Casting mold for J2 ARM casting

Abstract

The utility model relates to a casting mold for J2ARM castings, and belongs to the technical field of metal casting. In order to solve the problems that according to a traditional parting scheme, a machining face faces upwards, scum is prone to being generated, linear parting joints are many, and a core is fixed unstably, the following improvements are provided that a D parting scheme is adopted, the machining face is arranged on a lower box to reduce attachment of the scum, and a metal core support (upper floating prevention and bottom collapse prevention) is combined with a high-temperature adhesive for fixing, so that the stability of the core is enhanced; a continuous shape follow-up parting line is generated based on the casting profile curvature, and the number of joints is reduced; a screw rod fastening structure is adopted, and the adjacent cores are locked through the pre-embedded threaded holes and the through type stainless steel screw rods, so that the displacement risk during molten iron injection is eliminated. According to the mold, the defect rate of a machined surface is reduced, the parting line polishing time is shortened, the core rejection rate is reduced, and the mold is suitable for efficient production of complex cambered surface castings in the fields of automobiles, aviation and the like and has remarkable economical efficiency and practicability.

Description

Technical Field

[0001] This utility model relates to the field of metal casting mold technology, specifically a casting mold suitable for complex arc surface castings (such as J2ARM castings). Through improvements in the parting structure, core stabilizing components, and parting line design, the quality of castings and production efficiency are improved. Background Technology

[0002] In traditional casting processes, the parting line design often adopts the C-shaped scheme with the core facing downwards (e.g., Figure 3 (As shown). Although this solution can ensure the stability of the lower core, the machined surface (such as...) Figure 1 When the A side of the molten iron is facing upwards, slag and sand tend to accumulate on the surface of the upper box during the solidification process, leading to defects such as porosity and slag inclusions in the processing area, which seriously affects the yield.

[0003] To address the slag problem, existing technologies attempt to reduce impurities by adding filters or optimizing the gating system. However, filters are prone to clogging and are costly, and improvements to the gating system have limited effectiveness for complex castings. Furthermore, complex curved castings often use straight parting lines, resulting in numerous and unevenly distributed seams, requiring extensive manual grinding and increasing processing time.

[0004] Regarding core securing, traditional processes rely on the weight of the core tip or a simple support structure. However, for cores without cast holes (such as...),... Figure 6 In the case of cores #1 and #2, the buoyancy generated during molten iron injection can easily cause core displacement, resulting in uneven wall thickness or even leakage. Although existing technologies have attempted to use sand mold reinforcement or temporary supports, these methods are cumbersome and difficult to control precisely.

[0005] Therefore, there is an urgent need for an integrated process solution that can systematically solve the problems of scum defects, excessive seams, and core displacement while ensuring the stability of the parting process. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems in the existing technology, such as the upward-facing machining surface of the traditional C-partition scheme, which easily leads to slag defects, numerous straight parting seams, and core displacement. This invention provides a casting mold for J2 ARM castings, which improves casting quality and production efficiency through improvements in the parting structure, core stabilizing components, and parting line design.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a casting mold for J2 ARM castings, comprising an upper mold and a lower mold using a D parting scheme, wherein the cavity surface of the lower mold is a machined surface and the cavity surface of the upper mold is a non-machined surface;

[0008] The core assembly includes a carrying pole-shaped core head and a core body. The weakest part of the core body is provided with an upper anti-floating core support and a bottom anti-collapse core support. The core support is made of metal and is fixed by a high-temperature adhesive.

[0009] The conformal parting line extending along the outer contour of the casting has a parting surface gap of ≤1mm, and the parting line is a continuous smooth curve;

[0010] A screw fastening structure is provided between adjacent cores.

[0011] Preferably, the load-bearing part of the carrying pole type core head is provided with reinforcing ribs, the thickness of which is 5-10mm and the height is 15-25mm.

[0012] Preferably, the conformal parting line is generated based on the three-dimensional curvature data of the casting, and the region with a curvature radius ≤ 50 mm is fitted with a B-spline curve.

[0013] Preferably, the screw fastening structure includes a screw rod with a diameter of 6-10mm and a length that is dynamically adjusted according to the core spacing.

[0014] Preferably, the upper anti-floating core support and the bottom anti-collapse core support have trapezoidal groove structures in cross-section, which are fully in contact with the core body.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: reduced machining surface defect rate; reduced parting line cleaning time; reduced scrap rate caused by core floating. It can be widely used in the efficient production of complex arc surface castings in the automotive, aerospace and other fields, and has significant economic and industrial applicability. Attached Figure Description

[0016] Figure 1 Schematic diagram of the machining surface of the three-dimensional structure of the J2 ARM casting.

[0017] Figure 2 Schematic diagram of the non-machined surface of the three-dimensional structure of the J2 ARM casting.

[0018] Figure 3 Comparison diagram of schemes C and D of this utility model.

[0019] Figure 4 Detailed final design drawings of the core of this utility model.

[0020] Figure 5 : A schematic diagram of the generation of conformal parting lines in this utility model.

[0021] Figure 6 : Cross-sectional view of the screw rod fastening method of this utility model.

