阅读说明：本技术 飞轮壳加工工艺 (Flywheel housing processing technology ) 是由 杜智勇 杨靖康 钟向明 张志斌 王雪强 杨普 于 2021-01-20 设计创作，主要内容包括：本发明涉及飞轮壳加工工艺,其包括如下步骤：制备用于飞轮壳内壁成型的砂芯,采用特定喷涂剂喷涂砂芯形成砂芯喷涂体,采用设有单层环形浇道、非对称三向横流道的浇铸模具浇铸铝水形成飞轮壳毛坯,热处理,抛丸,机加工,即得。采用该飞轮壳加工工艺制备获得的飞轮壳的良品率达95％以上。(The invention relates to a flywheel housing processing technology, which comprises the following steps: preparing a sand core for forming the inner wall of the flywheel shell, spraying the sand core with a specific spraying agent to form a sand core spraying body, casting aluminum water by using a casting die provided with a single-layer annular runner and an asymmetric three-way transverse runner to form a flywheel shell blank, and carrying out heat treatment, shot blasting and machining to obtain the flywheel shell blank. The yield of the flywheel housing prepared by the flywheel housing processing technology reaches more than 95%.)

1. A flywheel housing processing technology is characterized by comprising the following steps:

preparing a sand core for molding the inner wall of the flywheel shell;

spraying the sand core by using a spraying agent to form a sand core spraying body; wherein the spraying agent is coating slurry with the density of 1.32-1.38, which is mainly formed by stirring white mud, bentonite and water;

placing the sand core spraying body in a casting mold provided with a single-layer annular runner and an asymmetric three-way transverse runner, and casting molten aluminum to form a flywheel shell blank; the casting process parameters of the flywheel shell blank are as follows: the density of molten aluminum is more than or equal to 2.66g/cm³The casting temperature is 650-730 ℃, the upper die temperature is 330-400 ℃, the bottom die temperature is 430-530 ℃, the number of the mold filling sections is multiple, the mold filling pressure of each section is 250 mbar-600 mbar, the mold filling time of each section is 2 s-15 s, the pressure maintaining time is 260 s-300 s, and the cooling time is 250 s-300 s;

heat treatment;

shot blasting;

and (4) machining to obtain the finished product.

2. The flywheel housing processing technology according to claim 1, wherein the casting technological parameters of the flywheel housing blank piece are as follows: the casting temperature is 680-710 ℃, the upper die temperature is 340-390 ℃, the bottom die temperature is 470-510 ℃ and the side die temperature is 320-380 ℃.

3. The flywheel housing processing technology according to claim 2, wherein the casting technological parameters of the flywheel housing blank piece are as follows: the number of the mold filling sections is 4-6, the mold filling time of each section is gradually reduced along with the increase of the number of the sections, and the mold filling pressure of each section is gradually increased along with the increase of the number of the sections.

4. The flywheel housing processing technology according to claim 3, wherein the casting technological parameters of the flywheel housing blank piece are as follows: the number of the mold filling sections is 5, the mold filling time of the first section is 15s, the mold filling pressure of the first section is 260mbar, the mold filling time of the second section is 10s, the mold filling pressure of the second section is 290mbar, the mold filling time of the third section is 8s, the mold filling pressure of the third section is 350mbar, the mold filling time of the fourth section is 3s, the mold filling pressure of the fourth section is 450mbar, the mold filling time of the fifth section is 2s, and the mold filling pressure of the fifth section is 580 mbar.

5. The process for machining the flywheel housing according to any one of claims 1 to 4, wherein the weight ratio of the white mud to the bentonite in the spraying agent is (4-5): 1.

6. The process for machining the flywheel casing according to claim 5, wherein the spraying agent further comprises zinc oxide, and the weight ratio of the white mud to the bentonite to the zinc oxide is (4-5): 1: 0.05.

7. The process for machining the flywheel housing according to claim 5, wherein the spraying process parameters of the sand core spraying body are as follows: the rotating speed of the sand core is 5-10 r/min, a spray gun is adopted to spray 4-8 circles of the side surface of the sand core in the horizontal direction, then the spray gun is lifted to spray 4-8 circles of the upper surface of the sand core at an angle of 45 degrees, and the thickness of the coating is 0.2-0.3 mm.

