CZ83399A3 - Process of mass production of castings from aluminium alloys and apparatus for making the same - Google Patents

Abstract

A method for producing light metal alloy castings, e.g. aluminum alloy is characterized by the fact that it includes the following steps: preparation of the mold (10) with the stamp mark (11a, 11b) made of physically treated sand; a movable closure device (31) in a mold near the inlet mold channel (22) and mold placement so that the inlet channel found at the bottom; inlet channel connection foty a tube (20) for filling the mold with the molten alloy below pressure; filling the mold with a metal alloy; before the start of solidification casting the shutters (31) in motion for closing the inlet channel and further rotate the mold by about 180? for in order to ensure the solidification of the metal in the gravitational mode

Description

Technical field

The invention relates to a new process for the production of aluminum alloy castings and to an apparatus for carrying out this process.

BACKGROUND OF THE INVENTION

The steady increase in aluminum consumption in the automotive industry requires the development of new processes tailored to the need to minimize manufacturing costs, mass production (several hundred thousand castings per year for each product type), and ultimately production of optimal quality castings, increasing geometry complexity castings, regulations limiting the pollution of the environment, where these demands lead research to systematic lightening of castings, their maximum compactness, optimal performance and integration of functions.

These qualities depend both on the metallurgical aspects (namely, the search for the best technical characteristics for the finest casting microstructure and the cleanest possible structure in the stressed zones), as well as the dimensional aspects (especially the dimensional accuracy of all casting dimensions, critical to vehicle performance) .

Certainly, there are a number of suitable processes for producing automotive castings. However, none of these processes seems to yet include a combination of properties that fully satisfies these requirements.

Methods of casting into metal molds, particularly gravity casting and low pressure casting, are certainly economically efficient and provide high metallurgical and dimensional quality. However, they are not suitable for the production of castings with complex shapes.

In these cases, the inner shapes are produced using a core of chemically treated sand. These methods are suitable only when it is possible, after opening the mold, to remove the finished castings as quickly as possible and to insert new cores into it. This means that the molding sequence must remain relatively simple, which proves to be incompatible in certain situations, for example in the case of engine blocks or cylinder heads where · * · Π * π π π π π π π π π π

Up to twelve cores need to be placed in the correct position (and over a complicated path), which takes a lot of time.

There are procedures known as sand packing, especially those developed by Co. Cosworth Castings, where these processes were developed to meet the above requirements. These processes have proven to be very costly since they require the use of a large amount of chemically treated sand. In addition, the Cosworth process requires the use of special zircon type sand instead of conventional quartz sand used in foundries, which also leads to high production costs. In addition, these processes do not allow metallurgical quality to be achieved by using metal component molds that allow the solidification of the aluminum alloy in the most critical zones of the mold to be accelerated as much as possible.

There is also a process called lost foam that can cope with the constraints that result from geometric complexity and mass production. The level of metallurgical quality obtained by this process is below that of the standard casting standard in metal mold (gravity or low pressure casting), making it an unsuitable process, especially for very stressed castings.

SUMMARY OF THE INVENTION

The present invention aims to alleviate the limitations of the prior art and to provide a casting process that better satisfies market requirements, especially the automotive industry, and which would remain economically viable in practice.

Another object of the present invention is to provide a casting process that uses, at least to some extent, physically treated sand, or fresh (raw) sand that does not present any particular problems (and does not affect the environment) as recycled chemically of sand. The present invention, in accordance with a first aspect, provides a process for casting a light alloy casting, for example an aluminum alloy, and is characterized in that it comprises the following steps:

- preparation of the mold with the emblem bed of physically treated sand,

- including a movable closure in the mold near the inlet channel of the mold,

- placing the mold in a position where the inlet channel is at the bottom of the mold,

- connecting the mold inlet channel to the pressurized molten alloy fill tube,

- filling the mold with said alloy,

- prior to any substantial solidification of the casting, closing the inflow channel by means of the movable closure, further rotating the mold by approximately 180 ° to ensure solidification in the gravity mode.

