Lower die structure and die for metal mold low-pressure casting process of high-voltage switch aluminum casting

Abstract

The invention relates to the technical field of casting of high-voltage switch castings, in particular to a lower die structure and a die of a high-voltage switch aluminum casting metal mold low-pressure casting process. The lower die structure comprises a lower die lower half part and a lower die upper half part detachably connected with the lower die lower half part; a casting cavity, a plurality of ingate openings and a plurality of ingate lining embedding openings are formed in the upper half part of the lower mold; the embedded ingate lining opening is communicated with the casting cavity through the ingate opening; the lower half part of the lower die is provided with an embedded straight runner lining opening internally provided with a heat-resistant lining and an embedded transverse runner lining groove communicated with the embedded straight runner lining opening; the groove for embedding the cross gate lining is communicated with the hole for embedding the inner gate lining, and heating parts are arranged on the two sides of the groove for embedding the cross gate lining and are used for heating molten aluminum in the cross gate; the lower die structure can realize feeding of molten metal, and is simple in structure, convenient to operate, low in cost, good in casting quality and high in yield. The problems that in the prior art, a metal mold low-pressure casting process of a cross gate is low in product yield, mold demolding is difficult, and the casting cost is high are solved.

Description

Technical Field

[0001] The invention relates to the technical field of high-voltage switch castings, in particular to a lower die structure and a die for a low-pressure casting process of a metal mold for a high-voltage switch aluminum casting. Background Art

[0002] With the advancement of casting technology, a large number of high-voltage switch aluminum castings adopt metal mold low-pressure casting process. Horizontal placement of castings is a major casting process layout method in low-pressure casting process, which is widely used in metal mold low-pressure casting process for high-voltage switch aluminum castings including cover plates, flanges, cylinder castings, etc.

[0003] The low-pressure casting process of metal molds in which the casting is placed horizontally can use risers to compensate for the heat section in the middle and upper part of the casting; use ingates to fill the mold and compensate for the heat section in the middle and lower part of the casting. The pouring system of the low-pressure casting process of metal molds in which the casting is placed horizontally is often set below the casting (filling the mold smoothly from bottom to top). Due to the requirements of the casting process, two or more ingates connected to the casting are often set. The lower cross runner connects the ingates together, and a straight runner is set below the cross runner. In the horizontal placement process of cover plate and flange castings, the flange side of the casting is usually facing up. On the one hand, this ensures stable filling. On the other hand, it is convenient for the casting to be demolded by the ejector rod after pouring with the casting in the upper mold. Usually, the mold is divided by the top surface of the cross runner, and the part above the cross runner is divided left and right by the vertical plane of the center line of the casting. In this case, the mold is a lower left and right structure. In order for cover plates, flanges, and cylinder castings to be able to be carried on the upper mold, the mold can be made into an upper and lower left and right structure; when the mold part above the cross runner cannot be divided left and right, the mold can only adopt an upper and lower mold structure, and the part between the cross runner and the casting needs to use a live block or sand core.

[0004] The Chinese utility model patent with the authorization publication number CN207746396U discloses a low-pressure casting mold for an all-aluminum thin-walled hollow rear subframe of an automobile, which includes an upper mold frame, an upper mold plate, a lower mold plate, a lower mold base and a negative pressure exhaust mechanism. A pair of rear subframe cavities of the upper mold plate and the lower mold plate are respectively provided with an overall open pouring system, and the total cross-sectional area ratio relationship of multiple straight runners, multiple horizontal runners and multiple inner runners is ∑A vertical <∑A horizontal <∑A inner, and the cross-sectional area ratio relationship of a single straight runner, horizontal runner and inner runner is A vertical >A horizontal >A inner; the utility model has the advantages of: its mold design is reasonable and has high tensile strength; the cavity adopts a one-mold two-cavity layout, which improves production efficiency, reduces one liquid riser and increases the relative output rate. However, since the mold is an upper and lower structure, the runner is arranged around the casting on the parting surface, with a long circumference, the casting process yield is low, and the hot nodes within the edge of the casting cannot be compensated through the inner runner. Water cooling is required to chill the hot nodes to make the local solidification earlier, which puts high demands on the water cooling effect. In addition, water cooling has high requirements on mold quality and sealing, and the mold manufacturing is complex and expensive.

[0005] The Chinese invention with the publication number CN114682765A discloses a low-pressure casting mold for an aluminum gear housing, comprising a metal mold mold composed of an upper mold and a lower mold, a gear inner cavity sand core, an upper mold cavity of the upper mold and a lower mold cavity of the lower mold forming a metal mold model cavity, the upper part of the gear inner cavity sand core is placed in the lower mold cavity of the lower mold, and a casting cavity is formed between the upper surface of the gear inner cavity sand core and the upper mold cavity surface of the upper mold, two sets of pouring systems are connected to the casting cavity, the pouring system includes a straight runner and a cross runner, the cross runner includes a horizontal cross runner section and a vertical cross runner section, one end of the vertical cross runner section is connected to the inner end of the horizontal cross runner section, and the other end of the vertical cross runner section is connected to a gear shrinkage runner, and the gear shrinkage runner is connected to a cavity located at the far end of the middle of the casting cavity for forming a gear inner cavity boss. The overall design of the mold conforms to the solidification temperature field gradient of the casting, and can prevent the casting from being retained in the mold, reduce deformation, and the pouring system has a wide shrinkage coverage and good shrinkage effect. However, the structure adopts double riser pipes and two sets of pouring systems, and a cross runner and a gear shrinkage runner are arranged in the sand core. Usually, the runner in the sand core is easy to stick to sand, the runner reuse rate is low, and the casting process yield rate is low.

