Machining method for special-shaped double-layer cooling structure part with allowance-free appearance
By reserving reference blocks when 3D printing parts, combined with fitter marking and CNC machining, the problems of machining accuracy and redundant prevention of parts of special-shaped channel structures are solved, and efficient processing and quality assurance are achieved.
Patent Information
- Application Number
- CN202311848255.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-29
- Publication Date
- 2025-07-01
AI Technical Summary
The prior art is difficult to effectively process special-shaped channel structure parts with no margin shape, especially in ensuring machining accuracy and preventing excess from entering the internal channel.
By reserving 4 reference blocks during the 3D printing process, combining fitter marking and CNC machining, the reference correcting efficiency of parts is ensured. At the same time, the internal passage is sealed before processing, and flexible materials and industrial plasticine are used to form a seal to prevent coolant and waste chips from entering; after processing, cleaning and drying are carried out to ensure that there is no excess in the passage.
It realizes efficient machining of parts with no margin of external shape and shaped channel structure, ensures the accuracy of the relative position relationship of the parts and the cleanliness of the internal channels, and improves the processing quality and reference correcting efficiency.
Smart Images
Figure CN120228510A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of machining, and particularly to a machining method for a special-shaped double-layer cooling structure part with a non-remnant shape. Background Art
[0002] A special-shaped channel structure part with a non-remnant shape of a certain product is one of the important components of aerospace products, and is used to protect key equipment of aerospace products from working effectively during the flight process of combustion heat release and aerodynamic heating.
[0003] Such parts are products formed by 3D printing. The outer surface, inner surface and internal channels are all formed by printing and do not require machining. CNC machining only needs to machine the butt-joint and mating positions with high machining accuracy, and it is necessary to ensure the relative positional relationship between the machined features and the non-machined outer surface, inner surface and internal channels. However, there is no alignment reference for CNC machining. In addition, during the CNC machining process, it is inevitable for foreign matters (such as waste pins, coolant, etc.) to enter the internal channel structure. It is difficult to remedy quality problems or uncontrollable foreign matters during part machining.
[0004] There is no mechanical machining experience that can be borrowed for machining such parts. Therefore, there is an urgent need for a CNC machining method suitable for special-shaped channel structure parts. Summary of the Invention
[0005] In view of the above analysis, the present invention aims to provide a machining method for a special-shaped double-layer cooling structure part with a non-remnant shape to complete the machining process and ensure the quality of the machined part.
[0006] In a first aspect, the present invention provides a machining method for a special-shaped double-layer cooling structure part with a non-remnant shape, including the following steps:
[0007] S1: Reserve a margin of 3-5 mm at the butt-joint and mating positions in the 3D printing handover state, leave four reference blocks on the front and rear end faces of the part, and print the theoretical end face lines on the front and rear end faces;
[0008] S2: Appearance inspection;
[0009] S3: Fitter marking. Perform three-dimensional scanning on the part. According to the three-dimensional scanning margin results, find the theoretical positions of each reference block in the horizontal and vertical directions, level the horizontal and vertical directions respectively, and find the theoretical horizontal plane and vertical plane by centering;
[0010] S4: CNC machining. Vertically clamp the part by using a pressing plate, a spacer block and a screw rod for installation, and align the reference;
[0011] S5: Before machining, block the internal channels;
[0012] S6: After machining, clean and dry the internal channels.
[0013] Further, the four reference blocks are respectively located at the front and rear end faces of the part, symmetrically up and down in the horizontal direction and symmetrically left and right in the vertical direction.
[0014] Further, the reference block on the front end face is (10 - 20) mm × (10 - 20) mm, and the reference block on the rear end face is (10 - 20) mm × (10 - 20) mm.
[0015] Further, in step S2, check that the part has no cracks, shrinkage porosity, and holes.
[0016] Further, in step S4, it includes: (1) Adjust and align the cross center line of the end face; make the cross center line parallel to the X-axis and Y-axis of the machine tool, and use this as the X-axis and Y-axis of the subsequent machining coordinate system;
[0017] (2) Adjust and align the theoretical line of the end face; make the normal vector of the end face parallel to the Z-axis of the machine tool, and use this as the Z-axis of the subsequent machining coordinate system;
[0018] (3) Through the handwheel of the machine tool, move the main shaft of the machine tool in the X, Y, and Z directions to align the cross center line of the outer profile surface.