Other preferred (but not limiting) aspects are the following:

- further measures are taken, between the mold filling step and the solidification step, to ensure that the lower part of the mold is closed and the mold is separated from the mold filling tube by the molten alloy,

- the closing step takes place less than 10 seconds after the filling step has been completed,

- the mold turning step is completed no more than 25 seconds after the mold is closed,

- the mold turning step is completed within a maximum of 15 seconds, preferably 5 seconds, after the mold has been closed.

- the mold turning step is completed within a maximum of 15 seconds, preferably 5 seconds, after the filling step has been completed,

- this process uses a mold made of quartz sand with a particle size of at least 40 AFS, preferably at least 55 AFS, or at least 80 AFS, where the particle size gives the surface excellent properties,

- the mold is formed from two frame halves, wherein the mold preparation step comprises the steps of casting two halves of the die stamp features in the two frame halves, placing the cores in both mold halves with the stamp features facing upward, and assembling the two frame halves,

- the step of assembling the two frame halves to form the mold in a horizontal position, the step further comprising a step that comprises tilting the mold to a generally vertical filling position,

- the cores are made of chemically treated sand,

- the cores are made of quartz sand with a particle size of at least 40 AFS,

- the solidification of the casting is followed by a step of separating the casting from the mold, the sandy beds of the stamp and core characters being treated separately,

- before the mold filling step, a solid cooling element (cooler) is inserted into the mold, at a distance from the filling area, and after solidification, the cooling step is restored to its original state.

According to a second aspect, the present invention provides a device for casting a light alloy casting, for example aluminum, characterized in that it comprises:

99

9 9 9 i 9 9

999 999

9

99

-499 · ♦ • · 9 ♦ 99

9 9

9 9

9 ·

- a mold which can be turned upside down by rotating about a substantially horizontal axis, the mold comprising an inlet channel for filling the mold with the molten alloy, and further comprising means for closing said inlet channel,

- a mold handling device, said handling means rotating it about a horizontal axis, and further comprising means for activating the shutters.

Preferred aspects are:

- the mold handling device (handling device) has means for progressively moving the mold in the direction of movement of the tube to fill the mold with the molten alloy.

- the handling device is able to move the mold by rotating it about a horizontal axis between the initial position, after leaving the assembly station, and the casting position,

- the handling device is able to move the mold about a vertical axis to be coupled, by means of a conveyor, to a low-pressure casting furnace comprising said filling tube, and is further able to move said mold by means of a conveyor,

According to a third aspect of the present invention, there is provided a mold for casting a light alloy casting, for example an aluminum alloy, which mold is provided with a molten alloy inlet channel under pressure, the mold being characterized in that it is assembled such that it can rotate about a horizontal axis, and in this way it can be turned upside down after filling, and further comprising means for mechanically closing the inflow channel.

Nonetheless, the following are the optional aspects that are preferred:

- the mold comprises at least one mold stamp feature made of physically treated sand, and wherein said sealing means comprises a metal plate included in the mold stamp feature guided by said means,

- the mold comprises a blind hole which ends at the level of one edge of said metal plate, said hole accommodating a rod for activating said plate,

said plate comprises at least one projection which fits into the opposite mold stamp in the initial position.

»* 99 99 99

9 9 9 9 9

998 9 9 9 9

99,999,999

9

99 99 99

Overview of the drawings

Other aspects, objects, and advantages of the present invention will become apparent upon reading the following detailed description of an illustrative embodiment, by way of example and by way of illustration in the drawings, in which:

Fig. 1 shows a perspective view of the mold and its cores to be used in the process of the invention during the assembly step; Fig. 2a shows the mold components to be assembled in an enlarged side view; Figs. 2b and 2c show the assembled mold. 3a to 3e show five successive steps of the casting process according to the present invention; figs. 4a to 4d show four successive steps that realize the fastening of the closing device in the mold; Fig. 5 is a perspective view of a region of the closure device in the situation shown in Fig. 4a; Figs. 6a to 6c show a front view of an item of a mold handling device that can be used in the process of the present invention during three consecutive phases; Figures 7a and 7b show a side view of the device of Figures 6a to 6c in two sequences 8a to 8c show a plan view of the device of FIGS. 6a to 6c and 7a and 7b and associated items over three successive phases.

