Lost foam full mold casting wedge sliding block grafting casting process

Abstract

The invention discloses an evanescent mode full mold casting wedge sliding block grafting casting process, belongs to the technical field of evanescent mode casting, and aims to solve the problems that rigid connection in an existing process is non-adjustable, sand is prone to leaking, and experience dependence is high. The process is realized based on a main mold, a base, a connecting piece and a wedge sliding block: an annular groove is formed in a predetermined grafting area of the main mold, a bottom bulge of the base is fixedly inserted into the groove, and a top bulge of the base is connected with the connecting piece; the connecting piece is of a spliced linear type or bent type, and the two ends of the connecting piece protrude to be matched with the grooves of the base and the wedge sliding block; after main mold pretreatment, base installation, connecting piece splicing, wedge sliding block connection and runner inspection, molten metal is poured synchronously. The position of the wedge sliding block can be flexibly adjusted to avoid interference and hot spots, sand leakage is prevented through cooperation of multiple circles of protrusions and grooves, the qualification rate and batch consistency of castings are improved, the trial and error cost is reduced, and the mold wedge sliding block grafting device is suitable for grafting of complex mold wedge sliding blocks.

Description

Technical Field

[0001] This invention relates to the field of advanced casting technology, and specifically proposes a lost foam casting process using a wedge slider grafting method. This process is particularly suitable for scenarios in lost foam casting where the main mold and the wedge slider need to be cast synchronously through grafting, while avoiding problems such as sand leakage, space interference, and insufficient feeding. Background Technology

[0002] In lost foam casting, small castings such as wedges and sliders, due to their thick structure, are prone to shrinkage cavities and porosity defects caused by insufficient feeding. Meanwhile, slag retention during traditional casting processes can lead to carbon buildup and sand holes. To address these issues, the industry has adopted a "grafting casting process," where the wedge and slider are grafted onto the main mold via an ingate. This utilizes the hydrostatic pressure of the molten metal for forced feeding and leverages the principle of slag flotation to reduce impurity residue.

[0003] However, existing grafting casting processes have significant drawbacks: First, the connection structure is rigidly fixed, and the relative position and angle between the wedge slider and the main mold are permanently locked after bonding. If the grafting area is located in the hot spot zone of the main mold or interferes with the sand box or chills, it cannot be adjusted or avoided. Second, the connection parts mostly use simple planar bonding or straight cylindrical sockets, and the fitting gaps lack an effective sealing structure, making it easy for sand to leak during molding and embedding, resulting in surface defects in the castings. Third, the process is highly dependent on the operator's experience, requiring the grafting position to be determined at once; a misjudgment will scrap the entire mold, resulting in a long trial-and-error cycle and high costs. Fourth, existing connectors lack standardized design and cannot be flexibly adapted to the internal structure of the main mold. For wedge sliders of different sizes or positions, connectors must be remade, resulting in poor process flexibility. These problems severely restrict the quality stability and production efficiency of wedge slider grafting casting, becoming a technical bottleneck that urgently needs to be solved in the field of lost foam casting. Summary of the Invention

[0004] In view of this, the present invention proposes a lost foam casting process for wedge-slider grafting, which aims to solve the problems of non-adjustable connection, easy sand leakage, high trial and error costs and poor process flexibility in the existing grafting process.

