Sand core for manufacturing auxiliary frame and sand core forming method
By adopting the U-shaped structure of hollow sand core, the problem of subframe cracks caused by solid sand core in the prior art is solved, the quality and qualification rate of subframes are improved, and material and production costs are saved.
Patent Information
- Application Number
- CN202411915087.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-24
- Publication Date
- 2025-05-06
AI Technical Summary
During the manufacturing process of the existing integrated hollow subframe, the solid sand core hinders the solid solidification and shrinkage of the aluminum liquid when the aluminum liquid is cooled and formed, resulting in cracks in the subframe, which seriously affects its quality and pass rate.
A hollow sand core is adopted, and a sand core body with a U-shaped structure includes a rear cross beam core, a left longitudinal beam core and a right longitudinal beam core. All sections are hollow, and sand injection holes and molding grooves are provided in appropriate positions to form a hollow sand core through a specific molding method.
It effectively solves the problem of subframe cracks caused by liquid aluminum solidification and shrinkage, improves the quality and pass rate of subframes, and reduces the amount of sand and curing agent, saving costs.
Smart Images
Figure CN119927148A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of sand cores, and in particular to a sand core for making a sub-frame and a sand core molding method. Background Art
[0002] The subframe is a supplementary component of the frame, used to connect the suspension and frame, and at the same time block the vibration transmitted from the wheel suspension to the frame to achieve quietness and ride comfort in the passenger compartment. Some models also install the engine on the subframe to isolate the engine's vibration and provide a better driving experience.
[0003] In the manufacturing process of the existing integrated hollow subframe, a solid sand core is first filled in the subframe forming mold, and then molten aluminum is added to the mold to form the subframe. After the molten aluminum is cooled and formed, the solid sand core is crushed and poured out, and the hollow subframe is completed. However, in the prior art, the solid sand core is used to manufacture such an integrated hollow subframe. When the molten aluminum is cooled and formed, the solid sand core will hinder the solidification and shrinkage of the molten aluminum and generate excessive casting stress, and even cause cracks in the subframe, which seriously affects the quality and pass rate of the subframe. Summary of the invention
[0004] In view of the above problems, the present invention provides a sand core and a sand core forming method for making a sub-frame. By adopting a hollow sand core, the quality and qualified rate of the sub-frame are improved.
[0005] The technical solution of the present invention is: a sand core for making a subframe, including a sand core body, the sand core body is a U-shaped structure including a rear cross beam core, a left longitudinal beam core, and a right longitudinal beam core, the cross-sections of the rear cross beam core, the left longitudinal beam core, and the right longitudinal beam core are all hollow, the left longitudinal beam core and the right longitudinal beam core are symmetrically arranged at the two ends of the rear cross beam core, the rear cross beam core, the left longitudinal beam core, and the right longitudinal beam core are all provided with sand shooting holes, a rear suspension bushing tube forming groove is provided at the connection between the left longitudinal beam core, the right longitudinal beam core and the rear cross beam core, a radially penetrating drive shaft avoidance forming hole is provided in the middle of the left longitudinal beam core and the right longitudinal beam core, and a rear swing arm front installation clearance forming part and a rear swing arm rear installation clearance forming part are respectively provided on both sides of each drive shaft avoidance forming hole.
[0006] Preferably, first sand-shooting holes are symmetrically arranged on both end surfaces of the rear cross beam core.
[0007] Preferably, a second sand-shooting hole and a third sand-shooting hole are respectively arranged on the corresponding end faces of the rear swing arm front installation clearance forming part and the rear swing arm rear installation clearance forming part of the left longitudinal beam core and the right longitudinal beam core.
[0008] Preferably, a fourth sand-shooting hole is provided at one end of the left longitudinal beam core and the right longitudinal beam core away from the rear cross beam core.