8. The process for machining the flywheel housing according to any one of claims 1 to 4, wherein the raw material for machining the flywheel housing is ZL104 aluminum alloy.

9. The casting mold for machining the flywheel housing is characterized by comprising a bottom mold, a side mold, a pouring gate structure and an upper mold;

the bottom die is provided with a first forming groove structure for forming a special-shaped end face on one side of the flywheel shell, the side die is provided with a second forming groove structure for forming the side wall of the flywheel shell, and the side die is arranged on the bottom die and arranged around the first forming groove structure to form a semi-forming cavity groove structure;

the pouring gate structure is arranged in the forming cavity groove structure and is provided with a single-layer annular pouring gate and an asymmetric three-way transverse flow passage;

the upper die is provided with a third forming groove structure for forming the special-shaped end face on the other side of the flywheel shell;

and during casting, the third type groove structure and the semi-forming cavity groove structure can be enclosed to form a flywheel shell forming cavity.

10. The casting mold for machining the flywheel housing as claimed in claim 9, further comprising an upper mold connecting plate, a connecting column and an ejection mechanism;

the upper die connecting plate is connected with the upper die through a connecting column;

the ejection mechanism comprises a supporting assembly and ejection columns, the supporting assembly is arranged between the upper die connecting plate and the upper die, one end of each ejection column is connected with the supporting assembly, the other end of each ejection column penetrates through the upper die, the ejection columns are multiple and correspond to the forming cavities in array distribution.

Technical Field

The invention relates to the technical field of machining, in particular to a flywheel housing machining process.

Background

The flywheel housing is an important basic structural part of the engine, is used for connecting the engine and the transmission, bears part of the weight of the engine and the transmission, protects the clutch and the flywheel, and is also a supporting part of the engine, and the processing quality of the flywheel housing directly influences the performance of the engine.

The flywheel housing with the structure shown in the figures 1 and 2 has a complex structure, is easy to deform during processing and has low yield.

Disclosure of Invention

Therefore, a flywheel housing processing technology is needed to be provided, and the yield of the flywheel housing can be improved to more than 95%.

The technical scheme of the invention is as follows:

the invention provides a flywheel housing processing technology, which comprises the following steps: preparing a sand core for molding the inner wall of the flywheel shell; spraying the sand core by using a spraying agent to form a sand core spraying body; wherein the spraying agent is coating slurry with the density of 1.32-1.38, which is mainly formed by stirring white mud, bentonite and water; placing the sand core in a casting mold provided with a single-layer annular runner and an asymmetric three-way transverse runner, and casting molten aluminum to form a flywheel shell blank; the casting process parameters of the flywheel shell blank are as follows: the density of molten aluminum is more than or equal to 2.66g/cm³The casting temperature is 650-730 ℃, the upper die temperature is 330-400 ℃, the bottom die temperature is 430-530 ℃, the number of the mold filling sections is multiple, the mold filling pressure of each section is 250 mbar-600 mbar, the mold filling time of each section is 2 s-15 s, the pressure maintaining time is 260 s-300 s, and the cooling time is 250 s-300 s; heat treatment; shot blasting; and (4) machining to obtain the finished product.

In some embodiments, the casting process parameters of the flywheel housing blank are as follows: the casting temperature is 680-710 ℃, the upper die temperature is 340-390 ℃, the bottom die temperature is 470-510 ℃ and the side die temperature is 320-380 ℃.

In some embodiments, the casting process parameters of the flywheel housing blank are as follows: the number of the mold filling sections is 4-6, the mold filling time of each section is gradually reduced along with the increase of the number of the sections, and the mold filling pressure of each section is gradually increased along with the increase of the number of the sections. Preferably, the casting process parameters of the flywheel housing blank piece are as follows: the number of the mold filling sections is 5, the mold filling time of the first section is 15s, the mold filling pressure of the first section is 260mbar, the mold filling time of the second section is 10s, the mold filling pressure of the second section is 290mbar, the mold filling time of the third section is 8s, the mold filling pressure of the third section is 350mbar, the mold filling time of the fourth section is 3s, the mold filling pressure of the fourth section is 450mbar, the mold filling time of the fifth section is 2s, and the mold filling pressure of the fifth section is 580 mbar.