[0019] Further, in step S5, use flexible materials and industrial putty to block the internal channel.
[0020] Preferably, the flexible material is a cloth strip or a tarpaulin.
[0021] Further, the termination position of the flexible material filling is 3 - 5 mm lower than the theoretical end face, and the termination position of the industrial putty is not lower than the theoretical end face by 3 - 5 mm.
[0022] Further, in step S6, use clean water to wash the internal channel, repeat the washing three times continuously, filter the water flowing out from the water outlet with a clean white cloth bag for each washing cycle, and check the excess substances in the bag. If no metal chips and non-metal excess substances are found each time, it is considered that the washing is qualified.
[0023] Further, the processing method further includes using a plugging tooling to be installed on the internal channel to seal the internal channel.
[0024] Further, the plugging tooling includes a sealing ring and a conforming aluminum plate.
[0025] Compared with the prior art, the present invention can at least achieve one of the following beneficial effects:
[0026] 1. The present invention provides a processing method for machining special-shaped structural parts with non-allowance outer-shaped cavities. During the process of printing parts, four reference blocks are reserved. Combining fitter marking and numerical control machining effectively ensures the relative positional relationship between the non-machined special-shaped outer surface and the upper and lower end faces to be machined, improves the reference alignment efficiency, enables the smooth completion of part machining, and ensures the machining quality of the parts.
[0027] 2. The parts processed by the present invention contain internal channels, and it is necessary to block the internal channels before machining. The method of combining flexible materials and industrial putty is used for blocking. First, the flexible material is placed in the channel, and then the industrial putty is placed on the surface of the flexible material, which can effectively prevent coolant and machining waste chips from entering the channel during the machining process.
[0028] 3. After the part machining is completed, the flexible material and industrial putty are removed, and then the channel is cleaned with clean water and continuously washed three times, effectively cleaning the channel and confirming that there is no excess in the channel; the channel is dried.
[0029] 4. After the machining, cleaning and drying are completed in the present invention, the channel is blocked by a blocking tooling and stored in the warehouse with the parts, effectively avoiding the entry of excess into the channel during the transportation process and protecting the channel to the greatest extent.
[0030] In the present invention, the above technical solutions can also be combined with each other to achieve more preferred combination schemes. Other features and advantages of the present invention will be described in the subsequent specification, and some advantages can be made obvious from the specification or understood by implementing the present invention. The objectives and other advantages of the present invention can be realized and obtained from the content specifically pointed out in the specification and the drawings. Description of the Drawings
[0031] The drawings are only for the purpose of showing specific embodiments and are not considered to be a limitation of the present invention. Throughout the drawings, the same reference signs denote the same components.
[0032] Figure 1 It is a schematic diagram of the reference block position;
[0033] Figure 2 It is a simplified diagram of the theoretical lines of the front and rear end faces;
[0034] Figure 3 It is a special-shaped channel structure part with a non-allowance outer shape;
[0035] Figure 4 It is an enlarged schematic diagram of the channel in the special-shaped channel structure part;
[0036] In the figure, 1. The reference block of the front end face; 2. The reference block of the rear end face. Detailed Embodiments
[0037] The preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings. The accompanying drawings form a part of the present invention and are used together with the embodiments of the present invention to explain the principles of the present invention, rather than to limit the scope of the present invention.
[0038] With the gradual development of 3D printing technology, more and more products are formed by 3D printing, with less or no machining allowance. For example, products in the aerospace field have their outer surfaces, inner surfaces, and internal channels all formed by printing and do not require machining, but machining is needed at the docking and mating positions.
[0039] Therefore, the present invention provides a processing method for a special-shaped double-layer cooling structure part with a non-remnant outer shape, including the following steps:
[0040] S1: Leave a machining allowance of 3 - 5 mm at the docking and mating positions in the 3D printing handover state. Leave four reference blocks on the front and rear end faces of the part, and print the theoretical end face lines on the front and rear end faces.
[0041] S2: Appearance inspection;
[0042] S3: Fitter marking. Perform a three-dimensional scan of the part. According to the three-dimensional scan allowance results, find the theoretical positions of each reference block in the horizontal and vertical directions, level the horizontal and vertical directions respectively, and find the theoretical horizontal plane and vertical plane by centering.