[0022] Markings in the diagram: 1-Upper box, 2-Lower box, 3-Machined surface, 4-Unmachined surface, 5-Core assembly, 51-Carrying core head, 52-Core body, 53-Upper anti-floating core support, 54-Bottom anti-sag core support, 6-Follow-shaped parting line, 7-Screw fastening structure. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0024] like Figures 1 to 6 As shown, a casting mold structure for a J2 ARM casting includes: an upper mold 1 and a lower mold 2 using a D-partition scheme, wherein the cavity surface of the lower mold 2 is a machined surface 3, and the cavity surface of the upper mold 1 is a non-machined surface 4; a core assembly 5, which includes a cantilever-type core head 51 and a core body 52, wherein the weakest part of the core body 52 is provided with an upper anti-floating core support 53 and a bottom anti-collapse core support 54, wherein the core supports 53 and 54 are made of metal and are fixed by high-temperature adhesive; a conformal parting line 6 extending along the outer contour of the casting, wherein the parting line 6 is a continuous smooth curve; and a screw fastening structure 7 provided between adjacent cores, including threaded holes pre-embedded in the contact surface of the cores and stainless steel screws penetrating the cores. The load-bearing part of the cantilever-type core head 51 is provided with reinforcing ribs, the thickness of which is 5-10mm and the height is 15-25mm. The diameter of the screw is 6-10mm, and the length is dynamically adjusted according to the core spacing.

[0025] J2 ARM casting process using molds

[0026] 1. Mold design and parting line preparation

[0027] Partition scheme selection: The D parting scheme is adopted, with the machined surface 3 facing down in the lower box 2 cavity, and the non-machined surface 4 located in the upper box 1 cavity.

[0028] Machining of conformal parting lines: Based on the three-dimensional model of the casting, the curvature data is extracted to generate a continuous parting line 6. The parting surface is milled by a five-axis machine tool, and the gap is controlled to be ≤1mm and the roughness is ≤Ra 6.3μm.

[0029] Upper and lower box assembly: Upper box 1 and lower box 2 are aligned by positioning pins, and the parting surface is evenly coated with refractory paint to prevent molten iron leakage.

[0030] 2. Core component fabrication and installation

[0031] Core molding: The core body 52 is made of furan resin sand, and the core head 51 adopts a carrying pole design. The load-bearing parts are reinforced with ribs (thickness 8mm, height 20mm).

[0032] Core support fixing: 310S stainless steel core supports 53 and 54 are embedded in the top and bottom of the core body 52, coated with high-temperature ceramic adhesive, and baked at 200℃ for curing.

[0033] Screw rod pre-embedding: Pre-embed an M8 threaded hole on the contact surface between core #1 and core #2.

[0034] 3. Secure the box and core tightly.

[0035] Core positioning: Install core assembly 5 into cavity 2 of the lower housing, and ensure that the core spacing error is ≤0.3mm by calibrating the position.

[0036] Screw rod tightening: Insert the 316L stainless steel screw rod and tighten it to 10 N·m using a torque wrench to prevent the core from floating when molten iron is poured in.

[0037] Box closing operation: The upper box 1 and the lower box 2 are closed, and the closing pressure is applied by the hydraulic device to ensure that the parting surface is tightly fitted.

[0038] 4. Pouring and cooling of molten iron

[0039] Iron preparation: HT250 gray cast iron, melting temperature 1450℃, pouring temperature controlled at 1380-1400℃.

[0040] Casting process: A bottom-pouring casting system is adopted, in which molten iron is poured steadily from the pouring cup of the lower box 2 to avoid turbulence that could lead to slag inclusions.

[0041] Cooling control: Open the box after natural cooling to avoid internal stress cracks caused by rapid cooling.

[0042] 5. Unpacking and Post-processing

[0043] Casting removal: Remove the upper box 1, remove the casting and clean the residual sand core.

[0044] Parting line cleaning: Use an angle grinder to remove burrs from parting line 6, reducing the grinding time per piece from 45 minutes to 25 minutes.

[0045] Quality inspection: Inspect the porosity and slag inclusion defect rate of machined surface 3 to ensure a pass rate of ≥95%; measure the wall thickness tolerance (within ±0.4mm).

[0046] The advantages of this invention are: reduced defect rate on machined surfaces, with slag concentrated on non-machined surfaces; reduced parting line seams, shortening grinding time; reduced scrap rate due to core displacement; and suitability for efficient production of complex castings in the automotive, aerospace, and other fields.

[0047] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A casting mold for a J2 ARM casting, characterized in that, include: The upper box (1) and lower box (2) adopt the D parting scheme. The cavity surface of the lower box (2) is a machined surface (3), and the cavity surface of the upper box (1) is a non-machined surface (4). The core assembly (5) includes a carrying pole type core head (51) and a core body (52). The weak part of the core body (52) is provided with an upper anti-floating core support (53) and a bottom anti-collapse core support (54). The core supports (53, 54) are made of metal and are fixed by high temperature adhesive. The conformal parting line (6) extends along the outer contour of the casting. The gap between its parting surfaces is ≤1mm. The conformal parting line (6) is a continuous smooth curve. A screw fastening structure (7) is provided between adjacent cores.

2. The casting mold according to claim 1, characterized in that: The load-bearing part of the carrying pole type core head (51) is provided with reinforcing ribs, the thickness of which is 5-10mm and the height is 15-25mm.

3. The casting mold according to claim 1, characterized in that: The conformal parting line (6) is generated based on the three-dimensional curvature data of the casting, and the region with a curvature radius ≤ 50 mm is fitted with a B-spline curve.

4. The casting mold according to claim 1, characterized in that: The screw fastening structure (7) includes a screw rod with a diameter of 6-10mm and a length that is dynamically adjusted according to the core spacing.

5. The casting mold according to claim 1, characterized in that: The upper anti-floating core support (53) and the bottom anti-collapse core support (54) have trapezoidal groove structures in cross sections, which are fully in contact with the core body (52).

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