A process for die casting a transmission side cover with ultra-long oil gallery holes

Abstract

The application discloses a die-casting manufacturing process of a gearbox side cover containing superfine long oil channel holes, and aims at superfine long holes with a core needle length being 10-20 times of the diameter of a needle hole, and comprises the following steps: step one, mold opening, the mold is sprayed, the temperature of the core needle before spraying is 200-240 DEG C, and the temperature of the needle after spraying is 160 DEG C; step two, the oil channel hole core needle is inserted into the mold, and after the mold is closed, the aluminum liquid is poured into the tank; step three, the aluminum liquid is filled into the ingate at a low speed of 0.3 m / s, then the product cavity is filled at a high speed of 4 m / s, after the filling is completed, the pressure is increased at a specific pressure of 70 MPa, the pressure increasing time is 8 s, and the product cooling time is 8 s; the superfine long core needle is cooled after the aluminum liquid is filled for 3 s, the cooling time is 15 s, and the water pressure is 10 kg / cm2; step four, after the product cooling is completed, the core needle is pulled out, and the product is ejected after the mold is opened. Through improvement of the material and structure of the superfine long oil channel hole core needle and optimization of the die-casting forming pouring scheme, the die-casting stability and reliability are improved, and the die-casting manufacturing and stable production of the gearbox side cover with superfine long oil channel holes are realized.

Description

Technical Field

[0001] This invention relates to a die-casting manufacturing process for a gearbox side cover containing ultra-thin and long oil passage holes, belonging to the field of aluminum alloy pressure casting technology. Background Technology

[0002] Traditionally, the length of the mandrel in die-casting parts is designed to be no more than five times its diameter to ensure that it does not deform, wobble, or even break under the high speed and pressure during the aluminum alloy filling and holding process. However, due to the increasing integration and complexity of aluminum alloy die-casting products in the automotive industry, the long oil passages in gearbox side covers are often die-cast to ensure surface density and reduce processing costs, posing a significant challenge to stable die-casting production. The wobble and deformation of the mandrel are difficult to control during the die-casting process of ultra-thin and long oil passages, and are also difficult to detect in a timely manner. This can lead to changes in the position of the bottom of the oil passage, causing local wall thickness deviations from the drawing requirements at the oil passage location. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides a die-casting manufacturing process for a gearbox side cover with ultra-fine oil passage holes. The length of the mandrel is 10-20 times the diameter of the hole. By improving the material and structure of the ultra-fine oil passage hole mandrel and optimizing the die-casting injection scheme, the stability and reliability of the ultra-fine oil passage hole mandrel are improved, thereby achieving the die-casting manufacturing and stable production of gearbox side covers with ultra-fine oil passage holes.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is: a die-casting manufacturing process for a gearbox side cover containing ultra-fine and long oil passage holes, comprising the following steps;

[0005] Step 1: With the mold open, spray the mold, focusing on the long needle area to ensure that the release agent effectively adheres to the surface of the ultra-fine long core needle. The core needle temperature before spraying is 200℃-240℃, and the needle temperature after spraying is 140℃-180℃.

[0006] Step 2: After spraying and drying the mold surface, insert the ultra-fine long oil channel hole mandrel into the mold to close the mold. After closing the mold, pour the molten aluminum into the material tank. The temperature of the aluminum alloy material is 660-670℃.

[0007] Step 3: After the molten aluminum is filled into the product's inner gate at a low speed of 0.2 m / s to 0.4 m / s, it is then filled into the product cavity at a high speed of 3 m / s to 5 m / s. After filling, a specific pressure of 60 MPa to 80 MPa is applied for pressurization for 5 to 10 seconds. The product is then cooled for 5 to 10 seconds. Simultaneously, the ultra-slender mandrel is cooled by high-pressure cooling 3 seconds after the molten aluminum is filled, with a cooling time of 15 seconds and a water pressure of 10 kg / cm².

[0008] Step 4: After the product has cooled down, the core is pulled out, and the product is ejected after the mold is opened.

[0009] Furthermore, the ultra-slender oil channel core pin is made of W360 material with a matrix hardness of HRC54-56, and its surface is treated with soft nitriding to increase the hardness of the core pin to HV700-900.

[0010] Furthermore, the ultra-thin, long oil channel core pin adopts a 0.7° draft angle and has a built-in φ5mm cooling water channel.

[0011] Furthermore, the product has four ingates, which are enclosed in a gating system, allowing the molten aluminum from the four ingates to reach the tail of the oil channel mandrel simultaneously.

[0012] Furthermore, the filling temperature of the ultra-slender oil channel core needle region is maintained between 150-180°C at the moving and fixed mold temperatures.

[0013] Furthermore, the high-pressure cooling control of the ultra-slender mandrel adopts point cooling machine control.

[0014] The beneficial effects of this invention are: this invention improves the material and structure of the ultra-slender oil passage mandrel, optimizes the die-casting injection scheme, improves the stability and reliability of the ultra-slender oil passage mandrel, and realizes the die-casting manufacturing and stable production of the gearbox side cover with ultra-slender oil passage holes. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the casting structure of the present invention;

[0016] Figure 2 For the present invention Figure 1 Schematic diagram of BB structure;

[0017] Figure 3 This is a schematic diagram of the ultra-slender oil channel hole type core needle structure of the present invention.

