阅读说明：本技术 一种3d打印汽车发动机壳体的铸造方法 (Casting method of 3D printing automobile engine shell ) 是由 雷玉翠 于 2021-08-26 设计创作，主要内容包括：本发明公开了一种3D打印汽车发动机壳体的铸造方法,包括以下步骤：(1)设计汽车发动机壳体和浇铸系统、确定浇铸工艺；(2)根据浇铸系统和浇铸工艺设计打印砂型,模流分析,进行3D打印铸型；(3)对砂型表面涂刷涂料并进行烘干；(4)将砂型表面修磨平整后按照设计的砂型进行合型,合型后采用低压铸造机进行浇铸；(5)待铸件完全冷却后开箱,对铸件进行打磨、抛丸,超声波探伤,得外观光洁的汽车发动机壳体。(The invention discloses a casting method of a 3D printing automobile engine shell, which comprises the following steps: (1) designing an automobile engine shell and a casting system, and determining a casting process; (2) designing a printing sand mold according to a casting system and a casting process, carrying out mold flow analysis, and carrying out 3D printing casting; (3) coating paint on the surface of the sand mold and drying; (4) carrying out mold assembly according to the designed sand mold after polishing and flattening the surface of the sand mold, and casting by adopting a low-pressure casting machine after mold assembly; (5) and opening the box after the casting is completely cooled, and polishing, shot blasting and ultrasonic flaw detection are carried out on the casting to obtain the automobile engine shell with smooth appearance.)

1. A casting method for a 3D printing automobile engine shell is characterized by comprising the following steps:

(1) designing an automobile engine shell and a casting system, and determining a casting process;

(2) designing a printing sand mold according to a casting system and a casting process, carrying out mold flow analysis, and carrying out 3D printing casting;

(3) coating paint on the surface of the sand mold and drying;

(4) carrying out mold assembly according to the designed sand mold after polishing and flattening the surface of the sand mold, and casting by adopting a low-pressure casting machine after mold assembly;

(5) and opening the box after the casting is completely cooled, and polishing, shot blasting and ultrasonic flaw detection are carried out on the casting to obtain the automobile engine shell with smooth appearance.

2. The automobile engine shell casting process according to claim 1, wherein the step (1) comprises modeling a sand blank body of the automobile engine shell in three-dimensional software, and reserving a sand draught and a sand layer thickness of a hoisting structure; and designing a corresponding pouring system and a riser system, and taking the casting, the pouring system and the riser system as cutters to find the difference with the sand damage.

3. The automobile engine housing casting process according to claim 2, wherein the 3D printed material and the printing process are determined according to the material of the automobile engine housing in the step (2).

4. The casting process of the automobile engine housing according to claim 1, wherein the 3D printing mold of the step (2) is subjected to mold flow analysis through mold flow analysis software, and a mixed mold is optimized.

5. The automobile engine housing casting process according to claim 3, wherein the 3D printed material is 100-150-mesh jewel sand, the printing thickness of each layer of the 3D printing is 0.1-0.3mm, and the printing speed is 2-4 m/s.

6. The automobile engine housing casting process according to claim 1, wherein the printing sand mold in the step (3) comprises an upper sand mold, a middle sand mold and a lower sand mold, the sand consumption of the sand molds is reserved for 40-50mm, the thickness of a coating layer is preset for 0.1-0.3mm, a plurality of positioning sand cones are arranged among the upper sand mold, the middle sand mold and the lower sand mold, a mold closing buckle is arranged on the side surface of the middle sand mold, and a separated exhaust hole is formed in the inner cavity of the sand mold.

7. The automotive engine case casting process according to claim 1, wherein the coating of step (3) is a water-based casting coating, and the coating process is a dip coating process.

8. The casting process of the automobile engine housing as claimed in claim 1, wherein the casting process of step (4) comprises the steps of temperature 680-720 ℃, pressure 0.5-1.0MPa and dwell time 20-40 min.

9. The automotive engine case casting process according to claim 7, wherein the water-based casting coating is prepared by a method comprising a refractory material, bentonite, anhydrous sodium carbonate, neutral water glass and water.

Technical Field

The invention relates to the technical field of casting processes, in particular to a casting method of a 3D printing automobile engine shell.