DETAILED DESCRIPTION OF THE INVENTION

Giant. 1 shows a mold 10 whose mold stamp features are formed by physically bonded sand, which does not contain a thermally or chemically treated resin, wherein 1

fresh sand is preferred.

It should be noted that the fresh sand is cost per unit weight 10 to 15 times lower than the cold sand of the flask type, moreover, this type of sand does not cause recycling problems or adversely affect the environment, as is the case with chemically treated sands.

d • ·

9 9 9 9 9 9 »« «« «« «9 9 9 9 9 9

9

This sand is used in a frame, i.e. essentially in a two-piece mold 10a and 10b, which consists of two frame halves 17a, 17b, each half of the frame comprising half of the stamp feature 11a, 11b obtained by conventional fresh sand mold making technology. and using the model.

Prior to closing the two frame halves together, each frame half is placed on the conveyor C in an open state, with the stamped feature facing upwards to facilitate mold assembly, which means placing the various cores and liners (core set 13 and individual secondary cores 12). ) intended to obtain the internal shapes of the casting produced. In the example shown, this is an engine block.

Said cores can be handled manually if they are smaller cores 12, or robots operating in series at a particular workstation (in the case of a core set of cores 13) can be used. Cores made of chemically treated sands (preferably of the cold flask type or Isocet sand) are preferred. For reasons of cost, quartz sand of S1O2 with particle sizes of about 55-60 AFS and above is preferred, with the best surface is obtained using the largest AFS particles).

FIG. 2 shows a main set of cores 13 having, in this example, in addition to the various chemical sand cores 131 forming the desired geometry, metal liners 132 designed to form cylinder liners and a solid metal cooling block 16 (coolers), as will be discussed later. Such a cooling block may be included in the core set 13 at the time the cores 131 are manufactured to keep the cores with the coolant together.

When the cores are fixed, the two frame halves are assembled so that the upper frame half, originally located next to the lower frame half with the upwardly stamped stamp, rotates 180 ° (see position in Fig. 2a) to fit the lower frame half includes position markers.

Figs. 2b and (2c) show the position of the mold K) at the time of the filling phase, the example shown relates to the engine block.

The low pressure filling takes place via the filling heads 14, the inlet channel 22 being located at the bottom of the mold. The flow direction of the liquid metal is indicated by arrows R1.

It should be noted that in this case gravitational loading was excluded due to the risk of turbulence and oxide formation. This is because the oxide in the fill system would in this case get into the casting where it would remain permanently.

On the other hand, the use of low-pressure filling allows perfect control of the filling operation without the occurrence of turbulence, while low-pressure filling from the outset provides t 99 9 9 9 9 9 9 9 9

9 9 9 99

9 · 9 9 9 9 9 999 99 9

9 9 9 9 9 9

9 99. The correct temperature gradient in the casting and in the mold, with the filling heads 14 representing the hottest region immediately after filling.

A practical low-pressure filling operation is by shifting the sand mold 10 towards the immersion tube (not shown in Figure 2a), which is connected to a sealed conventional low-pressure furnace. After this operation, the movement of the metal and control of the metal flow is initiated by pressurizing the furnace. An electromagnetic pump can also be used for this purpose.

An advanced feature of this process, according to the present invention, is the use of a mechanical device to close the filling system immediately after the filling is completed and before the mold is rotated 180 °. The purpose of this rotation is to bring the filling heads to the upper position and to begin to set under the same conditions as those which exist during gravity filling.

