Injection molding process for automobile parts

Abstract

The invention relates to an injection molding process for automobile parts, which comprises the following specific steps: screening raw materials by adopting a magnetic separation device to ensure the purity of the raw materials; uniformly mixing the screened raw materials by using a mixer; pre-drying the uniformly mixed raw materials; melting the mixed raw materials in a melting furnace, wherein the melting is divided into four-section type melting; an injection mold is selected and cleaned; selecting a release agent and uniformly brushing the release agent on the inner surface of the mold; high-flow hot air is introduced into the mold through a mold feeding opening; the mold is heated; performing injection molding; maintaining pressure, cooling and forming; the part is separated from the mold; and polishing and grinding the removed workpiece to obtain an automobile part product. By means of the magnetic separation device, iron impurities carried in raw materials can be adsorbed to the side wall of the magnetic suction barrel, screening is formed, and the production quality of subsequent products is improved; and a multi-section melting and pressure maintaining process is adopted, so that shrinkage marks and shrinkage cavities can be eliminated, and the appearance quality of a product is improved.

Description

Technical Field

[0001] The invention relates to the technical field of injection molding, in particular to an injection molding process for automobile parts. Background Art

[0002] Auto parts are mostly produced using the injection molding process, which includes melting the raw materials, then introducing the molten raw materials into an injection molding machine, which completes the injection action to form a product.

[0003] The existing injection molding process lacks pretreatment of raw materials, resulting in impurities such as iron filings being mixed into the raw materials, which ultimately affects the quality of automotive parts products; and the existing processing procedures are prone to cause problems such as shrinkage holes in the products, which will also cause a decline in product quality. Summary of the invention

[0004] The present invention aims to solve the deficiencies of the prior art and provide an injection molding process for automobile parts.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] An injection molding process for automobile parts, the specific steps are:

[0007] S1. Raw material screening:

[0008] Use magnetic separation device to screen the raw materials to ensure the purity of the raw materials;

[0009] S2. Mixing:

[0010] The screened raw materials are uniformly mixed using a mixer;

[0011] S3, Drying:

[0012] The uniformly mixed raw materials are pre-dried at a temperature of 100-105°C for 3-4 hours;

[0013] S4, raw material melting:

[0014] The mixed raw materials are melted in a furnace, and the melting is divided into four stages, the first stage temperature is 130-140°C, the second stage temperature is 140-150°C, the third stage temperature is 150-160°C, and the fourth stage temperature is 160-170°C;

[0015] S5. Injection molding preparation:

[0016] Select an injection mold and clean it; select a release agent and apply it evenly on the inner surface of the mold; introduce high-flow hot air into the mold through the mold feed port, and close the air outlet valve. After the mold is filled with high-pressure hot air, open the air outlet valve to discharge the excess release agent;

[0017] S6, mold closing:

[0018] Heat treatment of the mold;

[0019] S7, Injection molding:

[0020] The molten raw material in step S4 is introduced into the low-pressure injection molding machine, and the molten raw material is transported to the feed port of the mold by the low-pressure injection molding machine and injected into the mold, and the injection pressure is 35-70MPa;

[0021] S8, pressure holding, cooling and molding:

[0022] Before the parts are formed and solidified, the pressure is maintained at 15-20Mpa for 3-5 hours. After the pressure is maintained, the metal parts are cooled and shaped through the cooling system.

[0023] S9, demoulding:

[0024] Remove the part from the mold;

[0025] S10, post-processing:

[0026] The workpiece that comes out is polished and ground to obtain automobile parts products.

[0027] In step S1, the magnetic separation device used includes a shell, a magnetic suction cylinder is arranged in the shell, a magnetic suction block is arranged in the magnetic suction cylinder, a plurality of arc grooves are arranged on the side wall of the magnetic suction cylinder, the top of the magnetic suction cylinder is arranged at a conical tip structure, the top of the shell is a feed port and the bottom is a discharge port.

[0028] In step S5, the inner wall of the mold is cleaned by a laser cleaning machine, and light is directed to the dead corners of the mold and the parts that are difficult to clean for cleaning.

