A casting device and a casting method applied to a straight-through stop valve

Abstract

This invention discloses a casting apparatus and method for a straight-through gate valve. The casting apparatus includes a mold assembly, a riser system, and a cooling assembly. The mold assembly has a forming cavity, which has three interconnected forming cavities: a first forming cavity, a second forming cavity, and a third forming cavity. This invention merges the T-shaped hot joint between the shell and ribs and the L-shaped hot joint between the flange structure and the shell, which are present in traditional casting, into a single point. This avoids overlapping effects between two hot joints, thereby improving casting quality. By improving and optimizing the structure of the casting apparatus, the riser system and cooling assembly are used to adjust the flow direction of the molten metal in the casting, controlling the solidification sequence of the casting to obtain castings with acceptable casting quality and precision.

Description

Technical Field

[0001] This invention relates to the field of valve body casting technology, and specifically to a casting apparatus and casting method for a straight-through gate valve. Background Technology

[0002] A straight-through gate valve is a type of shut-off valve used to cut off or connect the medium in a pipeline. It is widely used in the transportation of media such as petrochemicals, natural gas, and oxygen. Straight-through gate valves are characterized by their simple structure, good sealing performance, long service life, and short switching stroke.

[0003] Figure 1 The figure shows a cross-sectional view of the internal cavity of a straight-through gate valve. The shell 01 and the inner cavity rib 02 intersect in a T-shape, forming a T-shaped hot spot at their intersection. At the same time, an L-shaped hot spot is formed at the intersection of the shell 01 and the flange 03. The small distance between the two hot spots causes the hot spot circles formed at the intersection area to overlap. Therefore, during the casting process, casting defects such as shrinkage cracks are very likely to occur. Moreover, this area is located in a stress concentration area, and defects such as shrinkage cracks will pose a safety hazard to the reliable use of the valve.

[0004] To mitigate this adverse effect, in existing technologies, two risers 04 are typically placed on the pre-formed shell during the casting stage to compensate for the shrinkage of the inner cavity stiffener 02, preventing casting defects such as shrinkage cracks at the inner cavity stiffener 02. Similarly, risers 04 are placed at the pre-formed flange 03 to compensate for the shrinkage and prevent casting defects such as shrinkage cracks at the inner cavity flange 03. For the specific number and orientation of the risers 04, please refer to [reference needed]. Figure 2 The diagram shows a structural schematic of the prior art. While this design can reduce casting defects such as shrinkage cracks at the inner cavity stiffener 02 and flange 03, thus improving casting quality;

[0005] However, this design has the following problems:

[0006] 1. Excessive heat concentration can also cause shrinkage cracks in castings, specifically leading to cracks and shrinkage at the junction of rib plate 02 and shell 01;

[0007] 2. Due to the close proximity of the riser platform to the flange, sand holes, cracks, and shrinkage porosity are prone to appear on the outer surface of the casting, reducing the appearance quality of the casting and making subsequent machining and cleaning difficult;

[0008] 3. This design uses two risers 04 to feed the inner cavity stiffener 02, which requires a large riser platform to be placed on the shell, resulting in increased weight of the casting and affecting casting accuracy. Summary of the Invention

[0009] The technical problem to be solved, or at least partially solved, by the present invention is that, in related technologies, castings are prone to shrinkage cracks, resulting in poor casting quality and precision.

[0010] This invention provides a casting apparatus for use in a straight-through gate valve, comprising:

[0011] A model component having a molding cavity within it; the molding cavity having a first molding cavity, a second molding cavity, and a third molding cavity that are connected and intersecting; the first molding cavity is suitable for molding a shell, the second molding cavity is suitable for molding a rib, and the third molding cavity is suitable for molding a flange structure.

[0012] A riser system suitable for storing molten metal, the riser system including a first riser; the first riser and the mold assembly are fixedly disposed, the first riser being disposed above the first molding cavity;

[0013] The system includes a cooling assembly comprising an arc-shaped chill; the arc-shaped chill and the model assembly are fixedly disposed, the arc-shaped chill is conformally mounted above the first molding cavity, the second molding cavity and the arc-shaped chill are respectively positioned on the inner and outer sides of the first molding cavity, the arc-shaped chill and the first riser are spaced apart, and the arc-shaped chill is disposed in the feeding direction from the first riser toward the second molding cavity.