The rotation must take place as soon as possible after closing the filling system. The tests carried out may demonstrate that if too long a time has elapsed since the filling system has been closed and the mold has been turned upside down, the casting will exhibit defects in the form of wrinkles or voids, which means that the casting cannot be used. The defects can be explained by initial solidification in the coldest areas of the mold before the upside-down.

When casting castings, such as parts of the engine block or cylinder of an automobile engine, the rotation must take place within 15 seconds, preferably within 5 seconds after completion of the closing operation,

The closing itself is carried out as soon as possible after the filling has been completed, in order to avoid wasting time and to prevent initial hardening in the inlet channel. It is best if the closure occurs at most 10 seconds after completion of the filling, although exceeding this time limit may not damage the casting.

Mechanical closing of the inlet before turning the mold has many advantages.

Firstly, this allows immediate pressure release and rotation of the casting which is no longer loaded by fluid pressure. This avoids the need to use a complex rotary seal on the sand mold.

In addition, mechanical closing in all situations guarantees that the flow of liquid metal stops immediately. If the pressure is released after the rotation has ended, the metal will continue to flow from the filling heads towards the filling circuit. Since the natural stopping of the flow takes a long time, usually about 10 seconds to several tens of seconds, this necessarily causes a delay in detaching the mold from the filling dip tube, and further requires sliding the liquid metal container under the mold and below its path leading to the next station. Spilled metal is permanently lost.

• * 99 99 99 • 9 9 9 9 9 9 9 9 9 • 9 9 99 9 9 9

9 9 9 9 9 9 9 999

9 9 9 9 9 9 9 _g_ * ·· ··· ·· · ♦ «« ··

Conversely, the closure device of the present invention allows the metal to remain in the mold and to be fully involved in the process (increasing the volume of the filling heads).

In practice, the closing operation can be accomplished by activating a metal flap located in the sand mold, which will be described in detail later (guillotine system), or other mechanical solution that would fulfill this function.

Giant. 2c shows the position of the mold 10 after it has been rotated through 180θ, and where the engine block to be manufactured is designated BM. Arrows F2 indicate the main collection of the cooling process, which cooling is essentially via a fixed cooler 16 located at the bottom.

More generally, the process of the present invention comprises one or more coolers located on opposite sides of the cooling head system, said coolers being assembled during a series of operations to assemble a main set of chemically bonded sand cores 13.

In the example of the cooler 16 in Figs. 1, 2a to 2c, it is possible to accentuate the thermal gradient that controls the hardening towards the filling heads.

In practice, these coolers consist of a cast iron block or other material that has the ability to absorb heat. These blocks may also have a shape that would partially correspond to the shape of the casting being produced.

Preference is given to refrigerators made in one piece. They can be placed in the core sleeve where they are used to produce chemically treated cores, and can also be placed in the core sleeve while the core sand is sprayed and treated with resin.

After hardening of the casting in a vertical position with the cooler at the bottom and the filling head at the top of the mold (Fig. 2c), the two-half frames are turned back to the horizontal position (flat) so that the separating gap is in horizontal position. The two mold halves are then carefully separated from each other. The casting is gripped by a coolant (s) and a chemically treated core system, for example by means of a robot, and the casting is further cleaned, for example by brushing, to remove remnants of physically and chemically treated sand from the casting.

Removing and separating both types of sand allows minimizing recycling costs.

In addition, the cooler or coolers 16 to be reused are restored to their original state at this stage of handling.

The casting is further subjected to conventional procedures, for example, it is stripped of sand residue, polished, heat treated, mechanically machined, and subjected to inspection cycles.

···

4

4 4 4 «« * 4 4

4 44

4 4 4 4 4 4 4 4 4 4

FIGS. 3a to 3e illustrate a process according to the present invention according to which shutters marked with reference numeral 30 (to be described later) are inserted in the liquid metal inlet channel 22 to be connected to the immersion tube 20.