[0006] It can be seen that in the prior art, the metal mold has a strong chilling effect on the aluminum liquid. For the metal mold low-pressure casting process with a cross runner, in order to ensure the shrinkage compensation capacity of the metal liquid in the inner runner, the cross runner size is usually large, resulting in a low casting process yield rate. Many castings have a low process yield rate due to the horizontal process layout of the cross runner, so other process layout methods are adopted. In addition, the casting process pouring system is below the casting. In order to demold the casting with the pouring system, if the mold adopts a three-open mold structure at the bottom left and right or a four-open mold structure at the top and bottom left and right, the mold is complex and the cost is high; if the mold adopts an upper and lower mold structure, on the one hand, due to the presence of the cross runner, the pouring system is generally high, the demolding resistance is large, and it is easy to have problems such as difficulty in demolding the casting, the casting cannot be lifted, or the casting is deformed due to demolding; on the other hand, if a live block is used, the on-site operation is troublesome, and the use of sand cores has poor surface quality compared to metal molds, and the runner reuse rate is low and the cost is high. Summary of the invention

[0007] Aiming at the problems in the prior art of low-pressure casting process of metal mold with horizontal runner, low product rate, difficulty in demoulding and high casting cost, the present invention provides a lower mold structure and mold for low-pressure casting process of metal mold for high-voltage switch aluminum casting.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] The present invention provides a lower mold structure of a metal mold low-pressure casting process for a high-voltage switch aluminum casting, comprising a lower mold lower half and a lower mold upper half detachably connected to the lower mold lower half;

[0010] The upper half of the lower mold is provided with a casting cavity, a plurality of ingates and a plurality of inlaid ingates lining openings; the shape of the casting cavity is consistent with the outer surface of the casting; the ingates openings correspond to the inlaid ingates lining openings one by one, and one end of the ingates openings is connected to the casting cavity, and the other end is connected to the corresponding inlaid ingates lining openings;

[0011] The lower half of the lower mold is provided with an inlaid straight runner lining opening and an inlaid cross runner lining groove; the inlaid cross runner lining groove is connected with the inlaid straight runner lining opening; the inlaid straight runner lining opening is connected with the inlaid cross runner lining groove; the inner side of the inlaid cross runner lining groove is provided with a cross runner heat-resistant lining, and the inner side of the inlaid straight runner lining opening is provided with a straight runner heat-resistant lining; a heating part is provided on the lower half of the lower mold on both sides of the inlaid cross runner lining groove.

[0012] Furthermore, the heating part includes a plurality of heating holes arranged on the lower half of the lower mold on both sides of the inlaid runner lining groove, and the heating holes are equipped with heating tubes.

[0013] Furthermore, on the lower half of the lower mold, a first anti-fire portion is circumferentially arranged on the outer side of the inlaid cross runner lining groove.

[0014] Furthermore, a second anti-fire part is provided on the upper half of the lower mold at a position corresponding to the first anti-fire part, and the second anti-fire part is connected to the first anti-fire part by a mortise and tenon structure.

[0015] Furthermore, a filter screen installation portion is provided at a position where the lower portion of the ingrate opening and the corresponding inlaid ingrate liner opening are connected, for installing the filter screen.

[0016] Furthermore, the interior of the heat-resistant lining of the cross runner and the heat-resistant lining of the straight runner are coated with a thermal insulation coating.

[0017] Furthermore, a first positioning portion is provided on the lower half of the lower mold, and a second positioning portion is provided on the upper half of the lower mold at a position corresponding to the first positioning portion.

[0018] Furthermore, the distance from one end of the ingrate opening close to the casting cavity to the parting surface between the upper half of the lower mold and the lower part of the lower mold is greater than 30 mm, and an ingrate heat-resistant lining is provided inside the inlaid ingrate lining opening.

[0019] Furthermore, the flow area of ​​the heat-resistant lining in the groove of the embedded cross runner lining is ≥1.5 times the flow area of ​​the heat-resistant lining in the runner at the shrinkage compensation heat node.

[0020] The present invention provides a low-pressure casting process die for a high-voltage switch aluminum casting metal mold, comprising the above-mentioned lower mold structure.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention discloses a lower mold structure for a low-pressure casting process of a metal mold for a high-voltage switch aluminum casting, comprising a lower mold lower half and a lower mold upper half detachably connected to the lower mold lower half; by splitting the lower mold into an upper part and a lower part, the structure is simple, and it is convenient to make or install a straight runner heat-resistant lining in a straight runner opening, to make or install a cross runner heat-resistant lining in a cross runner groove, and to make or install an ingate heat-resistant lining in an ingate opening. The upper half of the lower mold is provided with a casting cavity, a plurality of ingrown runner openings and a plurality of inlaid ingrown runner lining openings; the shape of the casting cavity is consistent with the outer surface of the casting; the ingrown runner openings correspond one-to-one with the inlaid ingrown runner lining openings, and one end of the ingrown runner opening is connected with the casting cavity, and the other end is connected with its corresponding inlaid ingrown runner lining opening; the lower half of the lower mold is provided with inlaid straight runner lining openings and inlaid cross runner lining grooves; the inlaid cross runner lining grooves are connected with the inlaid straight runner lining openings; the inlaid straight runner lining openings are connected with the inlaid cross runner lining grooves; a cross runner heat-resistant lining is provided on the inner side of the inlaid cross runner lining groove, and a straight runner heat-resistant lining is provided on the inner side of the inlaid straight runner lining openings; a heating unit is provided on the lower half of the lower mold on both sides of the inlaid cross runner lining groove. The metal mold works together with the heating part through insulation measures to ensure that when the casting is completely solidified, the cross runner and the straight runner remain in the aluminum liquid state. When the pouring is completed and the pressure is released, the aluminum liquid in the cross runner, the straight runner and part of the inner runner returns to the low-pressure casting furnace for repeated use. In this way, the weight of the casting with the pouring system is significantly reduced, the casting process yield is significantly improved, the casting cost is reduced, and the economy of low-pressure casting is further improved. It can effectively avoid the problem of low process yield of horizontal process layout in casting process design and being forced to adopt other process layout methods. By setting the heat-resistant lining and heating part of the lower part of the lower mold, the metal mold can be insulated and heated, the aluminum liquid has a strong shrinkage compensation ability, the casting quality is better, and the sand core structure is not used, which further ensures the casting quality of the casting; when the pouring is completed, only the ingrowth of the pouring system is solidified, and the casting demoulding only needs to overcome the friction resistance of the ingrowth above the cross runner, and the demoulding resistance is small, and the casting is basically not difficult to demould and the demoulding deformation will not occur; at the same time, since the blank casting only has an ingrowth, the pouring riser is easy to clean later, and the cleaning workload is small. Compared with three-opening molds, four-opening molds or upper and lower molds with live blocks and sand core structures, the on-site operation is simple and the work efficiency is high. This lower mold structure can be applied to the production of high-quality and high-yield castings of various low-pressure castings, with the characteristics of low cost, wide applicability and high economic value.