[0005] The technical solution of this invention is implemented as follows: This invention provides a lost foam casting process for using a wedge-slider grafting casting, comprising the following steps: (1) Pre-treatment of main mold: In the predetermined grafting area of ​​the main mold, multiple concentric annular grooves are processed; (2) Base installation: Prepare a base made of special foam material for lost foam casting. The bottom surface of the base is provided with multiple concentric ring protrusions. The number and shape of the ring protrusions are consistent with the ring groove of the main mold. Align the ring protrusions with the ring groove and insert them. The gap between the protrusions and the ring grooves should be ≤0.5mm. Fill the gap with special adhesive for lost foam casting at high temperature. (3) Connector splicing: Prepare at least one connector made of lost foam special foam material. The connector has a through flow channel inside and multiple concentric annular protrusions (interval forming a labyrinth groove structure) on both end faces. Select a straight or curved connector according to the internal structure of the main mold and the preset position of the wedge slider. Insert the annular protrusion at one end of the connector into the annular protrusion on the base away from the end face of the main mold and fill the mating area with high temperature lost foam special adhesive. (4) Wedge slider connection: Multiple concentric annular grooves are machined on the end face of the wedge slider connection (the number and shape are consistent with the annular protrusion on the other end of the connector). The annular grooves are aligned with the annular protrusion on the other end of the connector and inserted, so that the main mold cavity and the wedge slider cavity are connected through the through flow channel. High temperature lost foam special adhesive is filled at the mating point. (5) Synchronous casting: After the main mold and the wedge slider are connected, the molding sand is embedded, and the molten metal is poured into the cavity of the main mold. The molten metal flows into the cavity of the wedge slider through the through flow channel to complete the synchronous casting.

[0006] In some embodiments, in step (2), the number of annular protrusions on the bottom surface of the base is 2-4 rings, the height of each annular protrusion is 3-8mm, and the width is 2-5mm; the depth of the annular groove of the main mold is consistent with the height of the annular protrusion, and the width is consistent with the width of the annular protrusion.

[0007] In some embodiments, the preset bending angle of the bent connector in step (3) is any one of 15°, 30°, 45°, 60° or 90°.

[0008] In some implementations, the number of connectors in step (3) is determined according to the following rules: when the straight distance between the wedge slider and the base is ≤100mm, one connector is selected; when the straight distance is >100mm, two to three connectors are selected; adjacent connectors are engaged by inserting the annular protrusions on their respective end faces, and the through channels of all connectors are coaxial, with no steps on the inner wall of the channel.

[0009] In some embodiments, the high-temperature lost foam adhesive used in steps (2), (3), and (4) is an STMMA foam adhesive, which has a curing time of 1.5-2.5 hours and a combustion residue of <0.1%.

[0010] In some implementations, the predetermined grafting area of ​​the main mold in step (1) satisfies the following: the distance between the area and the hot spot area of ​​the main mold is ≥50mm, and the distance between the area and the inner wall of the sand box and the chill is ≥30mm; and the lowest point of the wedge slider cavity is ≥20mm lower than the lowest point of the main mold cavity.

[0011] In some embodiments, the end face edge of the base away from the main mold in step (3) is provided with an angle scale with an accuracy of ±1°; when adjusting the angle of the connector, the angle scale is used as a reference so that the angle deviation of the connector in the same batch of processes is ≤±1°.

[0012] In some implementations, after step (4) is completed, a flow channel patency check step is also included: compressed air with a pressure of 0.2-0.3MPa is introduced from the pouring port of the main mold cavity and continued for 10-20 seconds to observe whether there is a stable airflow at the opening of the wedge slider cavity.

[0013] In some embodiments, the foam material of the base in step (2) and the connector in step (3) is the same as that of the main mold and the wedge slider, which is EPS (expandable polystyrene) or STMMA (expandable styrene-methyl methacrylate copolymer).

[0014] In some implementations, when multiple connectors are used for splicing, a high-temperature lost foam adhesive with a thickness of 0.5-1mm is first applied to the mating joint of adjacent connectors, and then the annular protrusion is inserted; after the insertion is completed, a 10-15mm wide foam tape of the same material as the connector is wrapped around the mating joint.