The shutters 30 are first opened and the feed tube 20 is connected to the mold 10b by moving the mold in the direction of arrow F3 (FIG. 3a). More specifically, through the aperture 21 in the mold frame, the fill tube 2θ comes into contact with the physically treated sand of the mold. Low-pressure filling follows (Fig. 3b). The caps are moved to isolate the mold cavities now filled from the filling system (arrow F4 in Fig. 3c), followed by the separation of the dip tube 20 from the mold 10 in the direction F5 (Fig. 3d). Finally, the mold is turned upside down about the horizontal axis A (arrow F6 in Fig. 3e).

Alternatively, rotation about the A axis can be initiated immediately after closing and during furnace decompression. This allows even the last alloy droplets to solidify within the dip tube 20 during the rotation step without having to rotate under pressure, which is a critical step due to the tightness of the contact surfaces between the fill tube 2θ and the fresh mold sand. This alternative also allows a slight increase in production in this process.

It should be noted here that disconnecting the filling system from the mold as soon as possible makes it possible to increase production, and to connect the filling system to the other mold as quickly as possible.

Figures 4a to 4d illustrate an embodiment of the closure 30. The closure 30 comprises a small metal plate 31, made, for example, of steel or cast iron, having a thickness of about 2 to 5 mm and inserted into a single stamp of fresh sand mold (in this case 11b). during its manufacture, so as to be aligned in line with the metal inlet channel 22. At the end facing the inlet channel 22, the plate 31 has two transverse projections 31a that facilitate its placement at the time of manufacture of the mold half 11b, as well as better guidance. plate during its movement to the closing position. For this reason, the opposing features of the stamp 1fa have two additional cavities 33 into which the projections may engage during assembly.

The use of fresh sand for stamp features allows the closure to be manufactured without difficulty, while the flexibility of the fresh sand allows the plate 31 to move as long as it remains thin enough without damaging the mold.

Fig. 4a shows the construction of the stamp feature 11b with the sample plate PM, wherein the stamp feature comprises a closure plate 31 and two projections 31a.

Fig. 4b shows a method of assembling the two mold halves, and further the ends of the protrusions 31a that fit into opposing features.

Fig. 4c shows the cavity 34 formed in the feature of the stamp 11b, in which the rod 216 and the ram head 216a are inserted to perform the action on the plate 31, after

4 * · ·

4 ♦ ·

4 • · 4 4 · · ·

• ·

The purpose of closing the inlet channel 22 before the closure. The bottom of the cavity ends at a small distance from the end of the plate 31 opposite the inlet opening.

Fig. 4d illustrates a situation in which the ram, by means of a rod 216 and head 216a, pushes against the plate 31 and locally forces fresh sand to form a closure.

6a to 6c show an example of a mold handling device item EQ comprising a main stand 100 with a movable frame 106 mounted on a base plate via a shaft 104 so as to be able to rotate about a vertical axis B as a carousel by an electric motor.

Mounted on the frame 106 is a secondary stand 200 that receives and rotates the mold as will be discussed later.

The secondary stand includes a frame 202 that is mounted to rotate, for example, about the gear 108, the rotation about the horizontal axis A being effected by a suitable electric motor (not shown).

The mold 10 is fitted into this frame 202 so that its inlet channel 22 is oriented outwardly and is located between the pressure plate 204 which is compressed by the ram 208 and the support plate 210. Guide rollers 206, 212 defining bearing surfaces in different directions allow the mold 10 to be guided and held in position by the device.

These figures also illustrate a stamper 214 and an outlet rod 216 thereof that allow the operation of a shut-off plate 31 disposed in a mold as previously described.

7a and 7b show the same device, in a side elevational view, with the furnace 300 connected to the feed tube 20. The figure shows that the secondary rack 200 is mounted by sliders 110 on the guide rails 220 attached to the main rack 106, allowing sliding. movement when the mold 10 together with the inlet channel 22 faces the filling tube 20, wherein the secondary stand can move closer to and away from the filling tube due to the action of the ram (not shown).