[0029] In step S6, the mold is heated at a temperature of 100°C.

[0030] In step S7, when the molten raw material is injected into the mold, it is injected at a speed of 80-100 mm / s at the beginning. As the injection time increases, the injection rate gradually decreases, and the minimum injection speed is 10-20 mm / s.

[0031] In step S8, the cooling system used to cool and shape the metal part adopts normal temperature cooling.

[0032] The automotive parts products obtained in step S10 are subsequently packaged and put into storage after final inspection.

[0033] The beneficial effects of the present invention are as follows: the present invention can adsorb the iron impurities entrained in the raw materials on the side wall of the magnetic suction cylinder through the magnetic separation device to form screening, which is beneficial to the production quality of subsequent products; the use of a multi-stage melting and pressure holding process is beneficial to eliminating shrinkage marks and shrinkage holes and improving the appearance quality of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a process flow chart of the present invention;

[0035] Figure 2 is a schematic diagram of a screening device used in step S1 of the present invention;

[0036] In the figure: 1-shell; 2-magnetic cylinder; 3-magnetic block; 4-arc groove; 5-feeding port; 6-discharging port;

[0037] The following is a detailed description of the embodiments of the present invention with reference to the accompanying drawings. DETAILED DESCRIPTION

[0038] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The embodiments are only used to explain the present invention and are not used to limit the scope of the present invention. The present invention is described in more detail by way of example with reference to the accompanying drawings in the following paragraphs. The advantages and features of the present invention will become clearer according to the following description. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, and are only used to facilitate and clearly assist in explaining the purpose of the embodiments of the present invention.

[0039] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a component centered. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a component centered. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a component centered. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0041] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0042] An injection molding process for automotive parts, such as Figure 1As shown, the specific steps are:

[0043] S1. Raw material screening:

[0044] Use magnetic separation device to screen the raw materials to ensure the purity of the raw materials;

[0045] Magnetic separation device such as Figure 2 As shown, it comprises a shell 1, a magnetic suction cylinder 2 is arranged in the shell 1, a magnetic suction block 3 is arranged in the magnetic suction cylinder 2, a plurality of arc grooves 4 are arranged on the side wall of the magnetic suction cylinder 2, the top of the magnetic suction cylinder 2 is arranged at a conical tip structure, the top of the shell 1 is a feed port 5 and the bottom is a discharge port 6;

[0046] The magnetic separation device can adsorb the iron impurities carried in the raw materials on the side wall of the magnetic suction cylinder 2 to form a screening, which is beneficial to the production quality of subsequent products.

[0047] S2. Mixing:

[0048] The screened raw materials are uniformly mixed using a mixer.

[0049] S3, Drying:

[0050] The uniformly mixed raw materials are pre-dried at a temperature of 100-105°C for 3-4 hours.

[0051] S4, raw material melting:

[0052] The mixed raw materials are melted in a furnace in four stages, with the first stage at a temperature of 130-140°C, the second stage at a temperature of 140-150°C, the third stage at a temperature of 150-160°C and the fourth stage at a temperature of 160-170°C.

[0053] S5. Injection molding preparation:

[0054] Select the injection mold and clean the mold;

[0055] During mold cleaning, the inner wall of the mold is cleaned by a laser cleaning machine, and the light is directed to the dead corners of the mold and the parts that are difficult to clean for cleaning;

[0056] Select a release agent and apply it evenly on the inner surface of the mold; introduce high-flow hot air into the mold through the mold feed port, and close the air outlet valve. After the mold is filled with high-pressure hot air, open the air outlet valve to discharge excess release agent.

[0057] S6, mold closing:

[0058] The mold is heated at 100°C.

[0059] S7, Injection molding:

[0060] The molten raw material in step S4 is introduced into the low-pressure injection molding machine, and the molten raw material is transported to the feed port of the mold by the low-pressure injection molding machine and injected into the mold, and the injection pressure is 35-70MPa;

[0061] When the molten raw material is injected into the mold, it is injected at a speed of 80-100 mm / s at the beginning. As the injection time increases, the injection rate gradually decreases, and the minimum injection speed is 10-20 mm / s.

