Sand mould device for knuckle of DISA vertical line

Abstract

The utility model belongs to the technical field of automobile part casting device, concretely relates to a sand mould die device for DISA vertical line knuckle. The sand mould die device for DISA vertical line knuckle, including mutually cooperate's first mould base body, second mould base body, the forming surface of first mould base body and second mould base body is opposite arrangement, two cooperation form vertical parting's complete sand mould cavity, single set mould once forming two pieces mirror image symmetry's knuckle casting, whole set pouring system cancels horizontal cross gate forming structure, vertical gate forming muscle lower end symmetry divides two branch flow short muscle, first mould base body surface contour cooperation knuckle outside whole contour forming, second mould base body surface contour cooperation knuckle inside whole contour forming. The sand mould die device provided by the utility model simplifies sand mould pouring system structure, reduces the runner residual to improve the process yield, reduces the cost under the premise of guaranteeing the inside quality of knuckle casting.

Description

Technical Field

[0001] This utility model belongs to the technical field of automotive parts casting equipment, specifically relating to a sand mold device for a steering knuckle with DISA vertical lines. Background Technology The automotive steering knuckle is a crucial safety component in the chassis system. Its structure typically includes journals, flanges, and wishbone arms, with significant differences in wall thickness across these parts, resulting in several thick, hot spots (such as the root of the journal and the transition radius between the flange and the wishbone arm). In high-speed, high-volume production using the DISA vertical molding line, the casting process for steering knuckles has long faced the following technical challenges: First, the process yield is low. To ensure the internal quality of the castings, traditional steering knuckle sand mold structures often employ a complex gating system architecture with a horizontal sprue, multiple ingates, and a slag trap. This results in a large amount of residual material in the gating system, leading to a process yield generally below 50%. For example, existing steering knuckle sand mold structures using 2-3 risers only achieve a yield of around 38%. Furthermore, the multi-part layout on the DISA vertical line, limited by mold size, and the use of a 4-part layout to ensure product appearance and internal quality, further restricts the improvement of the process yield.

[0002] Secondly, controlling shrinkage porosity is difficult. Steering knuckles, being multi-hotspot castings, are prone to shrinkage porosity and other defects due to the pasty solidification characteristics of ductile iron. A single riser cannot effectively cover multiple independent hotspots simultaneously for feeding, and an improperly designed riser neck modulus can lead to premature closure of the feeding channel or molten iron backflow, resulting in shrinkage porosity within the casting. Existing research indicates that for automotive steering knuckles produced on the DISA line, additional feeding risers are needed for shrinkage cavities in shock absorber holes, and for shrinkage cavities in ABS mounting holes, the riser neck modulus needs to be increased from 3.1mm to 4.2mm. Furthermore, while traditional multi-riser processes can improve shrinkage porosity to some extent, the increased number of risers directly leads to a decrease in process yield and an increase in the complexity of casting process design.

[0003] Furthermore, the mold structure is complex and maintenance costs are high. The excessive number of runners and ingate inserts in traditional processes not only increases the difficulty of mold processing, but also increases the cost of daily maintenance and replacement.

[0004] Chinese patent CN207103751U discloses a sand mold structure for a steering knuckle in an automotive steering system. The sand mold body has six casting cavities, arranged in pairs to form three groups. A common sand core is placed between the two casting cavities in each group. Each casting cavity is connected to a riser and an ingate. The riser uses a bottom-pouring connection to connect with the ingate. All ingates are connected to a gating runner. However, this technology still uses a gating runner + multiple ingate structures, making the gating system relatively complex and resulting in a significant amount of residual gating material. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the problem of poor internal quality of steering knuckle castings in the prior art, especially the problem of shrinkage porosity. It provides a sand mold device for steering knuckles with DISA vertical lines, which simplifies the structure of the sand casting system, reduces the residual in the gating system to improve the process yield, and reduces the manufacturing and maintenance costs of the mold while ensuring the internal quality of the steering knuckle casting.