[0023] The heating part includes a plurality of heating holes arranged on the lower half of the lower mold on both sides of the lining groove of the embedded cross runner, and the heating holes are equipped with heating tubes. The arrangement of the heating holes and the heating tubes can realize heating and heat preservation of the aluminum liquid inside the cross runner, realize rapid demoulding and reflux of the aluminum liquid to the low-pressure casting furnace, and has a simple structure.

[0024] By connecting the second anti-fire part and the first anti-fire part with a mortise and tenon structure, the aluminum liquid can be prevented from overflowing during the low-pressure casting process, and the upper and lower parts of the lower mold can be tightly connected.

[0025] A filter screen installation portion is provided at the position where the lower part of the ingrate opening and the corresponding inlaid ingrate liner opening are connected, which is used to install the filter screen, and can filter out impurities in the aluminum liquid, ensure the purity of the aluminum liquid, and further ensure the quality of the casting.

[0026] The heat-resistant lining is coated with a heat-insulating coating inside. The setting of the heat-insulating coating can realize shrinkage compensation for the casting to ensure the quality of the casting, further protect the heat-resistant lining, and prevent damage to the heat-resistant lining when subsequently cleaning the oxide scale inside the runner.

[0027] A first positioning portion is provided on the lower half of the lower mold, and a second positioning portion is provided on the upper half of the lower mold at a position corresponding to the first positioning portion. The arrangement of the first positioning portion and the second positioning portion can realize rapid positioning and installation of the upper and lower parts of the lower mold, thereby improving installation efficiency and reducing installation difficulty.

[0028] The flow area of ​​the heat-resistant lining in the groove of the embedded cross runner lining is ≥1.5 times the flow area of ​​the heat-resistant lining of the entrapment, ensuring that the cross runner can fully compensate for the local hot node through the entrapment. The present invention provides a low-pressure casting process mold for a high-voltage switch aluminum casting, including the above-mentioned lower mold structure. The mold has a simple structure, convenient operation, easy demoulding, low cost, and good casting quality and high yield rate. It is an advanced technology in the field of low-pressure casting. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the structure of a high-voltage switch aluminum casting according to Example 3 of the present invention, wherein a is a schematic diagram of the front side of the part, and b is a schematic diagram of the back side of the part.

[0030] Figure 2 This is a schematic diagram of a metal mold low-pressure casting process for a high-voltage switch aluminum casting according to Example 3 of the present invention.

[0031] Figure 3 This is a schematic diagram of the cross-section of the lower mold structure of a high-voltage switch aluminum casting metal mold low-pressure casting process according to Example 3 of the present invention.

[0032] Figure 4This is a schematic diagram of the upper half structure of the lower mold of a low-pressure casting process of a high-voltage switch aluminum casting metal mold in Example 3 of the present invention.

[0033] Figure 5 This is a schematic diagram of the assembly of the upper half structure of the lower mold of the lower mold structure of a high-voltage switch aluminum casting metal mold low-pressure casting process in Example 3 of the present invention.

[0034] Figure 6 This is a schematic diagram of the lower half structure of the lower mold of a low-pressure casting process of a high-voltage switch aluminum casting metal mold in Example 3 of the present invention.

[0035] Figure 7 This is a simplified assembly diagram of the lower mold lower half structure of the lower mold structure of a high-voltage switch aluminum casting metal mold low-pressure casting process in Example 3 of the present invention.

[0036] Figure 8 This is a schematic diagram of the aluminum casting structure of a high-voltage switch in Example 4 of the present invention.

[0037] Fig. 9 This is a schematic diagram of a metal mold low-pressure casting process for a high-voltage switch aluminum casting according to Example 4 of the present invention.

[0038] Fig.10 This is a cross-sectional view of the lower mold structure of a high-voltage switch aluminum casting metal mold low-pressure casting process according to Example 4 of the present invention.

[0039] Fig.11 This is a schematic diagram of the upper half structure of the lower mold of a low-pressure casting process of a high-voltage switch aluminum casting metal mold in Example 4 of the present invention.

[0040] Fig.12 This is a schematic diagram of the lower half structure of the lower mold of a low-pressure casting process of a high-voltage switch aluminum casting metal mold in Example 4 of the present invention.

[0041] Fig.13 This is a simplified assembly diagram of the lower mold lower half structure of the lower mold structure of a high-voltage switch aluminum casting metal mold low-pressure casting process in Example 4 of the present invention.