Background

The automobile engine shell has the characteristics of precision and light weight, and has the characteristics of complex structure, uneven wall thickness, hollow structure and the like, the risk of internal defects is high, the side holes are more and dense, the position degree difficulty of cold iron arrangement and exhaust is high, the influence factors are more, the mutual influence is realized, the complexity of the overall design is high, and the casting can not be completed by the traditional casting process.

Disclosure of Invention

In order to solve the technical problems in the prior art, the invention provides a casting method of a 3D printing automobile engine shell.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a casting method of a 3D printing automobile engine shell comprises the following steps:

(1) designing an automobile engine shell and a casting system, and determining a casting process;

(2) designing a printing sand mold according to a casting system and a casting process, carrying out mold flow analysis, and carrying out 3D printing casting;

(3) coating paint on the surface of the sand mold and drying;

(4) carrying out mold assembly according to the designed sand mold after polishing and flattening the surface of the sand mold, and casting by adopting a low-pressure casting machine after mold assembly;

(5) and opening the box after the casting is completely cooled, and polishing, shot blasting and ultrasonic flaw detection are carried out on the casting to obtain the automobile engine shell with smooth appearance.

Further, the step (1) comprises modeling a sand blank body of the automobile engine shell in three-dimensional software, and reserving the sand-eating quantity and the thickness of a sand layer of a hoisting structure; and designing a corresponding pouring system and a riser system, and taking the casting, the pouring system and the riser system as cutters to find the difference with the sand damage.

Further, the 3D printing material and the printing process are determined according to the material of the automobile engine shell in the step (2).

Further, the 3D printing casting mold in the step (2) is subjected to mold flow analysis through mold flow analysis software, and a mixed casting mold is optimized.

Further, the 3D printing material is 100-150-mesh Baozhu sand, the printing thickness of each layer of the 3D printing is 0.1-0.3mm, and the printing speed is 2-4 m/s.

Further, the printing sand mold in the step (3) comprises an upper sand mold, a middle sand mold and a lower sand mold, the sand consumption of the sand mold is reserved for 40-50mm, the thickness of a coating layer is preset for 0.1-0.3mm, a plurality of positioning sand cones are arranged among the upper sand mold, the middle sand mold and the lower sand mold, a mold closing buckle is arranged on the side face of the middle sand mold, and a separated exhaust hole is formed in the inner cavity of the sand mold.

Further, the coating of the step (3) is a water-based casting coating, and the coating process is a dip coating process.

Further, the casting process in the step (4) comprises the steps of temperature of 680-720 ℃, pressure of 0.5-1.0MPa and dwell time of 20-40 min.

Further, the preparation method of the water-based casting coating comprises a refractory material, bentonite, anhydrous sodium carbonate, neutral water glass and water.

The invention has the beneficial effects that:

according to the invention, the 3D printing is adopted to realize the dieless casting and flexible production, the manufacturing cost is reduced, the manufacturing period is shortened, the strength of the sand mold is improved through the water-based coating, the 3D printing technology and the low-pressure casting are combined to develop and trial-produce a new product, the cost and the period are well controlled, and the quality of the product is well ensured.

Drawings

The invention is further illustrated by the following figures and examples.

Fig. 1 is an isometric schematic view of a 3D printed automotive engine housing according to the present invention.

Fig. 2 is a schematic diagram of the static stress analysis of the housing prepared in embodiment 1 of the 3D printed automobile engine housing according to the invention.

Fig. 3 is a schematic diagram of the static stress analysis of the housing prepared in embodiment 2 of the 3D printed automobile engine housing according to the present invention.

Fig. 4 is a schematic diagram of the static stress analysis of the housing prepared in embodiment 3 of the 3D-printed automobile engine housing according to the present invention.

Fig. 5 is a schematic diagram of the static stress analysis of the housing prepared in embodiment 4 of the 3D printed automobile engine housing according to the present invention.

Detailed Description

The present invention will now be described in detail with reference to the accompanying drawings. This figure is a simplified schematic diagram, and merely illustrates the basic structure of the present invention in a schematic manner, and therefore it shows only the constitution related to the present invention.