[0014] Optionally, the riser system further includes a pair of second risers, which are fixedly disposed with the model assembly. The second riser is disposed above the third molding cavity, and the second riser and the first riser are spaced apart.

[0015] Optionally, the cooling assembly further includes a second square chill, which is fixedly disposed with the model assembly; the cooling end face of the second square chill is conformally mounted at the lower edge of the outer side of the third molding cavity.

[0016] Optionally, the cooling assembly further includes at least one first square chill, which is disposed below the first molding cavity, and the first riser and the first square chill are disposed opposite each other on both sides of the first molding cavity.

[0017] As a preferred embodiment, the casting apparatus further includes a gating system, which is fixedly disposed on the model assembly. The gating system is connected to the molding cavity, and the output end of the gating system is disposed below the molding cavity.

[0018] As a preferred embodiment, there are two third molding cavities, with the first molding cavity and the second molding cavity disposed between the two third molding cavities; the gating system includes a main channel and two branch channels; one end of the main channel is adapted to be connected to an external gating port, and the other end of the main channel is connected to the two branch channels, with the output ports of the two branch channels respectively disposed below the two third molding cavities.

[0019] As a preferred embodiment, the model assembly includes an upper outer mold model, a lower outer mold model, and a sand core model, wherein the sand core model is installed within the space enclosed by the upper outer mold model and the lower outer mold model.

[0020] As a preferred embodiment, the model assembly further includes a chilling structure, which includes an outer chilling part and an inner chilling part. The outer chilling part is fixedly disposed on the upper outer mold model and the lower outer mold model, and is conformally disposed at the intersection of the first molding cavity and the third molding cavity. The inner chilling part is fixedly disposed on the sand core model, and is conformally disposed at the intersection of the first molding cavity and the second molding cavity.

[0021] As a preferred embodiment, the model assembly further includes a positioning structure disposed outside the third molding cavity to facilitate positioning of a portion of the flange structure.

[0022] A casting method for a straight-through gate valve includes the following steps:

[0023] Create model components and attach the riser system and cooling components to the model components;

[0024] After the model assembly is assembled, a molding cavity is formed inside the model assembly. The molding cavity has a first molding cavity, a second molding cavity, and a third molding cavity that are connected and intersecting. The first molding cavity is suitable for molding a shell, the second molding cavity is suitable for molding a rib, and the third molding cavity is suitable for molding a flange structure. After the model assembly is assembled, the first riser of the riser system is positioned above the first molding cavity, and the arc-shaped chill of the cooling assembly is installed above the first molding cavity. The arc-shaped chill and the first riser are spaced apart, and the arc-shaped chill is located in the feeding direction from the first riser toward the second molding cavity.

[0025] Molten metal is poured into the forming cavities through the gating system to fill the first forming cavity, the second forming cavity, and the third forming cavity accordingly.

[0026] Cool and solidify to form a casting.

[0027] The technical solution provided by this invention has the following advantages:

[0028] 1. The casting apparatus provided by the present invention includes a mold assembly, a riser system and a cooling assembly. The riser system is suitable for storing molten metal. The mold assembly has a forming cavity. The forming cavity has a first forming cavity, a second forming cavity and a third forming cavity that are connected and intersecting. The first forming cavity is suitable for forming a shell, the second forming cavity is suitable for forming ribs, and the third forming cavity is suitable for forming a flange structure.

[0029] This invention merges the T-shaped hot joint formed between the shell and ribs, and the L-shaped hot joint formed between the flange structure and the shell, in traditional casting, into the intersection of these three elements. This avoids the overlapping influence between the two hot joints, thereby improving casting quality. Specifically, by placing the first riser above the first forming cavity, and placing the second forming cavity and the arc-shaped chill correspondingly on the inner and outer sides of the first forming cavity, with the arc-shaped chill positioned in the feeding direction of the first riser towards the second forming cavity, the molten metal from the first riser can be transferred to the second forming cavity to feed the ribs. By setting a first riser on the shell, the riser platform of the first riser has ample assembly space, avoiding its proximity to the formed flange structure, thus reducing the adverse effects of sand holes and shrinkage cracks on the outer surface of the casting, improving the appearance quality of the casting. Simultaneously, by setting a first riser, the weight of the riser platform is reduced, preventing increased casting weight and ensuring reliable casting accuracy. This invention, through improving and optimizing the structure of the casting device, effectively improves casting quality and accuracy.

