A corrosion-resistant front barrel for injection molding machine

Abstract

The utility model relates to the field of injection molding machines, and discloses a corrosion-resistant front barrel of an injection molding machine, comprising a front barrel body with an inner hole, a first corrosion-resistant structure for preventing the inner hole from being corroded by gas is arranged on the inner hole, and a second corrosion-resistant structure for preventing the end face from being corroded by gas is arranged on the end face where the front barrel body cooperates with the injection molding machine. The corrosion-resistant front barrel of the injection molding machine can prevent corrosive gas from corroding the inner hole and the end face where the front barrel body cooperates with the injection molding machine, thereby protecting the front barrel body and extending the service life of the front barrel body.

Description

Technical Field

[0001] The utility model relates to the field of injection molding machines, in particular to a corrosion-resistant front barrel of an injection molding machine. Background Art

[0002] With the vigorous development of the new energy industry, plastic battery cases and plastic switches are being used more and more widely. In order to meet the growing demand for such plastic products, injection molding machines are usually used for rapid preparation.

[0003] However, in order to ensure the safety of such plastic products during use, flame retardants are usually added to the plastic particles, or plastic particles that are inherently flame retardant are used, such as POM raw materials, so that the final product meets the flame retardant level in national safety standards. Flame retardants or flame retardant plastic particles will produce highly corrosive gases due to high-temperature heating and shear decomposition of raw materials.

[0004] In the prior art, the front barrel of the injection molding machine adopts the inner hole electroplating treatment to prevent corrosion, but the end surface of the front barrel is not specially treated. The specific structure can be referred to Figure 1 , causing the injection molding machine to produce a large amount of corrosive gas during the process of plasticizing such plastic products. The corrosive gas penetrates into the fitting end surface of the front barrel and the barrel on the injection molding machine and corrodes the end surface, causing the front barrel to fail. Utility Model Content

[0005] The utility model aims at the disadvantage that the end surface of the front barrel matched with the injection molding machine in the prior art is easily corroded by gas, and provides a corrosion-resistant front barrel of the injection molding machine.

[0006] In order to solve the above technical problems, the utility model is solved by the following technical solutions:

[0007] A corrosion-resistant front barrel of an injection molding machine comprises a front barrel body with an inner hole, a first corrosion-resistant structure for preventing the inner hole from being corroded by gas is arranged on the inner hole, and a second corrosion-resistant structure for preventing the end face from being corroded by gas is arranged on the end face of the front barrel body that cooperates with the injection molding machine.

[0008] By adopting the above scheme, a second anti-corrosion structure is set on the front barrel body to limit the corrosive gas from penetrating into the fitting end face of the front barrel body and the injection molding machine to corrode the end face; the first anti-corrosion structure limits the corrosive gas from corroding the inner wall of the inner hole. The combination of the two protects the front barrel body and extends the service life of the front barrel body.

[0009] Preferably, the second anti-corrosion structure includes a groove recessed on the end face of the front barrel body that cooperates with the injection molding machine, and an anti-corrosion layer embedded in the groove and having a thickness consistent with the depth of the groove. The groove is concentrically arranged with the inner hole and the inner hole is recessed at the bottom of the groove. The anti-corrosion layer is annular and its ring width is equal to the ring width of the groove. The ring width of the groove is the difference between the radius of the groove and the radius of the inner hole close to one end thereof.

[0010] By adopting the above scheme, the end face of the anti-corrosion layer close to the injection molding machine is flush with the end face of the front barrel body close to the injection molding machine, ensuring that after the front barrel body is installed on the injection molding machine, the anti-corrosion layer and the injection molding machine fit together, limiting the corrosive gas from penetrating into the fitting end face of the front barrel body and the injection molding machine, thereby protecting the end face; the inner diameter of the anti-corrosion layer is equal to the inner diameter of the end of the inner hole close to the anti-corrosion layer, avoiding the existence of a ring width difference between the anti-corrosion layer and the groove, thereby ensuring that the corrosive gas will not contact the front barrel body, thereby achieving the purpose of protecting the front barrel body.

[0011] Preferably, the anti-corrosion layer is a composite metal layer made by laser cladding cobalt-based alloy powder in the groove.

[0012] By adopting the above scheme, the cobalt-based alloy powder has good corrosion resistance, and the cobalt-based alloy powder is formed into a corrosion-resistant composite metal layer through the laser cladding process.

[0013] Preferably, the hardness of the composite metal layer is 46-52 HRC.

[0014] With the above solution, too high hardness will cause the composite metal layer to be too hard or too brittle and easily damaged; too low hardness will cause the composite metal layer to be too soft and reduce its corrosion resistance. Therefore, the hardness of the composite metal layer is maintained between 46 and 52 HRC to ensure its corrosion resistance while extending its service life.