In some embodiments, the casting process parameters of the flywheel housing blank are as follows: the degassing refining temperature is 720-780 ℃, and the degassing refining time is 15-20 min.

In some embodiments, the weight ratio of the white mud to the bentonite in the spraying agent is (4-5): 1, and the density of the coating after mixing and stirring is 1.32-1.38. The spraying agent can also comprise zinc oxide, and the weight ratio of white mud, bentonite and zinc oxide is (4-5) to 1: 0.05.

In some embodiments, the processing raw material of the flywheel housing is ZL104 material, and the aging temperature is correspondingly controlled to be 190-210 ℃.

The spraying technological parameters of the sand core spraying body are as follows: the rotating speed of the sand core is 5-10 r/min, a spray gun is adopted to spray 4-8 circles of the side surface of the sand core in the horizontal direction, then the spray gun is lifted to spray 4-8 circles of the upper surface of the sand core at an angle of 45 degrees, and the thickness of the coating is 0.2-0.3 mm.

In some of these embodiments, the process parameters of the heat treatment are: the temperature is 200-210 ℃, and the time is 7-8 h.

In some of these embodiments, the process parameters of the shot blasting are: the shot blasting time is 15-25 min, and the shot blasting power is 7.5-15 kW.

The invention also provides a casting mould for processing the flywheel shell, which comprises a bottom mould, a side mould, a pouring channel structure and an upper mould; the bottom die is provided with a first forming groove structure for forming a special-shaped end face on one side of the flywheel shell, the side die is provided with a second forming groove structure for forming the side wall of the flywheel shell, and the side die is arranged on the bottom die and arranged around the first forming groove structure to form a semi-forming cavity groove structure; the pouring gate structure is arranged in the forming cavity groove structure and is provided with a single-layer annular pouring gate and an asymmetric three-way transverse flow passage; the upper die is provided with a third forming groove structure for forming the special-shaped end face on the other side of the flywheel shell; and during casting, the third type groove structure and the semi-forming cavity groove structure can be enclosed to form a flywheel shell forming cavity.

Furthermore, the casting die for machining the flywheel housing further comprises an upper die connecting plate, a connecting column and an ejection mechanism; the upper die connecting plate is connected with the upper die through a connecting column; the ejection mechanism comprises a supporting assembly and ejection columns, the supporting assembly is arranged between the upper die connecting plate and the upper die, one end of each ejection column is connected with the supporting assembly, the other end of each ejection column penetrates through the upper die, the ejection columns are multiple and correspond to the forming cavities in array distribution.

The invention has the beneficial effects that:

according to the flywheel housing processing technology, the sand core for forming the inner wall of the flywheel housing is prepared, the sand core is sprayed by using a specific spraying agent to form a sand core spraying body, the casting die provided with the single-layer annular runner and the asymmetric three-way transverse runner is used for casting molten aluminum to form a flywheel housing blank, and the flywheel housing blank is subjected to heat treatment, shot blasting and machining treatment, so that the yield of the flywheel housing can be up to 95% or more in the whole.

Drawings

FIG. 1 is a schematic view of a flywheel housing according to the present invention.

Fig. 2 is another perspective structural view of the flywheel housing of fig. 1.

Fig. 3 is a schematic view of a casting mold for flywheel housing processing.

Fig. 4 is a schematic structural view of a bottom mold in the casting mold of fig. 3.

Fig. 5 is another perspective view of the side form of the casting mold of fig. 3.

Fig. 6 is a schematic structural view of an upper mold, a connecting structure and an ejection mechanism of the casting mold of fig. 3.

Fig. 7 is an exploded view of the casting mold of fig. 3.

Fig. 8 is a comparison between the spray effects of example 2 and comparative example 3.