[0030] 2. The casting apparatus provided by the present invention further includes a second square chill in the cooling component, which is fixedly arranged with the mold component; the molten metal flowing into the third forming cavity is cooled by the second square chill, and the cooling end face of the second square chill is conformally installed at the lower edge of the outer side of the third forming cavity, so that the molten metal located at the lower edge of the third forming cavity is cooled and solidified first.

[0031] 3. The casting apparatus provided by the present invention further includes one or more first square chills in the cooling assembly. The first square chills are disposed below the first forming cavity, and the first riser and the first square chills are disposed opposite each other on both sides of the first forming cavity. The first square chills cool the molten metal flowing into the first forming cavity, causing the molten metal located on the lower side of the first forming cavity to solidify and form first.

[0032] 4. The casting apparatus provided by the present invention further includes a chilling structure in the model assembly. By setting the chilling structure at the intersection of the first forming cavity, the second forming cavity and the third forming cavity, the molten metal at the intersection is rapidly chilled and solidified, thereby avoiding the adverse effects of shrinkage cracks. Attached Figure Description

[0033] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the structure of a straight-through stop valve after casting in the prior art.

[0035] Figure 2 This is a three-dimensional schematic diagram of the casting stage of a straight-through gate valve in the prior art;

[0036] Figure 3 This is a cross-sectional view of the casting apparatus provided in an embodiment of the present invention from a top perspective;

[0037] Figure 4 for Figure 3 Schematic diagram of the structure of the casting and model components;

[0038] Figure 5 This is a partial schematic diagram of the sand core model in the casting apparatus provided in an embodiment of the present invention;

[0039] Figure 6 This is a side view schematic diagram of the casting apparatus provided in an embodiment of the present invention;

[0040] Figure 7 for Figure 6 Schematic diagram of the structure of the casting, riser system and cooling components;

[0041] Figure 8 This is a schematic diagram of a casting in a casting apparatus provided in an embodiment of the present invention;

[0042] Figure 9 This is a schematic diagram showing the connection between the casting, riser system, and gating system in the casting apparatus provided in an embodiment of the present invention;

[0043] Figure 10 This is a three-dimensional schematic diagram of a casting in a casting apparatus provided in an embodiment of the present invention.

[0044] Explanation of reference numerals in the attached figures:

[0045] 01-Shell; 02-Firming plate; 03-Flange; 04-Riser; 05-Riser patch;

[0046] 11 - Upper outer mold model; 12 - Lower outer mold model;

[0047] 13-Sand core model; 131-Core skeleton; 132-Core skeleton transverse spikes;

[0048] 141-External quenching part; 142-Internal quenching part;

[0049] 151 - First positioning sand mold; 152 - Second positioning sand mold; 153 - Third positioning sand mold;

[0050] 16 - Air outlet channel;

[0051] 21-Shell; 22-Stiffening plate;

[0052] 23-Flange structure; 231-Left flange; 232-Right flange; 233-Upper flange;

[0053] 241 - Shell riser patch; 242 - Flange riser patch;

[0054] 31 - First riser; 32 - Second riser;

[0055] 41-Main channel; 42-Branch channel; 43-Inner gate channel;

[0056] 51 - Curved chill; 52 - First square chill; 53 - Second square chill. Detailed Implementation

[0057] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0059] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connection," "linking," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0060] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0061] Example 1

[0062] Figure 1 The diagram shows the structure of a straight-through gate valve after casting in the prior art. The shell 01 and the inner cavity rib plate 02 intersect in a T-shape, and a T-shaped hot spot is formed at the junction of the two. At the same time, an L-shaped hot spot is formed at the junction of the shell 01 and the flange 03. The distance between the two hot spots is small, which causes the hot spot circles formed at the junction area to overlap. Therefore, casting defects such as shrinkage cracks are very easy to occur in the casting process.

[0063] In traditional casting model and process design, Figure 2 This is a three-dimensional schematic diagram of the casting stage of a straight-through gate valve in the prior art. In this diagram, the shell 01 needs to be fitted with two risers 04 and a riser supplement 05 is added. The casting needs to be effectively fed by the riser supplement added to the shell 01. The casting has a poor appearance and the subsequent cleaning of the casting surface is difficult.

[0064] To address the technical problems described above, this embodiment provides a casting apparatus, including a mold assembly, a riser system, and a cooling assembly.

