Low-pressure casting process for multi-platform general aluminum auxiliary frame

Abstract

The invention relates to a low-pressure casting technology for a multi-platform universal aluminum auxiliary frame. The low-pressure casting technology comprises the steps that firstly, a plurality of mounting holes are formed in the auxiliary frame to meet the using requirements of different vehicle types; 2, setting an upper die, a lower die and a parting line of die design according to the structure of the auxiliary frame product; 3, judging a plurality of thick and large hot spots on the product and an area with high quality requirement by analyzing the structure of the auxiliary frame; fourthly, a runner, a riser and a feeding channel of the auxiliary frame are designed according to the positions of the multiple thick and large hot spots; 5, a cooling insert is designed according to the simulation result of the auxiliary frame to help the product to be better formed; sixthly, a sand outlet and sand core positioning are designed according to the structure of the auxiliary frame product; seventhly, the position of a mold ejector rod and an exhaust channel are designed according to the structure of the auxiliary frame product; and 8, setting a mold filling pressure curve of field production. The aluminum auxiliary frame of a complex structure can be formed, and the risers and the feeding channels are designed in the thick and large positions prone to shrinkage porosity to guarantee the product quality.

Description

Technical Field

[0001] The invention relates to the technical field of automobiles, and in particular to a low-pressure casting process for a multi-platform universal aluminum subframe. Background Art

[0002] Nowadays, the requirements for lightweight automobile chassis are constantly increasing. As the core component of automobile chassis, aluminum alloy subframe has obvious lightweight effect compared with traditional steel subframe, so it has received the focus of attention of major automobile manufacturers. But at the same time, higher and higher requirements are put forward for low-pressure casting process. The advantages of low-pressure casting are controllable filling speed and pressure, smooth filling process, casting molding under pressure, strong metal liquid shrinkage compensation ability, and few casting defects. For the production and manufacturing of aluminum subframes, it is necessary to optimize the existing low-pressure casting process to improve product quality and reduce scrapped parts. Among them, the design of the pouring system is one of the main contents of the casting process design. Its function is to guide the metal liquid to fill the mold smoothly, compensate for shrinkage, block slag, and exhaust, so that the casting meets the principle of sequential solidification. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a multi-platform universal aluminum subframe low-pressure casting process, which can form aluminum subframes with complex structures, and design risers and shrinkage-feeding channels at thick and easy-to-shrink locations to ensure product quality; and the production process is smooth by setting the on-site pressure curve, and scrapped parts are less likely to occur.

[0004] The technical solution adopted by the present invention to solve the technical problem is: to provide a multi-platform universal aluminum subframe low-pressure casting process, comprising the following steps:

[0005] Step 1: multiple mounting holes are provided on the subframe to meet the use requirements of different vehicle models;

[0006] Step 2: Set the upper and lower molds and the parting line of the mold design according to the product structure of the subframe. The upper mold occupies two-thirds and the lower mold occupies one-third. At the same time, ensure that the parting line has a smooth transition and sharp corners are not allowed in principle.

[0007] Step 3: Analyze the subframe structure to identify multiple thick and large hot spots and areas with high quality requirements on the product;

[0008] Step 4: Design the runner, riser and feeding channel of the subframe according to the locations of multiple thick and large hot spots;

[0009] Step 5: Design cooling inserts based on the subframe simulation results to help the product form better;

[0010] Step 6: Design the sand opening and sand core positioning according to the subframe product structure;

[0011] Step 7: Design the mold ejector position and exhaust channel according to the subframe product structure;

[0012] Step 8: Setting the filling pressure curve for on-site production: It is divided into liquid raising, filling, pressurization, pressure maintaining and pressure relief.

[0013] As a supplement to the technical solution described in the present invention, the step three is specifically that the mold is designed with a total of six feed ports for the product, namely the first liquid inlet port, the second liquid inlet port, the third liquid inlet port, the fourth liquid inlet port, the fifth liquid inlet port and the sixth liquid inlet port, the first liquid inlet port is provided in the center of the upper part of the aluminum subframe, the second liquid inlet port and the third liquid inlet port are provided on the inner sides of the two sides of the lower part of the aluminum subframe, the fourth liquid inlet port and the fifth liquid inlet port are provided symmetrically on the sides of the middle part of the aluminum subframe, and the sixth liquid inlet port is provided in the center of the middle part of the aluminum subframe, the sixth liquid inlet port is located in the middle part of the cavity, and is used to connect the middle high point crossbeam position to ensure complete filling of the product; at the same time, three independent risers are provided inside the cavity, which can reduce the weight of the runner and improve the yield; for the thick and large hot node area, shrinkage channels are provided to connect to the risers to ensure product quality.