[0006] This utility model provides a sand mold device for steering knuckles of the DISA vertical line, including a first mold base and a second mold base that cooperate with each other. The forming surfaces of the first mold base and the second mold base are arranged opposite to each other. The two cooperate to form a complete sand mold cavity with vertical parting. It adopts a one-mold-two-piece layout, which can form two mirror-symmetrical steering knuckle castings at one time. It perfectly fits the standard 750×535mm mold plate size of the DISA vertical line and meets the needs of high-speed, large-volume and standardized production lines.

[0007] The first mold base forming plate integrates a sprue cup forming boss, a vertical sprue forming rib, a short sprue rib, and mirror-symmetrically arranged left and right steering knuckle forming punches. This eliminates the traditional transverse sprue forming structure, significantly simplifying the overall gating system architecture. The vertical sprue forming rib is centrally located along the longitudinal direction of the plate, ensuring the symmetry and stability of the pouring process. Two short sprue ribs symmetrically branch off from the lower end of the vertical sprue forming rib, precisely connecting the left and right steering knuckle forming punches respectively, forming a centrally symmetrical dual-channel synchronous filling structure. This allows for simultaneous and uniform filling of both castings, avoiding forming defects caused by uneven filling or excessive temperature differences in a single casting.

[0008] Meanwhile, each steering knuckle forming punch features an integrally formed double-feeding riser structure: a first feeding riser boss corresponding to the thick, hot section of the steering knuckle journal, and a second feeding riser boss corresponding to the hot section of the transition radius between the flange and the fork arm. This achieves targeted, independent feeding for the two core, independent, thick, hot sections of the steering knuckle, completely solving the technical challenge of a single riser not being able to fully cover multiple hot sections. All feeding riser bosses adopt a spherical or near-spherical top-mounted structure and are integrally milled with the mold base, resulting in strong structural stability and high forming precision.

[0009] A controllable fracture neck forming rib is provided between the feeding riser boss and the mold cavity. The cross-sectional dimensions of the controllable fracture neck forming rib are smaller than those of the short runner rib, short gating rib, and riser root. At the same time, it strictly matches the hot spot modulus design of the casting, and controls the riser neck modulus Mn and hot spot modulus Mc after molding to meet the optimal ratio relationship of Mn=0.60~0.75Mc. This can ensure that the molten iron in the riser continuously feeds the hot spot during the solidification process of the casting, and avoid defects such as shrinkage porosity and shrinkage cavities caused by premature closure of the feeding channel and molten iron backflow.

[0010] The second mold base forming plate is designed with a forming structure that complements the first mold base's casting structure, cavity structure, feeding structure, and positioning structure. It also features short sprue ribs that are specifically designed to align with the short sprue ribs. The short sprue ribs and short sprue ribs are precisely spliced ​​together to form a complete and sealed casting channel, ensuring smooth molten iron filling. The surface of the second mold base is designed to fit the overall contour of the steering knuckle's inner side, responsible for forming the internal holes, the inner side of the fork arm, and the mounting reference surface of the casting. After the first mold base and the second mold base are closed, the inner and outer contours complement each other and precisely enclose each other, forming a complete, sealed, and high-precision steering knuckle forming cavity.

[0011] In this invention, the entire mold gating system consists only of vertical sprue forming ribs, short runner ribs, and short sprue ribs, eliminating the redundant structures of traditional horizontal sprues, multi-level ingates, and slag collection bags, thus minimizing the amount of metal residue in the gating system. Simultaneously, all sprue forming ribs, riser forming bosses, hot-spot forming punches, cavity forming punches, and mold closing positioning bosses are integrally machined with the corresponding mold base, eliminating independent inserts and separate parts, thereby reducing processing, assembly, and maintenance costs.