[0065] See Figures 3 to 6 The model assembly has a molding cavity formed inside; the model assembly includes an upper outer mold model 11, a lower outer mold model 12 and a sand core model 13. The sand core model 13 is installed in the space enclosed by the upper outer mold model 11 and the lower outer mold model 12. The molding cavity has a first molding cavity, a second molding cavity and a third molding cavity that are connected and intersecting. The first molding cavity is suitable for molding the shell 21, the second molding cavity is suitable for molding the rib plate 22, and the third molding cavity is suitable for molding the flange structure 23.

[0066] See Figure 7 and Figure 9 The riser system is suitable for storing molten metal in castings. The riser system includes a first riser 31. The first riser 31 and the mold assembly are fixedly arranged, and the first riser 31 is located above the first forming cavity.

[0067] See Figure 9 The cooling assembly includes an arc-shaped chill 51; the arc-shaped chill 51 and the model assembly are fixedly arranged, the arc-shaped chill 51 is conformally installed above the first molding cavity, the second molding cavity and the arc-shaped chill 51 are respectively placed on the inner and outer sides of the first molding cavity, the arc-shaped chill 51 and the first riser 31 are spaced apart, and the arc-shaped chill 51 is arranged in the feeding direction of the first riser 31 toward the second molding cavity.

[0068] In this embodiment, see Figure 9 The riser system also includes a pair of second risers 32, which are fixedly disposed with the mold assembly. The second risers 32 are positioned above the third molding cavity, and are spaced apart from the first riser 31. This invention simultaneously feeds the flange structure 23 of the third molding cavity through the paired second risers 32.

[0069] As a preferred embodiment, the casting apparatus also includes a gating system, which is fixedly mounted on the mold assembly and connected to the forming cavity. The output end of the gating system is located below the forming cavity. The gating system pours molten metal into the forming cavity of the mold assembly from top to bottom. As heat is dissipated, the molten metal gradually solidifies and cools within the forming cavity.

[0070] In this embodiment, see Figure 4 and Figure 9 The flange structure 23 includes a left flange 231 and a right flange 232, and the third forming cavity is suitable for forming the left flange 231 and the right flange 232.

[0071] As a preferred embodiment, for the cast straight-through gate valve, the left flange 231 and right flange 232 have two third forming cavities, with the first and second forming cavities positioned between the two third forming cavities; see [link / reference]. Figure 9 The gating system includes a main channel 41 and two branch channels 42. One end of the main channel 41 is adapted to be connected to an external gating port, and the other end of the main channel 41 is connected to the two branch channels 42. The output ports of the two branch channels 42 are respectively located below the two third molding cavities.

[0072] In this embodiment, see Figure 3 The gating system includes an inner gating channel 43. The first riser 31 and the second riser 32 are respectively equipped with the inner gating channel 43, and the molten metal for feeding is introduced into the molding cavity through the inner gating channel 43.

[0073] See Figures 7 to 10 The cooling assembly also includes a second square chill 53, which is fixedly set with the model assembly. The second square chill 53 cools the molten metal flowing into the third molding cavity. The cooling end face of the second square chill 53 is conformally installed at the lower edge of the outer side of the third molding cavity, so that the molten metal located at the lower edge of the third molding cavity is cooled and solidified first.

[0074] See Figure 7The first riser 31 is fixed to the upper outer mold model 11. The first riser 31 is located at the center of the upper outer mold model 11. At least one arc-shaped chill 51 is placed on each side of the first riser 31 to cover the structure at the intersection of the stiffener 22 and the shell 21, so as to quickly cool this area and effectively prevent the generation of cracks.

[0075] See Figure 6 , Figure 7 as well as Figure 10 The cooling assembly also includes one or more first square chills 52, which are disposed below the first forming cavity. The first riser 31 and the first square chills 52 are disposed opposite each other on both sides of the first forming cavity. The first square chills 52 cool the molten metal flowing into the first forming cavity, causing the molten metal located on the lower side of the first forming cavity to solidify and form first.

