A method for additive and subtractive manufacturing of complex internal flow channels in an engine cylinder block

Abstract

The application discloses a kind of complex inner flow channel of engine cylinder body additive-subtractive composite manufacturing method, comprising the following steps, step 1, by additive manufacturing, engine cylinder body is printed to the preset height of complex inner flow channel, the printing work of base body is completed;Step 2, carry out subtractive work on base body, obtain one part structure of complex inner flow channel;Step 3, independently carry out additive-subtractive composite manufacturing outside cylinder body, another part structure of complex inner flow channel is manufactured into shape;Step 4, the one part structure of complex inner flow channel in step 2 is aligned with the another part structure of complex inner flow channel in step 3, welding is completed to manufacture the complex inner flow channel of engine cylinder body.Achieve different flow channel manufacturing without changing additive manufacturing direction, and the purpose that inner surface can be complete inner surface processing.

Description

Technical Field

[0001] This invention belongs to the field of intelligent manufacturing, specifically to a composite manufacturing method for adding or subtracting materials in complex internal flow channels of an engine cylinder block. Background Technology

[0002] The cylinder block is a crucial component of an engine, forming its main structural structure. Pistons, crankshafts, and other parts and accessories are mounted and supported within the cylinder block's framework. The cylinder block also connects each cylinder to the crankcase, providing a pathway for the flow of oil, water, and air. Currently, cylinder blocks are typically formed using open-mold casting. This casting process is prone to defects such as sand holes, shrinkage cavities, porosity, and uneven material structure. During engine operation, the power generation and output process subject the cylinder block to significant loads and severe vibrations, and these defects can cause the cylinder block to fail under high loads. Furthermore, cylinder block product development generally requires multiple technological iterations, each necessitating experimental verification. However, the open-mold casting process first handles the complex manufacturing and assembly of the casting core and cavity, resulting in each iteration consuming a significant amount of time and greatly increasing product development costs. Additive manufacturing is based on the principle of discrete stacking. The manufacturing process directly shapes the components based on the input of a digital model. Applying additive manufacturing can not only produce complex components but also avoid casting defects. Furthermore, it can be used to quickly prototype, verify, and iterate products according to product development needs by modifying the digital model, which greatly shortens the product development cycle and reduces costs.

[0003] Arc wire additive manufacturing technology is suitable for forming large and complex parts, but there is currently no suitable process for forming cylinder blocks. This is mainly due to the following two points: First, the cylinder block integrates water channels, air channels, and oil channels. The direction of these channels is sometimes parallel to the additive manufacturing direction and sometimes perpendicular to it. The forming process designed according to a certain flow channel will affect the forming of other flow channels. Second, the low-level surface quality brought about by the arc wire additive manufacturing process means that the design of the forming process must also consider the subtractive manufacturing process after additive manufacturing. Since the cylinder block includes many internal surface structures, some internal surfaces are difficult for the cutting tool to reach, such as the surface of the external cooling water cavity of the cylinder barrel. This greatly increases the difficulty of subsequent subtractive processing.

[0004] In summary, the existing technology for engine cylinder blocks suffers from problems such as high machining difficulty and low surface quality in the flow channels. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a composite manufacturing method for additive and subtractive materials for complex internal flow channels in engine cylinder blocks, so as to achieve the purpose of not having to change the additive manufacturing direction when manufacturing different flow channels, and the inner surface can be completely machined.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for manufacturing complex internal flow channels in an engine cylinder block using additive and subtractive materials composites includes the following steps:

[0008] Step 1: Using additive manufacturing, the engine cylinder block is printed to a predetermined height at the complex internal flow channel, completing the printing of the substrate;

[0009] Step 2: Perform subtractive processing on the substrate to obtain a portion of the complex internal flow channel structure;

[0010] Step 3: Independently carry out composite manufacturing of additive and subtractive materials outside the cylinder block to manufacture another part of the complex internal flow channel structure.

[0011] Step 4: Align one part of the complex internal flow channel structure from Step 2 with the other part of the complex internal flow channel structure from Step 3, and weld them together to complete the manufacturing of the complex internal flow channel in the engine cylinder block.