[0062] S8, pressure holding, cooling and molding:

[0063] The pressure is maintained before the parts are formed and solidified. The pressure is 15-20Mpa and the time is 3-5h. After the pressure is maintained, the metal parts are cooled and shaped through the cooling system, and cooled at room temperature.

[0064] S9, demoulding:

[0065] Release the part from the mold.

[0066] S10, post-processing:

[0067] The removed workpieces are polished and ground to obtain automotive parts products, which are then packaged and put into storage after final inspection.

[0068] The present invention can adsorb iron impurities entrained in the raw materials on the side wall of the magnetic suction cylinder through the magnetic separation device to form screening, which is beneficial to the production quality of subsequent products; the use of a multi-stage melting and pressure holding process is beneficial to eliminating shrinkage marks and shrinkage holes and improving the appearance quality of the product.

[0069] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the present invention, or are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. An injection molding process for automobile parts, characterized in that: The specific steps are: S1. Raw material screening: Use magnetic separation device to screen the raw materials to ensure the purity of the raw materials; S2. Mixing: The screened raw materials are uniformly mixed using a mixer; S3, Drying: The uniformly mixed raw materials are pre-dried at a temperature of 100-105°C for 3-4 hours; S4, raw material melting: The mixed raw materials are melted in a furnace, and the melting is divided into four stages, the first stage temperature is 130-140°C, the second stage temperature is 140-150°C, the third stage temperature is 150-160°C, and the fourth stage temperature is 160-170°C; S5. Injection molding preparation: Select an injection mold and clean it; select a release agent and apply it evenly on the inner surface of the mold; introduce high-flow hot air into the mold through the mold feed port, and close the air outlet valve. After the mold is filled with high-pressure hot air, open the air outlet valve to discharge the excess release agent; S6, mold closing: Heat treatment of the mold; S7, Injection molding: The molten raw material in step S4 is introduced into the interior of a low-pressure injection molding machine, and the molten raw material is transported to the feed port of the mold by the low-pressure injection molding machine and injected into the mold, and the injection pressure is 35-70 MPa; S8, pressure holding, cooling and molding: Before the parts are formed and solidified, the pressure is maintained at 15-20Mpa for 3-5 hours. After the pressure is maintained, the metal parts are cooled and shaped through the cooling system. S9, demoulding: Remove the part from the mold; S10, post-processing: The workpiece that comes out is polished and ground to obtain automobile parts products.

2. The injection molding process of an automobile part according to claim 1, characterized in that: In step S1, the magnetic separation device used comprises a shell (1), a magnetic suction cylinder (2) is arranged in the shell (1), a magnetic suction block (3) is arranged in the magnetic suction cylinder (2), a plurality of arc grooves (4) are arranged on the side wall of the magnetic suction cylinder (2), the top of the magnetic suction cylinder (2) is arranged at a conical tip structure, the top of the shell (1) is a feed port (5) and the bottom is a discharge port (6).

3. The injection molding process of an automobile part according to claim 2, characterized in that: In step S5, the inner wall of the mold is cleaned by a laser cleaning machine, and light is directed to the dead corners and hard-to-clean parts of the mold for cleaning.

4. The injection molding process of an automobile part according to claim 3, characterized in that: In step S6, the mold is heated at a temperature of 100°C.

5. The injection molding process of an automobile part according to claim 4, characterized in that: In step S7, when the molten raw material is injected into the mold, it is injected at a speed of 80-100 mm / s at the beginning. As the injection time increases, the injection rate gradually decreases, and the minimum injection speed is 10-20 mm / s.

6. The injection molding process of an automobile part according to claim 5, characterized in that: In step S8, the cooling system used to cool and shape the metal part adopts normal temperature cooling.

7. The injection molding process of an automobile part according to claim 6, characterized in that: The automotive parts products obtained in step S10 are subsequently packaged and put into storage after final inspection.

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