[0076] In one embodiment, a row of first square chills 52 is arranged at the center of the upper end of the lower outer mold 12 to obtain a larger heat exchange area. Since the shell 21 has a relatively thin wall thickness, while the stiffener 22 has a relatively thick thickness, typically more than twice the thickness of the shell 21; when the wall thicknesses on both sides of the intersection are significantly different, the thinner wall side solidifies earlier, while the thicker wall side solidifies later, resulting in very low matrix strength. The first solidified area will crack the casting along the weaker area during shrinkage, making it very easy for open cracks to appear at the intersection. By using chills to cool the casting and increasing the heat dissipation area, the intersection can solidify earlier and build strength as soon as possible, thus preventing the casting from cracking.

[0077] In a preferred embodiment, the thickness of the first square chill 52 is 1 to 1.2 times the thickness of the stiffener 22.

[0078] In this embodiment, see Figures 3 to 5 The sand core model 13 includes a core skeleton 131 and core crossbars 132. Two core crossbars 132 are provided, one on the left and one on the right. The two core crossbars 132, together with the core skeleton, reinforce the strength of the sand core. The distance between the stiffening plate 22 and the right end face of the right flange 232 is greater than 20mm, facilitating machining and clamping. To ensure the internal quality of the casting, the stiffening plate 22 needs a 1:10 slope transition from the center to the left flange 231. Simultaneously, to prevent sand from adhering to the sharp corners of the casting, the intersection of the stiffening plate 22 and the shell 21 needs a radius of R15 or greater.

[0079] In one embodiment, the core skeleton 131 is made of welded steel core.

[0080] In this embodiment, the model assembly also includes a chilling structure. By setting the chilling structure at the intersection of the first molding cavity, the second molding cavity, and the third molding cavity, the molten metal at the intersection is rapidly chilled and solidified, thus avoiding the adverse effects of shrinkage cracks.

[0081] See Figure 3 The cooling structure includes an outer cooling part 141 and an inner cooling part 142. The outer cooling part 141 is fixedly mounted on the upper outer mold model 11 and the lower outer mold model 12, and is conformally mounted at the junction of the first molding cavity and the third molding cavity. The inner cooling part 142 is fixedly mounted on the sand core model 13, and is conformally mounted at the junction of the first molding cavity and the second molding cavity.

[0082] In one embodiment, the outer cooling section 141 and the inner cooling section 142 are respectively set as chromite sand layers. Chromite sand has excellent high temperature resistance and no phase change characteristics, so as to effectively avoid the problem of sand sticking to the outer wall of the casting. Filling the intersection of the stiffener 22 and the shell 21 with chromite sand can effectively avoid the problem of thin wall caused by sand core deformation.

[0083] In one embodiment, the external cooling part 141 is configured as an annular structure formed by the upper outer mold model 11 and the lower outer mold model 12 together forming a film.

[0084] In one embodiment, the internal cooling section 142 is configured as an arc-shaped structure at its outer edge.

[0085] As a preferred embodiment, the model assembly also includes a positioning structure disposed on the outside of the third forming cavity to facilitate positioning of the flange structure 23.

[0086] See Figure 4 The positioning structure includes a first positioning sand mold 151 and a second positioning sand mold 152. The first positioning sand mold 151 is located at the left end of the left flange 231, and the second positioning sand mold 152 is located at the right end of the right flange 232.

[0087] In one embodiment, both the first positioning sand mold 151 and the second positioning sand mold 152 are configured as water glass self-hardening sand cores.

[0088] In one embodiment, the model assembly is provided with an air outlet channel 16, and the first positioning sand mold 151 and the second positioning sand mold 152 are respectively provided with air outlet channels 16, which are used for venting the molding cavity.

[0089] Further, see Figure 4 and Figure 9 The flange structure 23 also includes an upper flange 233, and the molding cavity formed within the model assembly also has a fourth cavity, which is suitable for molding the upper flange 233.

[0090] See Figure 4 The positioning structure also includes a third positioning sand mold 153, which can be used to indicate the position of the lower box, prevent the sand core from falling back, and avoid the problem of incorrect casting flow.

[0091] See Figure 9 The first and third forming cavities are each designed with spaces to accommodate the supplementary structures. These supplementary structures serve as feeding spaces for the casting and solidify after the casting. The supplementary structures include a shell riser supplement 241 and a flange riser supplement 242. The shell riser supplement 241 is located at the upper end of the first forming cavity, and the flange riser supplement 242 is located at the outer end.