[0012] Furthermore, the first feeding riser boss precisely corresponds to the journal hot spot punch arrangement, and the second feeding riser boss precisely corresponds to the flange fork arm transition hot spot punch arrangement, forming a dual hot spot independent fixed-point feeding forming structure, which specifically solves the shrinkage defects at the transition position of the steering knuckle journal and flange fork arm, and comprehensively improves the internal quality of the casting.

[0013] Compared with the prior art, the beneficial effects of this utility model are: (1) This utility model adopts a simplified gating system structure without a horizontal runner. The entire gating system consists only of a vertical runner, short ribs for branching, and short ribs for alignment. It completely eliminates the redundant architecture of the traditional horizontal runner + multi-stage ingate + slag collection bag, greatly reducing the metal redundancy residue in the gating system and effectively improving the casting process yield. Compared with the yield of about 38% of the traditional process, this structure can increase the process yield to more than 60%, significantly reducing the cost of production materials and improving the economic benefits of mass production. At the same time, the symmetrical cavity layout of two pieces in one mold is precisely adapted to the DISA vertical line and matches the high-speed continuous operation mode of the production line, making it highly adaptable to production.

[0014] (2) This utility model is equipped with a dual independent fixed-point feeding riser structure, which respectively corresponds to the two major high-incidence areas of core defects: the thick hot section of the steering knuckle journal and the hot section of the transition R angle between the flange and the fork arm. It realizes multi-hot section partitioning, independent and precise feeding, which solves the problems of incomplete feeding coverage and redundant weight increase of traditional single riser feeding. At the same time, by limiting the modulus ratio and cross-sectional size of the controllable fracture fine neck forming rib, the solidification sequence of the riser neck is precisely controlled, ensuring that the feeding channel is effective throughout the process, completely eliminating shrinkage porosity and shrinkage defects at the hot section position of the casting, greatly improving the internal quality and product qualification rate of the steering knuckle casting, and ensuring the reliability of the use of automotive chassis safety components.

[0015] (3) This utility model adopts a fully integrated integral processing and molding structure. All cavities, sprues, risers, and positioning structures are integrally milled and formed with the mold base. There are no separate inserts or replacement parts, which completely simplifies the overall structure of the mold, reduces the difficulty of mold processing and assembly errors, shortens the production process, and improves production efficiency. The integrated structure has strong stability and is wear-resistant and durable, which can significantly reduce the daily maintenance, repair and replacement costs of the mold. It is suitable for the long-term high-speed and large-volume production conditions of DISA vertical line, effectively reducing the production and maintenance costs of enterprises. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the molding surface (a) and cross-sectional structure (b) of the first mold base of the sand-cast body for the steering knuckle of the DISA vertical line according to this utility model.

[0017] Figure 2 This is a schematic diagram of the molding surface (c) and cross-sectional structure (d) of the second mold base of the sand-cast body for the steering knuckle of the DISA vertical line according to this utility model.

[0018] Figure 3 A schematic diagram of the sand mold formed on the first mold base surface; Figure 4 A schematic diagram of the sand mold formed on the second mold base forming surface.

[0019] In the diagram: 1. Sprue cup forming boss; 2. Vertical runner forming rib; 3. Short runner rib; 4. Left steering knuckle forming punch; 5. Right steering knuckle forming punch; 6. First feeding riser boss; 7. Second feeding riser boss; 8. Journal hot joint punch; 9. Flange fork arm transition hot joint punch; 10. Mold closing positioning punch; 11. Controllable fracture narrow neck forming rib; 12. First mold base; 13. Second mold base; 14. Short runner rib; 15. Overall outline of the outer side of the steering knuckle; 16. Overall outline of the inner side of the steering knuckle. 17. Sprue cup forming boss b; 18. Left steering knuckle forming punch b; 19. Right steering knuckle forming punch b; 20. First feeding riser boss b; 21. Second feeding riser boss b; 22. Journal hot joint punch b; 23. Flange fork arm transition hot joint punch b; 24. Mold closing positioning punch b; 25. Controllable fracture fine neck forming rib b. Detailed Implementation

[0020] The present invention will be further described below with reference to specific embodiments.

