Complete set of parts for casting molten metal, sand casting mold assembly and casting equipment

Abstract

The utility model relates to a complete set of parts, a sand casting mold assembly and casting equipment for casting molten metal. The complete set of parts and the assembly comprise a sand casting mold (2) for casting metal parts, a short long nozzle (9) comprising a short cylinder (10), and a mold / long nozzle connecting mechanism (14). The mould (2) comprises a bore (7) extending over a bore length (d7) from a bore inlet to an inlet (6i) of the housing (6), in fluid communication with a cavity defining the shape of the metal part. The mold / long nozzle coupling mechanism (14) is configured for receiving and maintaining a short long nozzle (9) in a long nozzle casting position in which the short barrel is inserted into the hole (7), separated from the housing inlet (6i) by a short barrel-free distance (d710gt; 0), where k = d710 / d7, preferably between 0.2 and 0.8.

Description

Technical Field

[0001] The utility model relates to a mold assembly, which comprises a sand casting mold, a short shroud, and a mold / shroud connection mechanism for connecting the short shroud to the sand casting mold at a shroud casting position. Using a short shroud instead of a known long shroud significantly reduces the cost of casting metal with a shrouded metal flow in a casting application, because a large amount of expensive refractory materials used to form the shroud are saved. Background Art

[0002] In a foundry, metal parts are produced by casting metal from a ladle nozzle into a hole leading to the cavity of a sand casting mold that defines the geometry of the part to be cast. One of the main challenges of this metal casting process is to avoid air entrapment when casting the metal into the hole. This can lead to defects including bubbles and oxide films that cause cracks in the casting.

[0003] In order to avoid air entrainment, it is known in the art to protect the molten steel from air entrainment and double film formation during the casting process by using a shroud extending along the entire length of the bore. A sealing gasket may be applied to the inlet of the shroud to prevent air from being sucked into the metal flow at the contact interface between the ladle nozzle and the shroud. The gasket also has the advantage of protecting the nozzle and the shroud from mechanical damage when in contact, since the ceramic material is brittle. The outlet of the shroud is introduced into a housing, which may be provided with a filtering unit to prevent solid particles from flowing into the mould cavity. A mould / shroud coupling mechanism serves to ensure reproducible and stable positioning of the shroud in the bore of the sand casting mould.

[0004] A system for casting molten metal is disclosed in EP 3463715. The system comprises:

[0005] a sand casting mould comprising a casting cavity having an inlet and a hole extending between an upper surface of the mould and the inlet,

[0006] A shroud, comprising a shroud base and a hollow shaft, wherein the shroud base is located outside the mold adjacent to the upper surface, and the hollow shaft is received in the hole and is movable in the hole.

[0007] In order to form a sealing contact between the nozzle and the base of the shroud, EP 3463715 B1 proposes a mold / shroud coupling mechanism, which includes a lifting mechanism located at the upper surface of the mold. The lifting mechanism includes a first collar and a second collar arranged concentrically, wherein the first collar is fixed to the upper surface of the mold and the second collar is rotatably connected to the upper surface of the mold and supports the shroud base of the shroud. The snap-on system includes a follower engaged in a chute, which allows the second collar to be lifted by rotation relative to the upper surface of the mold, thereby causing a linear movement of the shroud. The rotation of the snap-on system is performed by the operator. Once the base of the shroud is in contact with the nozzle, the lifting mechanism no longer moves during the entire casting operation, thereby ensuring a stable and reproducible process. However, the lack of freedom of movement of the shroud during casting can also be a problem, because the flow of molten metal through the shroud causes vibrations that propagate to the contact area between the nozzle and the base of the shroud, which can cause wear and even cracking of the refractory. Furthermore, the fixed snap-on structure requires operator intervention, thus increasing costs and safety risks when operating at heights above the workshop floor.

[0008] In order to solve this problem, an alternative mold / long nozzle connection mechanism is proposed in PCT / EP 2022 / 072007, in which the first ring and the second ring are connected by a spring, so that when a vertical load is applied to the long nozzle seated on the first ring, the long nozzle is driven downward in the hole, thereby forming a dynamic seal between the nozzle and the long nozzle inlet and between the long nozzle outlet and the filter housing.

[0009] Casting metal parts with a shroud as described above is very advantageous in casting applications because air entrainment on the metal flow applied by the shroud is significantly reduced. However, this solution increases the cost of the process because the shroud is made of refractory materials that are more expensive than any material used in the sand casting mold.

[0010] The present invention proposes a solution for producing metal parts in a foundry, which combines the advantages of the closed casting assembly described above at a much lower cost. This and other advantages of the present invention will be described in more detail below. Utility Model Content

[0011] The invention is defined in the accompanying independent claims. The dependent claims define preferred embodiments. In particular, the invention relates to a kit of parts for casting molten metal, the kit of parts comprising a short shroud, a sand casting mould, and a mould / shroud coupling mechanism.

[0012] The short shroud includes:

[0013] A shroud base attached to the proximal end of a short barrel having an axial length (d10) measured along the Z axis, and the short shroud having:

[0014] a shroud hole extending along the Z axis from a shroud inlet opening at the shroud base to a shroud outlet opening at the downstream end of the short barrel,

[0015] Wherein, the sand casting mold comprises:

[0016] a casting cavity having a cavity inlet,

[0017] a housing selected from a filter housing and a diverter housing, the housing having a housing outlet in fluid communication with the cavity inlet and a housing inlet (6i) in fluid communication with the below-mentioned aperture,

[0018] a bore extending along the Z axis a bore length (d7) between a bore inlet opening at the upper surface of the sand casting mould and a bore outlet opening at a downstream end located at the level of the housing inlet, the downstream end comprising a bore constriction, wherein

[0019] the bore constriction forms a bore constriction defining a bore outlet opening in the housing, wherein the bore diameter decreases by at least 10% in the flow direction along the Z axis,

[0020] Among them, the mold / long nozzle connection mechanism includes:

[0021] a seat member configured to receive the shroud base and to hold the short shroud in the shroud casting position, wherein the downstream end of the short barrel (10) is inserted into the hole,

[0022] The length of the shaft (d10) is shorter than the length of the hole (d7) (i.e., d10 < d7), such that at the tundish casting position, the downstream end of the short barrel is spaced from the housing inlet by a distance (d710) without the short barrel, and this distance without the short barrel is proportional to the length of the hole (d7) by a proportionality factor (k) (i.e., d710 = k d7), where the proportionality factor (k) is preferably at least 20% (i.e., k ≥ 0.2), more preferably at least 35% (i.e., k ≥ 0.35), and where the proportionality factor (k) is preferably not greater than 90% (i.e., k ≤ 0.9), more preferably not greater than 80% (i.e., k ≤ 0.8), more preferably not greater than 70% (i.e., k ≤ 0.7), and most preferably not greater than 60% (i.e., k ≤ 0.6). In absolute terms, the penetration depth of the short barrel (10) into the hole (7) at the tundish casting position ( = d7 - d710) is preferably at least equal to 3 cm (i.e., d7 - d710 ≥ 3 cm), more preferably at least equal to 5 cm (i.e., d7 - d710 ≥ 5 cm), and most preferably at least equal to 10 cm (i.e., d7 - d710 ≥ 10 cm). In the case of 5 cm ≤ d7 - d710 ≤ 3 cm, a sealing material (e.g., gasket) is preferably provided between the hole (7) and the short barrel (10) to ensure the airtightness of the gap formed therebetween.

[0023] In a preferred embodiment, the mold / tundish coupling mechanism comprises:

[0024] · a base member that is fixed relative to the upper surface,

[0025] · a seat member that is configured to receive the tundish base and hold the short tundish (9) in the tundish casting position,

[0026] The base member and the seat member each include a central hole, and these central holes are aligned with each other to define an introduction portion toward the hole for the tundish. The seat member is coupled to the base member by at least one flexible element such that the seat member is spaced from the base member, and when a load parallel to the Z-axis is applied to the seat member, the seat member can move relative to the base member from the seat rest position to the seat casting position, and applying the load to the seat member deforms at least one flexible element, thereby driving the short tundish seated in the seat member to the tundish casting position.

[0027] The flexible element preferably comprises:

[0028] · one or more elastic elements, which include springs, preferably helical springs or elastomeric materials at the process temperature, extending between the seat member and the base member, or

[0029] · a free-flowing material that is enclosed in one or more bags, and the one or more bags are configured to deform when a load is applied to the seat member.

[0030] The mould / shroud coupling mechanism preferably comprises at least three elastic elements, preferably at least three helical springs, extending between the seat member and the base member. The at least three elastic elements are spaced apart around the circumference of the central hole of the seat member and the base member. The at least three elastic elements are preferably equally spaced apart around the circumference of the central hole of the seat member and the base member.

[0031] The hole of the sand casting mold is defined by a wall, which is preferably lined with a lining over at least a portion of the hole length (d7), preferably over the entire hole length (d7), in order to strengthen the hole wall. The lining material may be selected from clay clinker (or clinker) preferably consisting of high temperature fired clay, sand core material or cellulose material.

[0032] The utility model also relates to a sand casting mold assembly, which comprises a short shroud as defined above and a sand casting mold, wherein the shroud base of the short shroud is seated on a seat component, the short cylinder of the short shroud is inserted into a hole, and the downstream end is separated from the shell inlet.

[0033] In a preferred embodiment, the mold / shroud coupling mechanism comprises a flexible element as described above. In this embodiment, the mold / shroud coupling mechanism is configured as follows:

[0034] In the seat rest position, the downstream end of the spool is maintained at a distance greater than the distance (d710) without the spool, and

[0035] When a load parallel to the Z axis is applied, in the seat casting position, the short shroud is maintained in the shroud casting position, wherein the downstream end of the stub is spaced from the shell inlet by a distance substantially equal to the distance without the stub (d710).

[0036] The utility model also relates to a casting device, which comprises:

[0037] a short shroud and sand casting mould as defined above,

[0038] a ladle comprising a nozzle arranged at the base of the ladle for distributing molten metal out of the ladle,

[0039] The shroud is configured to reversibly and sealingly engage into the shroud inlet of the short shroud. The ladle is configured to be displaced relative to the sand casting mold so that

[0040] o Positioning the shroud substantially aligned along the Z axis over the mold / shroud connection, and

[0041] ○ Lower along the Z axis until the shroud engages in the shroud inlet of the short shroud in the shroud casting position, wherein the downstream end of the stub is outside the shell inlet and separated from the shell inlet by a distance (d710) without the stub.

[0042] In a preferred embodiment, the casting apparatus comprises a ladle / shroud coupling mechanism configured for reversibly clamping a short shroud to the shroud, preferably without forming a seal between the shroud inlet and the shroud. The ladle / shroud coupling mechanism comprises:

[0043] o a base adapter fixed relative to the shroud base of the short shroud, the base adapter comprising retaining means, and

[0044] o A shroud adapter fixed relative to the base of the ladle or relative to the shroud and configured to engage retaining means of the base adapter to reversibly lock the short elongated shroud (9) to the shroud in a locked position.

[0045] For example, the retaining means of the base adapter may include one or more retaining pegs, and the nozzle adapter may include:

[0046] fastening hooks configured to reversibly engage the retaining pegs and preferably configured to self-engage with the retaining pegs, or

[0047] A snap-on coupling element configured to interact with one or more retaining pegs in order to reversibly lock the shroud to the shroud in a locked position.