[0012] Preferably, in step 1, the inner flow channel portion is filled during additive manufacturing.

[0013] Preferably, in step 4, one part of the complex internal flow channel structure in step 2 and the other part of the complex internal flow channel structure in step 3 are welded together by manual beveling welding.

[0014] Preferably, when the complex internal flow channel is the air intake passage of the oil-gas separator in the engine cylinder block, the air intake passage includes an oil baffle structure, specifically including the following steps.

[0015] Step 1: Using additive manufacturing, the engine cylinder block is printed to the height of the top surface of the oil-gas separator intake channel, thus completing the printing of the substrate.

[0016] Step 2: Perform a material reduction operation on the substrate from Step 1 to obtain the lower half of the oil-gas separator intake channel, which includes an oil baffle structure, wherein the height of the oil baffle is the height of the top surface.

[0017] Step 3: Independently manufacture the upper half of the oil-gas separator intake channel using additive and subtractive materials outside the cylinder block.

[0018] Step 4: Align the lower half of the oil-gas separator intake channel from Step 2 with the upper half of the oil-gas separator intake channel from Step 3, and weld the lower half and upper half of the structure together by manual beveling welding to complete the manufacturing of the oil-gas separator intake channel in the engine cylinder block.

[0019] Furthermore, in step 3, the additive and subtractive composite manufacturing specifically includes the following process: the upper half of the gas intake channel of the oil-gas separator is made by adding or subtracting materials separately, leaving a square hole. A protrusion with the same shape and size as the square hole is set above the oil baffle plate. The square hole and the protrusion of the oil baffle plate are positioned correspondingly so that the protrusion of the oil baffle plate can be inserted into the square hole. During the process of welding the upper half of the gas intake channel of the gas separator to the substrate, the square hole and the protrusion of the oil baffle plate are welded together.

[0020] Preferably, the additive manufacturing process employs a cold metal transition wire process, and preheating is performed before additive manufacturing and manual welding.

[0021] Furthermore, the preheating temperature range is 80–120°C.

[0022] Furthermore, the preheating time ranges from 30 to 60 minutes.

[0023] Preferably, in step 2, the subtractive processing includes milling and grinding.

[0024] Preferably, the preset height is half the height of the complex internal flow channel.

[0025] Compared with the prior art, the present invention has the following beneficial technical effects:

[0026] This invention provides a composite manufacturing method for complex internal flow channels in engine cylinder blocks, utilizing arc additive manufacturing to produce cylinder blocks with multi-directional, complex internal flow channels. This method eliminates the need for multiple clamping operations to change the additive manufacturing direction while ensuring the subtractive machining of the inner surface of the internal flow channels, thus guaranteeing the quality of the inner surface finish. This avoids the problem in existing technologies where, when the internal flow channels are complex, it is difficult to perform subtractive machining on the inner surface, resulting in compromised surface quality. Attached Figure Description

[0027] Figure 1 This is a diagram showing the internal flow channels of the cylinder block.

[0028] Figure 2 This is a schematic diagram of the internal flow channel structure of the cylinder block.

[0029] Figure 3 A horizontal cross-sectional view of the oil-gas baffle in the gas intake channel of the oil-gas separator;

[0030] Figure 4 A schematic diagram of the gas intake channel structure of an oil-gas separator;

[0031] Figure 5 A schematic diagram of the horizontal cross-section of the oil-gas baffle structure in the gas intake channel of the oil-gas separator;

[0032] Figure 6A model for the independent addition and subtraction composite manufacturing of the gas intake channel of the oil-gas separator;

[0033] Figure 7 A model for independently manufacturing the gas intake channel of an oil-gas separator with slots using additive and subtractive materials composite manufacturing;