[0021] like Figure 1-4 As shown, the sand mold device for steering knuckles of the present invention is adapted to the 750×535mm standard template of the DISA vertical molding line. It adopts a vertical parting and a mirror-symmetrical layout of two parts in one mold. The core is composed of a first mold base 12 and a second mold base 13 with complementary structures. After the molding surfaces of the two mold bases are closed, they can form two complete and mirror-symmetrical steering knuckle casting cavities. Two products are formed in one step, with high production efficiency and good molding consistency.

[0022] Specifically, such as Figure 1 As shown, the first mold base 12 is the outer forming mold. Its forming plate has a vertical sprue forming rib 2 centrally located longitudinally, and a sprue cup forming boss 1 integrated at the top for the material inlet of the forming gating system. The lower end of the vertical sprue forming rib 2 symmetrically branches into two short branching ribs 3, which are horizontally symmetrically arranged and respectively connect to the left left steering knuckle forming punch 4 and the right right steering knuckle forming punch 5, forming a centrally symmetrical dual-channel filling structure. The entire structure eliminates the traditional horizontal sprue, retaining only a simplified structure of a vertical main sprue + short branching sprues, minimizing metal loss in the gating system and improving the process yield. The entire mold gating system consists only of the vertical sprue forming rib 2, the short branching ribs 3, and the short sprue ribs 14.

[0023] To address the two major hot-spot defect areas in steering knuckle castings, this invention integrates a double-spherical top-mounted feeding riser structure on both the left steering knuckle forming punch 4 and the right steering knuckle forming punch 5. Specifically, the first feeding riser boss 6 precisely corresponds to the journal hot-spot punch 8, specifically designed to feed the thick hot-spot at the root of the steering knuckle journal; the second feeding riser boss 7 precisely corresponds to the flange fork arm transition hot-spot punch 9, specifically designed to feed the R-angle hot-spot at the transition between the flange and fork arm, achieving precise, targeted feeding of two independent hot-spot areas, thus fundamentally solving the problems of shrinkage porosity and voids in multi-hot-spot castings. All feeding riser bosses adopt a near-spherical structure, which, compared to traditional columnar risers, offers higher feeding efficiency and better metal utilization. Furthermore, all are integrally milled with the first mold base 12, ensuring high forming precision and no structural loosening.

[0024] At the connection points between each feeding riser boss and the casting cavity, controllable fracture neck forming ribs 11 are provided, and the cross-sectional dimensions of the controllable fracture neck forming ribs 11 are strictly smaller than the cross-sectional dimensions of the short runner ribs 3, the short sprue ribs 14, and the root of the riser. After mold forming, the riser neck modulus Mn and the hot spot modulus Mc are strictly controlled within the range of 0.60~0.75Mc. This modulus ratio ensures that the hot spot area of ​​the casting solidifies preferentially, and the molten iron in the riser can continuously feed throughout the solidification process of the casting, avoiding internal defects caused by premature closure of the feeding channel and molten iron backflow. At the same time, the small riser neck can achieve automatic fracture separation between the riser and the casting after the casting has cooled, greatly reducing the amount of subsequent grinding and cleaning work.

[0025] The four corners of the first mold base 12 are fixed with mold-closing positioning protrusions 10. These positioning protrusions are machined in one piece with high precision and can be precisely inserted into the positioning grooves of the second mold base 13 to achieve rapid and accurate mold closing between the two mold bases. This effectively avoids molding problems such as mold misalignment, cavity offset, and casting misalignment, ensuring product dimensional accuracy. Simultaneously, the entire surface of the first mold base 12 is integrally formed according to the overall outer contour 15 of the steering knuckle, completely replicating all the outer surface curves and contour structures of the steering knuckle, ensuring the precision of the casting's appearance. The surface contour of the first mold base 12 is formed in accordance with the overall outer contour 15 of the steering knuckle.