[0048] In a preferred embodiment, the mold / shroud coupling mechanism comprises a flexible element as described above. In this embodiment, by applying a load parallel to the Z axis to the seat member, the downstream end of the stub reaches a casting position spaced apart from the housing inlet by a distance (d710) without the stub.

[0049] The utility model also relates to a method for casting molten metal using the casting device as defined above, the method comprising the following steps.

[0050] lowering the ladle along the Z axis until the shroud is engaged in sealing contact in the shroud inlet and the short shroud, wherein the shroud base resting on the seat member is in the shroud casting position and the downstream end is outside the shell inlet and spaced apart from the shell inlet by a distance (d710) excluding the short barrel,

[0051] Allows molten metal to flow from the ladle through the nozzle, short shroud and shell to the casting cavity.

[0052] In a preferred embodiment, the mould / shroud coupling mechanism comprises a flexible element as described above. In this embodiment, the ladle is lowered along the Z-axis until the shroud engaged in the shroud inlet applies a load parallel to the Z-axis to the shroud base seated on the seat member, thereby opposing the flexible element to move the seat member relative to the base member along the Z-axis and forming a sealing contact between the shroud and the shroud inlet of the short shroud in the shroud casting position, wherein the downstream end is located outside the shell inlet and separated from the shell inlet by a distance (d710) without the short barrel.

[0053] In this embodiment, a short shroud is first accommodated in a sand casting mold, wherein a seat member receives the shroud base and holds the short shroud, with the downstream end located outside the shell inlet and spaced apart from the shell inlet by a distance greater than the distance (d710) without the short barrel, to form a sand casting mold assembly as described above. Then, the shroud is engaged into the shroud inlet by vertically lowering the ladle, and a sealing contact is formed between the shroud and the short shroud by further lowering the ladle so that the shroud applies a load to the shroud base to move the short shroud toward the shell inlet to a shroud casting position, wherein the downstream end is spaced apart from the shell inlet by the distance (d710) without the short barrel.

[0054] Alternatively, the shroud may be engaged into the shroud inlet of a short shroud and the short shroud clamped to the shroud by means of a ladle / shroud coupling mechanism by:

[0055] · Fix the base adapter to the shroud inlet of the short shroud with the retaining device

[0056] · A nozzle adapter joint fixed to the base of the ladle or fixed to the nozzle,

[0057] In order to lock the short long shroud (9) to the shroud (12) in the locked position.

[0058] The short shroud locked to the shroud can be positioned above the mold / shroud coupling mechanism in substantial alignment along the Z axis and lowered along the Z axis until the shroud base is seated on the seat member, wherein the short shroud is located in the hole and the downstream end is separated from the shell inlet by a distance greater than the distance (d710) without the short barrel. At this point, the ladle can be further lowered along the Z axis until the short shroud reaches the shroud casting position, wherein the downstream end (10d) is located outside the shell inlet and separated from the shell inlet by the distance (d710) without the short barrel, thereby forming a sealing contact between the short shroud and the short shroud. Metal casting can begin. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The present invention will be further explained in detail with reference to the accompanying drawings.

[0060] Figure 1 The steps of a metal casting method using a casting device according to an embodiment of the present invention are shown.

[0061] Figure 2 The steps of a metal casting method using a casting apparatus according to an alternative embodiment of the present invention are shown, the casting apparatus including a ladle / shroud coupling mechanism (140).

[0062] Figure 3 A stereoscopic view of an embodiment of a mold / long nozzle connection mechanism suitable for the utility model is shown.

[0063] Figure 4 The mold / shroud connection mechanism and the short shroud accommodated therein are shown along the Figure 3 Cross section along the cutting line IV-IV.

[0064] Figure 5 A perspective view of a casting apparatus according to the invention is shown, wherein the shroud of the ladle is located vertically above a short shroud in the shroud casting position, wherein the shroud base is received in a seat member of the mould / shroud coupling mechanism. For clarity, the ladle is not shown.

[0065] Figure 6 Shows Figure 5 Cross-sectional view of a casting apparatus in which a shroud is reversibly and sealingly engaged into a shroud base, albeit with a slight coaxial misalignment with the bore axis.

[0066] Figures 7a to 7c The cross-sectional views of the mold / long nozzle connection mechanism and the shroud in the casting device according to the utility model are shown, (7a) is the state when the ladle moves above the mold so that the shroud is aligned with the long nozzle inlet, (7b) is the state when the ladle is lowered so that the shroud is close to the long nozzle inlet or contacts the long nozzle inlet, and (7c) is the state when the ladle is further lowered to squeeze the flexible element to form a sealing contact.

[0067] Figure 8 A three-dimensional bottom view of a seat component of a mold / long nozzle coupling mechanism according to an embodiment of the present invention is shown.

[0068] Figure 9a A cross-sectional view of a ladle / shroud coupling mechanism in a casting apparatus before a short shroud is clamped to the shroud is shown according to an embodiment of the present invention.

[0069] Figure 9b Shows Figure 9aA cross-sectional view of a ladle / shroud coupling in a casting apparatus of the type shown in FIG. 1 , wherein a short shroud is coupled to the shroud, even though not sealed to the shroud, and the short shroud is held vertically above the mould / shroud coupling.

[0070] Fig.9c Shows Figure 9a A cross-sectional view of a ladle / shroud and mould / shroud coupling in a casting apparatus, wherein a base adapter is received in a seat member of the mould / shroud coupling holding a short shroud, and wherein the flexible element is in a rest state.

[0071] Figure 9d Shows Figure 9a A cross-sectional view of a ladle / shroud and mold / shroud connection mechanism in a casting apparatus, wherein, with the short shroud clamped to the shroud, the ladle is further lowered vertically until the shroud applies a load to the compliant member, thereby forming a sealing contact between the shroud and the short shroud.

[0072] Fig.10 The figure shows the short shroud being clamped before the shroud in the shroud casting position. Figure 9a View of the ladle / shroud connection in a casting plant.

[0073] Fig.11 Shows Fig.10 00130] View of a ladle / shroud coupling mechanism in a casting apparatus with a short shroud being clamped to the shroud in the shroud casting position.

[0074] Fig.12 Shows Fig.10 Detailed cross-sectional view of the ladle / shroud connection.

[0075] Fig.13 Shows Fig.11 Detailed cross-sectional view of the ladle / shroud connection.

[0076] Fig.14 A detailed view of a ladle / shroud coupling mechanism in a casting apparatus according to the present invention is shown, wherein a short shroud is coupled to the nozzle and the ladle and the short shroud coupled thereto are translated vertically (upward or downward) above the mold.

[0077] Fig.15 A detailed cross-sectional view of a casting apparatus including a ladle / shroud coupling mechanism according to the present invention is shown, with a short shroud clamped to the shroud and in the shroud casting position.

[0078] Figures 16a to 16f Various embodiments of the flexible element in the present invention are shown.

[0079] Figures 17a to 17h Various embodiments of the kit of parts of the present invention are shown.

[0080] Fig.18a An example of a prior art long shroud is shown, having a major axis with a major axis length d10L.

[0081] Fig.18b An example of a short shroud of the present invention is shown, which has a short barrel with an axial length of d10.

[0082] Fig.18c Shown according to Fig.18a and Fig.18b Top view of the long shroud and the short shroud.

[0083] Fig.18d Graphically shows material weight savings vs. Fig.18a and Fig.18b The function relationship of the axial length (d10) of the shroud is shown, expressed in terms of a proportionality factor k, which is defined as k=d10 / d10L, where k=0 (ie, d10=0) to 100% (ie, d10=d10L). DETAILED DESCRIPTION

[0084] In a first aspect, the present invention relates to a kit of parts for casting molten metal, comprising a short shroud (9), a sand casting mould (2), and a mould / shroud coupling mechanism as shown, for example, in Figures 17(a) to 17(c).

[0085] For example Figure 4 , Figure 9a and Figures 17a to 17h As shown, the short shroud (9) includes a shroud base (11) attached to the proximal end of a short barrel (10) having an axial length (d10) measured along the axis Z. The short shroud has a shroud hole extending along the Z axis from a shroud inlet (9i) opening at the shroud base (11) to a shroud outlet (9o) opening at the downstream end (10d) of the short barrel. The short barrel (9) suitable for the present invention differs from the prior art shrouds in that the short barrel (10) has a significantly shorter axial length (d10) than the prior art shrouds, as discussed in detail below.

[0086] For example, Figure 5 , Figure 6 and Figures 17a to 17h As shown, the sand casting mold (2) comprises:

[0087] a hole (7) in fluid communication with the cavity (3),

[0088] a housing (6) comprising a housing inlet (6i) and a housing outlet (6o), and

[0089] One or more casting cavities (3).

[0090] The hole (7) extends a hole length (d7) between a hole inlet opening at an upper surface (8) of the sand casting mold along the Z axis and a hole outlet opening at a downstream end. The downstream end includes a hole tightening portion (7c) forming a hole constriction defining a hole outlet opening in the housing (6) wherein the hole diameter decreases by at least 10% in the flow direction along the Z axis.

[0091] The housing (6) is selected from a filter housing and a diverter housing. In both cases, the housing comprises a single housing inlet (6i) in fluid communication with the orifice outlet, and one or more housing outlets (6o) in fluid communication with one or more cavities (3). The housing is configured to distribute the molten metal flow passing through the housing from the housing inlet (6i) to one or more housing outlets (6o) connected to the casting cavities. The housing (6) may be a filter housing comprising a filter element for filtering and eliminating solid impurities in the molten metal flow.

[0092] The one or more casting cavities (3) have a geometry that defines the geometry of the component to be cast. Each of the one or more casting cavities (3) includes a cavity inlet (4) in fluid communication with a housing outlet (6o). Figure 5 and Figure 6 A mold (2) is shown comprising a single cavity (3), while Fig.15 and Figures 17a to 17h A mould comprising several cavities (3) is shown.

[0093] In use, molten metal is cast through the bore inlet, the molten metal flows into the shell and fills one or more cavities (3). If the molten metal is cast directly into the bore (7) without any special protection from exposure to the atmosphere, oxide inclusions are formed and entrained in the flowing melt, thereby forming defects in the cast metal part. This problem is largely solved by using a shroud that extends from the bore inlet through the shell inlet (6i) along the bore length (d7) into the shell (6), thereby forming a continuous flow path that is essentially sealed from the atmosphere from the ladle to the cavity (3). This is described, for example, in EP 3463715 and PCT / EP 2022 / 072007 as mentioned above, and such shrouds are available on the market as SHRO from Foseco. Obtained. The long nozzle must be seated on the mold / long nozzle coupling mechanism to ensure that it is repeatedly and stably maintained in the long nozzle casting position. Since the complete set of components of the present utility model further includes a long nozzle, namely a short long nozzle, it must also include a mold / long nozzle coupling mechanism (14) to accommodate and maintain the short long nozzle (9) in the long nozzle casting position.

[0094] The mold / long nozzle coupling mechanism (14) applicable to the present utility model includes a seat member (15), which is configured to receive the long nozzle base (11) and hold the short long nozzle (9) in the long nozzle casting position, wherein the downstream end (10d) of the short barrel (10) is inserted into the hole.