[0018] In the diagram: 1. Ultra-thin long oil channel core pin, 11. Cooling water channel, 2. Spot cooler, 3. Mold, 4. Ingate 1, 5. Ingate 2, 6. Ingate 3, 7. Ingate 4. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of the invention.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0021] This implementation example Figure 1 , Figure 2 and Figure 3 As shown, it is a die-casting manufacturing process for a gearbox side cover with ultra-fine and long oil passage holes, including the following steps;

[0022] Step 1: With mold 3 in the open state, spray mold 3, focusing on spraying the long needle area to ensure that the release agent effectively adheres to the surface of the ultra-fine long core needle. The core needle temperature is 220℃ before spraying and 160℃ after spraying.

[0023] Step 2: After spraying and drying the surface of mold 3, insert the ultra-fine long oil channel hole mandrel 1 into mold 3 to close the mold. After closing the mold, pour the aluminum liquid into the material tank. The temperature of the aluminum alloy material is 660-670℃.

[0024] Step 3: After the molten aluminum is filled into the product's inner gate at a low speed of 0.3 m / s, it is then filled into the product cavity at a high speed of 4 m / s. After filling, a specific pressure of 70 MPa is applied for 8 seconds, followed by a product cooling time of 8 seconds. Simultaneously, the ultra-slender mandrel is cooled using a high-pressure cooling method 3 seconds after the molten aluminum is filled, with a cooling time of 15 seconds and a water pressure of 10 kg / cm².

[0025] Step 4: After the product has cooled down, the core is pulled out, and the product is ejected after the mold is opened.

[0026] This invention addresses a gearbox side cover with ultra-thin oil passage holes. It optimizes the material selection for the mandrel with these holes, replacing the traditional SKD61 material with W360. The matrix hardness is HRC54-56, higher than the conventional HRC48-50. Surface soft nitriding treatment further enhances the mandrel's hardness to HV700-900, improving its resistance to deformation. Simultaneously, the mandrel features a 0.7° draft angle and a built-in φ5mm cooling water channel. During product cooling and solidification, high-pressure water is injected through this channel to cool the mandrel, reducing surface burns and aluminum adhesion, lowering the clamping force on the mandrel, and minimizing deformation during demolding.

[0027] This invention improves the design of the casting system by using an encircling pouring method to fill the area at the tail of the ultra-slender core pin that is prone to swaying under stress. The angle adjustment and flow control of ingates 1-4, 2-5, 3-6, and 4-7 ensure that the molten aluminum from ingates 1-4, 2-5, 3-6, and 4-7 arrives at the tail of the core pin in the oil channel simultaneously. Furthermore, by adjusting the feeding angle, the upward radial force exerted on the core pin by the feeding positions of ingates 1-4 and 2-5 is balanced with the downward radial force exerted on the core pin by the feeding positions of ingates 3-6 and 4-7. This ensures that the radial force on the core pin is balanced when filling the oil channel area, preventing deformation caused by the molten aluminum.

[0028] The casting is made of ADC12 aluminum alloy. During the injection filling process, a low-speed filling rate of 0.3 m / s is used to fill the product's inner gate, followed by a high-speed filling rate of 4 m / s into the product cavity. After filling, a specific pressure of 70 MPa is applied to ensure product molding and internal quality. Simultaneously, the temperature of the mandrel area is maintained between 150-180℃ in both the moving and fixed molds before filling. High-pressure cooling of the ultra-slender mandrel is controlled by a spot cooler. Water is introduced to cool the mandrel 3 seconds after filling begins, with a cooling time of 15 seconds and a water pressure of 10 kg / cm².

[0029] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A process for die casting a transmission side cover having an ultra- long oil gallery hole, characterized in that, It comprises the following steps: Step one: mold (3) open mold state, mold (3) is sprayed, focus on spraying long needle position, to ensure that the release agent is effectively adhered to the surface of the superfine long core needle, the temperature of the core needle before spraying is 200-240 DEG C, and the temperature of the needle after spraying is 140-180 DEG C; Step two: after the surface of the mold (3) is sprayed and dried, the superfine long oil channel core needle (1) is inserted into the mold (3), and the mold is closed. After the mold is closed, the aluminum liquid is poured into the trough, and the aluminum alloy material temperature is 660-670 DEG C; Step three: after the aluminum liquid is filled into the product ingate at a low speed of 0.2 m / s (m / s)-0.4 m / s (m / s), the product cavity is filled at a high speed of 3 m / s (m / s)-5 m / s (m / s), and the specific pressure is increased to 60 MPa-80 MPa after filling, the pressure increasing time is 5-10 s (seconds), and the product cooling time is 5-10 s (seconds); at the same time, the superfine long core needle is cooled by high-pressure cooling method after the aluminum liquid is filled for 3 s, and the cooling time is 15 s (seconds), and the water pressure is 10 kg / cm²; Step four: after the product is cooled, the core is pulled out, and the product is ejected after the mold is opened; the material of the superfine long oil channel core needle (1) is selected from W360 material, the base hardness is HRC 54-56, the surface is treated by soft nitriding to improve the hardness of the core needle to HV 700-900; the superfine long oil channel core needle (1) adopts a demolding slope of 0.7°, and a cooling water channel (11) with a diameter of 5 mm is arranged inside; the product ingate is provided with four, which are ingate one (4), ingate two (5), ingate three (6) and ingate four (7), which adopt a surrounding pouring mode, and the aluminum liquid at the positions of the four ingates reaches the tail of the oil channel core needle at the same time; the temperature of the superfine long oil channel core needle (1) is maintained at 150-180 DEG C between the movable and fixed molds before filling; the high-pressure cooling control of the superfine long oil channel core needle (1) adopts point cooling machine (2) control cooling.

Images