Air inlet channel wind tunnel test model manufacturing method based on 3D printing sand mold core casting

Abstract

The invention belongs to the technical field of wind tunnel test model manufacturing, and particularly relates to an air inlet channel wind tunnel test model manufacturing method based on 3D printing sand mold core casting, which comprises the following steps: step 1, designing a sand mold structure of a corresponding form according to a model segmentation structure; 2, sectional sand mold 3D printing forming is carried out; thirdly, molten metal liquid is poured; fourthly, size detection and ultrasonic flaw detection are conducted on the formed blank, and polishing and fine trimming are conducted; fifthly, the refined segmented models are fixedly connected in sequence, and then the inner cavity of the air inlet channel is integrally polished and painted; and 6, checking the appearance of the model, and checking size detection data. Based on a sand mold 3D printing process, all curved surfaces and complex structures of the model can be flexibly manufactured; the sand mold does not need to be made after traditional mold making, traditional mold making, modeling and core making processes are replaced, and the construction period is greatly shortened.

Description

Technical Field

[0001] The present invention belongs to the technical field of wind tunnel test model manufacturing, and particularly relates to a method for manufacturing an inlet wind tunnel test model based on 3D printing sand core casting. Background Art

[0002] Conventional wind tunnel test models are mostly made of metal materials through traditional machining methods. For large-sized models, the preparation time of metal materials is also involved. Therefore, the production of metal structure models has problems such as long cycle and high cost. For complex internal shape inlet models, it is often difficult to achieve internal machining through mechanical insertion.

[0003] At present, the development of 3D printing technology is becoming more and more mature, and its application in the manufacturing of wind tunnel test models is also increasing, which can realize complex configurations that are difficult to present by traditional machining. However, non-metal 3D materials, such as photosensitive resin, nylon and other materials, cannot bear large loads. And when printing and manufacturing large-sized shell structures, large-scale warping deformation is likely to occur.

[0004] Metal 3D structures are delicate and have high strength, but the printing price is high, even much higher than traditional machining. It can only be used as a processing method for key fine components and is not suitable as a main processing method for large-sized model bodies. Summary of the Invention

[0005] In order to overcome the above problems and achieve the purpose of low-cost and rapid manufacturing of large-sized complex internal shape inlet wind tunnel test models, the present application provides the following technical solutions:

[0006] A method for manufacturing an inlet wind tunnel test model based on 3D printing sand core casting, comprising the following steps:

[0007] Step 1, design a sand mold structure with a corresponding shape according to the segmented structure of the model;

[0008] Step 2, perform 3D printing and forming of the segmented sand mold. Through binder jet 3D printing technology, layer-by-layer bonding of granular materials is carried out to obtain the segmented sand mold;

[0009] Step 3, pour molten metal into the printed sand mold; after cutting the riser and runner, perform heat treatment and sandblasting on the formed blank;

[0010] Step 4, perform dimensional inspection and ultrasonic flaw detection on the formed blank. After passing the inspection, perform polishing and finishing;

[0011] Step 5, assemble the refined segmented models. Use the structural connection flanges reserved at both ends of the segmented models to fixedly connect the refined segmented models in sequence, and then perform overall polishing and painting on the inner cavity of the inlet;

[0012] Step 6: Inspect the appearance of the model and check the dimensional inspection data.

[0013] Furthermore, in Step 1, when designing the sand mold structure of the corresponding form, design the flange interface of the model segmented structure as needed.

[0014] Furthermore, the granular material described in Step 2 is silica sand, ceramic sand or coated sand.

[0015] Working principle of this application:

[0016] Compared with the prior art, the substantial features and progress of the technical solution of this application lie in that it adopts the casting molding method to realize the manufacture of large-size thin-walled model structures. Compared with the traditional sand casting process, a sand mold 3D printer is introduced to replace the traditional mold making, molding and core making processes. The sand mold 3D printing process directly manufactures complex sand molds and cores with a three-dimensional digital model. There is no need to make a sand mold after the traditional mold making. Through the binder jet printing technology, granular materials such as silica sand, ceramic sand, and coated sand are bonded layer by layer to obtain the sand mold / sand core. After cleaning and assembling, the molten metal liquid is poured into the sand mold, and the metal parts after cooling and solidification are taken out to obtain the casting blank.