FIGS. 8a to 8c show a plan view of a device already described in connection with a conveyor C on which the molds are assembled, a low-pressure furnace 300 and a conveyor C by which the products are transported towards the cooling station after casting and rotation.

The following is a description of the different stages of the casting operation:

First, a mold is mounted on the conveyor C, which lies in a horizontal position facing the handling device EQ into which it has been inserted, the secondary stand 200 being pre-oriented to the desired position (Figs. 6a and 8a).

0 * «0

-11 • 0 0 ♦ 0 0 • · «0

0 0

0

0

900 t

0

0

0

0 0

The EQ device rotates 90θ about the vertical axis B so that the mold is facing the furnace and at the same time, or separately, the mold rotates 90θ to assume the vertical casting position (Figs. 8b and 8b).

The mold is then moved towards the furnace 300 such that the feed tube is tightly connected to the inlet channel 22 (FIG. 7a) and the low pressure casting operation begins.

Upon completion of the casting operation, the inlet duct 22 is closed, the furnace pressure is lowered so that the metal level is below the level of the feed tube 20, the mold 10 is detached from the feed tube 20 and rotated 180θ about a horizontal axis as previously described (Figs. 6c and 7b).

Simultaneously, or separately, the rack 200 rotates 90θ about a vertical axis so as to bring the mold to a position in which it is facing the exit conveyor G (FIG. 8c) to convey the mold to the cooling station.

An example of a manufactured engine block according to the prior art method (Example 1) and an example of the same engine block produced by the process of the present invention will now be described in the following sequence.

Example 1

The 18 kg 4-cylinder in-line engine block is manufactured using the low-pressure charge system shown in Figure 2, which does not use refrigerators but uses fresh zircon type sand with 113 AFS particles and the following composition (in percent / weight):

bentonite: 1.8% water: 1.5% of the balance is zircon sand.

The cores for the inner ends (small sides of the block) are made of chemically treated sand. The alloy used for casting has the following composition (in percent / weight):

Si: 8.6%

Cu: 2.2%

Mg: 0.3%

Fe: 0,4%

Mn: 0.3% balance is aluminum

The metal temperature during casting is 720θ0.

The filling operation is carried out at low pressure and takes 15 seconds.

-12 • 11 ·· · · * * · * * *

1 · · · 9 · 9 · · · · · · · 9 9 9 9

The filling system closes 2 seconds after the filling is complete.

The rotation of 180θ takes 30 seconds after the filling system is closed.

Examination of the engine block revealed a high degree of porosity (from 1.5 to 3%) for the crankshaft bearings and the presence of bubbles and cavities in the casting, which may occur up to one centimeter, which is completely unacceptable for this type of casting.

Example 2

The same engine block is produced using a quartz fresh sand mold with a particle size of 55-65 AFS and with the same bentonite and water concentration as in Example 1. The inner and end cores are made of chemically treated sand as in Example 1. The closure operation begins 2 seconds after filling.

The 180θ rotation starts 1 second after closing and lasts 4 seconds. It is preferable to decompress the low pressure furnace which is used to fill the mold with liquid metal during the rotation phase.

Examination of the block shows that there are no defects, bubbles and cavities, and that the alloy structure (using a cooler) in the crankshaft bearings is intact (less than 0.5% porosity).

The present invention is by no means limited to the embodiments set forth and shown herein, those skilled in the art will readily understand how various variations and modifications may be made in accordance with the principles of the present invention.