[0015] The present invention has the following advantages over the prior art: The lost foam casting process for using a wedge slider grafting addresses the problems of existing grafting processes, such as rigid, unadjustable connections, easy sand leakage, high dependence on operator experience, poor feeding effect, insufficient process flexibility, and poor stability. Through a flexible interlocking structure and a series of connectors, the spatial position and angle of the wedge slider relative to the main mold are adjustable, effectively avoiding hot spots and tooling interference that are unavoidable with traditional fixed connections. Simultaneously, the reliable seal formed by the combination of multiple concentric annular protrusions and grooves and a special adhesive solves the problem of easy sand leakage in traditional simple bonding or socket structures. Furthermore, standardized operation... The process incorporates references (such as angle scales and pre-defined grafting area requirements) and flow channel inspection procedures, reducing reliance on operator experience and preventing module scrapping due to one-time decision-making errors in traditional processes. Furthermore, the optimized relative position of the wedge sliders ensures adequate feeding, while the smooth flow channel reduces casting defects and improves casting quality. The modular, connectable connector design enhances process flexibility, eliminating the need for repetitive fabrication of specialized structures and reducing production and trial-and-error costs. The standardized selection of foam materials further ensures process stability in mass production. Overall, this process represents a significant improvement over traditional grafting processes in terms of practicality, reliability, and economy. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram showing the connection state of the mold and connector used in this invention; Figure 2 for Figure 1 Exploded view; Figure 3 This is an exploded view of the connector used in this invention; Figure 4 This is a connection diagram of another connector used in this invention.

[0018] In the diagram: 1-Main mold, 2-Base, 3-Connector, 4-Wedge slider. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] Detailed description of the structure of each component Example 1 1.1 Component Parameters Main mold 1: Three concentric annular grooves are machined in the predetermined grafting area (60mm from the hot spot area of ​​the mold, 40mm from the inner wall of the sand box, avoiding the interference path of the chills); the annular grooves are 5mm deep, 3mm wide, and 8mm apart, and the center of the grooves coincides with the installation center of the base 2 to ensure accurate positioning.

[0021] Base 2: It is a disc-shaped STMMA foam part with a diameter of 100mm and a thickness of 20mm. Its bottom surface is machined with 3 concentric annular protrusions (protrusion height 5mm, width 3mm, and a fitting gap of 0.3mm with the annular groove of the main mold 1). The top surface is machined with annular protrusions with the same parameters as the bottom surface annular protrusions. An angle scale with an accuracy of ±1° (range 0-360°) is engraved on the edge of the top surface for adjusting the horizontal angle of the connector 3.

[0022] Connector 3: It adopts a 30° bent structure (to match the 30° corner of the main mold 1 in this area), with a length of 120mm and an internal through-flow channel (diameter of 25mm, matching the inner runner diameter of the wedge slider 4); both ends of connector 3 are machined with 3 concentric annular protrusions (parameters are consistent with the annular protrusions on the top surface of base 2) to ensure the insertion fit with base 2.

[0023] 4. The inclined wedge slider has 3 concentric annular grooves machined on the connecting end face facing the connector 3 (the parameters are completely matched with the annular protrusions on the end face of the connector 3); the lowest point of its internal cavity is 25mm lower than the lowest point of the cavity of the main mold 1 to meet the static pressure compensation requirements of the molten metal.

[0024] Adhesive: STMMA foam-specific high-temperature adhesive is used, with a curing time of 2 hours and a combustion residue of 0.08%, avoiding residual impurities during casting.

[0025] 1.2 Implementation Steps 1. Pre-treatment of main mold: Use a CNC engraving machine to process an annular groove in the predetermined grafting area of ​​the main mold 1 to ensure that the groove is uniform in size, smooth in the inner wall, and free of burrs or defects.

[0026] 2. Base installation: Align the annular protrusion on the bottom surface of the base 2 with the annular groove of the main mold 1 and slowly insert it, ensuring that the protrusion is fully embedded in the groove; evenly fill the gap between the protrusion and the groove with high-temperature adhesive to avoid air bubbles; let stand for 2 hours until the adhesive is completely cured, so that the base 2 and the main mold 1 form a sealed and firm connection.

[0027] 3. Connector assembly: Hold the 30° bent connector 3 and insert it with the annular protrusion at one end aligned with the annular protrusion on the top surface of the base 2. Refer to the angle scale of the base 2 and rotate the connector 3 to the target angle (ensure that the installation position of the wedge slider 4 avoids interference). After adjustment, fill the mating gap with high-temperature adhesive and let it stand to cure.

[0028] 4. Wedge slider connection: Align the annular groove of the wedge slider 4 with the annular protrusion at the other end of the connector 3 and insert it. Slightly adjust the position of the wedge slider 4 to ensure that the cavity of the main mold 1 and the cavity of the wedge slider 4 are connected through the through flow channel of the connector 3. Fill the gap between the annular groove and the annular protrusion with high-temperature adhesive and let it stand to cure.