[0009] The technical solution of the present invention also includes a method for forming a sand core for making a subframe, comprising the following steps: 1) Manufacturing U-shaped sand core forming mold; The U-shaped sand core forming mold comprises an upper mold and a lower mold, wherein the upper mold is provided with a plurality of sand injection ports, the upper and lower mold surfaces are provided with air inlets, and a plurality of air inlet channels are provided inside, each air inlet channel is connected with a corresponding air inlet, and each air inlet channel is provided with a plurality of air vents connected with the mold inner cavity, so that the air vents are distributed throughout the entire mold inner cavity surface; 2) Sand screening: Screen the molding sand raw materials and select the molding sand raw materials with a mesh size of 40 to 50 as new sand; 3) Sand mixing: mixing new sand with recycled old sand; 4) Mixing resin: The molding sand mixed in step 3) is transferred to a mixing bucket, and resin is added to the mixing bucket, and the molding sand and resin are mixed evenly through the mixing bucket; 5) Sand shooting: The molding sand and resin mixture in the mixing bucket is shot into the interior of the U-shaped sand core molding mold through the sand shooting port on the U-shaped sand core molding mold; 6) Crusting: triethylamine gas is introduced into the U-shaped sand core forming mold through the air inlet to solidify the resin on the surface of the molding sand resin mixture in the inner cavity of the U-shaped sand core mold to form a crust, thereby forming a U-shaped sand core; 7) Remove the remaining sand: Take out the U-shaped sand core and put it on the dumping equipment, pour out the unsolidified sand inside the U-shaped sand core through the sand shooting port on the U-shaped sand core to form a U-shaped hollow sand core, and recycle the poured sand as old sand.
[0010] Preferably, in step 1), the diameter of the vent hole is 10 mm, a vent plug is provided in the vent hole, and a plurality of small holes with a diameter of 0.5 mm are evenly provided on the vent plug; and the average spacing of the vent hole diameters is 30 mm.
[0011] Preferably, in step 3), the mixing ratio of new sand to old sand is 7:3.
[0012] Preferably, in step 4), when mixing the resins, the temperature in the mixing bucket is maintained at 25°C.
[0013] Preferably, in step 6), the ventilation time of introducing triethylamine gas into the U-shaped sand core forming mold is 4 to 6 seconds.
[0014] Preferably, in step 6), the crust thickness of the U-shaped sand core is 12 to 18 mm.
[0015] The advantages of the present invention are: 1. The present invention is a sand core with a hollow structure, which greatly reduces the amount of sand used and the amount of curing agent used to solidify the sand, thereby saving costs.
[0016] 2. When the hollow sand core of the present invention is used to manufacture a sub-frame, the problem of cracks in the sub-frame caused by the solidification and shrinkage of aluminum liquid can be effectively solved, thereby improving the quality and pass rate of the sub-frame. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a schematic diagram of the U-shaped hollow sand core structure; Figure 2 for Figure 1 AA section view; Figure 3 Flow chart for manufacturing U-shaped hollow sand core; Figure 4 The utility model relates to a sub-frame manufactured by adopting the U-shaped hollow sand core. DETAILED DESCRIPTION
[0018] See also Figure 1 and Figure 2 A sand core for making a subframe, comprising a sand core body, the sand core body is a U-shaped structure including a rear cross beam core 1, a left longitudinal beam core 2, and a right longitudinal beam core 3 integrally formed, the cross sections of the rear cross beam core 1, the left longitudinal beam core 2, and the right longitudinal beam core 3 are all hollow, the left longitudinal beam core 2 and the right longitudinal beam core 3 are symmetrically arranged at the two ends of the rear cross beam core 1, the two end surfaces of the rear cross beam core 1 are symmetrically arranged with first sand shooting holes 8, the left longitudinal beam core 2 and the right longitudinal beam core 3 are provided with a front-mounted yielding forming part 6 of the rear swing arm, and a rear-mounted yielding forming part 7 of the rear swing arm A second sand-shooting hole 9 and a third sand-shooting hole 10 are respectively arranged on the end surface; a fourth sand-shooting hole 11 is respectively arranged at one end of the left longitudinal beam core 2 and the right longitudinal beam core 3 away from the rear cross beam core 1; a rear suspension bushing tube forming groove 4 is respectively arranged at the connection between the left longitudinal beam core 2, the right longitudinal beam core 3 and the rear cross beam core 1; a radially penetrating drive shaft avoidance forming hole 5 is respectively arranged in the middle part of the left longitudinal beam core 2 and the right longitudinal beam core 3; a rear swing arm front installation clearance forming part 6 and a rear swing arm rear installation clearance forming part 7 are respectively arranged on both sides of each drive shaft avoidance forming hole 5.