[0095] The key point of the present utility model is that the axial length (d10) of the short barrel (10) is shorter than the hole length (d7), that is, d10 < d7. Thus, contrary to the prior art long nozzle system as described above, at the long nozzle casting position, the downstream end (10d) of the short barrel is separated from the housing inlet (6i) by a distance (d710) without the short barrel, and this distance without the short barrel is greater than zero. The distance without the short barrel (d710) can be defined as being proportional to the hole length (d7) by a proportionality factor (k < 1). For example, the proportionality factor (k) can be at least 30%, preferably at least 40%, more preferably at least 50% (i.e., d710 = kd7, preferably where k ≥ 0.3, preferably where k ≥ 0.4, more preferably where k ≥ 0.5).

[0096] To ensure a tight contact between the short barrel (10) and the hole wall, the short barrel (10) must penetrate into the hole (7) by at least a certain distance. For example, the proportionality factor (k) can be no greater than 90% (i.e., k ≤ 0.9), preferably no greater than 80% (i.e., k ≤ 0.8), more preferably no greater than 70% (i.e., k ≤ 0.7), and most preferably no greater than 60% (i.e., k ≤ 0.6). A proportionality factor (k) less than one requires the short barrel (10) to have a length (d10) such that the short barrel does not penetrate the entire hole length (d7) of the hole (7). The penetration depth of the short barrel (10) in the hole (7) at the long nozzle casting position can be defined as equal to (d7 - d710). The penetration depth is preferably at least equal to 3 cm (i.e., d7 - d710 ≥ 3 cm), more preferably at least equal to 5 cm (i.e., d7 - d710 ≥ 5 cm), and most preferably at least equal to 10 cm (i.e., d7 - d710 ≥ 10 cm).

[0097] The long nozzle with a short barrel (10) is advantageous because much less refractory material is required to produce the short long nozzle than the prior art long nozzle, and the short barrel has an axial length (d10) as Fig.18b shown, and this axial length is less than as Fig.18aThe axial length (d10L) of the prior art shroud is shown (which must be greater than d7). The cost of the most expensive consumable parts in the metal casting process with the shroud is proportionally reduced. The weight of the short shroud is also proportionally reduced, which facilitates its handling. Another advantage of the short shroud (9) is that Figure 2 , wherein at station (1a) a short shroud (9) is coupled to a shroud (12) below a ladle (103) moving around the workshop. Moving a ladle coupled with a short shroud (9) is much easier than moving a ladle with a long shroud as in the prior art (see, for example, PCT / EP 2022 / 072007).

[0098] Short shroud(9)

[0099] like Fig.15 As shown, during casting, the molten metal contained in the ladle (103) is distributed through the shroud (12) located in the lower part of the ladle (103), whereby the molten metal flows into the mold cavity (3) through the short shroud (9), the shroud-free distance (d710) of the hole (7), the shell (6) and the feed channel (5). The short shroud (9) includes a shroud base (11) attached to the proximal end of a hollow shaft (10), wherein the shroud hole opens at a shroud inlet (9i) in the shroud base and extends to a shroud outlet (9o) opened at the distal end (10d) of the hollow shaft.

[0100] The gist of the invention is to replace the long shroud (9L) described in the prior art (e.g. EP 3463715 and PCT / EP 2022 / 072007) extending from the bore inlet to the shell inlet (6i) along the entire bore length (d7) by a short shroud (9), the shroud outlet (9o) of which is spaced from the shell inlet (6i) by a distance (d710) not including the stub. This reduction in shaft length (d10) results in a corresponding saving of expensive material and thus in a reduction in costs, while retaining the advantages described in the aforementioned documents.

[0101] The shroud base (11) of the short shroud (9) of the utility model is the same as the shroud base of the long axis shroud described in the cited prior art. The shroud inlet (9i) is therefore formed to receive the shroud (12) and form a sealed interface therewith. For the long shrouds of the prior art, the shroud (12) of the ladle (103) must be sealingly engaged in the shroud inlet (9i) to prevent air from being sucked into the molten metal flow through the interface between the shroud and the shroud inlet (9i), while preventing the molten metal from leaking from the interface. The sealed contact between the shroud (12) and the shroud inlet (9i) can be achieved by matching the complementary geometric shapes of the shroud end and the shroud inlet. The shroud inlet can have the geometry of a cup, whether curved or truncated conical, and the shroud end can have a corresponding protruding matching geometry. Pressure may be applied at the interface by movement along the Z axis of the ladle (103) which drives the nozzle tip into the mating shroud inlet (9i). If required, a sealing joint or gasket may be applied to ensure an enhanced seal to the interface. A static seal or a dynamic seal may be formed between the moving nozzle (12) and the shroud inlet (9i). The dynamic seal may comprise an expandable sealing material, such as a gasket stuck in the shroud inlet, as described for a sliding gate in WO 2013 / 088249 A2. As Figure 17e to Figure 17h As shown, the shroud hole of the short shroud (9) can be equipped with a lining insert (9L). This lining insert (9L) is advantageously made of a consumable material, which is selected because of its durability under the specific conditions of a single sand casting operation and its effectiveness in keeping the shroud hole largely free of molten metal residues. For example, this consumable material can be a combination of cellulose, a selected grade of mineral and a binder. As an alternative, the insert can be composed of a refractory material. The thickness of the lining insert (9L) is generally in the range of 3mm to 10mm. This is in contrast to the wall thickness of the short shroud (9) itself, which is typically between 15mm and 20mm. With this configuration, the short shroud (9) can be effectively reused in multiple sand casting operations. This can be achieved by simply replacing the lining insert (9L) after each operation, thereby enabling the reuse of a single short shroud (9). Furthermore, the liner insert (9L) advantageously comprises an integral gasket (9g) designed to seamlessly connect with the shroud (12) of the ladle (103). However, if the liner insert (9L) itself has the necessary mechanical properties to accommodate the shroud (12), it is not necessary to design the gasket (9g) as an integral part. This is particularly applicable when the insert comprises a material such as cellulose. In addition, in order to enhance the resistance of the short shroud (9) to molten metal leakage and thermal shock, a metal tank (not depicted in the figure) can be lined on its outer surface. The liner insert (9L) offers a variety of installation options. Such as Fig.17e and Fig.17f As shown in Fig.17f and Figure 17h , the lining insert can be pre - assembled onto the short submerged entry nozzle (9) before being incorporated into the sand - casting mold assembly. Alternatively, the insert (9L) can be installed onto the short submerged entry nozzle (9) after the short submerged entry nozzle is installed within the sand - casting mold assembly, and the process is shown in Figure 17g and Figure 17h . Figure 17g and Figure 17h as shown in Figure 17g and Figure 17h .

[0102] The short submerged entry nozzle (9) of the present utility model differs from the long submerged entry nozzle (9L) of the cited prior art in that the latter's long - axis length with d10L>d7 is replaced by a short cylinder (10) with an axis length of d10<d7<d10L. The axis lengths of both the long and short submerged entry nozzles are defined as the following part of the submerged entry nozzle, which includes the submerged entry nozzle outlet (9o) and whose hole has a substantially constant hydraulic diameter (Dh10), where the hydraulic diameter is defined as the ratio 4A / P, where A is the cross - sectional area of the hole and P is the perimeter of the hole. For a circular cross - section, the hydraulic diameter (Dh) is equal to the diameter of the hole.

[0103] Fig.18a and Fig.18c shows an example of the long submerged entry nozzle of the cited prior art, which has a simplified geometry, including a submerged entry nozzle base (11) having a cylindrical part with a diameter (Dhi), then a submerged entry nozzle inlet (9i) with a frustoconical shape having a smaller diameter (Dh10), and the submerged entry nozzle inlet is attached to a cylindrical long axis (10) with a length (d10L) having a constant hole diameter (Dh10). This simplified geometry reasonably represents the actual submerged entry nozzle geometry and is sufficient for the purpose of showing the material savings when shortening the cylinder length (d10). The wall thickness (tw) is constant. Fig.18b shows the corresponding short submerged entry nozzle (9) according to the present utility model, which has the same submerged entry nozzle base (11) and a short cylinder with the same diameter but a shorter submerged entry nozzle length (d10), where d10 = a×d10L. Table 1 lists the values of the different dimensions of the long submerged entry nozzle (9L) and examples of the corresponding calculated weights (m9L) considering a refractory material with a density of ρ = 2.4 g / cm 3 In the case of an axis length of 100 cm, Fig.18a the long submerged entry nozzle (9L) weighs approximately 11 kg.

[0104] Table 1: Fig.18a Examples of the values of the dimensions of the long submerged entry nozzle

[0105] Dhi 7.7cm Dh10 5.9cm tw 1.7cm d9 106.0cm d11a 2.0cm d11b 4.0cm d10L 100.0cm m9L 11kg

[0106] Fig.18bshows a corresponding short submerged entry nozzle (9) according to the present utility model. Since the difference between the short submerged entry nozzle (9) and Figure 9a the long submerged entry nozzle lies only in that the shorter axial length d10 < d10L, thus Fig.9c the top view of the long submerged entry nozzle for Figure 9a and Figure 9b the long and short submerged entry nozzles is the same. The axial length (d10) of the short barrel (10) according to the present utility model is shorter than the long axial length (d10L) of the long submerged entry nozzle. The submerged entry nozzle length (d10) can be expressed as being proportional to the long axial length (d10L) by a scale factor (a), such as d10 = a × d10L < d10L, where a < 1, and preferably between 0.2 and 0.8 (as Fig.18a shown), more preferably between 0.35 and 0.6. Fig.18d Graphically shows the relative weight reduction ((m9L - m9) / m9L) between the weight (m9) of the short submerged entry nozzle (9) and the weight (m9L) of the long submerged entry nozzle (9L) as a function of the scale factor a = d10 / d10L. The light shaded area defines the preferred range 0.2 < a < 0.8 (i.e., d10 = 20 cm to 80 cm), which results in a weight reduction between 75% and 20% respectively. Thus, the weight of the short submerged entry nozzle (9) is between 2 kg and 7.9 kg, rather than 11 kg. The dark shaded area defines the more preferred range, 0.35 < a < 0.6 (i.e., d10 = 40 cm to 60 cm), which results in a weight reduction between 60% and 40% respectively. Thus, the weight of the short submerged entry nozzle (9) is between 3.9 kg and 6.4 kg, rather than 11 kg. This has the advantage of reducing the cost of the disposable submerged entry nozzle and also greatly simplifies the handling of the submerged entry nozzle by the operator.

[0107] The short submerged entry nozzle (9) is made of a refractory material, such as fused silica, alumina - graphite material or other materials known in the art. The outer wall of the submerged entry nozzle base (11) can have a tapered shape with inclined shoulders (23), and these inclined shoulders rest on the seat member (15). In one embodiment, the shoulders rest on a filler (22) that fills the space between the sleeve of the seat member (15) and the submerged entry nozzle base, as Figure 4 shown. Alternatively, the shoulders of the submerged entry nozzle directly rest on the seat element, as Fig.9c , Figure 9d , Fig.12 and Fig.13 shown.