[0029] 5. Runner inspection and pouring preparation: Use compressed air at a pressure of 0.25MPa to enter through the pouring port of the main mold 1 and continue to ventilate for 20 seconds; observe whether there is a stable airflow at the cavity opening of the wedge slider 4 to confirm that the runner is unblocked and there is no air leakage at the connection points; then perform molding and sand embedding, and pour the molten metal according to the preset process parameters.

[0030] 1.3 Implementation Results Sealing performance: No sand particles seep into the joints during the molding and sand embedding process, and there are no sand holes on the surface of the casting.

[0031] Interference avoidance: The 30° curved connector 3 fits perfectly with the corner structure of the main mold 1, and the minimum distance between it and the sand box and chill is 35mm, with no interference.

[0032] Casting quality: The wedge slider 4 was tested by UT flaw detection and found to be free of shrinkage cavities and porosity defects, with a pass rate of 100%; the surface roughness Ra≤6.3μm, which meets the product requirements.

[0033] Batch consistency: For 10 castings produced in the same batch, the angle deviation of the wedge slider 4 is ≤ ±0.8°, and the dimensional tolerance meets the CT8 grade requirements in GB / T6414-2022 "Dimensional Tolerances, Geometric Tolerances and Machining Allowances of Castings".

[0034] Example 2 2.1 Component Parameters Main mold 1: The pre-defined grafting area is 55mm away from the heat-retaining zone and 35mm away from the inner wall of the sand box. There is a 60° corner in this area; process 4 concentric annular grooves (groove depth 6mm, groove width 4mm, groove spacing 10mm).

[0035] Base 2: Parameters are the same as in Example 1 (diameter 100mm, thickness 20mm, with 3 rings of protrusions machined on both the bottom and top surfaces).

[0036] Connector 3: It adopts a combination of "one 60° curved structure (100mm in length) + one straight structure (80mm in length)"; the diameter of the through flow channel of both is 25mm, and both ends are machined with annular protrusions with the same parameters as the annular protrusions on the top surface of the base 2; the splice is wrapped with 12mm wide STMMA foam tape (material is the same as connector 3) to enhance sealing and firmness.

[0037] The inclined wedge slider 4 is 160mm away from the base 2. The connecting end face is machined with 4 concentric annular grooves (the parameters match the annular protrusions on the end face of the connector 3). The lowest point of the internal cavity is 25mm lower than the lowest point of the cavity of the main mold 1.

[0038] Adhesive: Same as in Example 1.

[0039] 2.2 Implementation Steps 1. Main mold pretreatment and base installation: The steps are the same as in Example 1. After processing the annular groove in the main mold 1, insert the annular protrusion of the base 2 into the groove and fill it with adhesive for curing.

[0040] 2. Connector assembly: First, insert the annular protrusion at one end of the 60° bent connector 3 into the annular protrusion on the top surface of the base 2. Adjust the angle according to the angle scale and then fill with adhesive to cure. Then, insert the annular protrusion at one end of the straight connector 3 into the annular protrusion at the other end of the bent connector 3. Fill the gap with adhesive and wrap foam tape around the outside of the joint. Let it stand to cure.

[0041] 3. Wedge slider connection, flow channel inspection and pouring: Align the annular groove of the wedge slider 4 with the annular protrusion at the other end of the straight connector 3, insert and fix it, and check the flow channel according to the method of Example 1 before molding, embedding sand and pouring.

[0042] 2.3 Implementation Results Structural adaptability: After the two connectors 3 are spliced ​​together, they fit perfectly against the 60° corner of the main mold 1, with no part rubbing or interfering with the inner wall of the mold.

[0043] Sealing and firmness: There is no sand leakage at the joints, and the foam tape effectively prevents leakage in the gaps before the adhesive cures; during the pouring process, connector 3 did not fall off or shift.

