A pouring and gating structure of a 3D printing sand mold integral casting middle trough

Abstract

This utility model provides a gating and riser structure for a central trough in a 3D-printed sand mold integral casting, belonging to the field of sand casting technology. The structure includes a sprue, an upper horizontal gating, a lower horizontal gating, an upper ingate, a lower ingate, several top risers, several connecting risers, and several riser insulation sleeves. The sprue is divided into upper and lower horizontal gatings, with the upper horizontal gating connecting to the upper ingate and introduced from one end face of the casting. The lower horizontal gating and lower ingate are connected in an "earth" shape. The ingate overlaps the edge of the central trough casting and also acts as a trough tie. Multiple top risers are provided at the top of the casting. Connecting risers are provided at the middle and bottom plate structures of the central trough, vertically connecting the middle plate and the bottom plate. The connection between the middle and bottom plates has necking structures at both the top and bottom for easy riser removal. Riser insulation sleeves are added to the connecting parts. The gating and riser structure ensures smooth pouring and filling, and provides a reasonable temperature distribution between the top and bottom, significantly reducing shrinkage cavities and porosity defects that occur during the solidification process of integral castings in the middle groove, and improving the internal density of the casting.

Description

Technical Field

[0001] This utility model relates to a gating and riser structure for integral casting of a central trough using 3D printed sand molds, which is used in the casting production of integral central troughs using 3D printed sand molds and belongs to the field of sand casting technology. Background Technology

[0002] In recent years, the application of 3D printing technology in sand casting has gradually developed. Through additive manufacturing technologies such as binder jetting, high-precision, integrated sand molds can be directly printed, avoiding mold parting errors and enabling optimized design of complex structures, gating systems, and risers. Currently, the central troughs used in coal mine conveyors are mostly cast-welded structures, and the use of 3D-printed sand molds for integral casting is still relatively rare. The following technological challenges exist in the integral sand casting of central troughs:

[0003] The central trough is a long trough structure composed of two side troughs and middle and bottom plates. Its wall thickness is uneven and the difference between thin and thick is large. When casting as a whole, it is easy to generate air entrapment and slag inclusion. It is also easy to cause incomplete filling or cold shut due to insufficient fluidity of molten metal. The temperature distribution is unreasonable, which is not conducive to solidification and feeding.

[0004] The middle and bottom plates of the central channel are large flat plate structures with a cavity between them. The cavity height is insufficient, which means that the middle plate located below the pouring position cannot be equipped with an independent riser for feeding.

[0005] Therefore, there is an urgent need for a 3D-printed sand mold integral casting gating and riser structure for the central channel. By optimizing the arrangement of the gating system and risers, the efficiency of molten metal filling and feeding capacity can be improved, providing technical support for the production of high-quality central channel castings. Utility Model Content

[0006] To address the aforementioned issues, this invention provides a gating and riser structure for integral sand casting of a central trough using 3D printed sand molds. This structure is particularly suitable for integral sand casting of central trough castings for coal mine conveyors. By optimizing the gating system and riser layout, the quality of the castings is improved and defects are reduced.

[0007] The technical method adopted by this utility model to solve the technical problem is as follows: The structure includes a straight gating system 1, an upper horizontal gating system 21, a lower horizontal gating system 22, an upper inner gating system 31, a lower inner gating system 32, a number of top risers 4, a number of connecting risers 5, and a number of riser insulation sleeves 6.

[0008] The pouring position of the central slot casting 7 is with the bottom plate 72 as the top surface. The sprue 1 is located on one side of the length direction of the central slot casting 7, and is divided into upper and lower horizontal runners 21 and 22. The upper runner is flush with the top of the casting, and the lower runner is located at the bottom of the casting. The horizontal runner 21 connects to the upper ingate 31 and is introduced from one end face of the central slot casting 7. The lower horizontal runner 22 and the lower ingate 32 are connected in an "earth" shape. The ingate overlaps on the groove edge of the groove structure of the central slot casting 7 and also acts as a groove tie. Several top risers 4 are arranged on the top of the central slot casting 7 according to the thermal points. A connecting riser 5 is provided at the structure between the middle plate 71 and the bottom plate 72 of the casting, which vertically connects the middle and bottom plates of the casting. A riser insulation sleeve 6 is added to the riser section connecting the middle and bottom plates.

[0009] The diameter of the riser section 5 located between the middle and bottom plates is designed according to the thermal section of the middle plate 71 that needs to be shrunk, and the diameter of the riser section located on the bottom plate 72 is designed according to the thermal section of the bottom plate 72 and below that needs to be shrunk.

[0010] The upper and lower ends of the riser insulation sleeve 6 have a necking structure. The diameter of the necking is 1 / 2 of the diameter of the riser section at this point, and the height is 10-15mm. This facilitates the removal of the riser and the grinding of the cut surface after the casting is poured.