As shown in fig. 1 to 5, a casting method for a 3D printing automobile engine shell comprises the following steps:

(1) designing an automobile engine shell and a casting system, modeling a sand blank body of the automobile engine shell in three-dimensional software, and reserving the sand-eating quantity and the thickness of a sand layer of a hoisting structure; designing a corresponding pouring system and a riser system, and determining a casting process by taking the casting, the pouring system and the riser system as cutters and calculating the difference with the sand casting;

(2) designing a printing sand mold according to the material quality, a casting system and a casting process of an automobile engine shell, taking 100-150-mesh baozhu sand as a raw material, taking each layer of printing thickness as 0.1-0.3mm, and the printing speed as 2-4m/s to perform 3D printing casting mold, performing mold flow analysis on the 3D printing casting mold through mold flow analysis software, optimizing a mixed casting mold, wherein the printing sand mold comprises an upper sand mold, a middle sand mold and a lower sand mold, the sand consumption of the sand mold is reserved for 40-50mm, a coating layer is preset for 0.1-0.3mm, a plurality of positioning sand cones are arranged among the upper sand mold, the middle sand mold and the lower sand mold, a mold closing buckle is arranged on the side surface of the middle sand mold, and a separated exhaust hole is formed in an inner cavity of the sand mold;

(3) coating a water-based casting coating on the surface of the sand mould through a dip-coating process and drying;

(4) grinding and flattening the surface of the sand mold, then carrying out mold assembly according to the designed sand mold, and casting by adopting a low-pressure casting machine after mold assembly, wherein the casting process comprises the steps of carrying out casting at the temperature of 680-720 ℃, the pressure of 0.5-1.0MPa and the pressure maintaining time of 20-40 min;

(5) and opening the box after the casting is completely cooled, and polishing, shot blasting and ultrasonic flaw detection are carried out on the casting to obtain the automobile engine shell with smooth appearance.

The preparation method of the water-based casting coating comprises a refractory material, bentonite, anhydrous sodium carbonate, neutral water glass and water.

Example 1

The casting method of the 3D printing automobile engine shell comprises the following steps:

(1) designing an automobile engine shell and a casting system, modeling a sand blank body of the automobile engine shell in three-dimensional software, and reserving the sand-eating quantity and the thickness of a sand layer of a hoisting structure; designing a corresponding pouring system and a riser system, and determining a casting process by taking the casting, the pouring system and the riser system as cutters and calculating the difference with the sand casting;

(2) designing a printing sand mold according to the material quality, a casting system and a casting process of an automobile engine shell, taking 100-mesh baozhu sand as a raw material, carrying out 3D printing casting with the printing thickness of each layer being 0.1mm and the printing speed being 2m/s, carrying out mold flow analysis on the 3D printing casting through mold flow analysis software, optimizing a mixed casting, wherein the printing sand mold comprises an upper sand mold, a middle sand mold and a lower sand mold, the sand consumption of the sand mold is reserved for 40mm, the coating layer is preset for 0.3mm, a plurality of positioning sand cones are arranged among the upper sand mold, the middle sand mold and the lower sand mold, a mold closing buckle is arranged on the side surface of the middle sand mold, and a separated exhaust hole is formed in an inner cavity of the sand mold;

(3) coating a water-based casting coating on the surface of the sand mould through a dip-coating process and drying;

(4) grinding and flattening the surface of the sand mold, then carrying out mold assembly according to the designed sand mold, and casting by adopting a low-pressure casting machine after mold assembly, wherein the casting process comprises the steps of carrying out casting at the temperature of 680 ℃, the pressure of 0.5MPa and the pressure maintaining time of 20 min;

(5) and opening the box after the casting is completely cooled, and polishing, shot blasting and ultrasonic flaw detection are carried out on the casting to obtain the automobile engine shell with smooth appearance.