[0042] Among them, 1-lower half of the lower mold, 2-upper half of the lower mold, 11-inlaid cross runner lining groove, 12-inlaid straight runner lining opening, 13-first anti-fire part, 14-heating hole, 15-heating tube, 16-first positioning part, 17-gating heat-resistant lining, 101-cross runner heat-resistant lining, 102-sprue heat-resistant lining, 21-casting cavity, 22-inlaid gating lining opening, 23-second anti-fire part, 24-filter installation part, 25-second positioning part, 26-gating opening, 3-arc top, 4-flange, 5-cylinder. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0044] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0045] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0046] Example 1

[0047] The present invention discloses a lower mold structure of a metal mold low-pressure casting process for a high-voltage switch aluminum casting, comprising a lower mold lower half 1 and a lower mold upper half 2 detachably connected to the lower mold lower half 1; by splitting the lower mold into an upper part and a lower part, the structure is simple, and it is convenient to make or install a straight runner heat-resistant lining in a straight runner opening, to make or install a cross runner heat-resistant lining in a cross runner groove, and to make or install an ingate heat-resistant lining in an ingate opening 26.

[0048] The upper half 2 of the lower mold is provided with a casting cavity 21, a plurality of ingrate openings 26 and a plurality of inlaid ingrate lining openings 22; the shape of the casting cavity 21 is consistent with the outer surface of the casting; the ingrate openings 26 correspond to the inlaid ingrate lining openings 22 one by one, and one end of the ingrate opening 26 is connected to the casting cavity 21, and the other end is connected to the corresponding inlaid ingrate lining opening 22;

[0049] The lower mold lower half 1 is provided with an inlaid straight runner lining opening 12 and an inlaid cross runner lining groove 11; the inlaid cross runner lining groove 11 is connected with the inlaid straight runner lining opening 22; the inlaid straight runner lining opening 12 is connected with the inlaid cross runner lining groove 11; the inner side of the inlaid cross runner lining groove 11 is provided with a cross runner heat-resistant lining 101, and the inner side of the inlaid straight runner lining opening 12 is provided with a straight runner heat-resistant lining 102; a heating part is provided on the lower mold lower half 1 on both sides of the inlaid cross runner lining groove 11.

[0050] The metal mold works together with the heating part through the heat preservation measures, so that when the casting is completely solidified, the cross runner and the straight runner still maintain the aluminum liquid state. When the pouring is completed and the pressure is released, the cross runner, the straight runner and part of the inner runner aluminum liquid return to the low-pressure casting furnace for reuse. In this way, the weight of the casting with the pouring system is significantly reduced, the casting process yield is significantly improved, and the casting cost is reduced, thereby further improving the economy of low-pressure casting, and effectively avoiding the problem that the casting process design of the casting has a low process yield of the horizontal process layout and is forced to adopt other process layout methods. By setting the heat-resistant lining and the heating part of the lower half 1 of the lower mold, the metal mold is heat-insulated, the aluminum liquid has a strong shrinkage compensation ability, and the casting quality is better. At the same time, the sand core structure is not used, which further guarantees the casting quality of the casting. When the casting is demolded, it only needs to overcome the friction resistance of the inner runner above the cross runner, and the demolding resistance is small, and the problem of difficult demolding and demolding deformation of the casting will basically not occur. Since the blank casting only has an inner runner, the pouring head is easy to clean in the later stage, and the cleaning workload is small. Compared with three-opening molds, four-opening molds or upper and lower opening molds with movable blocks and sand core structures, the on-site operation is simple and the work efficiency is high. This lower mold structure can be applied to the production of high-quality and high-yield castings of various low-pressure castings, and has the characteristics of low cost, wide application and high economic value.

[0051] Example 2

[0052] The present invention provides a lower mold including a lower mold half 1 and a lower mold upper half 2 detachably connected to the lower mold lower half 1;

[0053] The upper part of the lower mold is provided with a casting cavity 21, a plurality of ingrow openings 26 and a plurality of inlaid ingrow lining openings 22; the shape of the casting cavity 21 is consistent with the outer surface of the casting; the ingrow openings 26 correspond to the inlaid ingrow lining openings 22 one by one, and one end of the ingrow openings 26 is connected to the casting cavity 21, and the other end is connected to the corresponding inlaid ingrow lining openings 22; the lower mold lower part 1 and the upper mold 2 are separated along the top surface of the inlaid horizontal runner lining groove 11; the inlaid straight runner lining openings 12 are connected to the The inlaid runner lining groove 11 is connected, and the diameter of the inlaid straight runner lining opening 12 is the same as the width of the inlaid runner lining groove 11, the inner diameter of the lower mouth of the inlaid straight runner lining opening 12 is greater than or equal to the inner diameter of the riser tube by more than 5mm, and less than or equal to the inner diameter of the riser tube plus 20mm, and the height of the inlaid straight runner lining opening 12 is greater than or equal to 20mm and less than or equal to 35mm; the inner side of the inlaid runner lining groove 11 is provided with a runner heat-resistant lining 101, and the inner side of the inlaid straight runner lining opening 12 is provided with a straight runner heat-resistant lining Lining 102, the heat-resistant lining 101 of the runner and the heat-resistant lining 102 of the sprue are coated with a thermal insulation coating; the wall thickness of the heat-resistant lining 102 of the sprue inside the inlaid sprue lining opening 12 is greater than or equal to 5mm, and the gap between it and the inlaid sprue lining opening 12 is less than or equal to 1mm, and the height is less than or equal to 1mm of the inlaid sprue lining opening 12, and the thermal insulation coating is a high-temperature resistant coating such as a zinc oxide coating, and the coating thickness is less than or equal to 1mm; the heat-resistant lining inside the inlaid runner lining groove 11 is a shell structure, and the wall thickness is greater than or equal to 5mm, and the fitting clearance with the inlaid runner lining groove 11 is less than or equal to 1mm, the heat-resistant lining is a ceramic material or a refractory material; a heating part is arranged on the lower half 1 of the lower mold on both sides of the inlaid runner lining groove 11, and the heating part includes a plurality of heating holes 14 arranged on the lower half 1 of the lower mold on both sides of the inlaid runner lining groove 11, and the heating holes 14 are installed with heating pipes 15, and the length of the heating holes 14 is greater than the distance from the side of the inlaid runner lining groove 11 away from the entrance of the heating holes 14 to the entrance of the heating holes 14. Preferably, if the height of the ingate is less than or equal to 30mm, the ingate heat-resistant lining 17 may not be required, otherwise the height of the ingate heat-resistant lining 17 is greater than or equal to 10mm, and when the ingate heat-resistant lining 17 exists, the inside of the ingate heat-resistant lining 17 is coated with a thermal insulation layer.