[0019] See also Figure 3 A method for forming a sand core for a subframe comprises the following steps: 1) Manufacturing U-shaped sand core forming mold; The U-shaped sand core forming mold comprises an upper mold and a lower mold, wherein a plurality of sand injection ports are arranged on the upper mold, air inlets are arranged on the surfaces of the upper and lower molds, and a plurality of air inlet channels are arranged inside the upper and lower molds, each of which is communicated with a corresponding air inlet, and each of which is provided with a plurality of vents connected to the inner cavity of the mold, wherein the diameter of the vent is 10 mm, a vent plug is arranged in the vent, and a plurality of small holes with a diameter of 0.5 mm are evenly arranged on the vent plug; the average spacing of the diameter of the vent is 30 mm, so that the vents can be ensured to be distributed throughout the surface of the inner cavity of the mold, and when triethylamine gas is introduced, the surface of the molding sand resin mixture is simultaneously solidified and crusted; 2) Sand screening: Screen the molding sand raw materials and select the molding sand raw materials with a mesh size of 40 to 50 as new sand; 3) Sand mixing: mixing new sand with recycled old sand, wherein the mixing ratio of new sand to old sand is 7:3.
[0020] 4) Mixing resin: The molding sand mixed in step 3) is transferred to the mixing bucket, and the resin is added into the mixing bucket. The molding sand and the resin are evenly mixed through the mixing bucket. When mixing the resin, the temperature in the mixing bucket is maintained at 25°C to ensure that the resin can be cured smoothly later.
[0021] 5) Sand shooting: The molding sand and resin mixture in the mixing bucket is shot into the interior of the U-shaped sand core molding mold through the sand shooting port on the U-shaped sand core molding mold; 6) Crusting: triethylamine gas is introduced into the U-shaped sand core molding mold through the air inlet for 4 to 6 seconds to ensure the thickness of the crust of the U-shaped sand core, and the resin on the surface of the molding sand-resin mixture in the inner cavity of the U-shaped sand core mold is solidified and crusted to make the crust thickness of the U-shaped sand core 12 to 18 mm. The purpose of this setting is that if the crust thickness of the U-shaped sand core is less than 12 mm, the strength of the U-shaped sand core is insufficient when the subframe is made, resulting in an unqualified subframe; if the crust thickness of the U-shaped sand core is greater than 18 mm, the strength of the U-shaped sand core is too high, which is not conducive to crushing and pouring out the U-shaped sand core after the subframe is made.
[0022] 7) Remove the remaining sand: Take out the U-shaped sand core and put it on the dumping equipment, pour out the unsolidified sand inside the U-shaped sand core through the sand shooting port on the U-shaped sand core to form a U-shaped hollow sand core, and recycle the poured sand as old sand.
[0023] See also Figure 4After the U-shaped hollow sand core is placed in the sub-frame forming mold, aluminum liquid is poured into the sub-frame forming mold to integrally form the sub-frame in the sub-frame forming mold. The sub-frame includes a hollow rear cross beam 12, a hollow left longitudinal beam 14, and a hollow right longitudinal beam 13 formed by the rear cross beam core 1, the left longitudinal beam core 2, and the right longitudinal beam core 3 of the U-shaped hollow sand core, respectively, and a solid center cross beam 15 and a solid front cross beam 16 formed by the sub-frame forming mold. The hollow rear cross beam 12, the hollow left longitudinal beam 14, and the hollow right longitudinal beam 13 of the sub-frame are respectively provided with a first sand leakage hole 21, a second sand leakage hole 22, a third sand leakage hole 23, and a fourth sand leakage hole 24 formed by a first sand shooting hole 8, a second sand shooting hole 9, a third sand shooting hole 10, and a fourth sand shooting hole 11. After the sub-frame is manufactured, the broken U-shaped hollow sand core is poured out through these sand leakage holes. The hollow left longitudinal beam 14 and the hollow right longitudinal beam 13 of the auxiliary frame also have a rear swing arm front mounting concession molding part 6 and a rear swing arm rear mounting concession molding part 7 respectively formed by a U-shaped hollow sand core and a rear swing arm front mounting part 18 and a rear swing arm rear mounting part 19 formed by a auxiliary frame molding mold, and a rear suspension bushing tube 17 and a drive shaft hole 20 are also formed on the left and right longitudinal beams respectively.
[0024] The U-shaped hollow sand core of the present invention uses a hollow cold sand core process, which has higher production efficiency than a solid hot sand core. After the subframe is formed, the sand shock effect is better, which significantly reduces the processing cycle.
[0025] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification made to the present invention by those skilled in the art without departing from the spirit of the present invention shall fall within the protection scope of the present invention.