[0011] The beneficial effects of this utility model are: by optimizing the design of the gating and riser structure, adopting a stepped gating system, and connecting the heat-insulating risers, the smooth filling of the mold is achieved, which significantly reduces the shrinkage cavities and porosity defects generated in the solidification process of the integral casting of the central groove casting, and improves the internal density of the casting. Attached Figure Description

[0012] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0013] Figure 1 This is a schematic diagram of the structure of this utility model;

[0014] Figure 2 This is a perspective view of the present invention;

[0015] Figure 3 This is another perspective view of the present invention;

[0016] Figure 4 This is an enlarged cross-sectional view of the connecting riser and riser insulation sleeve;

[0017] In the figure: 1—straight sprue, 21—upper horizontal sprue, 22—lower horizontal sprue, 31—upper inner sprue, 32—lower inner sprue, 4—top riser, 5—connecting riser, 6—riser insulation sleeve, 7—middle channel casting, 71—middle plate, 72—bottom plate. Detailed Implementation

[0018] like Figure 1As shown, the pouring position of the middle groove casting 7 is that the bottom plate 72 is used as the top surface, and it is further preferably poured with an upward inclination of 10°. The gating and riser structure is designed according to the pouring position of the middle groove casting 7. This structure includes a sprue 1, a cross-riser 21 / 22, an ingate 31 / 32, and risers (a top riser 4, a connected riser 5), and the sand mold is formed by 3D printing technology.

[0019] As Figure 2 , Figure 3 , Figure 4 shown, the gating system is arranged as follows

[0020] (1) Sprue 1: Vertically arranged on one side of the casting in the length direction, with a circular cross-section.

[0021] (2) Layered runner:

[0022] Upper layer: The cross-riser 21 is led out from the middle section of the sprue 1, flush with the top surface of the casting (bottom plate 72), and connects to the upper-layer ingate 31 to introduce molten metal from the end face of the casting;

[0023] Lower layer: The cross-riser 22 is led out from the bottom of the sprue, located below the casting, and is connected to the lower-layer ingate 32 in a "tu" shape. The ingate overlaps on the groove edge of the groove structure and also serves as a rib to enhance the structural stability. This ingate is removed after heat treatment.

[0024] (3) Risering system:

[0025] Top riser 4: A number of top risers 4 are arranged at the top of the middle groove casting 7 according to the hot spot distribution;

[0026] Connected riser 5: The connected riser 5 is arranged at the bottom plate 72 and vertically connects the bottom plate 72 and the middle plate 71 to solve the problem that it is difficult to place risers for feeding due to insufficient local structural space, and at the same time feeds the middle and bottom plates to improve the quality of the casting. The diameter of the riser section between the middle and bottom plates is designed according to the hot spot to be fed of the middle plate 71, and the diameter of the riser section on the bottom plate 72 is designed according to the hot spot to be fed including the bottom plate 72 and the following parts.

[0027] Riser insulation sleeve 6: A riser insulation sleeve 6 is added to the riser section connecting the middle and bottom plates. The riser insulation sleeve 6 is a cylindrical structure with necked-down structures at the upper and lower ends. The necked-down diameter is 1 / 2 of the riser section diameter here, and the height is 10 mm, which is convenient for cutting off the riser and grinding the cut surface after pouring. The material of the riser insulation sleeve 6 is preferably a heat-insulating and exothermic material.

[0028] After the casting is poured, solidified and cooled, the ingate at the groove opening is retained, and other gating and riser structures are cut off, and the cut surface is polished to ensure the smoothness of the casting surface.

[0029] The ingate at the groove opening is cut off after the casting is heat-treated.

Claims

1. A gating and riser structure for a central groove in a 3D-printed sand mold integral casting, characterized in that: The structure includes a sprue (1), an upper horizontal sprue (21), a lower horizontal sprue (22), an upper ingate (31), a lower ingate (32), several top risers (4), several connecting risers (5), and several riser insulation sleeves (6). Among them, the sprue (1) is divided into upper and lower horizontal sprues (21) and lower horizontal sprues (22). The upper horizontal sprue (21) is connected to the upper ingate (31) and introduced from one end face of the middle slot casting (7). The lower horizontal sprue (22) is connected to the lower ingate (32) in an "earth" shape. The ingate overlaps on the groove edge of the middle slot casting (7). Several top risers (4) are set on the top of the middle slot casting (7). A connecting riser (5) is provided at the middle and bottom plate structure of the casting, which vertically connects the middle plate (71) and the bottom plate (72) of the casting. A riser insulation sleeve (6) is provided at the riser section connecting the middle and bottom plates.

2. The gating and riser structure for a central groove in a 3D-printed sand mold integral casting according to claim 1, characterized in that: The upper and lower ends of the riser insulation sleeve (6) are necked structures, with the necking diameter being 1 / 2 of the diameter of the riser section at this location and a height of 10-15mm.

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