[0054] On the lower half 1 of the lower mold, a first anti-fire part 13 is circumferentially arranged along the outside of the runner heat-resistant lining 101 in which the runner lining groove 11 is embedded; on the upper half 2 of the lower mold, a second anti-fire part 23 is arranged at a position corresponding to the first anti-fire part 13, and the second anti-fire part 23 is connected to the first anti-fire part 13 by a mortise and tenon structure, the width of the first anti-fire part 13 and the second anti-fire part 23 is greater than or equal to 10 mm, the height is greater than or equal to 10 mm, the draft is greater than or equal to 5°, and the fitting clearance between the first ignition cannon 13 and the second fireproof cannon 23 is less than 0.5 mm. A filter screen installation portion 24 is provided at the position where the lower part of the ingrow opening 26 is connected to the inlaid ingrow lining opening 22. The filter screen installation portion 24 is 5 to 20 mm away from the casting surface. The draft angle between the filter screen installation portion 24 and the casting surface is not less than 2°. If the upper half 2 of the lower mold is not inlaid with the ingrow lining opening 22, the surface below the filter screen installation portion 24 is the same surface as the parting surface of the upper half 2 of the lower mold; if the upper half 2 of the lower mold is inlaid with the ingrow lining opening 22, the inlaid ingrow lining opening 22 of the upper half 2 of the lower mold is 2 and the entrapment heat-resistant lining 17 have a gap of less than or equal to 1mm, the depth of the embedded entrapment lining opening 22 is greater than the height of the entrapment heat-resistant lining, and is less than or equal to the height of the entrapment heat-resistant lining 17 plus 0.2mm, and glass fibers are wound around the outer circumference of the entrapment heat-resistant lining 17, so that the entrapment heat-resistant lining 17 can be installed in the embedded entrapment lining opening 22 of the upper half of the lower mold 2; the lower half of the lower mold 1 is provided with a first positioning portion 16, and the upper half of the lower mold 2 is provided with a second positioning portion 25 at a position corresponding to the first positioning portion 16. The second positioning portion 25 is provided on the parting surface of the upper half of the lower mold 2, and is a diagonal positioning pin, the first positioning portion 16 is a positioning hole matching the positioning pin, and the matching clearance between the positioning pin and the positioning hole is less than 0.5mm.

[0055] During assembly, the heat-resistant lining 102 of the straight runner coated with the thermal insulation layer is wound with glass fibers and installed into the inlaid straight runner lining opening 12 of the lower mold lower half 1; the heat-resistant lining 101 of the horizontal runner coated with the thermal insulation layer is installed into the inlaid horizontal runner lining groove 11 of the lower mold lower half 1; the heat-resistant lining 17 of the insulated inner runner coated with the thermal insulation coating is wound with glass fibers and installed into the inlaid inner runner lining opening 22 of the upper mold 2. The lower mold lower half 1 and the upper mold 2 are molded together and fixed together to complete the assembly of the lower mold.

[0056] Example 3

[0057] See also Figures 1 to 7 The present invention provides a lower mold structure of a metal mold low-pressure casting process for a high-voltage switch aluminum casting, which is a lower mold structure of a high-voltage switch aluminum cover plate casting:

[0058] The high-voltage switch aluminum cover casting is placed horizontally, with the flange 4 at the top and the arc-shaped top 3 at the bottom. An inner runner is arranged between the middle position of the arc-shaped top 3 and the thicker boss structure. A horizontal runner is arranged below the inner runner to connect the two inner runners, and a straight runner is arranged below the runner. The lower mold structure includes a lower mold lower half 1 and a lower mold upper half 2 detachably connected to the lower mold lower half 1;

[0059] The upper half 2 of the lower mold is provided with a casting cavity 21, two ingrate openings 26 and two inlaid ingrate lining openings 22; the shape of the casting cavity 21 is consistent with the outer surface of the arc-shaped top 3; the ingrate openings 26 correspond to the inlaid ingrate lining openings 22 one by one, and one end of the ingrate opening 26 is connected to the casting cavity 21, and the other end is connected to the corresponding inlaid ingrate lining opening 22;

[0060] The lower mold lower half 1 is provided with an inlaid straight runner lining opening 12 and an inlaid cross runner lining groove 11; a heating part is provided on the lower mold lower half 1 on both sides of the inlaid cross runner lining groove 11, and the heating part includes a plurality of heating holes 14 provided on the lower mold lower half 1 on both sides of the inlaid cross runner lining groove 11, and a heating tube 15 is installed on the heating hole 14, and the length of the heating hole 14 is greater than the distance from the side of the inlaid cross runner lining groove 11 away from the entrance of the heating hole 14 to the entrance of the heating hole 14.