[0092] See Figure 7 , Figure 9 and Figure 10 The upper end of the third forming cavity has a riser platform for the second riser 32 and an insulating boss for fixing the second riser 32. See the figure. There are 6 second risers 32. Two second risers 32 are set at the outer end of the third forming cavity on the left, two second risers 32 are set at the outer end of the third forming cavity on the right, and two second risers 32 are set at the upper end of the first forming cavity.

[0093] The model component provided by the present invention has the following solidification sequence: the first riser 31 first fills the upper part of the shell 21 and stiffener 22, while the second riser 32 fills the lower flange riser patch 242 and the left flange 231 and right flange 232, and then fills the corresponding part of the shell 21 and stiffener 22 through the left flange 231 and right flange 232, and finally fills the part of the shell 21 that is far away from the flange structure 23 through the stiffener 22.

[0094] Specifically, in this embodiment, the shell 21 is the thinnest and solidifies first. The stiffener 22 is slightly thicker and remains partially liquid while the shell 21 solidifies, serving to support the shrinkage of the shell 21. When the stiffener 22 solidifies, the left flange 231 and right flange 232 are thicker and also remain partially liquid, serving to support the shrinkage of the stiffener 22. When the left flange 231 and right flange 232 are mostly solidified, the flange riser patch 242 remains partially liquid, serving to support the shrinkage of the left flange 231 and right flange 232. The second riser 32 is not only the thickest but also has its own insulation properties, serving as the last part to support the shrinkage of the flange riser patch 242.

[0095] Example 2

[0096] This embodiment provides a casting method for a straight-through gate valve, which includes the following steps:

[0097] Create model components and attach the riser system and cooling components to the model components;

[0098] After the model assembly is molded, a molding cavity is formed inside the model assembly. The molding cavity has a first molding cavity, a second molding cavity, and a third molding cavity that are connected and intersecting. The first molding cavity is suitable for molding the shell 21, the second molding cavity is suitable for molding the rib plate 22, and the third molding cavity is suitable for molding the flange structure 23 of the part. When the model assembly is molded, the first riser 31 of the riser system is set above the first molding cavity, and the arc-shaped chill 51 of the cooling assembly is installed above the first molding cavity. The arc-shaped chill 51 and the first riser 31 are spaced apart, and the arc-shaped chill 51 is located in the feeding direction of the first riser 31 toward the second molding cavity.

[0099] Molten metal is poured into the molding cavity through the gating system to fill the first molding cavity, the second molding cavity, and the third molding cavity. The shell 21, stiffener 22, left flange 231, right flange 232, flange riser patch 242, and second riser 32 are formed step by step. After the molten metal in the molding cavity and riser assembly has completely cooled and solidified, the casting is finally formed.

[0100] This invention merges the T-shaped hot joint formed between the shell 21 and the stiffener 22, and the L-shaped hot joint formed between the flange structure 23 and the shell 21, into the intersection of the three in traditional casting. This avoids the overlapping influence between the two hot joints, thereby improving casting quality. By placing the first riser 31 above the first forming cavity, and placing the second forming cavity and the arc-shaped chill 51 on the inner and outer sides of the first forming cavity respectively, and placing the arc-shaped chill 51 in the feeding direction of the first riser 31 toward the second forming cavity, the molten metal from the first riser 31 can be transferred to the second forming cavity to feed the stiffener 22. By setting a first riser 31 on the shell 21, the riser platform of the first riser 31 has ample assembly space, avoiding its proximity to the formed flange structure 23, thus reducing the adverse effects of sand holes and shrinkage cracks on the outer surface of the casting, which is beneficial to the appearance quality of the casting. At the same time, by setting a first riser 31, the weight of the riser platform is reduced, avoiding the increase in casting weight and ensuring reliable casting accuracy.

[0101] This embodiment improves and optimizes the structure of the casting apparatus, utilizing a riser system and cooling components to adjust the flow direction of molten metal feeding in the casting, controlling the solidification sequence of the casting to obtain castings with acceptable casting quality and precision. This embodiment reduces the adverse effects of shrinkage cracks at the two hot spots in the casting, reduces the number of risers in the shell 21, reduces the amount of molten steel used in the casting raw materials, improves the quality of the casting, and reduces its weight, thus improving the appearance quality of the casting.