[0044] Metal molten fluidity: The through-flow channel of connector 3 is coaxial and the inner wall is smooth without steps, so the metal molten fluid flows smoothly without air entrapment; the wedge slider 4 is fully filled and there are no defects of insufficient casting.

[0045] Example 3: Material Consistency Example 3.1 Component Parameters Main mold 1 and wedge slider 4: material changed to EPS foam (density 18kg / m³); two concentric annular grooves are machined on the main mold 1 (groove depth 3mm, groove width 2mm, groove spacing 8mm); two concentric annular grooves are machined on the connecting end face of the wedge slider 4 (parameters match the annular grooves of the main mold 1).

[0046] Base 2 and connector 3: both are made of EPS foam (same as main mold 1); base 2 has a diameter of 90mm and a thickness of 18mm, with two annular protrusions on the bottom surface (height 3mm, width 2mm, and a fitting gap of 0.2mm with the annular groove of main mold 1), and an annular protrusion on the top surface with the same parameters as the annular protrusions on the bottom surface; connector 3 uses a 15° bent structure (length 90mm, internal through-flow channel diameter 22mm).

[0047] Adhesive: Uses a special high-temperature adhesive for EPS foam (curing time 1.5h, combustion residue 0.07%).

[0048] 3.2 Implementation Steps Similar to Example 1, the following steps are performed in sequence: "Main mold 1 is processed with an annular groove → Base 2 is installed and fixed → Connector 3 is assembled → Wedge slider 4 is connected → Runner inspection → Molding sand embedding and pouring".

[0049] 3.3 Implementation Results Uniform vaporization: During the casting process, the vaporization rates of the base 2, connecting parts 3, main mold 1, and inclined wedge slider 4 are synchronized, with no abnormal gas or gaps caused by material differences, and the casting is free of porosity defects.

[0050] Connection reliability: The adhesive is well compatible with EPS foam, and there is no detachment or leakage at any connection point during casting. The structural stability meets the process requirements.

[0051] Casting quality: The surface of the wedge slider 4 is smooth, with no carbon slag or inclusions caused by gasification residue, and the UT inspection pass rate is 100%.

[0052] Comparative Example 1 1.1 Operation Method Main mold 1: The pre-selected grafting area does not have an annular groove processed; it is only smoothed by sanding.

[0053] Base 2: A flat disc without annular protrusions (100mm in diameter, 20mm in thickness, STMMA foam), which is directly bonded to the flat area of ​​the main mold 1 using ordinary lost foam adhesive.

[0054] Connector 3: It is a non-adjustable straight tube (120mm in length, without annular protrusions, and flat at both ends), which is bonded to the base 2 and the wedge slider 4 respectively by ordinary adhesive.

[0055] 4. The connecting end face is not machined with an annular groove, but only polished flat; after the position is adjusted by the operator's experience, it is bonded to the connecting part 3.

[0056] No runner inspection steps: Directly carry out molding, sand embedding, and pouring.

[0057] 1.2 Implementation Results Sealing defects: During the molding and sand embedding process, sand particles seeped into the plane bonding gap between the base 2 and the main mold 1, and between the connecting part 3 and the base 2 / wedge slider 4, resulting in a sand hole defect rate of 25% in the casting.

[0058] Interference problem: The straight pipe fittings could not fit the corner of the main mold 1, and the two modules were forced to be scrapped due to the interference between the connector 3 and the inner wall of the mold.

[0059] Casting quality: Due to the inability to adjust the position of the wedge slider 4, it was not in the optimal feeding area, resulting in a shrinkage cavity and porosity defect rate of 18%; the UT flaw detection pass rate was only 82%.

[0060] Comparative Example 2 2.1 Operation Method Main mold 1: A shallow groove (not a multi-ringed groove) with a depth of 1mm is machined in the predetermined grafting area for the rough positioning of the base 2.

[0061] Base 2: The bottom surface has no annular protrusions, and it is positioned by only fitting with shallow grooves and fixed with ordinary adhesive.

[0062] Connector 3: It is a single 60° rigid structure (no splicing function, angle is not adjustable), with both ends being flat, and is connected to the base 2 and the wedge slider 4 by ordinary adhesive.