[0043] S4: CNC machining. Vertically clamp the part using a pressing plate, a spacer block, and a screw rod for installation, and align the reference.
[0044] S5: Before machining, block the internal channels;
[0045] S6: After machining, clean and dry the internal channels.
[0046] Compared with the prior art, the present invention provides a processing method that leaves a machining allowance at the docking and mating positions during the part manufacturing process, facilitating subsequent machining. In addition, two reference blocks are provided on each of the front and rear end faces of the part, and combined with fitter marking and CNC machining, the relative position relationship between the non-machined special-shaped outer surface and the upper and lower end faces that need to be machined is effectively guaranteed, improving the reference alignment efficiency, enabling the part machining to be successfully completed, and ensuring the machining quality of the part.
[0047] It should be noted that referring to Figure 1 , the part in the present invention is a complex special-shaped cabin structure part, which is trapezoidal as a whole and contains channels inside. The outer surface, inner surface, and internal channels of the part do not require machining. The left side of the part is the front end face, the right side is the rear end face, and the front end face and the rear end face are mating faces that need to be machined.
[0048] Specifically, the reference blocks described above are respectively located at the front and rear end faces of the part, symmetrically up and down in the horizontal direction and symmetrically left and right in the vertical direction.
[0049] Specifically, the reference block on the front end face is (10 - 20) mm × (10 - 20) mm, and the reference block on the rear end face is (10 - 20) mm × (10 - 20) mm.
[0050] Preferably, the reference block on the front end face is 15 mm × 20 mm, and the reference block on the rear end face is 15 mm × 15 mm.
[0051] It should be noted that with reference to Figure 1 , using 3D printing technology to form complex-shaped cabin structure parts, the complex-shaped cabin structure contains internal channels. During the forming and preparation process of the parts, reference blocks are directly printed on the front and rear end faces of the parts, two on each of the front and rear end faces. Their function is to facilitate aligning the horizontal and vertical reference planes, which is beneficial for subsequent processing. The reference blocks are located on the front and rear end faces, and the farther the placement positions are from each other, the higher the accuracy of the theoretical reference plane found. And the size of the reference block on the front end face and the reference block on the rear end face is preferably in the range of 10 - 20 mm; when the size of the reference block is less than 10 mm, it is impossible to ensure accurate alignment of the horizontal and vertical reference planes; when the size of the reference block is greater than 20 mm, it affects the structure of the part, and during the removal in subsequent processing, it increases the overall duration.
[0052] With reference to Figure 2 , the reference blocks on the front end face and the reference blocks on the rear end face are used as reference lines, and then the theoretical end face lines on the front and rear end faces are found.
[0053] Specifically, in step S2, check that the part has no cracks, shrinkage porosity, and holes.
[0054] After printing and forming, before processing, conduct an overall appearance inspection of the part to ensure that there are no defects such as cracks, shrinkage porosity, and holes in the part. It is also necessary to check whether the internal channels of the part are protected in real time to prevent foreign objects from entering the internal channels.
[0055] Specifically, in step S3, according to the 3D scanning allowance results, find the theoretical positions of each reference block in the horizontal and vertical directions, level the horizontal and vertical directions respectively, and find the theoretical horizontal plane and vertical plane by centering.
[0056] It should be noted that the four reference blocks are respectively located at the front and rear end faces of the part. First, the part is placed horizontally. According to the scanning results and based on the allowances of each reference block in the horizontal direction, the supports of the part in the horizontal direction are respectively adjusted in the reverse direction so that the theoretical horizontal planes of the four reference blocks are on the same plane, and then the horizontal reference plane (line) of the part can be determined. Similarly, based on the allowances of the reference block in the left - right direction, the theoretical reference planes on the left and right of the reference block are found, and then the center - divided reference plane is used to determine the theoretical center line (vertical plane) of the part in the left - right direction.
[0057] Specifically, in step S4, vertical clamping is adopted with the front end face of the part facing downwards.
[0058] It should be noted that in the present invention, vertical clamping is adopted, and the part is placed vertically with the front end face facing downwards or the rear end face facing downwards, which is convenient for the operator to align the reference. Secondly, the influence of gravity on the deformation of the workpiece during the machining process is smaller in vertical clamping.