[0017] This application has the following beneficial effects:

[0018] 1. Based on 3D printing technology, various curved surfaces and complex structures of the model can be flexibly made.

[0019] 2. Based on the sand mold 3D printing process, there is no need to make a sand mold after the traditional mold making, which replaces the traditional mold making, molding and core making processes, and greatly shortens the construction period.

[0020] 3. Compared with the demand for metal materials in traditional machining, for the large-sized special-shaped thin-walled structural parts in the present invention, the casting technology is used, and the material cost can be greatly reduced.

[0021] 4. The metal casting process can ensure the demand for rigidity and strength of the wind tunnel test model.

[0022] 5. Based on the above manufacturing technology and structural design, it is possible to realize the development of a short-cycle and low-cost model that meets the requirements of wind tunnel tests. Description of the Drawings

[0023] Figure 1 It is a schematic flow chart of the method for manufacturing an intake wind tunnel test model based on 3D printed sand cores provided by the embodiment of this application. Detailed Embodiments

[0024] To make the objectives, technical solutions and advantages of this application clearer, the technical solutions in the present invention will be described clearly and completely below. Apparently, the described embodiments are only a part rather than all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without any creative efforts shall fall within the protection scope of the present invention.

[0025] Embodiment 1:

[0026] A method for fabricating an intake duct wind tunnel test model based on 3D printed sand cores casting includes the following steps:

[0027] Step 1: Design a sand mold structure corresponding to the morphology according to the model segmentation structure; the structure should consider the flange interfaces of the model segmentation and the uniform allowance for subsequent polishing of the model.

[0028] Step 2: Use binder jet 3D printing technology to bond the granular materials layer by layer to obtain segmented sand molds.

[0029] Step 3: Pour molten metal into the printed sand mold using a slit gating system. After cutting the riser and runner, heat treatment and sandblasting are performed on the formed blank; in this process, 3D printed sand core casting is the same as the traditional casting method, but the surface roughness of 3D printed sand core castings is slightly higher than that of traditional casting, and the grinding time is slightly shorter.

[0030] Step 4: Perform dimensional inspection and ultrasonic flaw detection on the formed blank. After passing the inspection, polishing and finishing are carried out.

[0031] Step 5: Use the structural connection flanges reserved at both ends of the segmented model to fixedly connect the refined segmented models in sequence, and then perform overall polishing and painting on the inner cavity of the intake duct.

[0032] Step 6: Check the appearance of the model and verify the dimensional inspection data.

[0033] Further, the granular material described in Step 2 is silica sand, ceramic sand or coated sand.

[0034] The above embodiments are only used to illustrate the technical concept and characteristics of the present invention, and their purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it accordingly, and cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention shall be covered within the protection scope of the present invention.

Claims

1. A method for fabricating an intake duct wind tunnel test model based on 3D printed sand cores and molds, characterized in that, Including the following steps: Step 1: Design a sand mold structure with a corresponding shape according to the model segmentation structure; Step 2: 3D print the segmented sand mold. Through binder jetting 3D printing technology, layer by layer bonding of particulate materials is carried out to obtain the segmented sand mold; Step 3: Pour molten metal into the printed sand mold. After cutting the riser, heat treatment and sandblasting are carried out on the formed blank; Step 4: Carry out dimensional inspection and ultrasonic flaw detection of the formed blank. After passing the inspection, polishing and finishing are carried out; Step 5: Assemble the refined segmented models. Using the structural connection flanges reserved at both ends of the segmented models, fix and connect the refined segmented models in sequence, and then carry out overall polishing and painting of the inner cavity of the air intake duct; Step 6: Check the appearance of the model and verify the dimensional inspection data.

2. The method for manufacturing an intake air duct wind tunnel test model based on 3D printed sand cores and molds according to claim 1, wherein In the said Step 1, when designing the sand mold structure with a corresponding shape, design the flange interface of the model segmentation structure according to needs.

3. The method for manufacturing an intake duct wind tunnel test model based on 3D printed sand cores and molds according to claim 1, wherein, The particulate material described in Step 2 is silica sand, ceramic sand or coated sand.

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