[0061] The inlaid runner lining groove 11 is connected with the inlaid runner lining opening 22; the lower mold lower half 1 and the lower mold upper half 2 are parted along the top surface of the inlaid runner lining groove 11; the inlaid straight runner lining opening 12 is connected with the inlaid runner lining groove 11, and the aperture of the inlaid straight runner lining opening 12 is the same as the width of the inlaid runner lining groove 11, and the inner diameter of the lower opening of the inlaid straight runner lining opening 12 is greater than or equal to the inner diameter of the riser 5mm or more, less than or equal to the inner diameter of the riser pipe plus 20mm, the height of the inlaid straight runner liner opening 12 is greater than or equal to 20mm, less than or equal to 35mm; the inner side of the inlaid cross runner liner groove 11 is provided with a cross runner heat-resistant lining 101, the inner side of the inlaid straight runner liner opening 12 is provided with a straight runner heat-resistant lining 102, the cross runner heat-resistant lining 101 and the straight runner heat-resistant lining 102 are both coated with a thermal insulation coating; the straight runner heat-resistant lining The wall thickness of the lining 102 is greater than or equal to 5mm, and the gap between it and the embedded straight runner lining opening 12 is less than or equal to 1mm, and the height is less than or equal to 1mm of the embedded straight runner lining opening 12. The thermal insulation coating is a high-temperature resistant coating, such as a zinc oxide coating, and the coating thickness is less than or equal to 1mm; the runner heat-resistant lining 101 is a shell structure, the wall thickness is greater than or equal to 5mm, and the fitting gap between it and the embedded cross runner lining groove 11 is less than or equal to 1mm, and the heat-resistant lining is a ceramic material or a refractory material; the distance from one end of the runner opening 26 close to the casting cavity 21 to the parting surface between the upper half 2 of the lower mold and the lower part 1 of the lower mold is greater than 30mm, and a runner heat-resistant lining 17 is arranged on the inner side of the embedded runner lining opening 22, and the runner heat-resistant lining 17 is coated with a zinc oxide coating, and the flow area of ​​the heat-resistant lining in the embedded cross runner lining groove 11 is ≥1.5 times the flow area of ​​the runner heat-resistant lining 17.

[0062] The inner sides of the inlaid runner lining groove 11 and the inlaid straight runner lining opening 12 are both provided with heat-resistant linings, and the inner sides of the heat-resistant linings are coated with a heat-insulating coating;

[0063] On the lower mold lower half 1, a first anti-fire part 13 is circumferentially arranged on the outside of the heat-resistant lining along the outer side of the inlaid runner lining groove 11; on the upper mold upper half 2, a second anti-fire part 23 is arranged at a position corresponding to the first anti-fire part 13, and the second anti-fire part 23 is connected to the first anti-fire part 13 by a mortise and tenon structure, the width of the first anti-fire part 13 and the second anti-fire part 23 is greater than or equal to 10mm, the height is greater than or equal to 10mm, the draft is greater than or equal to 5°, and the fitting clearance between the first ignition cannon 13 and the second ignition cannon 23 is less than 0.5mm. A filter screen installation part 24 is arranged at the position where the lower part of the ingate opening 26 and its corresponding inlaid ingate lining opening 22 are connected, for installing the filter screen.

[0064] The filter screen installation part 24 is 5 to 20 mm away from the casting surface, and the draft angle between the filter screen installation part 24 and the casting surface is not less than 2°. If the upper half 2 of the lower mold is not inlaid with an ingate lining opening, the surface below the filter screen installation part 24 is the same surface as the parting surface of the upper half 2 of the lower mold, and the total flow cross-sectional area of ​​the filter screen installation part 24 should be greater than the flow area of ​​the heat-resistant lining 17 of the straight runner; if the upper half 2 of the lower mold is provided with an inlaid ingate lining opening 22, the inlaid ingate lining opening 22 of the upper half 2 of the lower mold 2 and the gap between the heat-resistant lining 17 of the entrapment channel is not greater than 1mm, the depth of the embedded entrapment channel lining opening 22 is greater than the height of the heat-resistant lining of the entrapment channel, and is less than or equal to the height of the heat-resistant lining 17 plus 0.2mm, and the glass fiber is wound around the outer circumference of the heat-resistant lining 17 of the entrapment channel, so that the heat-resistant lining 17 of the entrapment channel can be installed on the embedded entrapment channel lining opening 22 of the upper half of the lower mold 2; the parting surface of the upper half of the lower mold 2 has a diagonal positioning pin, which matches the positioning hole of the lower half of the lower mold 1, and the gap is less than 0.5mm. The lower half of the lower mold 1 is provided with a first positioning portion 16, and the position corresponding to the first positioning portion 16 on the upper half of the lower mold 2 is provided with a second positioning portion 25. The matching gap between the first positioning portion 16 and the second positioning portion 25 is less than 0.5mm, and the first positioning portion 16 and the second positioning portion pin hole are matched and connected, the hole diameter is greater than or equal to 20mm, the depth is greater than or equal to 20mm, and the draft angle is not less than 5°.

[0065] During assembly, the heat-resistant lining 102 of the straight runner coated with the insulation layer is wound with glass fibers and installed into the inlaid straight runner lining opening 12 of the lower mold lower half 1. The heat-resistant lining 101 of the horizontal runner coated with the insulation layer is installed into the inlaid horizontal runner lining groove 11 of the lower mold lower half 1, and the heat-resistant lining 17 of the insulated inner runner coated with the insulation coating is wound with glass fibers and installed into the inlaid inner runner lining opening 22 of the upper mold 2. The lower mold lower half 1 and the upper mold 2 are molded together and fixed together to complete the assembly of the lower mold.