[0108] The main purpose of the long axis of the long shroud (9L) of the cited prior art is to span the distance separating the end of the shroud (12) from the shell inlet (6i) to prevent the flowing molten metal from contacting the air between the ladle (103) and the cavity (3) of the mold (2). Protection of the molten melt from contact with the air can also be achieved by a short shroud (9) whose short barrel does not reach the shell inlet (6i) and is separated from the shell inlet by a distance (d710) that does not contain the short barrel by ensuring a sealed contact between the short barrel (10) and the hole (7).

[0109] A simple way to form a seal between the short barrel (10) and the hole (7) is to size the short barrel (10) so that only a small gap is left between the short barrel (10) and the wall of the hole (7) when the short shroud (9) is in the shroud casting position. When the molten metal flows through the shroud (12) and the short shroud (10) to fill the hole (7), some of the metal flows into the gap between the short barrel (10) and the cold wall of the hole (7) and solidifies, thereby forming a solid layer that seals the hole (7) from the atmosphere. In order to enhance the seal, a sealing gasket or sealing material can be provided to seal the gap from the atmosphere. Similarly, in addition to sealing materials known in the art, especially if the mold / shroud connection mechanism (14) includes a flexible element or an elastic element, an expansion material as described in WO 2013 / 088249 can be used to form a dynamic seal.

[0110] The shroud outlet (9o) may comprise one or more orifices for distributing molten metal into the bore (7).

[0111] Mould / Shroud Connection Mechanism(14)

[0112] In order to receive a short shroud (9) and to maintain it in the shroud casting position for the duration of the casting operation, the mould according to the invention is equipped with a mould / shroud coupling mechanism (14). The type of mould / shroud coupling mechanism is not important for the invention, as long as it performs the dual functions of receiving a short shroud (9) and maintaining it in the shroud coupling position for the entire duration of the casting operation. However, a mould / shroud coupling mechanism (14) of the following type is preferred: (1) having a flexible element, and (2) a lifting coupling.

[0113] Mold / shroud connection mechanism with flexible element (14)

[0114] A preferred type of mould / shroud coupling (14) comprises a flexible element (17), such as Figure 3 and Figure 4 As shown. Figure 6As shown, the mold / long nozzle coupling mechanism (14) is configured to accommodate the long nozzle (9) of the casting device (1) in the long nozzle casting position, which is defined as the position when the short barrel (10) is accommodated in the hole (7) and the distal end (10d) of the short barrel is separated from the shell inlet (6i) by a distance (d710) not containing the short barrel. During the casting operation, the molten metal flows out of the ladle through the nozzle (12), which is sealingly engaged in the long nozzle inlet (9i) in the long nozzle casting position. The molten metal then flows through the short barrel (10) and along the hole (7), and then enters the shell (6) through the hole outlet at the hole tightening part (7c), and flows out of the shell through the shell outlet (6o) into the feed channel to fill the casting cavity (3).

[0115] Base member (16) and seat member (15)

[0116] like Figure 3 and Figure 4 As shown, the mold / shroud coupling mechanism (14) includes a base member (16) fixed to the upper surface (8) of the mold (2) and a seat member (15) configured to receive the shroud base (11) and hold the short shroud (9) in the shroud casting position. Figure 3 and Figure 4 As shown in , the seat member (15) is connected to the base member (16) by at least one flexible element (17), so that when the mold / long nozzle connection mechanism (14) is in a rest state, the seat member (15) is separated from the base member (16), and when a load is applied to the seat member (15) along the Z axis, the seat member can move relative to the base member (16) and preferably toward the base member (16), and the load applied to the seat member deforms the at least one flexible element (17) to reduce the rest distance (h0) to the casting distance (h1), thereby separating the seat member (15) from the base member (16). The flexible element (17) is described in more detail, and the flexible element is defined as an element that deforms significantly along the Z axis when a load is applied along the Z axis.

[0117] The flexible element (17) is configured to deform in the case of applying a vertical (i.e., along the Z-axis) and downward load from the nozzle (12) of the ladle (103) to the long nozzle base (11) received in the seat member (15), so as to drive both the seat member (15) and the short long nozzle (9) to descend from the rest distance (h0) from the hole inlet to the casting distance (h1 < h0), wherein the short long nozzle (9) reaches the long nozzle casting position, and the long nozzle outlet (9o) is separated from the housing inlet (6i) by a distance (d710) without the short barrel. When the load along the Z-axis is released from the short long nozzle (9) and the seat member (15), the seat member can: return to its rest distance (h0) from the hole inlet if the flexible element (17) is an elastic element; remain at the casting distance (h1) as a plastic element if the flexible element (17) is a plastic element; or return with a delay at the rest distance (h0) or at some point between the casting distance and the rest distance (h1, h0) if the flexible element is a viscoelastic element (17).

[0118] In a preferred embodiment of the mold / long nozzle coupling mechanism (14) including the flexible element (17), it is not necessary to manually adjust the position of the short long nozzle (9) received in the seat member (15) relative to the nozzle (12) to engage the long nozzle inlet (9i) with the nozzle (12) of the ladle (103). In an embodiment of the present invention, the short long nozzle is coupled to the mold at the rest distance (h0) from the hole inlet, that is, the long nozzle base rests on the seat member (15) of the mold / long nozzle coupling mechanism (14), the short barrel (10) is received in the hole (7), and the long nozzle outlet (9o) is separated from the housing inlet (6i) by a distance greater than d710 (the long nozzle outlet (9o) is actually separated from the housing inlet (6i) by a distance [d710+(h0 - h1)]). In the rest state, the long nozzle base (11) rests on the seat member (15), and the seat member is maintained at the rest distance (h0) from the base member (16) by the reaction force of the flexible element (17) so biased. The nozzle (12) of the ladle (103) is lowered to engage the long nozzle inlet (9i), which is achieved only by first moving the ladle to align it with the long nozzle inlet (9i) along the Z-axis and locate it above the long nozzle inlet, and then lowering the ladle (103) along the Z-axis until the nozzle engages the long nozzle inlet (9i), as Figure 7a and Figure 7b shown. In Figure 7a it, the nozzle is aligned with the long nozzle inlet (9i) along the Z-axis and is located at a certain distance from the long nozzle inlet. Then, the ladle is lowered, that is, moved downward along the Z-axis towards the long nozzle base (11), so that the nozzle engages the long nozzle inlet (9i) of the long nozzle, as Figure 7bAs shown. At this stage, the shroud and the shroud inlet (9i) are not coupled to form a sealing contact. In order to seal the shroud into the shroud inlet (9i) and prevent air and molten metal from leaking through the gap between the shroud and the shroud inlet (9i), then as shown Figure 7c The ladle is further lowered as shown, so that the shroud contacts the shroud base (11) resting on the seat member (15) of the mold / shroud coupling mechanism (14) and applies a load on the shroud base along the Z axis, thereby moving the seat member (15) toward the base member (16) from the rest distance (h0) to the casting distance (h1) by deforming the flexible element (17), so that on the one hand,

[0119] The shroud can form a sealing contact with the shroud inlet (9i), and on the other hand,

[0120] The short shroud (9) reaches the shroud casting position, wherein the shroud outlet (9o) is spaced from the shell inlet (6i) by a distance (d710) excluding the short barrel.

[0121] like Figure 7c As shown in FIG. , the movement of the seat member (15) relative to the base member (16), driven by the downward translation of the ladle and made possible by the deformation of the compliant member (17), reduces the distance (h0-h1) between the seat member (15) and the base member (16) from the rest distance (h0) to the casting distance (h1) (where h1 <h0)。

[0122] Another advantage of the mould / shroud coupling mechanism (14) comprising a flexible element (17) is the absorption of energy generated by the movement between the shroud and the short shroud, for example caused by shocks when lowering the ladle (103) or by vibrations during the casting operation. This reduces wear caused by friction between the moving elements.

[0123] The mold / shroud connection mechanism (14) in the mold of the utility model preferably also allows compensation for lateral and / or oblique misalignment between the shroud and the shroud inlet (9i), such as Figure 6 As shown. When lowering the ladle in order to engage the nozzle into the shroud inlet (9i), lateral misalignment may occur. In the absence of a flexible element (17) in the mould / shroud coupling mechanism (14) as has been the case to date, lateral misalignment may prevent the formation of a sealing contact between the nozzle and the shroud inlet (9i) or may cause significant material stresses to compensate for such misalignment in order to establish a sealing contact. In the present invention, the flexible element compensates for the lateral misalignment, thereby reducing material stresses and potential failures in the casting equipment.

[0124] like Figure 3 , Figure 4and Figure 5 As shown, the base member (16) and the seat member (15) of the mold / long nozzle coupling mechanism (14) according to the utility model can each include a central hole, which is aligned with each other and has a hole entrance to define an introduction path toward the hole (7) for the short long nozzle (9). Figure 3 , Figure 4 and Figure 5 In the embodiment of the present invention, the base member (16) has a central hole (20) which is circular and forms an introduction path to the hole (7), through which the short barrel (10) of the short shroud (9) can be inserted into the hole (7) until the shroud base (11) rests on the seat member (15) in the rest position, as shown in FIG. Figure 4 As will be discussed below, a short shroud may be introduced into the hole (7) by an operator (e.g. Figure 1 (1a)) or by lowering the ladle (with a short shroud attached to the ladle) into the hole (as shown in Figure 2 (1a) Figure 2 (1) and Figure 2 (2)).

[0125] In one embodiment, the short shroud is seated on the seat member (15) before the ladle is lowered to establish contact between the shroud and the shroud inlet (9i) (see Figure 1 (1a) & (1) and Figure 7a ), the seat member (15) may be formed by a sleeve (21) provided with arms (18) distributed around the circumference of the sleeve and extending radially outwardly from the sleeve, such as Figure 3 & Figure 4 A centering pin (19) can be used to center the flexible element.

[0126] The geometry of the sleeve may match the geometry of the outer wall of the shroud base (11) so as to snugly receive the shroud base (11). Figure 4 and Figure 7a As shown, the shroud base (11) can be snugly received by the seat member (15) by filling the seating gap with a filler (22) preferably made of molding sand, thereby forming a seat on which the shoulder (23) of the shroud base (11) rests when the shroud (9) is in the casting position. The filler (22) of molding sand can contain an organic binder, such as furan, alkaline-phenolic binder. In addition, other binders can be used, such as inorganic binders or clay minerals.

[0127] A preferred embodiment of the mold / shroud connection mechanism (14) with a flexible element (17) is Figure 3. The mold / long nozzle coupling mechanism includes a seat member (15), which includes a sleeve configured to receive and retain the long nozzle base (11). The seat member is connected to the base member (16) by a compliant member (17) in the form of a spiral spring (17s). The seat member (15) has three radially outwardly extending arms (18), which are evenly distributed on the circumference of the sleeve at a certain radial distance from the axis of symmetry of the drive passage. It will be understood by those skilled in the art that the seat member can have any other shape, for example, it can be disc-shaped, and the number of arms extending outward can vary.

[0128] The base member (16) is preferably rigidly fixed to the upper surface (8) of the mold (2). For example, the base member can be connected with an adhesive (organic or mineral) or with a fastening device (such as screws, rivets, etc.). Alternatively, the base member (16) can be seated in a matching recess and held in place by gravity and by a load parallel to the Z axis applied by the nozzle (12). The latter embodiment has the following advantages: the mold / long nozzle connection mechanism can be easily removed before destroying the mold (2) to remove the cast metal part. This is sufficient to keep the central hole (20) of the base member concentric with the hole (7) during the entire casting operation. The base member also includes three radially outwardly extending arms (18) that are aligned with corresponding arms of the seat member (15). The flexible element (17) is formed by three coil springs (17s) sandwiched between the arms of the seat member and the arms of the base member.