[0015] Preferably, the depth of the groove is 1 to 1.5 mm.

[0016] Using the above solution, the depth of the groove is consistent with the thickness of the anti-corrosion layer. If it is too deep, the anti-corrosion layer will easily fall off, and if it is too shallow, the corrosion resistance of the anti-corrosion layer cannot be guaranteed. Therefore, the depth of the groove is maintained between 1 and 1.5 mm to ensure that the anti-corrosion layer has corrosion resistance while avoiding falling off, thereby extending the service life.

[0017] Preferably, the ring width of the groove is 3 to 4 mm.

[0018] By adopting the above scheme, the ring width of the groove is consistent with the ring width of the anti-corrosion layer. If it is too wide, the anti-corrosion layer will easily fall off, and if it is too narrow, the corrosion resistance of the anti-corrosion layer cannot be guaranteed. Therefore, the ring width of the groove is maintained between 3 and 4 mm, ensuring that the anti-corrosion layer has corrosion resistance while avoiding falling off, thereby extending the service life.

[0019] Preferably, the first anti-corrosion structure comprises a chrome plating layer provided on the inner annular wall of the inner hole.

[0020] By adopting the above solution, the chrome-plated layer serves as a protective layer to prevent the inner hole from being corroded by corrosive gases.

[0021] Preferably, the thickness of the chrome plating layer is 0.03-0.06 mm, and the hardness of the chrome plating layer is greater than or equal to 850 HV.

[0022] When adopting the above scheme, if the thickness of the chrome-plated layer is too thick, it will easily fall off, and if it is too thin, its corrosion resistance cannot be guaranteed. Therefore, the thickness of the chrome-plated layer is maintained between 0.03 and 0.06 mm, which ensures its corrosion resistance while avoiding falling off and extending its service life; the hardness of the chrome-plated layer is greater than or equal to 850HV to prevent it from being too soft and affecting its corrosion resistance.

[0023] The utility model has remarkable technical effects due to the adoption of the above technical scheme: by arranging a corrosion-resistant composite metal layer, when the front barrel body is installed on the injection molding machine, the composite metal layer and the injection molding machine fit together to limit the corrosive gas from entering the fitting end face of the front barrel body and the injection molding machine to corrode the end face; the inner diameter of the composite metal layer is equal to the inner diameter of the end of the inner hole close to the composite metal layer, avoiding the ring width difference between the composite metal layer and the groove, thereby ensuring that the corrosive gas will not contact the front barrel body, achieving the purpose of protecting the front barrel body and extending the service life of the front barrel body. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is an axonometric view of the front barrel in the prior art;

[0025] Figure 2 2 is a half-section schematic diagram of a corrosion-resistant front barrel of an injection molding machine in an embodiment when no corrosion-resistant layer is provided;

[0026] Figure 3 2 is a half-section schematic diagram of a corrosion-resistant front barrel of an injection molding machine in an embodiment when an anti-corrosion layer is provided;

[0027] Figure 4 It is an axonometric view of a corrosion-resistant front barrel of an injection molding machine in an embodiment.

[0028] The names of the parts indicated by the numerical labels in the above drawings are as follows: 1. front barrel body; 2. inner hole; 3. threaded hole; 4. through hole; 5. groove; 6. anti-corrosion layer; 7. chrome plating layer. DETAILED DESCRIPTION

[0029] The utility model is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0030] Example

[0031] A corrosion-resistant front barrel for an injection molding machine, Figures 2 to 4 , including a front barrel body 1. When the front barrel body 1 is installed on the injection molding machine, one end face is in contact with the injection molding machine. An inner hole 2 is concavely provided on the end face of the front barrel body 1 that cooperates with the injection molding machine, and a chrome-plated layer 7 is provided on the inner ring wall of the inner hole 2 to prevent the inner hole 2 from being corroded by corrosive gas. A threaded hole 3 is concavely provided on the other end face of the front barrel body 1, and the threaded hole 3 is concentric with and connected to the inner hole 2. A plurality of through holes 4 are evenly spaced around the inner hole 2 on the front barrel body 1.

[0032] A second anti-corrosion structure is also provided on the front barrel body 1 to limit the corrosive gas from penetrating into the end surface between the front barrel body 1 and the injection molding machine to corrode the end surface.

[0033] The second anti-corrosion structure includes a groove 5 concavely arranged on the end surface of the front barrel body 1 provided with the inner hole 2, the groove 5 and the inner hole 2 are concentrically arranged and the diameter of the groove 5 is larger than the diameter of the inner hole 2, and finally the inner hole 2 is concavely arranged at the bottom of the groove 5, that is, the cross-section of the groove 5 and the inner hole 2 is stepped. The difference between the radius of the groove 5 and the radius of the inner hole 2 close to one end thereof is the ring width of the groove 5.