[0014] As a supplement to the technical solution described in the present invention, the step five is specifically to view the solidification process of the aluminum subframe through simulation software, determine the risky position, set a reasonable insert shape and cooling parameters, use cooling to appropriately adjust the local temperature, and reduce the occurrence of defects.

[0015] As a supplement to the technical solution described in the present invention, the step six is ​​specifically as follows: the sub-frame is a thin-walled part, the interior of which is formed by a sand core, and the sand outlet and sand core positioning are designed according to the product structure of the sub-frame. The sand outlet needs to be evenly distributed, and the size of the sand outlet needs to be increased at thick and large positions to ensure smooth sand discharge of the product.

[0016] As a supplement to the technical solution described in the present invention, the sand core needs to be designed with X positioning, Y positioning and Z positioning, wherein there are two X positioning and two Y positioning, and the four positionings are respectively located at the outermost sand outlets around the product; the Z positioning needs to ensure the support of the sand core, so it is designed in the lower mold or side of the sand core.

[0017] As a supplement to the technical solution described in the present invention, the step seven is specifically as follows: the positions of the ejector pins are respectively distributed on the upper mold of the product and the surrounding flow channels to maintain a uniform distribution, which is easy to eject the mold. The mold exhaust position is generally designed at the intersection of aluminum liquid during filling and the high point of the product to reduce the occurrence of air holding.

[0018] As a supplement to the technical solution described in the present invention, the step eight is specifically to set the filling pressure curve for on-site production, S1 liquid raising: under the conditions of liquid raising pressure of 160mbar and liquid raising speed of 20mbar / s, the aluminum liquid reaches the runner, S2 filling: the filling pressure is increased to 240mbar, the filling speed is 10mbar / s, and the aluminum liquid fills the mold cavity, S3 pressurization: after the filling is completed, the pressure is quickly increased to 350mbar, and the pressurization speed is 32mbar / s, S4 pressure holding: after the pressure reaches 350mbar, this pressure is maintained for 150S, S5 pressure relief: after the solidification of the aluminum subframe is completed, the pressure is relieved to return the excess aluminum liquid to the holding furnace.

[0019] Beneficial effects: The present invention relates to a low-pressure casting process for a multi-platform universal aluminum subframe, which designs multi-platform universal parts to match the use requirements of different models and saves development and design costs; it can form aluminum subframes with complex structures, and design risers and shrinkage-feeding channels at thick and easy-to-shrink locations to ensure product quality; the mold structure is reasonably designed to extend the service life of the mold and reduce cost increases; the production process is smooth through the setting of the on-site pressure curve, and scrapped parts are less likely to occur. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a step diagram of the present invention;

[0021] Figure 2 is a schematic diagram of a casting system of the aluminum subframe of the present invention;

[0022] Figure 3-4 It is a structural schematic diagram of the aluminum subframe sand core positioning of the present invention;

[0023] Figure 5 It is a schematic structural diagram of the shrinkage-feeding ribs of the product formed by the shrinkage-feeding channel of the present invention;

[0024] Figure 6 It is a schematic structural diagram of the cooling insert described in the present invention.

[0025] Illustration: 1. The first liquid inlet flow channel, 2. The second liquid inlet flow channel, 3. The third liquid inlet flow channel, 4. The fourth liquid inlet flow channel, 5. The fifth liquid inlet flow channel, 6. The sixth liquid inlet flow channel, 7. X positioning, 8. Y positioning, 9. Z positioning, 10. Shrinkage ribs, 11. Cooling inserts. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0027] The embodiment of the present invention relates to a multi-platform universal aluminum subframe low pressure casting process, such as Figure 1-6 As shown, the following steps are included:

[0028] Step 1: multiple mounting holes are provided on the subframe to meet the use requirements of different vehicle models;

[0029] Step 2: According to the structure of the sub-frame product, set the upper and lower molds and the parting line of the mold design. The upper mold occupies two-thirds and the lower mold occupies one-third. At the same time, ensure that the parting line has a smooth transition. In principle, sharp corners are not allowed. The existing technical solution is to open the upper and lower molds and use core pulling for parting on the side.