[0129] Figure 3 Three helical springs (17s) are shown as the preferred flexible element (17). However, the flexible element (17) can have other configurations, some examples of which are shown in Figures 16a to 16f and discussed in more detail in the next section.

[0130] When the shroud base (11) of the short shroud (9) is seated in the seat member (15), the flexible element (17) (e.g., a helical spring (17s)) maintains the seat member (15) at the rest distance (d0) (see Figure 4 and Figure 7b). When the ladle (103) is lowered, the shroud engages the shroud inlet (9i) and applies a load along the Z axis to the seat member (15), which deforms the flexible element (17) and drives the seat member to the casting distance (h1) and drives the short shroud (9) to the shroud casting position, where the shroud outlet (9o) is separated from the shell inlet (6i) by a distance (d710) that does not contain the short barrel. At this stage, a sealed contact is formed between the shroud (12) and the shroud inlet (9i) by the matching geometry of the two elements and by applying a load between the two and optionally by a sealing member. Metal melt can be cast through the shroud and the short shroud (9), the metal melt filling the hole (7) and flowing into the shell (6) and into the cavity (3). The small gap between the short barrel (10) and the hole wall is quickly filled with metal, which solidifies and forms a seal when it contacts the cold mold. Optionally, a sealing member (e.g., a gasket) can be used to ensure the sealing of the small gap.

[0131] Flexible Components(17)

[0132] At least one flexible element (17) of the mould / shroud coupling mechanism of the embodiments discussed above allows the short shroud (9) to be dynamically moved to the shroud casting position by its deformation when a load is applied along the Z axis. The load is applied by lowering the ladle (103) along the Z axis until the shroud (12) contacts the shroud inlet (9i) and exerts a force thereon. The flexible element (17) is an element that deforms significantly along the Z axis when a load is applied along the Z axis. The flexible element (17) may exhibit elastic properties, viscoelastic properties or purely plastic properties.

[0133] Elastic elements are flexible elements (17) that absorb energy when elastically deformed and release this energy immediately when the load is removed. A mold / shroud connection including elastic elements can be used multiple times with different molds (2) without having to replace the elastic elements, because they return to their resting state after use, ready to be used again. Examples of elastic elements include, for example Figure 3 , Figure 4 , Fig.16a , Fig.16b The coil spring (17s) shown or Fig.16e Leaf spring shown.

[0134] A viscoelastic element is a flexible element (17) having an elastic modulus (E') and a loss modulus (E"). After the load is released, the viscoelastic element does not return to its original geometry or returns to its original geometry with a time delay. Only the latter type of viscoelastic element can be used multiple times in different casting operations. Examples of viscoelastic elements include Fig.16d Elastomeric material (such as rubber) as shown, or Fig.16cThe hydraulic damper or pneumatic damper shown may be made with a spring and a buffer arranged in parallel.

[0135] A plastic element is a flexible element (17) which cannot recover, even partially, its original geometry when the load is released. This is, for example, the case of a flexible element such as a beam which is configured to deform plastically significantly when a load is applied along the Z axis. This can also be the case of a Fig.16f In the case of the free-flowing material shown, the free-flowing material is enclosed in one or more bags or flexible containers, which are configured to deform viscously when a load is applied to the seat member (15). The free-flowing material can be a granular material (such as sand, etc.), which can absorb energy by causing viscous flow to resist the load applied by the nozzle to the long nozzle and the seat member (15). The flexible element can also include disposable elements, which are configured to be broken or crushed by plastic deformation when a load is applied. When the load is released, the plastic element maintains its deformed configuration. Each time the mold / long nozzle connection mechanism (14) is to be used again, the plastic element must be reshaped or removed and replaced with a new, undeformed plastic element.

[0136] Coil springs (17s) are the preferred flexible element (17) due to their ready availability, their tolerance to casting conditions and the fact that they can be reused multiple times without any repairs between two consecutive uses. The elastic element is also more suitable for maintaining the sealing contact between the shroud inlet (9i) and the shroud (12) during the casting operation when the ladle (103) and the shroud (12) move slightly up and down due to vibrations during casting.

[0137] Preferably, the mould / shroud coupling mechanism (14) comprises at least three elastic elements, preferably at least three helical springs (17s), extending between the seat member (15) and the base member (16), wherein the at least three elastic elements are preferably equally spaced around the circumference of the central holes of the seat member (15) and the base member (16), such as Figure 3 , Figure 4 and Figure 5 Preferably, at least three helical springs, preferably evenly distributed, extend between the seat member (15) and the base member (16). The advantage of this design is that during the casting process, the flexible element (17) is not overheated by the molten metal flowing from the shroud inlet (9i) through the shroud hole to the hollow shaft of the shroud.

[0138] Mould / shroud connection mechanism with lifting mechanism (14)

[0139] A mould / shroud coupling mechanism (14) comprising a lifting coupling system suitable for use with the present invention is described in EP3463715 and is referred to hereinafter as the "lifting mechanism". The lifting mechanism comprises a seat member (15) in the form of an inner collar which is concentrically seated within an outer collar forming a base member (16). The inner collar comprises an annular seat configured to receive and support a shroud base (11) wherein a short barrel passes through a central hole and a hole entrance to be inserted in a hole (7). Two pegs and a handle extend radially out of and are distributed on the outer surface of the inner collar.

[0140] The base member (16) formed by the outer collar comprises a cylindrical wall surrounding an annular base. The base 70 is mounted on the upper surface of the mould in the same manner as the base member of the mould / shroud coupling mechanism with a compliant member as described above, i.e. glued, screwed or simply placed on top of the upper surface of the mould, preferably in a matching recess, thereby preventing any lateral movement (in a plane perpendicular to the Z axis, which plane defines the upper surface of the mould).

[0141] The cylindrical wall of the outer collar is cut away so as to provide at least two inclined or helical surfaces which rise from the upper surface of the mould at a given azimuth from a rest position at h0 by a distance (h1-h0) to a casting position at h1. The inner collar is inserted into the outer collar, and the pegs of the inner collar rest on the inclined surfaces of the outer collar at the rest position h0. By rotating the inner collar using the handle, the pegs travel along the inclined surfaces, so that the inner collar and therefore the short shroud 9 supported by the inner collar are lifted upwards until the casting position h1 is reached. Thus, the inner and outer collars act as cylindrical cams, and the pegs constitute followers.

[0142] Unlike the mold / long shroud coupling mechanism with flexible elements as described above, the lifting mechanism drives the short shroud away from the shell inlet (6i) to reach the long shroud casting position. Therefore, the long shroud outlet (9o) is closer to the shell inlet (6i) and separated from the shell inlet by a distance d710-(h1-h0) in the rest position than in the long shroud casting position, where it is separated from the shell inlet by a distance (d710) without the short barrel.

[0143] In use, the ladle (103) and the shroud (12) are lowered along the Z axis until they touch or nearly touch the shroud inlet (9i) without forming a sealing contact. Sealing contact is formed by lifting the shroud inlet (9i) onto the shroud (12) by rotating the inner collar relative to the outer collar as described above.

[0144] The mould / shroud coupling mechanism with flexible elements as described above is advantageous over a lifting mechanism for the following reasons. Firstly, it allows for more automation because the flexible elements provide a dynamic, self-adjusting sealing contact mechanism that requires no human intervention other than lowering the ladle to engage the shroud into the shroud opening. Secondly, as explained in more detail below, the lifting mechanism operates simply by first inserting the short shroud into the hole (7), then Figure 1 The lowered ladle is ready for use. The mould / shroud coupling mechanism with flexible elements also offers the possibility to couple a short shroud directly to the shroud and drive the short cylinder (10) into the hole (7) by controlling the displacement of the ladle (103) and its shroud (12).

[0145] Sand Casting Molds(2)

[0146] The mould (2) is a sand casting mould made of compacted sand with a binder. The mould comprises a hole (7) extending from a hole inlet to a hole outlet, the hole outlet being located in a hole constriction (7c) and opening in a shell inlet (6i) leading to a shell (6). The sand casting mould (2) comprises one or more mould cavities (3) fluidly connected to the shell (6) via a feed channel (5). If the sand casting mould comprises more than one cavity, a single feed channel (5) may be connected to the shell outlet (6o) and branched towards different cavities, such as Fig.17a and Fig.17c Alternatively, several feed channels (5) may be connected to corresponding housing outlets (6o), each feed channel leading to a different cavity, such as Fig.17b Finally, Fig.15 As shown, a plurality of feed channels may be coupled to corresponding housing outlets (6o), and each feed channel branches toward a different cavity. An exhaust channel (13) may be provided for exhausting the cavity to maintain a substantially constant pressure in the headspace when the cavity is filled with molten metal. The cavity (3) of the sand casting mold of the utility model with corresponding feed channels (5) is the same as the cavity currently used and is well known to those skilled in the art. Therefore, it will not be discussed in detail below.

[0147] Hole (7)

[0148] The bore (7) extends over a bore length (d7) from the bore inlet to the shell inlet (6i). The portion of the bore other than the constriction (7c) is preferably cylindrical, having a circular cross section, or slightly conical, tapering in the flow direction, the taper angle preferably being no greater than 2 degrees, more preferably no greater than 1 degree. The downstream end of the bore (87) is formed by the constriction (7c), which forms a bore constriction defining a bore outlet, wherein the bore diameter decreases by at least 10% in the flow direction along the Z axis. The bore outlet opens into the shell inlet (6i). The constriction (7c) allows pressure to build up in the bore (7) so that the bore is completely filled with molten metal during the casting operation, thereby reducing air entrapment and the formation of turbulence.

[0149] The cell walls may be formed from compacted sand forming the bulk of the mould (2), such as Fig.17a and Fig.17e This is the cheapest solution. However, the sand forming the hole wall may be eroded by the fast-flowing molten metal, thereby entraining sand particles into the housing (6) together with the molten metal. If the housing includes a filter unit, the sand particles can be trapped, but at the expense of pressure loss. In order to reduce or even avoid the risk of erosion, the hole wall can be made of a thin layer of molten metal over the entire hole length (d7) (e.g. Fig.17b as shown) or only over a portion of the hole length (d7) (as shown Fig.17c and Figure 17g The lining material must be cheaper than the refractory material forming the short shroud (9), otherwise the material and cost savings achieved by using the short shroud will be offset by the additional material and cost required to form the lining (7s). The only function of the lining (7s) is to prevent sand particles from being eroded and entrained in the metal flow. Any cheap material that forms a dense surface that resists erosion during a single casting operation can be used to form the lining (7s). For example, any clay clinker (or clinker), preferably composed of high-temperature fired clay, sand core material or cellulose material, can be advantageously used to form the lining (7s) because it is cheap and forms a dense surface that is resistant to erosion by the flowing metal. In an alternative embodiment, the hole (7) is characterized by a dual material lining method. Specifically, the downstream section of the hole length (d7) is lined with a first material, as depicted in the lining (7s). In contrast, the upstream section of the hole length (d7) is lined with a second material (7m), which is characterized by high dimensional accuracy relative to the first material. This dual material lining configuration is Fig.17d , Fig.17f and Figure 17h The main function of the second material (7m) is to ensure effective sealing of the gap between the short shroud (9) and the hole (7). The second material is not limited to a specific type and can include various substances, such as molding sand, ceramic or core sand. The key criterion for selecting this material is its dimensional accuracy to ensure an optimal seal.