Detailed Description

The principles and features of this invention are described below in conjunction with examples which are set forth to illustrate, but are not to be construed to limit the scope of the invention. Unless defined otherwise, 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 belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Embodiment 1 casting die utensil is used in bell housing processing

Referring to fig. 3 to 7, the present embodiment provides a casting mold for flywheel housing processing shown in fig. 1 and 2, which includes a bottom mold 110, a side mold 120, an upper mold 130, a runner structure 140, an upper mold connecting plate 210, a connecting column 220, and an ejection mechanism 300.

In this embodiment, the bottom mold 110 is provided with a first forming groove structure for forming a special-shaped end surface on one side of the flywheel housing 1. The side edges around the bottom die 110 are provided with 4 side die mounting positions.

In this embodiment, the side mold 120 is provided with a second forming groove structure for forming the side wall of the flywheel casing, and the side mold 120 is disposed on the bottom mold 110 and surrounds the first forming groove structure to form a semi-forming cavity groove structure. The side form 120 comprises a first side form 121, a second side form 122, a third side form 123 and a fourth side form 124, and the side of the second side form 122 and the fourth side form 124 is provided with a groove structure of a protruding part of the flywheel housing.

In this embodiment, the upper mold 130 is provided with a third forming groove structure for forming the irregular end surface on the other side of the flywheel housing. The pouring gate structure 140 is arranged in the forming cavity groove structure, the pouring gate structure 140 is provided with a single-layer annular pouring gate and an asymmetric three-way transverse flow passage, and the transverse flow passage towards the direction of the convex part of the flywheel housing is larger in size. During casting, the third type groove structure and the semi-forming cavity groove structure can be enclosed to form a flywheel housing forming cavity.

In the present embodiment, the upper mold connecting plate 210 is connected to the upper mold 130 through a connecting column 220. The ejection mechanism 300 comprises a supporting assembly and a plurality of ejection columns, the supporting assembly is arranged between the upper die connecting plate and the upper die 130, one end of each ejection column is connected with the supporting assembly, the other end of each ejection column penetrates through the upper die 130, the ejection columns are multiple, the ejection columns correspond to the forming cavities and are distributed in an array mode, and ejection of flywheel housing castings after casting forming is facilitated.

Example 2

The embodiment provides a flywheel housing processing technology, which comprises the following steps:

and S1, preparing the sand core 2 for molding the inner wall of the flywheel shell. The sand core 2 is made of phase-change precoated sand.

S2, preparing a spraying agent, and spraying the sand core by using the spraying agent to form a sand core spraying body:

in the step, the spraying agent is coating slurry with the density of 1.32-1.38, which is prepared by uniformly stirring white mud, bentonite and a proper amount of water, and the weight ratio of the white mud to the bentonite is 4: 1. The spraying agent after stirring is filtered by using the filter screen, so that the spray gun nozzle is prevented from being blocked by undissolved particles.

In this step, the spraying process parameters are as follows: the rotating speed of the sand core on the rotary plate is 6-8 r/min, the spray gun needs to be separated from the sand core by about 20 cm, 4-6 circles of the side surface of the sand core are sprayed in the horizontal direction, the spray gun is lifted to spray the upper surface of the sand core by 4-6 circles at an angle of 45 degrees, then whether the side surface is exposed with the natural color or not is observed, 1-2 circles of spraying is supplemented, and finally 1-2 circles of spraying is supplemented on the upper surface. And testing the thickness of the surface coating of the sand core by using a hexagonal wet film comb, wherein the thickness is controlled within the range of 0.2-0.3 mm.