[0059] Specifically, in step S4, it includes: (1) Adjusting and aligning the cross - center line of the end face; making the cross - center line parallel to the X - axis and Y - axis of the machine tool, and using this as the X - axis and Y - axis of the subsequent machining coordinate system.
[0060] (2) Adjusting and aligning the theoretical line of the end face; making the normal vector of the end face parallel to the Z - axis of the machine tool, and using this as the Z - axis of the subsequent machining coordinate system.
[0061] (3) Through the handwheel of the machine tool, adjusting the movement of the machine tool spindle in the X, Y, and Z directions to align the cross - center line of the outer profile surface.
[0062] It should be noted that in the present invention, the end face is the left and right end faces, and the cross - center line includes a vertical line and a horizontal line, which is convenient for determining the coordinate system in the subsequent machining.
[0063] Specifically, in step S5, the internal channel is blocked with flexible materials and industrial putty.
[0064] Preferably, the flexible material is a cloth strip or a tarpaulin.
[0065] Specifically, the termination position of the flexible material filling is 3 - 5 mm lower than the theoretical end face; the termination position of the industrial putty is not lower than the theoretical end face by 3 - 5 mm.
[0066] It should be noted that in the present invention, the internal channels in the complex - shaped cabin - body structure parts do not need to be machined. Therefore, before machining, the internal channels need to be protected to prevent waste chips, coolant, etc. generated during the machining process from entering the internal channels. First, a clean flexible material is selected to fill the internal channels, and after filling, it should be 3 - 5 mm lower than the theoretical end face; then industrial putty is covered on the surface of the flexible material so that the internal channels form a completely enclosed space.
[0067] Under the combined action of the flexible material and industrial plasticine, the entry of solid waste chips and liquid coolant into the internal channel is effectively prevented, and the flexible material and industrial plasticine are relatively soft and will not damage the surface of the part.
[0068] Specifically, in step S6, the internal channel is cleaned with clean water, and the cleaning is continuously repeated three times. Each time, the water flowing out of the water outlet in a cleaning cycle is filtered with a clean white cloth bag, and the excess matter in the bag is checked. If no metal chips and non-metal excess matter are found each time, the cleaning is considered qualified.
[0069] In order to ensure that there is no excess matter in the internal channel, the cleaned channel needs to be dried to ensure that there is no water trace and other impurities in the internal channel.
[0070] Specifically, the processing method further includes installing a plugging tooling on the internal channel to seal the internal channel.
[0071] Specifically, the plugging tooling includes a sealing ring and a conforming aluminum plate.
[0072] It should be noted that after processing and cleaning, the internal channel needs to be protected to prevent foreign objects and other impurities from entering the channel and causing damage to its use. Therefore, a plugging tooling is used to protect the internal channel to ensure that no foreign objects enter the internal channel of the part during the transportation process, storage stage, until before assembly.
[0073] In order to clearly explain the present invention, the following examples and comparative examples are used for illustration.
[0074] Example 1
[0075] A processing method for a special-shaped double-layer cooling structure part with a non-remnant shape includes the following steps: The part in the present invention is a complex special-shaped structure cabin body, with an internal channel structure in the cabin body and channel inlets and outlets at the front and rear end faces.
[0076] S1: Leave a margin at the docking and mating positions in the 3D printing handover state, that is, leave a margin at the left and right end faces, and the margin is 3 - 5 mm. Two reference blocks are respectively machined on the front and rear end faces of the part. The reference block on the front end face is 15 mm × 20 mm, and the reference block on the rear end face is 15 mm × 15 mm. And the theoretical end face lines are printed on the front and rear end faces (refer to Figure 1 and Figure 2 );
[0077] S2: Conduct an appearance inspection on the part before processing to check that the part has no defects such as cracks, shrinkage porosity, and holes.
[0078] S3: The fitter marks lines, performs three-dimensional scanning on the parts, and based on the results of the three-dimensional scanning allowance, finds the theoretical positions of each reference block in the horizontal and vertical directions, levels the horizontal and vertical directions respectively, and finds the theoretical horizontal plane and vertical plane by centering;
[0079] S4: CNC machining. The parts are vertically clamped by using a pressing plate, a spacer block and a screw rod. The small end is at the bottom and the reference is aligned.