Claims
1. A sand core for making a subframe, comprising a sand core body, characterized in that: The sand core body is a U-shaped structure formed integrally with a rear cross beam core (1), a left longitudinal beam core (2), and a right longitudinal beam core (3); the cross sections of the rear cross beam core (1), the left longitudinal beam core (2), and the right longitudinal beam core (3) are all hollow; the left longitudinal beam core (2), and the right longitudinal beam core (3) are symmetrically arranged at the two ends of the rear cross beam core (1); the rear cross beam core (1), the left longitudinal beam core (2), and the right longitudinal beam core (3) are all provided with sand shooting holes; a rear suspension bushing tube forming groove (4) is provided at the connection between the left longitudinal beam core (2), the right longitudinal beam core (3) and the rear cross beam core (1); a drive shaft avoidance forming hole (5) penetrating radially is provided in the middle of the left longitudinal beam core (2), and the right longitudinal beam core (3); and a rear swing arm front mounting clearance forming part (6) and a rear swing arm rear mounting clearance forming part (7) are respectively provided on both sides of each drive shaft avoidance forming hole (5).
2. The sand core for making a subframe according to claim 1, characterized in that: First sand-shooting holes (8) are symmetrically arranged on the end surfaces of both ends of the rear cross beam core (1).
3. The sand core for making a subframe according to claim 1, characterized in that: A second sand-shooting hole (9) and a third sand-shooting hole (10) are respectively arranged on the corresponding end surfaces of the rear swing arm front mounting clearance forming part (6) and the rear swing arm rear mounting clearance forming part (7) of the left longitudinal beam core (2) and the right longitudinal beam core (3).
4. The sand core for making a subframe according to claim 1, characterized in that: A fourth sand-shooting hole (11) is provided at one end of the left longitudinal beam core (2) and the right longitudinal beam core (3) away from the rear cross beam core (1).
5. A method for forming a sand core of a subframe as claimed in claim 1, characterized in that: The following steps are involved: 1) Manufacturing U-shaped sand core forming mold; The U-shaped sand core forming mold comprises an upper mold and a lower mold, wherein the upper mold is provided with a plurality of sand injection ports, the upper and lower mold surfaces are provided with air inlets, and a plurality of air inlet channels are provided inside, each air inlet channel is connected with a corresponding air inlet, and each air inlet channel is provided with a plurality of air vents connected with the mold inner cavity, so that the air vents are distributed throughout the entire mold inner cavity surface; 2) Sand screening: Screen the molding sand raw materials and select the molding sand raw materials with a mesh size of 40 to 50 as new sand; 3) Sand mixing: mixing new sand with recycled old sand; 4) Mixing resin: The molding sand mixed in step 3) is transferred to a mixing bucket, and resin is added to the mixing bucket, and the molding sand and resin are mixed evenly through the mixing bucket; 5) Sand shooting: The molding sand and resin mixture in the mixing bucket is shot into the interior of the U-shaped sand core molding mold through the sand shooting port on the U-shaped sand core molding mold; 6) Crusting: triethylamine gas is introduced into the U-shaped sand core forming mold through the air inlet to solidify the resin on the surface of the molding sand resin mixture in the inner cavity of the U-shaped sand core mold to form a crust, thereby forming a U-shaped sand core; 7) Remove the remaining sand: Take out the U-shaped sand core and put it on the dumping equipment, pour out the unsolidified sand inside the U-shaped sand core through the sand shooting port on the U-shaped sand core to form a U-shaped hollow sand core, and recycle the poured sand as old sand.
6. The molding method according to claim 5, characterized in that: In the step 1), the diameter of the vent hole is 10 mm, a vent plug is arranged in the vent hole, and a plurality of small holes with a diameter of 0.5 mm are evenly arranged on the vent plug; the average spacing of the diameters of the vent holes is 30 mm.
7. The molding method according to claim 5, characterized in that: In the step 3), the mixing ratio of new sand to old sand is 7:
3.
8. The molding method according to claim 5, characterized in that: In the step 4), the temperature in the mixing bucket was maintained at 25°C when the resins were mixed.
9. The molding method according to claim 5, characterized in that: In the step 6), the ventilation time of the triethylamine gas into the U-shaped sand core forming mold is 4 to 6 seconds.
10. The molding method according to claim 5, characterized in that: In the step 6), the crust thickness of the U-shaped sand core is 12 to 18 mm.