[0150] Housing(6)

[0151] The housing (6) is in fluid communication with the orifice outlet, thereby allowing molten metal to flow directly from the orifice (7) into the housing (6) through the orifice outlet and the housing inlet (6i). The housing (6) may be a flow divider that directs the flow of molten metal toward a feed channel (5) such as a manifold that leads to a corresponding cavity (3). The housing also serves to stabilize the flow of molten metal, thereby eliminating turbulence to produce a more laminar flow before it fills one or more cavities (3).

[0152] Preferably, the housing (6) is a filter housing provided with a filter unit to prevent solid particles from flowing into the feed channel (5) and the mold cavity (3). Figures 17a to 17c As shown in the square elements in the shell (6).

[0153] Sand casting mold components

[0154] The utility model also relates to a mold assembly, which comprises a mold (2) as defined above, a mold / long nozzle coupling mechanism (14) and a short long nozzle (9), wherein the long nozzle base (11) of the short long nozzle (9) is seated on a seat member (16) of the mold / long nozzle coupling mechanism (14) and the downstream end (10d) of the short cylinder (10) is located inside the hole (7) and outside the shell inlet (6i). This configuration of the sand casting mold assembly is suitable for performing the following operations: Figure 1 The casting process shown, wherein the short shroud (9) is first connected to the sand casting mold (2) via the mold / shroud coupling mechanism (14). The shroud base (11) is usually located outside the mold, that is, above and adjacent to the upper surface of the mold (8), and the short barrel (10) is engaged in the hole (7). At the rest position, the downstream end of the short barrel is separated from the shell inlet by a given distance. If the mold / shroud coupling mechanism does not allow the short shroud to move along the Z axis when the shroud base (11) is seated on the seat member (15), the given distance is d710, and the short shroud is in the shroud casting position. If the two types of mold / shroud coupling mechanisms (14) as described above (having a flexible element (17) and having a lifting mechanism) allow the short barrel to move up and down between the rest position (h0) and the casting position (h1) relative to the hole (7), the given distance is d710±|h0-h1|. The short shroud can be moved to the shroud casting position, wherein the downstream end (10d) of the short tube (10) is located at a short tube-free distance (d710) from the shell inlet (6i), as described above, that is,

[0155] If the mould / shroud coupling mechanism (14) comprises a flexible element (17), this is achieved by applying a load along the Z-axis towards the sand casting mould (2) to reduce the distance to d710, or

[0156] If the mould / shroud coupling (14) comprises a lifting mechanism, this is achieved by rotating the inner collar to increase the distance to d710.

[0157] In such Figure 5 In the long shroud casting position shown, the short barrel is separated from the shell inlet (6i) by a distance d710 that does not include the short barrel. Molten metal is supplied to the casting cavity (3) through a flow path extending from the ladle (103) to the casting cavity, flowing through the short shroud of the shroud (12), the short long shroud (9), the hole (7), the shell (6), the feed channel (5) and into the cavity. As with the long long shroud of the cited prior art, the flow path is essentially airtight and prevents reoxidation of the metal by protecting the metal from the atmosphere. The hole (7) extends along the Z axis and is sized to accommodate the short long shroud (9), with the gap between the hole wall and the short barrel as small as possible while still allowing the short long shroud (9) to move linearly along the Z axis within the hole (7). As described above, when the hole (7) is filled with molten metal, some of the molten metal will flow through the small gap and condense or solidify in contact with the cold sand casting mold material, thereby forming a sealed joint. Alternatively, the joint material may be applied as a paste or gasket to ensure a perfect seal between the stub (10) and the hole wall.

[0158] In an embodiment of the mould assembly according to the invention, the short shroud (9) is fixed to the seat member (15) by gravity or by means of a filler (22) of moulding sand which fills the annular gap between the shroud base (11) and the seat member (15) and defines a seat for the shroud base (11), such as Figure 4 shown.

[0159] In a preferred embodiment of the present invention, a gasket is placed in the shroud inlet (9i) to enhance the sealing contact between the shroud (12) and the shroud inlet (9i). The gasket may be formed, for example, of plasticized clay or expanded material.

[0160] Casting equipment

[0161] The utility model also relates to a casting device, which comprises a sand casting mold (2), a short shroud (9), a mold / shroud coupling mechanism (14), and a ladle (103) equipped with a shroud (12), which is arranged at the base of the ladle (103) for dispensing molten metal from the ladle. The shroud (12) is configured to reversibly and sealingly engage in the shroud inlet (9i). The ladle (103) is configured to shift relative to the sand casting mold (2) so as to position the shroud (12) substantially vertically (along the Z axis) above the mold / shroud coupling mechanism (14) and the hole inlet (9i), and to be vertically lowered along the Z axis until the shroud (12) is sealingly engaged in the shroud inlet (9i), wherein the shroud (9) is in the shroud casting position. Depending on the type of mould / shroud coupling mechanism (14) used, the short shroud (9) is already in the shroud casting position before the shroud (12) engages the shroud inlet (6i), or is brought to the shroud casting position by applying a load along the Z axis to the seat member (15) to deform the flexible element (17) or by rotating the inner collar to activate the lifting mechanism. The casting device may include a gasket, which is preferably located in the shroud inlet (9i). In the casting device, the short shroud (9) can be fixed to the seat member, preferably with a filler (22), or can be disassembled and removed from the seat member (15).

[0162] In order to enhance the sealing contact between the nozzle (12) and the shroud inlet (9i), the nozzle tip and the shroud inlet (9i) preferably have a matching geometry of the convex-concave geometry type. For example, the nozzle (12) can have a convex truncated conical geometry, while the shroud inlet (12) has a matching truncated conical cup shape, such as Figure 3 , Figure 4 , Figure 7a Alternatively, the nozzle (12) may be formed as a protruding spherical cap, while the long nozzle inlet (9i) may be formed as a spherical cup, as shown in FIG. Figure 5 and Figure 6 These types of convex / concave geometries allow for moderate inclination of the shroud relative to the short, long shroud (9). These geometries are also self-centering, correcting any small deviations in the alignment of the shroud relative to the short, long shroud (9).

[0163] Applying a load at the interface between the shroud and the shroud inlet (9i) is also important to ensure close contact. If a mold / shroud coupling mechanism including a flexible element (17) is used, the load can be applied when the ladle is lowered and the shroud tip is engaged into the shroud inlet (9i) and the flexible element (17) is pressed. If a mold / shroud coupling mechanism with a lifting mechanism is used, the load is applied by lifting the shroud inlet (9i) above the top of the shroud along the Z axis. The use of a flexible element is preferred because it reduces the risk of impact when the shroud is lowered into the shroud inlet (9i) and can also absorb vibrations of the ladle and shroud during the casting operation.

[0164] Ladle / Shroud Connection Mechanism(140)

[0165] A preferred embodiment of the casting apparatus according to the present invention comprises a ladle / shroud coupling mechanism (140) which is configured to reversibly clamp a short shroud (9) to a shroud (12), preferably without forming a seal between the shroud inlet (9i) and the shroud (12).

[0166] like Figure 2 and Figure 9a As shown, this allows the ladle to be moved with a short shroud suspended, which is advantageous when the shroud can be reused for multiple castings in a row, e.g. Figure 2 When a series of subsequent castings are performed using the same ladle and shroud (9), the shroud can be disengaged from the hole of the first mold after the metal casting is completed in the first mold by lifting the ladle upwards (see Figure 2 - Step 4). The ladle is then translated horizontally in order to position the shroud above the hole of the second mould (see Figure 2 - Step 5). Then, lower the ladle downwards (see Figure 2 (1)) until the shroud reaches the casting position (see Figure 2 (2)) and subsequent casting can then be carried out in the second mould. This operation can be repeated as long as the shroud is in the casting state. Afterwards, the used shroud can be removed (see Figure 2 - Step 1b) and load the new shroud into the ladle (see Figure 2 - Step 1a). This ladle / shroud connection mechanism allows the same shroud to be reused multiple times for multiple castings. This also saves operator workload, since the connection between ladle, shroud and mold can be done by the operator alone by giving commands to the ladle positioning system. Between two castings using the same shroud, the shroud heated by the previous casting in the mold does not need to be manipulated by the operator to position it in the subsequent casting position in the mold, thus improving safety.

[0167] Clamping the shroud to the nozzle can also be done using the long shroud of the cited prior art, as described in PCT / EP 2022 / 072007, but using a short shroud (9) instead is very advantageous because the ladle does not need to be lifted as high to remove the long shaft from the hole, and it is easier and less dangerous to translate a ladle with a short shroud attached in the workshop than to translate a ladle with a long shroud attached.

[0168] like Figure 9a As shown, the ladle / shroud coupling mechanism (140) includes a base adapter (140b) fixed to the shroud base (11) and includes a retaining device. The base adapter (140b) is usually made of metal and is fixed to the shoulder of the shroud using an adhesive filler (113) (such as cement, etc.). The ladle / shroud coupling mechanism (140) also includes a shroud adapter (140n), which is fixed to the base of the ladle (103) or to the shroud (12) and is configured to engage the retaining device of the base adapter (140b) to reversibly lock the short shroud (9) to the shroud (12) in a locked position. The unlocked position and the locked position of the ladle / shroud coupling mechanism (140) are respectively as shown in FIG. Fig.10 and Fig.11 The base of the ladle is the lowest part of the ladle in use. The nozzle adapter (140n) is preferably installed at the base of the bottom pouring ladle.

[0169] The base adapter (140b) and the shroud adapter (140n) are complementary to each other and are configured to releasably and loosely engage with each other in a locked position. An important aspect of the ladle / long shroud coupling mechanism (140) according to the utility model is that the base adapter (140b) and the shroud adapter (140n) are configured to loosely engage with each other in a locked position. This means that the long shroud inlet (9i) and the shroud adapter engage with each other with sufficient clearance relative to each other in the locked position so that they can form a certain degree of articulated movement relative to each other. When the short long shroud is attached to the ladle, this design allows relative movement of the short long shroud and the ladle, thereby significantly reducing the risk of damage to the long shroud when the short barrel (10) is inserted into the hole (7) of the mold. In the locked position, it is preferred that no sealing contact is formed between the shroud and the long shroud inlet (9i).

[0170] exist Fig.10 and Fig.11In a preferred embodiment of the ladle / shroud coupling mechanism represented in , the holding means of the base adapter (140b) comprises holding pegs (109), and the shroud adapter (140n) comprises fastening hooks (107) which are configured to reversibly engage the holding pegs (109), preferably configured to self-engage with the holding pegs (109). The self-engaging fastening hooks allow the shroud to be easily clamped to the ladle. This allows, for example, the ladle to be used to engage the holding means of the base adapter with the shroud adapter by lowering the ladle (e.g. Fig.11 and Fig.15 As shown) and in the first mold (2) according to the utility model, the long water nozzle (as shown) held in the casting position is picked up. Fig.10 ), then lift the ladle to remove the shroud from the hole (as shown Fig.14 and as shown in FIG. 16 ).