[0030] Step 3: Analyze the subframe structure to identify multiple thick and large hot spots and areas with high quality requirements on the product;

[0031] Step 4: Design the runner, riser and feeding channel of the subframe according to the locations of multiple thick and large hot spots;

[0032] Step 5: Design cooling insert 11 according to the subframe simulation results to help the product to be better molded;

[0033] Step 6: Design the sand opening and sand core positioning according to the subframe product structure;

[0034] Step 7: Design the mold ejector position and exhaust channel according to the subframe product structure;

[0035] Step 8: Setting the filling pressure curve for on-site production: It is divided into liquid raising, filling, pressurization, pressure maintaining and pressure relief.

[0036] The step three is specifically that the mold is designed with six feed ports for the product, namely the first liquid inlet flow channel port 1, the second liquid inlet flow channel port 2, the third liquid inlet flow channel port 3, the fourth liquid inlet flow channel port 4, the fifth liquid inlet flow channel port 5 and the sixth liquid inlet flow channel port 6. The first liquid inlet flow channel port 1 is provided in the center of the upper part of the aluminum subframe, the second liquid inlet flow channel port 2 and the third liquid inlet flow channel port 3 are provided on the inner sides of both sides of the lower part of the aluminum subframe, and the sides of both sides of the middle part of the aluminum subframe are respectively provided with left and right liquid inlet flow channels. A fourth liquid inlet flow channel opening 4 and a fifth liquid inlet flow channel opening 5 are symmetrically arranged. A sixth liquid inlet flow channel opening 6 is arranged in the middle of the aluminum subframe. The sixth liquid inlet flow channel opening 6 is located in the middle of the cavity and is used to connect the middle high point crossbeam position to ensure complete filling of the product. At the same time, three independent risers are arranged inside the cavity to reduce the weight of the flow channel and improve the yield rate. For thick and large hot section areas, shrinkage channels are arranged to connect to the risers to ensure product quality. The shrinkage channels will form shrinkage ribs 10 of the product. Please refer to Figure 5 shown.

[0037] The step five is specifically to check the solidification process of the aluminum subframe through simulation software, determine the risky position, set a reasonable shape of the cooling insert 11 and cooling parameters, and use cooling to properly adjust the local temperature to reduce the occurrence of defects.

[0038] The step six is ​​specifically as follows: the sub-frame is a thin-walled part, and the interior is formed by a sand core. The sand outlet and sand core positioning are designed according to the product structure of the sub-frame. The sand outlet needs to be evenly distributed, and the size of the sand outlet needs to be increased at thick and large positions to ensure smooth sand discharge of the product; the sand core needs to be designed with X positioning 7, Y positioning 8 and Z positioning 9, wherein there are two X positioning 7 and two Y positioning 8, and the four positionings are respectively located at the outermost sand outlets around the product; the Z positioning 9 needs to ensure the support of the sand core, so it is designed in the lower mold or side of the sand core.

[0039] Specifically, the ejector pins are located on the upper mold and surrounding flow channels of the product to maintain uniform distribution, which is convenient for ejection of the mold. The mold exhaust position is generally designed at the intersection of aluminum liquid and the high point of the product during filling to reduce the occurrence of air holding.

[0040] The step eight is specifically to set the filling pressure curve for on-site production, S1 liquid raising: under the conditions of liquid raising pressure of 160mbar and liquid raising speed of 20mbar / s, the aluminum liquid reaches the runner, S2 filling: the filling pressure is increased to 240mbar, the filling speed is 10mbar / s, and the aluminum liquid fills the mold cavity, S3 pressurization: after the filling is completed, the pressure is quickly increased to 350mbar, and the pressurization speed is 32mbar / s, S4 pressure holding: after the pressure reaches 350mbar, the pressure is maintained for 150S, S5 pressure relief: after the aluminum subframe is solidified, the pressure is relieved to return the excess aluminum liquid to the holding furnace.

[0041] The present invention designs multi-platform universal parts to match the use requirements of different models, saving development and design costs; it can form aluminum subframes with complex structures, and designs risers and shrinkage-feeding channels at thick and easy-to-shrink locations to ensure product quality; the mold structure is reasonably designed to extend the service life of the mold and reduce cost increases; the production process is smooth through the setting of the on-site pressure curve, and scrapped parts are less likely to occur.