Example 2

The casting method of the 3D printing automobile engine shell comprises the following steps:

(1) designing an automobile engine shell and a casting system, modeling a sand blank body of the automobile engine shell in three-dimensional software, and reserving the sand-eating quantity and the thickness of a sand layer of a hoisting structure; designing a corresponding pouring system and a riser system, and determining a casting process by taking the casting, the pouring system and the riser system as cutters and calculating the difference with the sand casting;

(2) designing a printing sand mold according to the material quality, a casting system and a casting process of an automobile engine shell, taking 100-mesh baozhu sand as a raw material, carrying out 3D printing casting with the printing thickness of each layer being 0.3mm and the printing speed being 2m/s, carrying out mold flow analysis on the 3D printing casting through mold flow analysis software, optimizing a mixed casting, wherein the printing sand mold comprises an upper sand mold, a middle sand mold and a lower sand mold, the sand consumption of the sand mold is reserved for 50mm, a coating layer is preset for 0.2mm, a plurality of positioning sand cones are arranged among the upper sand mold, the middle sand mold and the lower sand mold, a mold closing buckle is arranged on the side surface of the middle sand mold, and a separated exhaust hole is formed in an inner cavity of the sand mold;

(3) coating a water-based casting coating on the surface of the sand mould through a dip-coating process and drying;

(4) grinding and flattening the surface of the sand mold, then carrying out mold assembly according to the designed sand mold, and casting by adopting a low-pressure casting machine after mold assembly, wherein the casting process comprises the steps of carrying out casting at the temperature of 720 ℃, the pressure of 0.5MPa and the pressure maintaining time of 40 min;

(5) and opening the box after the casting is completely cooled, and polishing, shot blasting and ultrasonic flaw detection are carried out on the casting to obtain the automobile engine shell with smooth appearance.

Example 3

The casting method of the 3D printing automobile engine shell comprises the following steps:

(1) designing an automobile engine shell and a casting system, modeling a sand blank body of the automobile engine shell in three-dimensional software, and reserving the sand-eating quantity and the thickness of a sand layer of a hoisting structure; designing a corresponding pouring system and a riser system, and determining a casting process by taking the casting, the pouring system and the riser system as cutters and calculating the difference with the sand casting;

(2) designing a printing sand mould according to the material quality, a casting system and a casting process of an automobile engine shell, taking 150-mesh baozhu sand as a raw material, carrying out 3D printing casting with each layer of printing thickness of 0.1mm and printing speed of 4m/s, carrying out mould flow analysis on the 3D printing casting through mould flow analysis software, optimizing a mixed casting, wherein the printing sand mould comprises an upper sand mould, a middle sand mould and a lower sand mould, the sand consumption of the sand mould is reserved for 40mm, a coating layer is preset for 0.1mm, a plurality of positioning sand cones are arranged among the upper sand mould, the middle sand mould and the lower sand mould, a mold closing buckle is arranged on the side surface of the middle sand mould, and a separated exhaust hole is formed in an inner cavity of the sand mould;

(3) coating a water-based casting coating on the surface of the sand mould through a dip-coating process and drying;

(4) grinding and flattening the surface of the sand mold, then carrying out mold assembly according to the designed sand mold, and casting by adopting a low-pressure casting machine after mold assembly, wherein the casting process comprises the steps of carrying out casting at the temperature of 720 ℃, the pressure of 0.5MPa and the pressure maintaining time of 40 min;

(5) and opening the box after the casting is completely cooled, and polishing, shot blasting and ultrasonic flaw detection are carried out on the casting to obtain the automobile engine shell with smooth appearance.

Example 4

The casting method of the 3D printing automobile engine shell comprises the following steps:

(1) designing an automobile engine shell and a casting system, modeling a sand blank body of the automobile engine shell in three-dimensional software, and reserving the sand-eating quantity and the thickness of a sand layer of a hoisting structure; designing a corresponding pouring system and a riser system, and determining a casting process by taking the casting, the pouring system and the riser system as cutters and calculating the difference with the sand casting;

(2) designing a printing sand mould according to the material quality, a casting system and a casting process of an automobile engine shell, taking 150-mesh baozhu sand as a raw material, carrying out 3D printing casting with the printing thickness of each layer being 0.3mm and the printing speed being 4m/s, carrying out mould flow analysis on the 3D printing casting through mould flow analysis software, optimizing a mixed casting, wherein the printing sand mould comprises an upper sand mould, a middle sand mould and a lower sand mould, the sand consumption of the sand mould is reserved for 50mm, the coating layer is preset for 0.1mm, a plurality of positioning sand cones are arranged among the upper sand mould, the middle sand mould and the lower sand mould, a mold closing buckle is arranged on the side surface of the middle sand mould, and a separated exhaust hole is formed in an inner cavity of the sand mould;