[0171] Steering Fig.12 The base adapter (140b) may comprise a sleeve-like element having a truncated bearing surface (114) resting on an inclined edge (115) in a central hole (25) of a seat member (15), the inclined edge forming a seat for the base adapter (140b). The base adapter (140b) sits snugly in the seat member (15), but is held only by gravity. On the outer circumference of the base adapter (140b), two, three or four retaining pegs (109) extend outwardly in a radial direction. The retaining pegs (109) may be engaged by fastening hooks (107) attached to a nozzle adapter (140n), which nozzle adapter is attached to the ladle bottom plate (105).

[0172] The nozzle adapter (140n) is designed as a slot around the nozzle (12). On the side attached to the ladle (103), also called the proximal side, the first coupling member (11) includes a snap ring (106) that engages the ladle bottom plate (105). The nozzle adapter (140n) is detachably connected to the ladle (103). At the other end of the nozzle adapter (140n), also called the distal end, the nozzle adapter (140n) includes a plurality of pegs (111) to which fastening hooks (107) are rotatably attached.

[0173] When the shroud (12) is lowered into the shroud inlet (9i), the shroud adapter (140n) and the base adapter (140b) engage with each other. The coupling and locking of the shroud adapter and the base adapter can be achieved in different ways. The fastening hook (107) can be self-engaging. The inclined surface (112) of the fastening hook (107) slides on the retaining peg (109) so that the fastening hook (107) catches the retaining peg (109).

[0174] Alternatively, the base adapter (140b) may be rotated so that the retaining pegs (109) are placed between the securing hooks (107) when the ladle (103) is lowered, and then when the base adapter (140b) is rotated, locking of the retaining pegs (109) within the securing hooks (107) is achieved.

[0175] Once Fig.13 With the connection shown in , the ladle (103) (with the shroud (9) suspended therefrom) can be lifted to be inserted into the second mould in order to perform a second casting using the same shroud.

[0176] In another embodiment of the ladle / long shroud coupling mechanism (140), the retaining device of the base adapter (140b) includes one or more retaining pegs (109), and the shroud adapter (140n) includes a snap-on coupling element configured to interact with the one or more retaining pegs to reversibly lock the short long shroud (9) to the shroud (12) in a locked position.

[0177] The nozzle adapter (140n) may be in the form of a sleeve-like member that may be configured as a snap-on coupling element at one and / or both ends. The nozzle adapter (140n) may surround the nozzle and be releasably attached to the ladle bottom plate (105), such as Fig.12 and Fig.13 For example, at one end, the nozzle adapter (140n) may be configured as a snap ring (106) that engages a corresponding structure at the ladle floor.

[0178] In an embodiment of the ladle / shroud coupling mechanism according to the present invention, the base adapter and / or the nozzle adapter is rotatable around the longitudinal axis to at least allow the base adapter and the nozzle adapter to disengage by rotating the base adapter or the nozzle adapter around the longitudinal axis.

[0179] In the casting apparatus according to the present invention, the seat member (15) of the mold / shroud coupling mechanism (14) is configured to receive the base adapter (140b) and hold the short shroud (9), wherein the short shroud (10) is inserted into the hole (7). The base adapter (140b) is preferably fixed to the short shroud (9) using an adhesive material (113), such as Fig.12 and Fig.13 . Preferably, the outer wall of the shroud base (11) may have the shape of a truncated cone; thereby forming a shoulder (23) that rests on the binder material (113) and is retained therein. The binder material may be a filler or compact of molding sand and may preferably contain a binder (organic or inorganic). The base adapter may be designed as a sleeve-like element.

[0180] Preferably, if Figure 2 As shown in (2a) & (2), the casting apparatus according to the present invention allows the ladle to be connected to the short shroud (9) in situ, that is, when the short shroud is inserted into the hole (7) of the sand casting mold. Figure 2 (1a), a separate station for attaching the short shroud to the ladle is not necessary. First, the short barrel (10) of the short shroud (9) is inserted into the hole, and then the ladle is lowered along the Z axis to engage the shroud in the shroud opening (9i), as described above with reference to Figure 1 (1a) & (1) explained, and can start casting. Figure 1 In contrast to the embodiment of the present invention, when the shroud (12) engages the long shroud opening (9i), the base adapter and the long shroud adapter (140b, 140n) can lock with each other to clamp the short long shroud (9) to the shroud (12). At the end of the casting operation, when the ladle is driven upward and away from the sand casting mold (2), the short long shroud (9) does not remain in the hole (7), but is clamped to the shroud and withdrawn with the ladle, ready for use in a new sand casting mold (2) in the next casting operation. This operation can be repeated as long as the short long shroud (9) is in good operating condition. When it is worn and must be discarded, the short shroud is removed and discarded. A new short long shroud (9) can be inserted into the next sand casting mold for the next casting operation.

[0181] In the prior art, the so-called Harrison process proposed by Harrison Steel Castings involves attaching a fused silica shroud below the nozzle of a bottom pouring ladle. The mold is provided with a side riser for receiving the shroud. A pouring well is provided below the side riser, which feeds into the casting cavity. With the shroud attached, the ladle is aligned on the mold and then lowered to insert the shroud into the side riser. The stopper rod is then moved into an open position so that the molten metal contained in the ladle flows through the nozzle and the shroud into the mold. Once the mold is filled, the stopper is closed. The ladle is lifted until the shroud leaves the mold and then moved over the next mold to repeat the process. In order to attach the shroud below the nozzle of a bottom pouring ladle, the ladle is first fixed in an attachment station and then the shroud is fixedly attached to a shroud support assembly, which is connected to the ladle bottom plate.

[0182] One disadvantage of said rigid and fixed attachment of the shroud to the nozzle is that it is almost impossible to clean the nozzle by means of an oxygen lance. Since the material chosen for the shroud is fused silica, inserting the shroud into the side standpipe of the mould while being attached to the bottom of the ladle is a difficult and critical operation, since even the slightest tilt of the shroud may lead to the destruction of the shroud. When the ladle is moved around the workshop and the shroud protrudes from its bottom, it is advantageous to use a short shroud (9).

[0183] Method without using ladle / shroud connection mechanism (140)

[0184] The utility model also relates to a method for casting molten metal using the casting device according to the utility model. Figure 1 In the first embodiment of the method shown, the casting apparatus does not include a ladle / shroud coupling mechanism (140). Before the ladle approaches the mold, the short barrel (10) of the short shroud (9) is inserted into the hole (7), wherein the shroud base (11) sits on the seat member (15). In use, the Z axis is substantially vertical. The short shroud (9) can be moved by an operator (e.g. Figure 1 (1a) or by using one or more special tools or robots to insert into the mold (2). Figure 5 and Figure 6 As shown, the shroud base (11) sits on the seat member (15) and the short tube (10) is inserted into the hole (7), wherein the downstream end (10d) of the short tube (10) is located at a certain distance from the shell inlet (6i).

[0185] exist Figure 1 After step 1a in the above, the mold assembly is ready to receive molten metal. Figure 1 Steps (1)2(2) and Figure 7a As shown, a ladle (103) loaded with molten metal is brought above a first sand casting mold (2) equipped with a short shroud (9) (e.g., using a crane), wherein the shroud (12) is aligned with the shroud inlet (9i) along the Z axis. The ladle (103) is then lowered until the shroud (12) engages the shroud inlet (9i), as shown in FIG. Figure 1 (2) and Figure 7b The short shroud (9) is brought to the shroud casting position by moving it along the Z axis by a distance |h0-h1| or by applying a load along the Z axis to the flexible element (17) of the mold / shroud coupling (14) or by actuating a lifting mechanism to lift the short shroud into close contact with the shroud (depending on the type of mold / shroud coupling used).

[0186] When the short shroud (9) is in the shroud casting position and in close contact with the shroud, metal can be cast into the mold, such as Figure 1 (3). The sprue is opened, thereby allowing molten metal to flow from the ladle (103) through the sprue (12), the short sprue (9) and the shell (6) of the first sand mold to the casting cavity (3). Once the casting cavity is as shown in FIG. Figure 1 Once filled as shown in (3) & (4), the nozzle can be closed to stop the flow of molten metal, and the ladle can be retrieved and ready to be moved to the next mold to start a new casting operation, such as Figure 1 (5) & (1). The short shroud (9) remains inserted in the hole (7), is not clamped to the ladle, and remains inserted in the hole (7) of the first mold.

[0187] Breaking up sand casting molds to remove cast metal parts, e.g. Figure 1 (6). The mold / shroud connection mechanism (14) is also recovered for further use with a new mold. If the mold / shroud connection mechanism includes a lifting mechanism or an elastic element, it can be directly reused without any further operation. If the flexible element is a plastic element or a viscoelastic element, it may be necessary to replace or reshape the flexible element (17) before reusing the mold / shroud connection mechanism.

[0188] The ladle can be used for subsequent casting into a second mould, e.g. Figure 1 As shown in (5)&(1).

[0189] Method using a ladle / shroud connection mechanism (140)

[0190] exist Figure 2 In the second embodiment of the utility model shown, the casting equipment includes a ladle / long shroud coupling mechanism (140). The shroud (12) is provided with a shroud adapter (140n), and the short long shroud (9) equipped with a base adapter (140b) can:

[0191] ·As reference Figure 1 The embodiments described and Figure 2 (2a) is inserted into the hole (7), or the short shroud can be

[0192] ·like Figure 2 (1a) and fixed to the nozzle (12) by an operator or robot as described above.

[0193] Move the ladle (103) with or without the short long nozzle (9) so that the nozzle (12) is located above the hole entrance (along the Z axis), and lower the ladle so that

[0194] The shroud (12) engages the shroud inlet (9i), while the shroud adapter (140n) clamps the base adapter (140b), such as Figure 2 (2a) & (2), or

[0195] Lower the shroud (12) with the short shroud (9) locked in place to insert the short cylinder (10) into the hole (7) until the shroud base (11) sits on the seat member (15) of the mold / shroud coupling mechanism (14), as shown Figure 2 As shown in (1)&(2).

[0196] At this stage, the short shroud (9) can be moved to the shroud casting position, wherein the shroud inlet (9i) is in close contact with the nozzle (12) and the downstream end (10d) of the short sleeve (9) is at a distance (d710) from the shell inlet (6i) without the short sleeve. If the mold / shroud coupling mechanism (14) includes a flexible element (17), this is achieved by applying a load along the Z axis using the nozzle (12) and the ladle (103) to lower the seat member (15) and the short shroud (9) by a distance (h0-h1). If the mold / shroud coupling mechanism (14) includes a lifting mechanism, this is achieved by activating the lifting mechanism (e.g., by rotating the seat member (15) (=inner collar) on the inclined surface of the base member (16) (=outer collar)) to lift the short shroud (9) by a distance (h1-h0).

[0197] like Figure 2 (3), the sprue is opened, thereby allowing molten metal to flow from the ladle (103) through the sprue (12), the short sprue (9) and the shell (6) of the first sand mold (2) to reach the one or more cavities (3). When the one or more cavities (3) are filled with metal, as shown in FIG. Figure 2 As shown in (4) & (5), the shroud is closed and the ladle can be removed by lifting the ladle (103) away from the mould along the Z axis. Since the short shroud (2) is locked to the shroud (12), the short shroud (9) is removed from the hole (7) and removed with the ladle, ready for the next casting operation or, if worn, ready to be discarded.