[0063] Wedge slider 4: After the operator adjusts its position based on experience, it is bonded to the connector 3 without an angular reference.

[0064] No runner inspection steps: Directly carry out molding, sand embedding, and pouring.

[0065] 2.2 Implementation Results Poor adaptability: The single rigid connector 3 cannot be finely adjusted in angle. Due to the interference between the three modules and the corner of the main mold 1, the connector 3 needs to be remade, which increases the cost of trial and error.

[0066] Poor batch consistency: There is no angular scale reference. The angle deviation of the wedge slider 4 of 10 castings in the same batch is ±5°. The dimensional tolerance only meets the CT12 grade, which cannot meet the requirements of mass production.

[0067] Sealing defects: The gap in the shallow groove positioning is large, the sand leakage rate reaches 18%, and the surface quality of the casting is poor.

[0068] Comparative Example 3 3.1 Operating Procedures The connection method of base 2, connector 3, and wedge slider 4 is the same as that of comparative example 1 (flat bonding, without annular protrusions-grooves).

[0069] Sealing improvement: At the bonding points between the base 2 and the main mold 1, and between the connector 3 and the base 2 / wedge slider 4, wrap ordinary polyethylene foam tape (not the same material as the connector 3).

[0070] Other operations: Same as Comparative Example 1 (no flow channel inspection, adjust the position of the wedge slider 4 based on experience).

[0071] 3.2 Implementation Results Poor sealing stability: Ordinary tape has poor compatibility with STMMA foam. During vibration molding, 30% of the tape fell off, and the sand leakage rate was still 15% (far higher than 0% in Example 1).

[0072] Adjustability defects: The angle of connector 3 is fixed, and the shrinkage defect rate of 1 module reaches 12% because the wedge slider 4 is located below the hot spot area.

[0073] Low production efficiency: The tape wrapping process takes an extra 20 minutes per piece, which is 30% less efficient than in Example 1, making it unsuitable for mass production.

[0074] Examples 1-3 respectively verified the effectiveness of the present invention in typical scenarios, complex structure adaptation scenarios, and material consistency scenarios: Example 1 achieves precise sealing connection between the wedge slider 4 and the main mold 1 through multi-ring annular protrusion-groove cooperation, adjustable angle connectors, and standardized operation, with no sand leakage or interference, and a casting qualification rate of 100%; Example 2 adapts to the complex corners of the main mold 1 through the splicing of multiple connectors 3, ensuring smooth flow of molten metal; Example 3 avoids vaporization difference defects by ensuring the material consistency of the base 2, connectors 3, main mold 1, and wedge slider 4.

[0075] In contrast, Comparative Examples 1-3 all have significant defects: traditional planar bonding (Comparative Example 1) has a high sand leakage rate and frequent interference, with a casting defect rate of 18%; single non-adjustable connector (Comparative Example 2) has poor adaptability and low batch consistency; the combination of "planar bonding + tape sealing" (Comparative Example 3) has insufficient sealing stability and low efficiency.

[0076] In summary, this invention solves the problems of sand leakage, lack of adjustability, and poor quality in existing technologies through key technical features such as "multi-ring annular protrusion-groove fit, adjustable splicing angle connectors, and material consistency". The technical effect is significantly better than existing solutions, and it has full practicality and innovation.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A lost foam casting process for using a wedge-slider grafting casting method, characterized in that, Includes the following steps: (1) Pre-treatment of main mold: In the predetermined grafting area of ​​the main mold, multiple concentric annular grooves are processed; (2) Base installation: Prepare a base made of special foam material for lost foam casting. The bottom surface of the base is provided with multiple concentric annular protrusions. The number and shape of the annular protrusions are consistent with the annular groove of the main mold. Align the annular protrusions on the bottom surface of the base with the annular groove of the main mold and insert them. The fitting gap between the annular protrusions and the annular groove is ≤0.5mm. Fill the fitting gap with high temperature special adhesive for lost foam casting. (3) Connector splicing: Prepare at least one connector made of lost foam special foam material. The connector has a through flow channel inside. Both ends of the connector have multiple concentric annular protrusions. The annular protrusions are spaced to form a labyrinth groove structure. According to the internal structure of the main mold and the preset position of the wedge slider, select a straight connector or a curved connector. Insert the annular protrusion at one end of the connector into the annular protrusion on the base away from the end face of the main mold. Fill the joint with high temperature lost foam special adhesive. (4) Wedge slider connection: Multiple concentric annular grooves are machined on the connecting end face of the wedge slider. The number and shape of the annular grooves are consistent with the annular protrusions on the other end of the connector. The annular grooves of the wedge slider are aligned with the annular protrusions on the other end of the connector and inserted, so that the main mold cavity and the wedge slider cavity are connected through the through flow channel of the connector. High temperature lost foam adhesive is filled at the mating point between the wedge slider and the connector. (5) Synchronous casting: The main mold and the wedge slider that have completed the above connection are shaped and embedded with sand; molten metal is poured into the cavity of the main mold, and the molten metal flows into the cavity of the wedge slider through the through flow channel of the connector to complete the synchronous casting and molding.

