressor. Professional CAD software is used for mold design to ensure the accuracy and reliability of the design. The mold is manufactured according to the design drawings. High-speed milling and EDM precision processing technology are usually used to heat treat the mold surface to improve its hardness and wear resistance, and the gap of the mold is adjusted to ensure the dimensional accuracy and surface quality of the die-casting.

[0048] Q2 die-casting machine adjustment is to select the appropriate die-casting machine model and tonnage according to the size and weight of the aluminum alloy shell, set the injection pressure, speed and time parameters according to the characteristics of the mold and aluminum alloy, and adjust the clamping force of the die-casting machine to ensure that the mold will not be displaced or deformed during high-pressure injection;

[0049] Q3 injection is to pour the aluminum alloy melted in step 1 into the injection chamber, and the temperature of the aluminum alloy needs to be controlled at 400-450 degrees Celsius. Temperature control within this range can ensure the fluidity of the aluminum alloy, thereby improving the quality and performance of the casting, and the liquid level must be lower than two-thirds of the injection chamber. The liquid level is kept within a certain range in the injection chamber to ensure that the aluminum alloy can evenly fill the mold cavity. After pouring, the injection chamber needs to be preheated to avoid cold shut and bubbles in the aluminum alloy during the injection process, and then start The dynamic die-casting machine performs high-pressure injection to inject the aluminum alloy into the mold cavity. At the beginning, slow injection is required, and the injection speed is 0.3-0.6m / s. When the stroke of the injection punch is 80-100mm, fast injection filling is started, and the speed must be greater than 6m / s. After the injection is completed, the mold with aluminum alloy liquid is quickly placed in a refrigerator so that it can be quickly cooled and solidified to form the required shell shape. When the aluminum alloy reaches an appropriate degree of solidification, the die-casting machine automatically opens the mold and ejects the die-casting from the mold;

[0050] Q4 refers to taking the aluminum alloy mold obtained in Q3 out of the die-casting machine with pliers. It is not advisable to use excessive force during the removal process. After the die-casting is taken out, it is necessary to conduct a preliminary inspection to observe whether its shape, size and surface quality meet the design requirements;

[0051] Step three is to use a special deburring tool to remove the flash and burrs on the die-casting of the formed aluminum alloy shell, and use a cutting machine to cut off the edge parts that exceed the design size to ensure the dimensional accuracy and appearance quality of the shell;

[0052] Step 4 is to process the required holes on the aluminum alloy shell according to the size of the automobile air-conditioning compressor and perform tapping to facilitate its subsequent assembly on the automobile air-conditioning compressor. After tapping, the shell surface needs to be fine-milled using a milling machine to improve its flatness and smoothness. If necessary, the aluminum alloy shell is heat-treated to improve its mechanical properties and stability.

[0053] Step five is to rinse the aluminum alloy shell treated in step four with clean water, and then dry it after rinsing to ensure that the surface of the shell is clean and free of water stains. Step six is ​​to inspect the quality of the aluminum alloy shell cleaned in step five to ensure its composite requirements, and install it on the automobile air-conditioning compressor, and then apply sealant to the connection to ensure its sealing performance.

[0054] In this embodiment, there are two stages, slow injection and fast injection, wherein the speed of the injection punch of the fast injection is greater than 6m / s to ensure the density and quality of the final casting. The cavity is divided into different temperature zones along the injection direction, and the temperature is lowered in stages to control the solidification shrinkage of the casting to avoid deformation or damage. The mold is opened 19-21s after the raw material fills the cavity to ensure that the casting has sufficient strength to avoid deformation or damage. This can not only meet the high performance requirements of the aluminum alloy housing of the automotive air-conditioning compressor, but also effectively solve various problems arising in the die-casting process, improve production efficiency and product quality, and reduce the impact on the environment.

[0055] The above generally describes the present invention in detail, but it is obvious to a person skilled in the art that some modifications or improvements can be made to the present invention. Therefore, modifications or improvements that do not depart from the spirit of the present invention are within the scope of protection of the present invention.

Claims

1. A die-casting method for an aluminum alloy housing die-casting, characterized in that: The following steps are involved: Step 1: Select materials and melt and refine; Step 2: die casting; Step 3: shaping and cutting edges; Step 4: Refining machining; Step 5: Cleaning and decontamination; Step 6: Assembly.