[0034] In the attached diagram: 1 is the first flow channel; 2 is the second flow channel; 3 is the third flow channel; and 4 is the fourth flow channel. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0036] like Figure 1 As shown, the cylinder block contains complex internal flow channels in multiple directions. According to conventional arc-wire additive manufacturing processes, only flow channels with the axial direction parallel to the printing direction can be manufactured (i.e., horizontal flow channels cannot be manufactured during vertical printing because overhanging printing would reduce the surface quality of the flow channels, and the upper surface of the flow channels cannot be processed by subtractive machining). From Figure 1 As can be seen, the shape and distribution of the internal flow channels in the cylinder block are extremely complex. In the existing technology of manufacturing cylinder blocks using electric arc additive manufacturing technology, when the cylinder block contains internal flow channels in multiple directions, it is necessary to clamp multiple times to change the additive direction. Repeated clamping will lead to positioning errors and prolong the processing time. When the internal flow channels are more complex, it is difficult to perform subtractive processing on the inner surface of the internal flow channels, thus failing to guarantee the surface quality of the inner surface. Regardless of which direction is used for printing, the problem of not being able to process the inner wall of the flow channel that is perpendicular to the axis direction will be encountered.

[0037] Example

[0038] like Figures 2 to 5 As shown, Figure 2 In the first flow channel 1, 1A is an inclined section, and 1B and 1C are vertical sections, which are connected to each other; in the second flow channel 2, 2A is a horizontal section, and 2B is a vertical section, which are connected to each other; the third flow channel 3 and the fourth flow channel 4 are two separate vertical straight channels.

[0039] The present invention discloses a composite manufacturing method for complex internal flow channels in an engine cylinder block, comprising the following steps:

[0040] Step 1: Using additive manufacturing, the engine cylinder block is printed to half the height of the complex internal flow channel (the internal flow channel is filled), completing the printing of the base material. The processing direction is distinguished by the direction at the beginning of the additive manufacturing process. Since additive manufacturing is a "layer-by-layer" process, the stacking direction is generally the direction of gravity. Therefore, the vertical direction here is the direction of gravity at the beginning of the additive manufacturing process, the horizontal direction is the direction perpendicular to the vertical direction, and the inclined direction is other directions.

[0041] Step 2: Perform subtractive machining on the substrate to obtain the lower half of the complex internal flow channel structure. The subtractive machining is mainly milling, but grinding can also be added. In this embodiment, the height is distinguished by approximately half, which does not need to be particularly precise, as long as both the upper and lower surfaces can be subtractively machined.

[0042] Step 3: Independently manufacture the upper part of the complex flow channel using additive and subtractive materials outside the cylinder block.

[0043] Step 4: Align the upper and lower parts of the inner flow channel structure and weld them together as one piece by manual beveling welding.

[0044] When the complex internal flow channel is specifically the air intake passage of the oil-gas separator in the engine cylinder block, the air intake passage includes an oil baffle structure, and the manufacturing method includes the following steps:

[0045] a) Using additive manufacturing, the engine cylinder block is printed up to the height of the upper top surface of the oil-gas separator's intake channel (with the inner flow channel portion being filled), completing the printing of the substrate; the upper top surface exceeds the higher side of the inner flow channel in the direction of gravity, completely covering the entire inner flow channel, followed by subtraction, as detailed in the attached figure. Figure 2 The arrow in section 1A points to the location.

[0046] b) Perform material reduction work on the substrate to obtain a partial structure of the oil-gas separator intake channel, including the oil baffle structure, wherein the height of the oil baffle is close to the height of the top surface;

[0047] c) The upper part of the oil-gas separator intake channel is manufactured independently outside the cylinder block through a composite process of adding and subtracting materials.

[0048] d) Align the upper and lower parts of the gas intake channel of the oil-gas separator and weld them together as one piece by manual beveling welding.

[0049] like Figures 6 to 7 As shown, the upper half of the gas intake channel of the oil-gas separator is made by adding or subtracting materials and has a square hole. A protrusion with the same shape and size as the directional hole is set above the oil baffle plate. The square hole and the oil baffle plate protrusion are positioned to correspond to each other, so that the oil baffle plate protrusion can be inserted into the square hole. During the process of welding the upper half of the gas intake channel of the gas separator to the base, the square hole and the oil baffle plate protrusion are welded together.