[0042] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0043] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" may include both "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0044] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0045] The above is a detailed introduction to a multi-platform universal aluminum subframe low-pressure casting process provided by the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for general technicians in this field, according to the ideas of the present application, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A low-pressure casting process for a multi-platform universal aluminum subframe, characterized in that: The following steps are involved: Step 1: multiple mounting holes are provided on the subframe to meet the use requirements of different vehicle models; Step 2: Set the upper and lower molds and the parting line of the mold design according to the subframe product structure. The upper mold occupies two-thirds and the lower mold occupies one-third, while ensuring a smooth transition of the parting line; Step 3: Analyze the subframe structure to identify multiple thick and large hot spots and areas with high quality requirements on the product; Step 4: Design the runner, riser and feeding channel of the subframe according to the locations of multiple thick and large hot spots; Step 5: Design cooling inserts (11) according to the subframe simulation results to help the product to be better molded; Step 6: Design the sand opening and sand core positioning according to the subframe product structure; Step 7: Design the mold ejector position and exhaust channel according to the subframe product structure; Step 8: Setting the filling pressure curve for on-site production: It is divided into liquid raising, filling, pressurization, pressure maintaining and pressure relief.

2. The multi-platform universal aluminum subframe low-pressure casting process according to claim 1 is characterized in that: The step three is specifically as follows: the mold is designed with six feed openings for the product, namely, a first liquid inlet flow channel opening (1), a second liquid inlet flow channel opening (2), a third liquid inlet flow channel opening (3), a fourth liquid inlet flow channel opening (4), a fifth liquid inlet flow channel opening (5) and a sixth liquid inlet flow channel opening (6); the first liquid inlet flow channel opening (1) is arranged at the center of the upper part of the aluminum subframe, the second liquid inlet flow channel opening (2) and the third liquid inlet flow channel opening (3) are arranged on the inner sides of both sides of the lower part of the aluminum subframe, and the aluminum A fourth liquid inlet flow channel opening (4) and a fifth liquid inlet flow channel opening (5) are symmetrically arranged on the sides of both sides of the middle part of the sub-frame, and a sixth liquid inlet flow channel opening (6) is arranged in the center of the middle part of the aluminum sub-frame. The sixth liquid inlet flow channel opening (6) is located in the middle part of the mold cavity and is used to connect the middle high point cross beam position to ensure complete filling of the product. At the same time, three independent risers are arranged inside the mold cavity to reduce the weight of the flow channel and improve the yield rate. For thick and large hot section areas, shrinkage compensation channels are arranged to connect to the risers to ensure product quality.

3. The multi-platform universal aluminum subframe low-pressure casting process according to claim 1 is characterized in that: The step five specifically includes checking the solidification process of the aluminum subframe through simulation software, determining risky positions, setting a reasonable cooling insert (11) shape and cooling parameters, and using cooling to appropriately adjust the local temperature to reduce the occurrence of defects.

4. The multi-platform universal aluminum subframe low-pressure casting process according to claim 1 is characterized in that: Specifically, the subframe is a thin-walled part, and the interior is formed by a sand core. The sand outlet and sand core positioning are designed according to the product structure of the subframe. The sand outlet needs to be evenly distributed, and the size of the sand outlet needs to be increased at thick and large positions to ensure smooth sand discharge of the product.

5. The multi-platform universal aluminum subframe low-pressure casting process according to claim 4 is characterized in that: The sand core needs to be designed with X positioning (7), Y positioning (8) and Z positioning (9), wherein there are two X positioning (7) and two Y positioning (8), and the four positionings are respectively located at the outermost sand outlets around the product; the Z positioning (9) needs to ensure the support of the sand core, so it is designed on the lower mold or side of the sand core.

6. The multi-platform universal aluminum subframe low-pressure casting process according to claim 1 is characterized in that: Specifically, the ejector pins are located on the upper mold and surrounding flow channels of the product to maintain uniform distribution, which is convenient for ejection of the mold. The mold exhaust position is generally designed at the intersection of aluminum liquid and the high point of the product during filling to reduce the occurrence of air holding.

7. The multi-platform universal aluminum subframe low-pressure casting process according to claim 1 is characterized in that: The step eight is specifically to set the filling pressure curve for on-site production, S1 liquid raising: under the conditions of liquid raising pressure of 160mbar and liquid raising speed of 20mbar / s, the aluminum liquid reaches the runner, S2 filling: the filling pressure is increased to 240mbar, the filling speed is 10mbar / s, and the aluminum liquid fills the mold cavity, S3 pressurization: after the filling is completed, the pressure is quickly increased to 350mbar, and the pressurization speed is 32mbar / s, S4 pressure holding: after the pressure reaches 350mbar, the pressure is maintained for 150S, S5 pressure relief: after the aluminum subframe is solidified, the pressure is relieved to return the excess aluminum liquid to the holding furnace.

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