[0026] The positions of the following components on the first mold base 12 are as follows: 1. Sprue cup forming boss; 4. Left steering knuckle forming punch; 5. Right steering knuckle forming punch; 6. First shrinkage riser boss; 7. Second shrinkage riser boss; 8. Journal hot joint punch; 9. Flange fork arm transition hot joint punch; 10. Mold closing positioning boss; 11. Controllable fracture fine neck forming rib. The corresponding positions of the components on the second mold base 13 are: 17. Sprue cup forming boss; 28. Left steering knuckle forming punch; 19. Right steering knuckle forming punch; 20. First shrinkage riser boss; 21. Second shrinkage riser boss; 22. Journal hot joint punch; 23. Flange fork arm transition hot joint punch; 24. Mold closing positioning boss; 25. Controllable fracture fine neck forming rib.

[0027] like Figure 2 As shown, the second mold base 13 is an inner forming mold. All cavities, feeding structures, and positioning structures on its forming surface are complementary and matched with the first mold base 12 to achieve complete fit and mold closing. Among them, the second mold base 13 is specially equipped with short sprue ribs 14. The short sprue ribs 14 and the diversion ribs 3 of the first mold base 12 are precisely aligned and spliced ​​together to form a complete, smooth, and sealed pouring channel, ensuring stable filling of molten iron without overflow or turbulence, and improving the casting quality.

[0028] The second mold base 13 is integrally formed based on the overall inner contour 16 of the steering knuckle, accurately replicating the key internal structures such as the internal holes, the inner curved surface of the wishbone, and the mounting reference surface of the steering knuckle. It complements the outer contour of the first mold base 12, forming a completely sealed, complete, and precisely dimensional steering knuckle casting cavity after mold closing. This simplifies the production process and reduces production costs. The surface contour of the second mold base 13 is formed in accordance with the overall inner contour 16 of the steering knuckle.

[0029] In this utility model, all the sprue cup forming bosses 1, vertical runner forming ribs 2, short runner ribs 3, steering knuckle forming punches, shrinkage riser bosses, controllable fracture neck forming ribs 11, mold closing positioning bosses 10, and short runner ribs 14 of the second mold base 13, as well as the inner cavity forming structure, are all integrally milled and formed with the corresponding mold base, without any separate inserts, replacement parts, or connecting parts. The overall structure of the mold has high strength, good consistency, and long service life, completely solving the problems of easy wear, easy loosening, and frequent maintenance of traditional insert molds.

[0030] The assembly and working process of this utility model is as follows: During assembly, the mold-closing positioning protrusions 10 at the four corners of the first mold base 12 are precisely aligned and closed with the second mold base 13, so that the short ribs 3 and the short sprue ribs 14 are spliced ​​together to form a complete pouring channel, and the inner and outer cavity contours are precisely enclosed to form a double-piece symmetrical molding cavity; During production, the molten iron enters the vertical runner through the pouring cup formed by the pouring cup forming boss 1, and flows through the vertical runner to the flow channel formed by the short ribs 3 and the short sprue ribs 14 on both sides, and is simultaneously and evenly filled into the left and right steering knuckle cavities; During the solidification of the casting, the two top-positioned feeding risers continuously feed the corresponding hot sections through the controllable fracture neck, ensuring that the casting is dense and defect-free inside; After cooling, the mold is opened and the part is taken out, the riser neck automatically breaks, and the finished product can be completed by simple cleaning, which is suitable for DISA vertical line high-speed continuous mass production.