[0102] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A casting device for use in a straight-through gate valve, characterized in that, include: The model component has a molding cavity formed therein; the molding cavity has a first molding cavity, a second molding cavity and a third molding cavity that are connected and intersecting, the first molding cavity is suitable for molding a shell (21), the second molding cavity is suitable for molding a rib plate (22), and the third molding cavity is suitable for molding a flange structure (23). A riser system suitable for storing molten metal, the riser system including a first riser (31); the first riser (31) and the mold assembly are fixedly disposed, the first riser (31) being disposed above the first molding cavity; The cooling assembly includes an arc-shaped chill (51); the arc-shaped chill (51) and the model assembly are fixedly arranged, the arc-shaped chill (51) is conformally installed above the first molding cavity, the second molding cavity and the arc-shaped chill (51) are respectively placed on the inner and outer sides of the first molding cavity, at least one arc-shaped chill (51) is placed on each side of the first riser (31) to cover the structure at the intersection of the rib plate (22) and the shell (21), the arc-shaped chill (51) and the first riser (31) are spaced apart, and the arc-shaped chill (51) is arranged in the feeding direction of the first riser (31) toward the second molding cavity.

2. The casting apparatus according to claim 1, characterized by The riser system also includes a pair of second risers (32), which are fixedly disposed with the model assembly. The second riser (32) is disposed above the third molding cavity, and the second riser (32) and the first riser (31) are spaced apart.

3. The casting apparatus according to claim 2, characterized by The cooling assembly also includes a second square chill (53), which is fixedly disposed with the model assembly; the cooling end face of the second square chill (53) is conformally installed at the lower edge of the outer side of the third molding cavity.

4. The casting apparatus according to claim 1, characterized by The cooling assembly further includes at least one first square chill (52), which is disposed below the first molding cavity, and the first riser (31) and the first square chill (52) are disposed opposite to each other on both sides of the first molding cavity.

5. The casting device according to any one of claims 1 to 4, characterized in that The casting device also includes a gating system, which is fixedly mounted on the model assembly. The gating system is connected to the molding cavity, and the output end of the gating system is located below the molding cavity.

6. The casting apparatus according to claim 5, characterized by The third molding cavity is provided in two places, and the first molding cavity and the second molding cavity are provided between the two third molding cavities; the gating system includes a main channel (41) and two branch channels (42); one end of the main channel (41) is adapted to be connected to an external gating port, and the other end of the main channel (41) is connected to the two branch channels (42), and the output ports of the two branch channels (42) are respectively provided below the two third molding cavities.

7. The casting apparatus according to any one of claims 1 to 4, characterized by The model components include an upper outer mold model (11), a lower outer mold model (12), and a sand core model (13). The sand core model (13) is installed in the space enclosed by the upper outer mold model (11) and the lower outer mold model (12).

8. The casting apparatus according to claim 7, characterized by The model assembly also includes a chilling structure, which includes an outer chilling part (141) and an inner chilling part (142). The outer chilling part (141) is fixedly disposed on the upper outer mold model (11) and the lower outer mold model (12). The outer chilling part (141) is conformally disposed at the intersection of the first molding cavity and the third molding cavity. The inner chilling part (142) is fixedly disposed on the sand core model (13). The inner chilling part (142) is conformally disposed at the intersection of the first molding cavity and the second molding cavity.

9. The casting apparatus according to claim 7, characterized by The model assembly also includes a positioning structure disposed outside the third molding cavity to accommodate positioning of the partial flange structure (23).

10. A casting method for a straight-through gate valve, characterized in that, Includes the following steps: Create model components and attach the riser system and cooling components to the model components; After the model assembly is closed, a molding cavity is formed inside the model assembly. The molding cavity has a first molding cavity, a second molding cavity, and a third molding cavity that are connected and intersecting. The first molding cavity is suitable for molding the shell (21), the second molding cavity is suitable for molding the rib (22), and the third molding cavity is suitable for molding the flange structure (23). When the model assembly is closed, the first riser (31) of the riser system is set above the first molding cavity. The arc-shaped chill (51) of the cooling assembly is installed above the first molding cavity. At least one arc-shaped chill (51) is placed on each side of the first riser (31) to cover the structure at the intersection of the rib (22) and the shell (21). The arc-shaped chill (51) and the first riser (31) are spaced apart. The arc-shaped chill (51) is located in the feeding direction of the first riser (31) toward the second molding cavity. Molten metal is poured into the forming cavities through the gating system to fill the first forming cavity, the second forming cavity, and the third forming cavity accordingly. Cool and solidify to form a casting.

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