2. The die-casting method of an aluminum alloy housing die-casting according to claim 1, characterized in that: The first step is to carefully select a suitable aluminum alloy grade according to the performance requirements of the aluminum alloy shell of the automobile compressor, generally A7075 aluminum alloy is selected, which is an aluminum alloy that can be strengthened by heat treatment and has excellent strength and good low-temperature strength. The selected A7075 aluminum alloy material is placed in a special aluminum alloy melting furnace, and its melting temperature is controlled between 650 degrees Celsius and 710 degrees Celsius to avoid overburning and underburning. During the refining process, 3.5-4.5% copper, 0.4-0.8% magnesium and 15-18% silicon need to be added to the melting furnace, and the mixture is stirred and heated to make the alloy homogenized. The stirring and heating time only takes 20 minutes. At the same time, necessary degassing and slag removal treatments need to be performed in this process.

3. The die-casting method of an aluminum alloy housing die-casting according to claim 1, characterized in that: The second step of die casting comprises the following steps: Q1: Mold preparation; Q2: Die casting machine adjustment; Q3: Injection; Q4: Take out the die casting and conduct preliminary inspection.

4. The die-casting method of an aluminum alloy housing die-casting according to claim 3, characterized in that: The Q1 mold preparation specifically refers to the mold structure design, including the cavity, core, gate and exhaust port, according to the design requirements of the aluminum alloy shell of the automobile air-conditioning compressor, using professional CAD software for mold design to ensure the accuracy and reliability of the design, and manufacturing the mold according to the design drawings. High-speed milling and EDM precision processing technology are usually used to heat treat the mold surface to improve its hardness and wear resistance, adjust the mold gap, and ensure the dimensional accuracy and surface quality of the die-casting.

5. The die-casting method of an aluminum alloy housing die-casting according to claim 3, characterized in that: The Q2 die-casting machine adjustment is to select the appropriate die-casting machine model and tonnage according to the size and weight of the aluminum alloy shell, set the injection pressure, speed and time parameters according to the characteristics of the mold and aluminum alloy, and adjust the clamping force of the die-casting machine to ensure that the mold will not be displaced or deformed during the high-pressure injection process.

6. The die-casting method of an aluminum alloy housing die-casting according to claim 3, characterized in that: The Q3 injection is to pour the aluminum alloy melted in step 1 into the injection chamber, and the temperature of the aluminum alloy needs to be controlled at 400-450 degrees Celsius, and the liquid level needs to be lower than two-thirds of the injection chamber. After pouring, the injection chamber needs to be preheated to avoid cold shut and bubbles in the aluminum alloy during the injection process, and then the die-casting machine is started for high-pressure injection to inject the aluminum alloy into the mold cavity. Slow injection is required at the beginning, and the injection speed is 0.3-0.6m / s. When the stroke of the injection punch is 80-100mm, fast injection filling is started, and the speed needs to be greater than 6m / s. After the injection is completed, the mold with aluminum alloy liquid is quickly placed in a refrigerator so that it can quickly cool and solidify, thereby forming the desired shell shape. When the aluminum alloy reaches an appropriate degree of solidification, the die-casting machine automatically opens the mold and ejects the die-casting from the mold.

7. The die-casting method of an aluminum alloy housing die-casting according to claim 3, characterized in that: The Q4 refers to taking the aluminum alloy mold obtained in Q3 out of the die-casting machine with pliers. It is not advisable to use excessive force during the removal process. After the die-casting is taken out, it is necessary to conduct a preliminary inspection to observe whether its shape, size and surface quality meet the design requirements.

8. The die-casting method of an aluminum alloy housing die-casting according to claim 1, characterized in that: The step three is to use a special deburring tool to remove the flash and burrs on the die-casting of the formed aluminum alloy shell, and use a cutting machine to cut off the edge parts that exceed the design size to ensure the dimensional accuracy and appearance quality of the shell.

9. The die-casting method of an aluminum alloy housing die-casting according to claim 2, characterized in that: The step four is to process the required holes on the aluminum alloy shell and perform tapping according to the size of the automobile air-conditioning compressor, so as to facilitate its subsequent assembly on the automobile air-conditioning compressor. After the tapping, the shell surface needs to be fine-milled using a milling machine to improve its flatness and smoothness. According to needs, the aluminum alloy shell can be heat-treated to improve its mechanical properties and stability.

10. The die-casting method of an aluminum alloy housing die-casting according to claim 9, characterized in that: Step five is to rinse the aluminum alloy shell treated in step four with clean water, and then dry it after rinsing to ensure that the surface of the shell is clean and free of water stains. Step six is ​​to inspect the quality of the aluminum alloy shell cleaned in step five to ensure its composite requirements, and install it on the automobile air-conditioning compressor, and then apply sealant to the connection to ensure its sealing performance.

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