[0066] Example 4

[0067] See also Figures 8 to 13 The present invention provides a lower mold structure for a low-pressure casting process of a metal mold for a high-voltage switch aluminum casting, which is a lower mold structure for a high-voltage switch aluminum sleeve casting part. The main body of the part is a flange structure at both ends of a cylinder 5. There is a circular groove on the back of the two flanges, and both flanges have 12 straight holes. The sleeve is placed horizontally, and the lower parts of the two flanges of the cylinder 5 are respectively connected to the ingates. The horizontal cross runner below the ingates connects the two ingates, and a straight runner is arranged below the cross runner. The lower mold structure includes a lower mold lower half 1 and a lower mold upper half 2 detachably connected to the lower mold lower half 1;

[0068] The upper half 2 of the lower mold is provided with a casting cavity 21, a plurality of ingrate openings 26 and a plurality of inlaid ingrate lining openings 22; the shape of the casting cavity 21 is consistent with the outer surface of the casting; the ingrate openings 26 correspond to the inlaid ingrate lining openings 22 one by one, and one end of the ingrate opening 26 is connected to the casting cavity 21, and the other end is connected to the corresponding inlaid ingrate lining opening 22;

[0069] The lower mold lower part 1 is provided with an inlaid straight runner lining opening 12 and an inlaid cross runner lining groove 11; the inlaid cross runner lining groove 11 is connected with the inlaid straight runner lining opening 22; the lower mold lower part 1 and the lower mold upper part 2 are parted along the top surface of the inlaid cross runner lining groove 11; the inlaid straight runner lining opening 12 is connected with the inlaid cross runner lining groove 11, and the aperture of the inlaid straight runner lining opening 12 is the same as the width of the inlaid cross runner lining groove 11, the inner diameter of the lower mouth of the inlaid straight runner lining opening 12 is greater than the inner diameter of the riser pipe 5mm, less than or equal to the inner diameter of the riser pipe plus 20mm, the height of the inlaid straight runner lining opening 12 is greater than or equal to 20mm, less than or equal to 35mm; the inner side of the inlaid cross runner lining groove 11 is provided with a cross runner heat-resistant lining 101, the inlaid straight runner A sprue heat-resistant lining 102 is arranged on the inner side of the runner lining opening 12, and the inside of the runner heat-resistant lining 101 and the runner heat-resistant lining 102 are coated with a thermal insulation coating; the wall thickness of the runner heat-resistant lining 102 is greater than or equal to 5 mm, and the gap between it and the embedded runner lining opening 12 is less than or equal to 1 mm, and the height is less than or equal to 1 mm of the embedded runner lining opening 12, and the thermal insulation coating is a high-temperature resistant coating such as a zinc oxide coating, and the coating thickness is less than or equal to 1 mm; the runner heat-resistant lining 101 is a shell structure, the wall thickness is greater than or equal to 5 mm, and the fitting gap between it and the embedded runner lining groove 11 is less than or equal to 1 mm, and the heat-resistant lining is a ceramic material or a refractory material; the distance from the runner opening 26 close to the casting cavity 21 to the embedded runner lining groove 11 is less than or equal to 30 mm.

[0070] The inner sides of the inlaid cross runner lining groove 11 and the inlaid straight runner lining opening 12 are both provided with heat-resistant linings, and the inside of the heat-resistant linings are coated with a thermal insulation coating; a heating part is provided on the lower half 1 of the lower mold on both sides of the inlaid cross runner lining groove 11, and the heating part includes a plurality of heating holes 14 arranged on the lower half 1 of the lower mold on both sides of the inlaid cross runner lining groove 11, and the heating holes 14 are installed with heating pipes 15; the length of the heating hole 14 is greater than the distance from the side of the inlaid cross runner lining groove 11 away from the entrance of the heating hole 14 to the entrance of the heating hole 14.

[0071] On the lower half 1 of the lower mold, a first anti-fire part 13 is circumferentially arranged on the outside of the cross runner heat-resistant lining 101; a second anti-fire part 23 is arranged at a position corresponding to the first anti-fire part 13 on the upper half 2 of the lower mold, and the second anti-fire part 23 is connected to the first anti-fire part 13 by a mortise and tenon structure, the width of the first anti-fire part 13 and the second anti-fire part 23 is greater than or equal to 10 mm, the height is greater than or equal to 10 mm, the draft is greater than or equal to 5°, and the fitting clearance between the first ignition cannon 13 and the second fireproof cannon 23 is less than 0.5 mm. A filter screen installation part 24 is provided at the lower part of the ingrow opening 26 and the corresponding inlaid ingrow lining opening 22, which is used to install the filter screen. The filter screen installation part 24 is 5 to 20 mm away from the casting surface, and the draft angle between the filter screen installation part 24 and the casting surface is not less than 2°. If the lower mold upper half 2 is not inlaid with an ingrow lining opening, the surface below the filter screen installation part 24 is the same surface as the parting surface of the lower mold upper half 2; the parting surface of the lower mold upper half 2 has a diagonal positioning pin, which matches the positioning hole of the lower mold lower half 1, and the gap is less than 0.5 mm. The lower mold lower half 1 is provided with a first positioning part 16, and the position corresponding to the first positioning part 16 on the lower mold upper half 2 is provided with a second positioning part 25. The fitting clearance between the first positioning portion 16 and the second positioning portion 25 is less than 0.5 mm, the first positioning portion 16 and the second positioning portion pin hole are matched and connected, the hole diameter is greater than or equal to 20 mm, the depth is greater than or equal to 20 mm, and the draft angle is not less than 5°.

[0072] During assembly, the straight runner heat-resistant lining 102 coated with an insulation layer is wrapped with glass fibers and installed into the embedded straight runner lining opening 12 of the lower half 1 of the lower mold; the horizontal runner heat-resistant lining 101 coated with an insulation layer is installed into the embedded horizontal runner lining groove 11 of the lower half 1 of the lower mold; the lower half 1 of the lower mold is molded together with the upper half 2 of the lower mold, and fixed together to complete the assembly of the lower mold.