[0050] The above additive manufacturing process uses a cold metal transition wire process, and preheating is required before additive manufacturing and manual welding to ensure manufacturing quality. The preheating temperature is between 80 and 120°C, and the preheating time is between 30 and 60 minutes.

Claims

1. A method for manufacturing a complex internal flow channel in an engine cylinder block using additive and subtractive materials, characterized in that, Includes the following steps, Step 1: Using additive manufacturing, the engine cylinder block is printed to a predetermined height at the complex internal flow channel, completing the printing of the substrate; Step 2: Perform subtractive processing on the substrate to obtain a portion of the complex internal flow channel structure; Step 3: Independently carry out composite manufacturing of additive and subtractive materials outside the cylinder block to manufacture another part of the complex internal flow channel structure. Step 4: Align one part of the complex internal flow channel structure from Step 2 with the other part of the complex internal flow channel structure from Step 3, and weld them together to complete the manufacturing of the complex internal flow channel in the engine cylinder block. When the complex internal flow channel serves as the intake passage for the oil-gas separator in the engine cylinder block, the intake passage includes an oil baffle structure, specifically comprising the following steps. Step 1: Using additive manufacturing, the engine cylinder block is printed to the height of the top surface of the oil-gas separator intake channel, thus completing the printing of the substrate. Step 2: Perform a material reduction operation on the substrate from Step 1 to obtain the lower half of the oil-gas separator intake channel, which includes an oil baffle structure, wherein the height of the oil baffle is the height of the top surface. Step 3: Independently manufacture the upper half of the oil-gas separator intake channel using additive and subtractive materials outside the cylinder block. Step 4: Align the lower half of the oil-gas separator intake channel from Step 2 with the upper half of the oil-gas separator intake channel from Step 3, and weld the lower half and upper half of the structure together by manual beveling welding to complete the manufacturing of the oil-gas separator intake channel in the engine cylinder block.

2. The method for manufacturing a complex internal flow channel in an engine cylinder block using additive and subtractive materials according to claim 1, characterized in that, In step 1, the inner flow channel is filled during additive manufacturing.

3. The method for manufacturing a complex internal flow channel in an engine cylinder block using additive and subtractive materials according to claim 1, characterized in that, In step 4, one part of the complex internal flow channel structure from step 2 is welded to another part of the complex internal flow channel structure from step 3 by manual beveling welding.

4. The method for manufacturing a complex internal flow channel in an engine cylinder block using additive and subtractive materials according to claim 1, characterized in that, In step 3, the composite manufacturing of additive and subtractive materials specifically includes the following process: the upper half of the gas intake channel of the oil-gas separator is made of additive and subtractive materials with a square hole, and a protrusion with the same shape and size as the square hole is set above the oil baffle. The square hole and the protrusion of the oil baffle are positioned to correspond to each other, so that the protrusion of the oil baffle can be inserted into the square hole. During the process of welding the upper half of the gas intake channel of the gas separator to the substrate, the square hole and the protrusion of the oil baffle are welded together.

5. The method for manufacturing a complex internal flow channel in an engine cylinder block using additive and subtractive materials according to claim 1, characterized in that, The additive manufacturing process employs a cold metal transition wire process and preheating is performed before additive manufacturing and manual welding.

6. The method for manufacturing a complex internal flow channel in an engine cylinder block using additive and subtractive materials according to claim 5, characterized in that, The preheating temperature range is 80~120℃.

7. The method for manufacturing a composite material for complex internal flow channels in an engine cylinder block according to claim 5, characterized in that, The preheating time ranges from 30 to 60 minutes.

8. The method for manufacturing a complex internal flow channel in an engine cylinder block using additive and subtractive materials according to claim 1, characterized in that, In step 2, the subtractive processing includes milling and grinding.

9. A method for manufacturing a complex internal flow channel in an engine cylinder block using additive and subtractive materials, as described in claim 1, characterized in that... The preset height is half the height of the complex internal flow channel.

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