φ φ ·· φ φφ * φ φφ φ

-13 • «φ φ φ Φ Φ Φ Φ Φ ·

Claims (19)

· Λ · φφφ «φ ΦΦ φ * ΦΦ PATENT CLAIMS A process for casting a light alloy casting, for example an aluminum alloy, is characterized in that it comprises the following steps consisting of: - preparation of a mold (10) with stamp mark (11a, 11b) made of physically treated sand, - the inclusion of a movable closure (31) in the mold near the mold inlet channel (22), the mold placement being aligned so that the inlet channel is located at the bottom, - connecting the mold inlet channel to the tube (20) to fill the mold with the molten alloy under pressure, - filling the mold with said alloy, - before the casting begins to solidify, the shutter (31) is moved to close the inflow channel, the mold is rotated by approximately 180θ to ensure solidification in the gravity mode. The method of claim 1, wherein the closing step is performed less than 10 seconds after the filling step has been completed. Method according to claim 1 or 2, characterized in that the rotation step is completed at most 25 seconds after the closing step has been completed. 4. The method of claim 3, wherein the rotating step is less than 15 seconds after the closing step has been completed. Method according to one of claims 1 to 4, characterized in that the mold is made of quartz sand with a particle size between 40 and 55 AFS. The method of claim 5, wherein the mold is made of quartz sand having a particle size of at least 80 AFS. Method according to one of claims 1 to 6, characterized in that the mold consists of two frame halves (10a, 10b) and in that the mold preparation comprises the steps of casting two halves of the stamp feature in the two frame halves, positioning the cores (12, 13). into two halves of a frame with stamped characters facing up, and from step assembly of both frame halves. The method of claim 7, wherein the step of assembling the two frame halves results in a mold placed in a horizontal position, and further comprising the step of deflecting the mold to a generally vertical filling position. Method according to any one of claims 7 and 8, characterized in that the cores (12, 16) are made of chemically treated sand. Method according to claim 9, characterized in that the cores (12, 13) are made of quartz sand with particles of at least 40 AFS. Process according to any one of claims 8 to 10, characterized in that it comprises, after starting the solidification of the casting, a step of separating the casting from the mold, wherein the seals of the stamp and the core can be restored separately. Method according to any one of claims 1 to 11, characterized in that it further comprises, prior to the mold filling step, the step of placing at least one cooler (16) in a mold area remote from the mold filling area, and coolers) to their original condition. 13. Apparatus for casting light alloy castings, for example aluminum alloys, comprising: - a mold (10) which can be turned upside down by rotating about a horizontal axis and which comprises an inflow channel 22 serving to supply molten alloy, and which comprises means for closing said inflow channel (31), - a ZEQ mold-handling device capable of rotating the mold about said horizontal axis and comprising means (214,216) for activating said closure. Device according to claim 13, characterized in that the mold handling device (EQ) comprises means for moving the mold in the direction of the pipe (20) in order to fill the mold with the molten alloy. -15 • · 4 4 4 4 4 4 4 ·· 4 4 4 444 444 4 4 4 4 4 44 Apparatus according to any one of claims 13 to 15, characterized in that the handling device can also move the mold about a horizontal axis, between an initial position when leaving the mold assembly station, and a casting position. Apparatus according to one of claims 13 to 15, characterized in that the handling device can also move the mold about a vertical axis in order to lay the mold on a conveyor (C) which transports the mold to a low-pressure casting furnace (300) connected to a feed tube (20). /, and use the / C> / conveyor to take it outside. A mold (10) for casting light alloy castings, for example, an aluminum alloy, is provided with an inflow channel (22) for filling the molten alloy under pressure, said mold being characterized in that it is mounted to it could rotate about the horizontal axis (A) so as to be able to rotate upside after filling, and further comprising means (30, 31) for mechanically closing said inflow channel. A mold according to claim 17, characterized in that it comprises at least one stamp feature (11b) made of physically treated sand, and further that the mechanical seals comprise a metal plate (31) included in the stamp feature and guided directly by said feature. A mold according to claim 18, characterized in that it comprises a blind hole (34) which terminates in line with the metal plate in which the rod (216) serving to activate said plate is accommodated. Mold according to any one of claims 18, 19, characterized in that said plate (31) has at least one guide extension (31a) which, in the initial position of the plate, fits into the opposite feature of the mold stamp (11a). C * ř < • « FIG.1 'fV HW-MS FIG.2b FIG.2c