[0073] Example 5

[0074] The present invention also provides a low-pressure casting process mold for a high-voltage switch aluminum casting, comprising the lower mold structure described in any one of Embodiments 1 to 4. The mold has a simple structure, convenient operation, easy demoulding, low cost, and good casting quality and high yield, and is an advanced technology in the field of low-pressure casting.

[0075] It should be noted that the lower mold structure provided by the present invention can set the shape of the casting cavity 21 and the positions of each runner according to the shape of the actual part and the process, and is not limited to the shape and position of the casting part described in the embodiment of the present invention. Therefore, it is not limited to the low-pressure casting process of aluminum castings of high-voltage switches. Any component mold using the design concept of the present invention is deemed to be within the scope of protection of the present invention.

[0076] In summary, the present invention provides a lower mold structure and mold for a low-pressure casting process of a high-voltage switch aluminum casting metal mold. The lower mold is divided into an upper and lower part, and a heating part and a heat preservation part are arranged on both sides of the inlaid cross runner lining groove 11 in the lower half, so as to realize the shrinkage compensation of the molten metal, and the shrinkage compensation ability is strong. Compared with the existing three-opening mold, four-opening mold or upper and lower opening molds with live blocks and sand core structures, the structure has the characteristics of simple structure, convenient operation and low cost. At the same time, during the demolding process, only the friction force above the cross runner needs to be overcome, and the demolding is convenient and not easy to deform. The molten metal in the cross runner can be refluxed back into the low-pressure casting furnace for reuse. The casting quality is good and the output rate is high, which further improves the economy of low-pressure casting.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to impose any limitation on the technical solution of the present invention. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can also be subjected to several simple modifications and substitutions, and these modifications and substitutions are also within the scope of protection covered by the claims.

Claims

1. A metal mold low-pressure casting process lower mold structure for high-voltage switch aluminum castings, characterized in that: It comprises a lower mold lower half (1) and a lower mold upper half (2) detachably connected to the lower mold lower half (1); The upper half (2) of the lower mold is provided with a casting cavity (21), a plurality of ingrate openings (26) and a plurality of inlaid ingrate lining openings (22); the shape of the casting cavity (21) is consistent with the outer surface of the casting; the ingrate openings (26) correspond to the inlaid ingrate lining openings (22) one by one, and one end of the ingrate opening (26) is connected to the casting cavity (21), and the other end is connected to the corresponding inlaid ingrate lining opening (22); The lower mold lower half (1) is provided with an inlaid straight runner lining opening (12) and an inlaid horizontal runner lining groove (11); the inlaid horizontal runner lining groove (11) is connected to the inlaid straight runner lining opening (22); the inlaid straight runner lining opening (12) is connected to the inlaid horizontal runner lining groove (11); a horizontal runner heat-resistant lining (101) is provided inside the inlaid horizontal runner lining groove (11), and a straight runner heat-resistant lining (102) is provided inside the inlaid straight runner lining opening (12); a heating unit is provided on the lower mold lower half (1) on both sides of the inlaid horizontal runner lining groove (11).

2. The lower mold structure of the metal mold low-pressure casting process of the high-voltage switch aluminum casting according to claim 1 is characterized in that: The heating part comprises a plurality of heating holes (14) arranged on the lower half (1) of the lower mold on both sides of the embedded runner lining groove (11), and the heating holes (14) are equipped with heating pipes (15).

3. The lower mold structure of the metal mold low-pressure casting process of the high-voltage switch aluminum casting according to claim 1 is characterized in that: On the lower half (1) of the lower mold, a first anti-fire portion (13) is circumferentially arranged on the outer side of the inlaid runner lining groove (11).

4. The lower mold structure of the metal mold low-pressure casting process of the high-voltage switch aluminum casting according to claim 3 is characterized in that: A second fire protection part (23) is provided on the upper half (2) of the lower mold at a position corresponding to the first fire protection part (13); the second fire protection part (23) is connected to the first fire protection part (13) by a mortise and tenon structure.

5. The lower mold structure of the metal mold low-pressure casting process of the high-voltage switch aluminum casting according to claim 1 is characterized in that: A filter screen installation portion (24) is provided at a position where the lower portion of the ingrate opening (26) and the corresponding inlaid ingrate lining opening (22) are connected, and is used for installing the filter screen.

6. The lower mold structure of the metal mold low-pressure casting process of the high-voltage switch aluminum casting according to claim 1 is characterized in that: The interior of the cross runner heat-resistant lining (101) and the straight runner heat-resistant lining (102) are both coated with a thermal insulation coating.

7. The lower mold structure of the metal mold low-pressure casting process of the high-voltage switch aluminum casting according to claim 1 is characterized in that: A first positioning portion (16) is provided on the lower half (1) of the lower die, and a second positioning portion (25) is provided on the upper half (2) of the lower die at a position corresponding to the first positioning portion (16).

8. The lower mold structure of the metal mold low-pressure casting process of the high-voltage switch aluminum casting according to claim 1 is characterized in that: The distance from one end of the ingrow opening (26) close to the casting cavity (21) to the parting surface between the lower mold upper half (2) and the lower mold lower part (1) is greater than 30 mm, and an ingrow heat-resistant lining (17) is arranged inside the inlaid ingrow lining opening (22).

9. The lower mold structure of the metal mold low-pressure casting process of the high-voltage switch aluminum casting according to claim 8 is characterized in that: The flow area of ​​the heat-resistant lining in the embedded runner lining groove (11) is ≥1.5 times the flow area of ​​the heat-resistant lining (17) in the runner at the shrinkage compensation heat node.

10. A low-pressure casting process mold for a high-voltage switch aluminum casting, characterized in that: The invention comprises the lower mold structure as described in any one of claims 1 to 9.

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