[0034] An anti-corrosion layer 6 is embedded in the groove 5. The anti-corrosion layer 6 is annular, and the thickness of the anti-corrosion layer 6 is equal to the depth of the groove 5. The ring width of the anti-corrosion layer 6 is equal to the ring width of the groove 5, that is, the end of the anti-corrosion layer 6 close to the injection molding machine is flush with the end of the front barrel body 1 that cooperates with the injection molding machine, ensuring that after the front barrel body 1 is installed on the injection molding machine, the anti-corrosion layer 6 fits the injection molding machine, limiting the corrosive gas from penetrating between the front barrel body 1 and the injection molding machine, thereby protecting the end face; the inner diameter of the anti-corrosion layer 6 is equal to the inner diameter of the end of the inner hole 2 close to the anti-corrosion layer 6, avoiding the difference in ring width between the anti-corrosion layer 6 and the groove 5, thereby ensuring that the corrosive gas will not contact the front barrel body 1, thereby achieving the purpose of protecting the front barrel body 1.

[0035] The anti-corrosion layer 6 is a composite metal layer, which is made by laser cladding cobalt-based alloy powder in the groove 5. The cobalt-based alloy powder has good corrosion resistance, and the composite metal layer formed by the cobalt-based alloy powder also has corrosion resistance.

[0036] If the hardness of the composite metal layer is too high, it will make the composite metal layer too hard or too brittle and easy to be damaged; if the hardness is too low, it will make the composite metal layer too soft and reduce the corrosion resistance. Therefore, the hardness of the composite metal layer is maintained between 46 and 52 HRC to ensure its corrosion resistance and extend its service life.

[0037] The depth of the groove 5 is consistent with the thickness of the composite metal layer. If it is too deep, the composite metal layer will easily fall off, while if it is too shallow, the corrosion resistance of the composite metal layer cannot be guaranteed. The ring width of the groove 5 is consistent with the ring width of the composite metal layer. If it is too wide, the composite metal layer will easily fall off, while if it is too narrow, the corrosion resistance of the composite metal layer cannot be guaranteed. Therefore, the depth of the groove 5 is maintained between 1 and 1.5 mm, and the ring width of the groove 5 is maintained between 3 and 4 mm, ensuring that the composite metal layer has corrosion resistance while avoiding falling off, thereby extending the service life.

[0038] If the thickness of the chrome-plated layer 7 is too thick, it will easily fall off, and if it is too thin, its corrosion resistance cannot be guaranteed. Therefore, the thickness of the chrome-plated layer 7 is maintained between 0.03 and 0.06 mm to ensure its corrosion resistance while avoiding falling off and extending its service life; the hardness of the chrome-plated layer 7 is greater than or equal to 850HV to avoid it being too soft and affecting its corrosion resistance.

[0039] In this embodiment, the preparation process of the front barrel body 1 is as follows:

[0040] 1. Select 42CrMoA alloy round body as the raw material for preparing the front barrel body 1, cut the material according to the drawing size and process the outer shape, threaded hole 3, through hole 4 and inner hole 2 according to the installation size requirements of various injection molding machine models.

[0041] The material of 42CrMoA alloy round bar is prior art and can be retrieved on the Internet.

[0042] 2. The front barrel body 1 is heated to 840-860°C in a quenching furnace and then quenched to room temperature. The quenched front barrel body 1 is tempered in a tempering furnace at 560-580°C. The tempering time in the tempering furnace is calculated as follows: the maximum inner diameter of the inner hole 2 increases by 30mm for each 40-60 minutes of insulation time to improve the overall hardness.

[0043] 3. The front barrel body 1 is end-face processed on a Japanese Dawei CNC lathe, and a groove 5 is opened on the end face. The depth of the groove 5 is 1 to 1.5 mm, and the ring width of the groove 5 is 3 to 4 mm to form a rough blank; the groove 5 is polished and cleaned on a polishing machine to make the surface smooth without burrs, rust and other surface quality problems.

[0044] 4. The laser cladding equipment performs laser cladding on the cleaned groove 5, laser cladding Högnäs 2541-cobalt-based alloy powder to form a composite metal layer, the hardness of the composite metal layer is 46-52HRC, the thickness of the composite metal layer is greater than or equal to the depth of the groove 5, the ring width of the composite metal layer is greater than or equal to the ring width of the groove 5, and insulation treatment is performed during cladding, and the insulation temperature is 100-200°C. The front barrel body 1 after laser cladding is plane-finished on a surface grinder, and the end face and inner ring wall of the composite metal layer are ground to the dimensional tolerance required by the drawing, so that the thickness of the composite metal layer is equal to the depth of the groove 5, and the ring width of the composite metal layer is equal to the ring width of the groove 5, that is, the end face of the composite metal layer close to the injection molding machine is flush with the end face of the front barrel body 1 close to the injection molding machine, and the inner diameter of the composite metal layer is equal to the inner diameter of the end of the inner hole 2 close to the composite metal layer.