S3, preparing molten aluminum, and casting and molding:

and (5) placing the sand core spraying body prepared in the step (S2) in a casting mould provided with a single-layer annular runner and an asymmetric three-way transverse runner, casting molten aluminum (the material is ZL104 aluminum alloy), and forming to form the flywheel shell blank. The casting process parameters of the flywheel shell blank are as follows: the density of the molten aluminum is 2.7g/cm³The aging temperature is 190-210 ℃, the casting temperature is 690-710 ℃, the upper mold temperature is 360-370 ℃, the bottom mold temperature is 495-505 ℃, and the side mold temperature is 350-360 ℃. The number of the mold filling sections is 5, the mold filling time of the first section is 15s, the mold filling pressure of the first section is 260mbar, the mold filling time of the second section is 10s, the mold filling pressure of the second section is 290mbar, the mold filling time of the third section is 8s, the mold filling pressure of the third section is 350mbar, the mold filling time of the fourth section is 3s, the mold filling pressure of the fourth section is 450mbar, the mold filling time of the fifth section is 2s, the mold filling pressure of the fifth section is 580mbar, the pressure maintaining time of each section is 280s, and the cooling time is 380 +/-20 s. The degassing refining temperature is 720-780 ℃, and the degassing refining time is 15-20 min.

S4, heat treatment:

and (4) carrying out heat treatment on the flywheel shell blank formed in the step S3: the temperature is 210 ℃, the time is 7 hours and 40 minutes, and the mechanical properties of the alloy material are changed.

S5, shot blasting:

performing shot blasting treatment on the flywheel housing blank after heat treatment: the shot blasting time is 20 minutes, the shot blasting machine power is 15kW, the effects of cleaning, color increasing and polishing the surface of the part are achieved, and the surface stress concentration is eliminated.

And S6, machining to form the flywheel housing with the polished end face and the assembling holes of various specifications.

Example 3

The embodiment provides a flywheel shell processing technology, which has the same basic process steps as the embodiment 2, and is characterized in that the temperature parameters in the flywheel shell blank casting process parameters are as follows: the density of the molten aluminum is 2.7g/cm³The casting temperature is 690-710 ℃, the upper die temperature is 340-355 ℃, the bottom die temperature is 470-490 ℃, and the side die temperature is 320-345 ℃.

Example 4

The embodiment provides a flywheel shell processing technology, which has the same basic process steps as those of embodiment 2, and is different in that the bottom die temperature and the upper die temperature in the flywheel shell blank casting process parameters are respectively as follows: the temperature parameters of (A) are: the density of the molten aluminum is 2.7g/cm³The casting temperature is 690-710 ℃, the upper die temperature is 380-390 ℃, the bottom die temperature is 500-510 ℃, and the side die temperature is 370-380 ℃.

Example 5

The embodiment provides a flywheel housing processing technology, which has the same basic processing steps as those of embodiment 2, and is different in that the spraying agent further comprises zinc oxide, the weight ratio of white mud to bentonite to zinc oxide is 4:1:0.05, and the density of the coating after mixing and stirring reaches 1.32-1.38.

Comparative example 1

The comparative example provides a flywheel housing processing technology, the basic process steps are the same as those of the embodiment 2, and the difference is that a pouring mold with a casting runner structure different from that of the embodiment 1 is adopted, namely, an equi-symmetric three-way transverse runner with the same size is adopted.

Comparative example 2

The comparative example provides a flywheel casing processing technology, the basic process steps are the same as those of the embodiment 2, and the difference is that the bottom die temperature and the upper die temperature of the casting process parameters in the flywheel casing blank are respectively as follows: the temperature of the upper die is 280 ℃ and the temperature of the bottom die is 400 ℃.

Comparative example 3

The embodiment provides a flywheel housing processing technology, which has the same basic processing steps as the embodiment 2, and the difference is that: the spray coating agent is a slurry containing white mud and bentonite in a weight ratio of 1: 4.

The process quality monitoring statistics were performed on the flywheel shells processed in examples 2 to 5 and comparative examples 1 to 3, respectively, and the statistical results are shown in the following table:

as can be seen from the above table, compared with comparative examples 1 and 2, in examples 1 to 5, the flywheel housing casting blank with the yield of more than 95% can be obtained by adopting the casting mold provided with the single-layer annular runner and the asymmetric three-way transverse runner and matching with specific casting process parameters.

With further reference to fig. 8, compared with comparative example 3, in examples 1 to 5, the problem that the inner cavity surface of the flywheel casing casting blank is seriously bonded with sand and the subsequent polishing workload is reduced can be solved by using the spraying agent compounded by specific components in specific proportions.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.