(3) coating a water-based casting coating on the surface of the sand mould through a dip-coating process and drying;

(4) grinding and flattening the surface of the sand mold, then carrying out mold assembly according to the designed sand mold, and casting by adopting a low-pressure casting machine after mold assembly, wherein the casting process comprises the steps of temperature of 720 ℃, pressure of 1.0MPa and pressure maintaining time of 40 min;

(5) and opening the box after the casting is completely cooled, and polishing, shot blasting and ultrasonic flaw detection are carried out on the casting to obtain the automobile engine shell with smooth appearance.

The automobile engine shells prepared in the embodiments 1 to 4 are subjected to static stress analysis, the same automobile engine shell is prepared under different casting processes, and the performance of the automobile engine shells prepared in the embodiments is sequentially tested to obtain an optimal casting process.

Table 1 test results of the performance of the automobile engine case prepared in each example

The automobile engine casings prepared in the embodiments 1 to 4 are compared in performance, wherein the performance of the embodiment 1 is the most excellent, because the material ratio and the casting process of the embodiment 1 are optimal, and meanwhile, the performance difference of the embodiments 2 to 4 is small, and the feasibility of the technical scheme of the application is reflected from the side.

Carry out the performance contrast with embodiment 1 and embodiment 2, can see that the change of temperature can produce huge influence to the casing displacement among the casting technology, in low pressure casting, use low temperature casting to help the interior atomic group of box to grow rapidly to stable crystal core, and then produce a large amount of heterogeneous nucleation, make the box contain a large amount of tiny equiaxed crystal, effectively improve the comprehensive mechanical properties of box, good anti deformation effect has, simultaneously from the deformation displacement volume of embodiment 2 ~ 4 risees and sees, the rise of temperature can make the casing take place the deformation displacement among the casting technology certainly.

The embodiment 1 and the embodiment 3 are compared with the embodiment 2 and the embodiment 4, wherein the deformation displacement of the shell is not greatly influenced by the thickness of the 3D printing and the 3D printing speed, but the surface roughness of the shell is greatly influenced, the adhesion between the sand mold and the shell is effectively reduced by the dense printing thickness, further the generation of flaws such as air holes and burrs is reduced, and the surface cleanliness of the shell is improved; the surface roughness of the embodiment 4 is far greater than that of the embodiments 1 to 3, and the reason is that the crystallization pressure of the embodiment 4 in the casting process is greater than that of other embodiments, so that the crystallization pressure is high, the feeding of the shell casting is facilitated, the shell compactness is improved, but the problems of sand sticking, sand expansion and the like between the shell and the sand mold can be caused by the excessive crystallization pressure, and further the surface roughness of the shell is not high.

Compared with the examples 3 and 4, the performance comparison of the examples 1 and 2 shows that the deformation displacement of the box body is greatly influenced by using the jewel sand with different specifications and meshes, because the jewel sand in the examples 3 and 4 has smaller meshes, compared with the examples 1 and 2, the particles in the jewel sand are more easily concentrated, and further the problems of thermal expansion, cracks and the like can be caused at high temperature, and the coarse sand is adopted in the examples 1 and 2, so that the using amount of auxiliary agents such as adhesives and resins can be reduced, the air diffusion effect of the precoated sand can be reduced, and the prepared shell has good stability and deformation resistance; meanwhile, the thickness of the coating used in the embodiments 1 and 2 is higher than that of the embodiments 3 and 4, and the application of the coating can effectively improve the surface heat resistance, chemical stability and sand adhesion resistance of the shell in the low-pressure casting of the metal shell, so that the deformation displacement of the shells prepared in the embodiments 1 and 2 is smaller than that of the embodiments 3 and 4, and the deformation displacement of the shell prepared in the embodiment 1 should be the minimum. In light of the foregoing description of preferred embodiments in accordance with the invention, it is to be understood that numerous changes and modifications may be made by those skilled in the art without departing from the scope of the invention. The technical scope of the present invention is not limited to the contents of the specification, and must be determined according to the scope of the claims.