[0080] (1) Adjust the cross center lines of the front and rear end faces before and after alignment; make the cross center lines parallel to the X-axis and Y-axis of the machine tool, and use them as the X-axis and Y-axis of the subsequent machining coordinate system;
[0081] (2) Adjust the theoretical lines of the aligned end faces; make the normal vectors of the front and rear end faces parallel to the Z-axis of the machine tool, and use them as the Z-axis of the subsequent machining coordinate system;
[0082] (3) Through the handwheel of the machine tool, adjust the movement of the machine tool spindle in the X, Y, and Z directions to align the cross center line of the outer profile surface;
[0083] S5: Before machining, first block the internal channel with a cloth strip, and the termination position is 4 mm lower than the theoretical end face; then cover the cloth strip with industrial plasticine, and the termination position is 3 mm higher than the theoretical end face. Refer to Figure 3 and Figure 4 , and then perform machining after blocking;
[0084] S6: After machining, clean and dry the internal channel;
[0085] Clean the internal channel with clean water, repeat the cleaning three times continuously, filter the water flowing out of the water outlet with a clean white cloth bag for each cleaning cycle, and check the excess substances in the bag. If no metal chips and non-metal excess substances are found each time, it is considered that the cleaning is qualified, and then dry the internal channel;
[0086] S7: Block the dried internal channel with a blocking tooling. The blocking tooling includes a sealing ring and a conforming aluminum plate, and then store it.
[0087] The above is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.
Claims
1. A processing method for a special-shaped double-layer cooling structure part with a non-redundant outer shape, characterized in that, It includes the following steps: S1: Leave a margin of 3 - 5 mm at the docking and mating positions of the 3D printing handover state. Leave four reference blocks on the front and rear end faces of the part, and print the theoretical end face lines on the front and rear end faces; S2: Appearance inspection; S3: Fitter marking. Perform three-dimensional scanning on the part. According to the three-dimensional scanning margin results, find the theoretical positions of each reference block in the horizontal and vertical directions, level the horizontal and vertical directions respectively, and find the theoretical horizontal plane and vertical plane by centering; S4: NC machining. Vertically clamp the part using a pressing plate, a spacer block and a screw rod, and align the reference; S5: Before machining, block the internal channels; S6: After machining, clean and dry the internal channels.
2. The processing method according to claim 1, characterized in that, The four reference blocks are respectively located on the front and rear end faces of the part, symmetrically up and down in the horizontal direction and symmetrically left and right in the vertical direction.
3. The processing method according to claim 2, wherein, The reference block on the front end face is (10 - 20) mm × (10 - 20) mm, and the reference block on the rear end face is (10 - 20) mm × (10 - 20) mm.
4. The processing method according to claim 1, characterized in that, In step S2, check that the part has no cracks, shrinkage porosity and holes.
5. The processing method according to claim 1, wherein In step S4, it includes (1) Adjust and align the cross center line of the end face; Make the cross center line parallel to the X-axis and Y-axis of the machine tool, and use this as the X-axis and Y-axis of the subsequent machining coordinate system; (2) Adjust and align the theoretical line of the end face; Make the normal vector of the end face parallel to the Z-axis of the machine tool, and use this as the Z-axis of the subsequent machining coordinate system; (3) Through the handwheel of the machine tool, adjust the movement of the machine tool spindle in X, Y, and Z to align the cross center line of the outer profile surface.
6. The processing method according to claim 1, characterized in that, In step S5, use flexible materials and industrial putty to block the internal channels; Preferably, the flexible material is a cloth strip or a tarpaulin.
7. The processing method according to claim 6, wherein The termination position of the flexible material filling is 3 - 5 mm lower than the theoretical end face; The termination position of the industrial putty is not lower than 3 - 5 mm of the theoretical end face.
8. The processing method according to claim 1, characterized in that, In step S6, clean the internal channels with clean water, repeat the cleaning three times continuously. Filter the water flowing out of the water outlet with a clean white cloth bag for each cleaning cycle, and check the excess substances in the bag. If no metal chips and non-metal excess substances are found each time, it is considered that the cleaning is qualified.
9. The processing method according to claim 1, characterized in that The processing method further includes installing a blocking tooling on the internal channels to seal the internal channels.
10. The processing method according to claim 9, characterized in that, The blocking tooling includes a sealing ring and a conforming aluminum plate.