[0198] like Figure 2 As shown in (6), when the metal solidifies, the sand casting mold (2) can be broken to remove the metal parts. The mold / long nozzle connection mechanism (14) is recovered and, if necessary, can be reused together with a new sand casting mold (2) after replacing or reshaping the deformed plastic element or viscoelastic element. The new sand casting mold can be used for the new metal casting method according to the utility model (see Figure 2 (1) or (2a)).

[0199] Figure 2 It shows how easy it is to move a ladle (103) around a workshop with the short shroud (9) locked to the nozzle (12), as opposed to a ladle that is attached to a long shroud instead. Both the mould / shroud coupling mechanism (14) and the short shroud (9) can be recycled and reused for multiple other casting operations, significantly reducing process costs.

[0200] List of Reference Numerals

[0201] 1 Casting equipment

[0202] 2 Sand casting mold

[0203] 2a Upper part of the mold

[0204] 2b Lower part of the mold

[0205] 3 Cavity

[0206] 4 cavity entrance

[0207] 5 Feed channel

[0208] 6 Housing

[0209] 6i Shell inlet

[0210] 6o Shell outlet

[0211] 7 holes

[0212] 7c Tightening section

[0213] 7m Second lining material

[0214] 7s lining

[0215] 8 Upper surface of the mold

[0216] 9 Short shroud

[0217] 9i Long shroud inlet

[0218] 9L Short shroud liner insert

[0219] 9g Integral gasket for liner insert

[0220] 9o Long shroud outlet

[0221] 10 Short tube with long shroud

[0222] 10d Downstream end of short tube

[0223] 11. Long shroud base

[0224] 12 Water outlet

[0225] 13 Feeder sleeve

[0226] 14 Mould / shroud connection mechanism

[0227] 15 Seat Component

[0228] 16 Base member

[0229] 17 Flexible elements

[0230] 17s Coil Spring

[0231] 18 Arm

[0232] 19 Centering pin

[0233] 20 Central hole in base member

[0234] 21 Sleeve

[0235] 22 Filling

[0236] 23 Shoulders

[0237] 103 Ladle

[0238] 105 Ladle bottom plate

[0239] 106 Clip ring

[0240] 107 Fastening hook

[0241] 109 Keep Pegs

[0242] 111 Bolt

[0243] 112 Inclined Surface

[0244] 113 Adhesive materials

[0245] 114 Support surface

[0246] 115 Slanted Edge

[0247] 140b Base Adapter

[0248] 140n nozzle adapter

[0249] aa=d10 / d10L

[0250] d7 hole length along the Z axis

[0251] d9 Length of the short shroud along the Z axis

[0252] d9L The length of the long shroud along the Z axis

[0253] d10 The axial length of the short tube along the Z axis

[0254] d10L The length of the major axis along the Z axis

[0255] d11 Base height along the Z axis

[0256] d11a Height of the cylindrical part of the shroud base along the Z axis

[0257] d11b Height of the frustoconical part of the shroud base along the Z axis

[0258] d710 Distance between the shell inlet (6i) and the downstream end (10d) of the short tube (10) in the long shroud casting position, excluding the short tube

[0259] Dh hydraulic diameter = 4A / P

[0260] Dhi Dh of the long shroud inlet (9i)

[0261] Dhix Dhix = Dhi = 2tw (where tw = wall thickness)

[0262] Dh10 Dh of the hole in the short tube (10)

[0263] Dh10x Dh10x = Dh10 = 2tw, where tw = wall thickness

[0264] kk=d710 / s7

[0265] tw short shroud wall thickness

Claims

1. A set of components for casting molten metal, the set of components comprising a short shroud (9), a sand casting mold (2) and a mold / shroud connection mechanism, wherein: The short submerged nozzle (9) includes: · A submerged nozzle base (11) attached to the proximal end of the short tube (10), the short tube having an axial length d10 measured along the Z-axis, and the short submerged nozzle having · A submerged nozzle hole extending along the Z-axis from a submerged nozzle inlet (9i) opening at the submerged nozzle base (11) to a submerged nozzle outlet (9o) opening at the downstream end (10d) of the short tube, wherein the sand casting mold includes: · A casting cavity (3) having a cavity inlet (4), · A housing (6) selected from a filter housing and a diverter housing, the housing having a housing outlet (6o) in fluid communication with the cavity inlet (4) and a housing inlet (6i) in fluid communication with the following, · A hole (7) extending along the Z-axis between a hole inlet opening at the upper surface (8) of the sand casting mold and a hole outlet opening at a downstream end at the level of the housing inlet (6i), the downstream end including a hole constriction (7c), wherein, · The hole constriction (7c) forms a hole contraction portion defining the hole outlet, the hole outlet opening into the housing (6), wherein the hole diameter decreases by at least 10% in the flow direction along the Z-axis, wherein the mold / submerged nozzle coupling mechanism (14) includes: · A seat member (15) configured to receive the submerged nozzle base (11) and hold the short submerged nozzle (9) in a submerged nozzle casting position, wherein the downstream end (10d) of the short tube (10) is inserted into the hole (7), characterized in that the axial length d10 of the short tube is shorter than the hole length d7, i.e., d10 < d7, such that in the submerged nozzle casting position, the downstream end (10d) of the short tube is spaced from the housing inlet (6i) by a distance d710 excluding the short tube, the distance d710 excluding the short tube being proportional to the hole length d7 by a proportionality factor k, i.e., d710 = k d7, wherein the proportionality factor k is at least 20%, i.e., k ≥ 0.2, and wherein the penetration depth d7 - d710 of the short tube (10) in the hole (7) in the submerged nozzle casting position is at least equal to 3 cm, and wherein the mold / submerged nozzle coupling mechanism (14) includes: · A base member (16) fixed relative to the upper surface (8), · A seat member (15) configured to receive the submerged nozzle base (11) and hold the short submerged nozzle (9) in the submerged nozzle casting position, wherein the base member (16) and the seat member (15) each include a central hole that is aligned with each other to define an introduction portion toward the hole (7) for the submerged nozzle (9), and wherein the seat member (15) is connected to the base member (16) by at least one flexible element (17), so that the seat member (15) is separated from the base member (16), and when a load parallel to the Z axis is applied to the seat member (15), the seat member can move from a seat rest position to a seat casting position relative to the base member, and the load is applied to the seat member to deform the at least one flexible element (17), thereby driving a short shroud (9) seated in the seat member (15) to reach the shroud casting position, Wherein, the flexible element (17) comprises one or more elastic elements, and the one or more elastic elements comprise a spring extending between the seat member (15) and the base member (16).

2. The kit of parts according to claim 1, wherein: The scaling factor k is at least 35%, ie k ≥ 0.

35.

3. The kit of parts according to claim 1, wherein: The penetration depth d7-d710 of the short tube (10) in the hole (7) at the shroud casting position is at least equal to 5 cm.

4. The kit of parts according to claim 1, wherein: The penetration depth d7-d710 of the short tube (10) in the hole (7) at the shroud casting position is at least equal to 10 cm.

5. The kit of parts according to claim 1, wherein: The spring is a coil spring (17s).

6. The kit of parts according to claim 1, wherein: The mould / shroud coupling mechanism (14) comprises at least three elastic elements extending between the seat member (15) and the base member (16), wherein the at least three elastic elements are spaced apart around the circumference of the central holes of the seat member (15) and the base member (16).

7. The kit of parts according to claim 6, wherein: The at least three elastic elements are at least three coil springs (17s).

8. The kit of parts according to claim 6, wherein: The at least three elastic elements are equally spaced around the circumference of the central apertures of the seat member (15) and the base member (16).

9. A kit of parts according to any one of the preceding claims, wherein: The hole (7) is defined by a wall which is lined (7s) over at least a portion of the hole length d7.

10. The kit of parts according to claim 9, wherein: The wall of the hole (7) is lined (7s) over the entire hole length d7.

11. The kit of parts according to claim 9, wherein: The lining material is selected from any one of clay clinkers consisting of high temperature fired clay, sand core material or cellulose material.

12. A sand casting mold assembly, characterized in that: The sand casting mold assembly comprises a short shroud (9) and a sand casting mold (2) as claimed in any one of the preceding claims, wherein the shroud base (11) of the short shroud (9) is seated on the seat member (15), wherein the short barrel (10) of the short shroud (9) is inserted into the hole (7), and the downstream end (10d) is spaced apart from the shell inlet (6i).

13. The sand casting mold assembly according to claim 12, wherein: The mold / shroud connection mechanism (14) is configured as follows: In the seat rest position, the downstream end (10d) of the short tube (10) is maintained at a distance greater than the short tube-free distance d710 from the housing inlet, and maintaining the short shroud in the shroud casting position at the seat casting position when a load parallel to the Z axis is applied, wherein the downstream end (10d) of the stub (10) is spaced from the shell inlet by a distance substantially equal to the distance d710 without the stub.

14. A casting device, characterized in that: include: A short shroud (9) and a sand casting mould (2) according to any one of claims 1 to 11, a ladle (103), the ladle comprising a nozzle (12) arranged at the base of the ladle (103) for diverting molten metal out of the ladle, wherein the shroud (12) is configured to reversibly and sealingly engage into the shroud inlet (9i) of the short shroud (9), and wherein the ladle (103) is configured to be displaced relative to the sand casting mould (2) so that o positioning the shroud (12) above the mould / shroud coupling mechanism (14) in substantial alignment along the Z axis, and ○ Lowered along the Z axis until the shroud (12) engages in the shroud inlet (9i) of the short shroud (9) in the shroud casting position, wherein the downstream end (10d) of the short tube (10) is located outside the shell inlet (6i) and is separated from the shell inlet by the distance d710 excluding the short tube.

15. The casting device according to claim 14, characterized in that The casting apparatus comprises a ladle / shroud coupling mechanism (140), the ladle / shroud coupling mechanism being configured to reversibly clamp the short shroud (9) to the shroud (12), wherein the ladle / shroud coupling mechanism (140) comprises: o a base adapter (140b) fixed to the shroud base (11) of the short shroud (9), the base adapter (140b) comprising retaining means, and ○ A nozzle adapter (140n), which is fixed to the base of the ladle (103) or to the nozzle (12) and is configured to engage the retaining device of the base adapter (140b) to reversibly lock the short long nozzle (9) to the nozzle (12) in a locked position.

16. The casting apparatus according to claim 14, wherein: The ladle / shroud coupling mechanism is configured so as not to form a seal between the shroud inlet (9i) and the shroud (12).

17. The casting apparatus according to claim 15, wherein: The retaining means of the base adapter (140b) comprises one or more retaining pegs (109), and the nozzle adapter (140n) comprises: a fastening hook (107) configured to reversibly engage the retaining peg (109), or A snap-on coupling element configured to interact with the one or more retaining pegs in order to reversibly lock the shroud (9) to the shroud (12) in the locking position.

18. The casting apparatus according to claim 17, wherein: The fastening hook is configured to self-engage with the retaining peg (109).

19. A casting apparatus according to any one of claims 14 to 18, wherein: By applying a load parallel to the Z-axis to the seat member (15), the downstream end (10d) of the stub reaches the casting position spaced apart from the housing inlet (6i) by the stub-free distance d710.

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