[0045] The specific parameters of the laser cladding process are as follows: main power of the equipment 5000-6000W (adjusted according to the size of the front barrel body 1), laser circular spot φ2, central gas 4L / min, protective gas 15L / min, powder feeding gas 1.2L / min, laser swing arc width 3.5-4.5mm (floating adjustment according to the size of the front barrel body 1 and the melting state of the porcelain), the front barrel body 1 swings each time The rotation angle is 1.6-2.5°, the total rotation angle is 381-385°, and the rotation speed is 430-1050° / min (floating adjustment according to the size of the front barrel body 1 and the melting state of the porcelain).

[0046] The composition of the Höganäs 2541-00 cobalt-based alloy powder is as follows: particle size 63-212um, carbon content 1.1%, silicon content 1.1%, iron content 1%, chromium content 28.5%, nickel content 1.5%, tungsten content 8%, and cobalt content 58.5%. The Höganäs 2541-00 cobalt-based powder is a prior art and can be retrieved on the Höganäs official website.

[0047] 5. The inner hole 2 is polished, and then the surface of the inner hole 2 is electroplated. The chrome plating layer has a single-side thickness of 0.03-0.06 mm and a hardness of not less than 850 HV.

[0048] The specific electroplating process is as follows:

[0049] Step 1: Install cathodic protection: Install the front barrel body 1 that needs to be electroplated with a hanger, and protect the parts that do not need to be electroplated with a pull-electric insulation device;

[0050] Step 2: Double-pass degreasing and cleaning: first ultrasonic degreasing (ratio 60-75g / l, bath temperature: 65-80℃, soaking for 3-6 minutes), then electrolytic degreasing (ratio 60-75g / L, bath temperature: 60-80℃, soaking for 2-3 minutes), and finally cold water cleaning and hot water cleaning;

[0051] Step 3: Place the barrel in the plating tank for electroplating: Place the clamped front barrel body 1 in the electroplating tank and keep it warm to 59-62°C. Start the switch power supply and calculate the current density of 35A to make the anode in the tank react. The reaction time is 100-240 minutes, so that a layer of hard chromium is produced on the surface of the inner hole 2.

[0052] Step 4: Cleaning and disassembly: After electroplating, wash with water and go to the unloading area to dismantle the hanger tooling and protective cathode;

[0053] Step 5: Polish the inner hole 2 after electroplating surface treatment with abrasive belt and cloth wheel to the requirements of the drawing, apply anti-rust oil and put it into the warehouse, which is the finished front barrel.

Claims

1. A corrosion-resistant front barrel of an injection molding machine, comprising a front barrel body (1) with an inner hole (2), a first corrosion-resistant structure for preventing the inner hole (2) from being corroded by gas being arranged on the inner hole (2), characterized in that: A second anti-corrosion structure is provided on the end surface of the front barrel body (1) that cooperates with the injection molding machine to prevent the end surface from being corroded by gas. The second anti-corrosion structure includes a groove (5) concavely arranged on the end surface of the front barrel body (1) that cooperates with the injection molding machine and an anti-corrosion layer (6) embedded in the groove (5) and having a thickness consistent with the depth of the groove (5). The groove (5) is concentrically arranged with the inner hole (2) and the inner hole (2) is concavely arranged at the bottom of the groove (5). The anti-corrosion layer (6) is annular and its annular width is equal to the annular width of the groove (5). The annular width of the groove (5) is the difference between the radius of the groove (5) and the radius of the inner hole (2) close to one end thereof.

2. The corrosion-resistant front barrel of an injection molding machine according to claim 1, characterized in that: The anti-corrosion layer (6) is a composite metal layer made by laser cladding cobalt-based alloy powder in the groove (5).

3. The corrosion-resistant front barrel of an injection molding machine according to claim 2, characterized in that: The hardness of the composite metal layer is 46-52HRC.

4. The corrosion-resistant front barrel of an injection molding machine according to claim 1, characterized in that: The depth of the groove (5) is 1 to 1.5 mm.

5. The corrosion-resistant front barrel of an injection molding machine according to claim 1, characterized in that: The ring width of the groove (5) is 3 to 4 mm.

6. The corrosion-resistant front barrel of an injection molding machine according to claim 1, characterized in that: The first anti-corrosion structure comprises a chrome plating layer (7) arranged on the inner annular wall of the inner hole (2).

7. The corrosion-resistant front barrel of an injection molding machine according to claim 6, characterized in that: The thickness of the chrome plating layer (7) is 0.03-0.06 mm, and the hardness of the chrome plating layer (7) is greater than or equal to 850 HV.

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