Claims

1. A sand mold device for a steering knuckle of a DISA vertical line, characterized in that, The first mold base (12) and the second mold base (13) cooperate with each other. The forming surfaces of the first mold base (12) and the second mold base (13) are arranged opposite to each other. The two cooperate to form a complete sand mold cavity with vertical parting. A single set of molds forms two mirror-symmetrical steering knuckle castings at one time. The first mold base (12) has a sprue cup forming boss (1), a vertical sprue forming rib (2), a branch rib (3), and a left steering knuckle forming punch (4) and a right steering knuckle forming punch (5) arranged in a mirror symmetrical manner. The vertical sprue forming rib (2) is arranged in the center along the longitudinal direction of the plate surface. The horizontal sprue forming structure of the entire gating system is eliminated. The lower end of the vertical sprue forming rib (2) is symmetrically divided into two branch ribs (3), which are connected to the left steering knuckle forming punch (4) and the right steering knuckle forming punch (5) respectively. Each steering knuckle forming punch has an integrally formed double-feeding riser forming structure, including a first feeding riser boss (6) corresponding to the thick hot section of the steering knuckle journal and a second feeding riser boss (7) corresponding to the transition R angle hot section between the flange and the fork arm. A controllable fracture fine neck forming rib (11) is set between the feeding riser boss and the cavity. The surface contour of the first mold base (12) is formed in accordance with the overall contour (15) of the outer side of the steering knuckle. The second mold base (13) has a molding structure that complements the first mold base's casting, cavity, shrinkage compensation, and positioning structures. The second mold base (13) also has a short sprue rib (14) that aligns with the short rib (3) to form a complete casting channel. The surface contour of the second mold base (13) is formed in accordance with the overall contour (16) inside the steering knuckle. After the outer contour (15) of the steering knuckle and the inner contour (16) of the steering knuckle are molded together, they complement each other to form a complete steering knuckle cavity.

2. The sand mold apparatus for a DISA vertical's knuckle as claimed in claim 1, wherein, The first feeding riser boss (6) and the second feeding riser boss (7) are both spherical or nearly spherical top riser forming structures, and are all integrally milled with the corresponding mold base.

3. The sand mold apparatus for a DISA vertical line knuckle as claimed in claim 1, wherein, The forming size of the controllable fracture fine neck forming rib (11) matches the hot section modulus of the casting. After forming, the riser neck modulus Mn and the hot section modulus Mc satisfy the proportional relationship Mn=0.60~0.75Mc.

4. The sand mold apparatus for a DISA vertical line knuckle as set forth in claim 1, wherein, The bottom of the vertical sprue forming rib (2) is symmetrically divided into two short ribs (3), which are respectively connected to the left and right steering knuckle forming punches to form a centrally symmetrical double-channel synchronous filling casting structure.

5. The sand mold apparatus for a DISA vertical line of knuckle as claimed in claim 1, wherein, After the first mold base (12) and the second mold base (13) are molded together, they form a symmetrical cavity layout of two molds, which is compatible with the 750×535mm template size of the DISA vertical line.

6. The sand mold apparatus for a DISA vertical line of knuckle as claimed in claim 1, wherein, The cross-sectional dimensions of the controllable fracture neck forming rib (11) are smaller than those of the short rib (3), the short sprue rib (14), and the riser root.

7. The sand mold apparatus for a DISA vertical line of knuckle as claimed in claim 2, wherein, The first feeding riser boss (6) is precisely positioned to correspond to the journal hot section punch (8), and the second feeding riser boss (7) is precisely positioned to correspond to the flange fork arm transition hot section punch (9), forming a dual hot section independent fixed-point feeding molding structure.

8. The sand mold device for the steering knuckle of the DISA vertical line according to claim 1, characterized in that, The entire mold gating system consists of only vertical runner forming ribs (2), short runner ribs (3), and short runner ribs (14).

9. The sand mold apparatus for a DISA vertical line of knuckle as claimed in claim 1, wherein, The first mold base (12) forms the entire outer surface of the casting by relying on the overall outline (15) of the outer side of the steering knuckle. The second mold base (13) forms the internal holes, the inner side of the fork arm and the mounting reference surface of the casting by relying on the overall outline (16) of the inner side of the steering knuckle. The two concave and convex curved surfaces complement each other to enclose the complete shape of the casting.

Images