2. The lost foam casting process for using a wedge-slider grafting method according to claim 1, characterized in that, In step (3), the preset bending angle of the bent connector is any one of 15°, 30°, 45°, 60° or 90°.

3. The lost foam casting process for using a wedge-slider grafting method according to claim 1, characterized in that, In step (2), the number of annular protrusions on the bottom surface of the base is 2-4 rings, the height of each ring protrusion is 3-8mm, and the width is 2-5mm; in step (1), the depth of the annular groove of the main mold is consistent with the height of the annular protrusion, and the width is consistent with the width of the annular protrusion.

4. The lost foam casting process for using a wedge-slider grafting method according to claim 1, characterized in that, The number of connectors in step (3) is determined as follows: when the straight distance between the wedge slider and the base is ≤100mm, one connector is selected; when the straight distance between the wedge slider and the base is >100mm, two to three connectors are selected; adjacent connectors are engaged by inserting the annular protrusions on their respective end faces, and the through channels of all connectors are coaxial, with no steps on the inner wall of the channel.

5. The lost foam casting process for using a wedge-slider grafting method according to claim 1, characterized in that, In steps (2), (3), and (4), the high-temperature lost foam adhesive is an STMMA foam adhesive. The curing time of the adhesive is 1.5-2.5 hours, and the combustion residue is <0.1%.

6. The lost foam casting process for using a wedge-slider grafting method according to claim 1, characterized in that, In step (1), the predetermined grafting area of ​​the main mold satisfies the following conditions: the distance between the area and the hot spot area of ​​the main mold is ≥50mm, the distance between the area and the inner wall of the sand box and the chill is ≥30mm, and the lowest point of the wedge slider cavity is ≥20mm lower than the lowest point of the main mold cavity.

7. The lost foam casting process for using a wedge-slider grafting method according to claim 1, characterized in that, In step (3), the edge of the base facing away from the main mold is provided with an angle scale, and the accuracy of the angle scale is ±1°. When adjusting the angle of the connector, the angle scale is used as a reference to ensure that the angle deviation of the connector in the same batch of processes is ≤±1°.

8. The lost foam casting process for using a wedge-slider grafting method according to claim 1, characterized in that, After step (4) is completed, the flow channel unobstructedness check step is also included: compressed air with a pressure of 0.2-0.3MPa is introduced from the pouring port of the main mold cavity and continuously ventilated for 10-20 seconds to observe whether there is a stable airflow at the opening of the wedge slider cavity.

9. The lost foam casting process for using a wedge-slider grafting method according to claim 1, characterized in that, The foam material of the base in step (2) and the connecting parts in step (3) is the same as the foam material of the main mold and the wedge slider, which is EPS or STMMA.

10. The lost foam casting process for using a wedge-slider grafting method according to claim 4, characterized in that, When multiple connectors are used for splicing, apply a 0.5-1mm thick high-temperature lost foam adhesive to the mating joints of adjacent connectors, and then insert the annular protrusions. After the insertion is completed, wrap a 10-15mm wide foam tape around the mating joint. The material of the foam tape is the same as that of the connector.

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