WO2004039548A1 - Pressurized casting installation for ceramic articles - Google Patents

Abstract

The invention concerns a pressurized casting installation for ceramic articles (35) comprising two treatment stations and including a mounting frame (1); two rotary plates (3, 4), rotatable about a horizontal axis (5, 6) between: a position wherein the front surface (7, 8) is vertical and faces the central part of the installation and a position wherein said front surface (7, 8) is horizontal and faces upwards; two vertical plates (18, 19) and means (27, 28, 29) for moving same between a moulding position and a retracted position; two platforms (22, 23) bearing the male part(s) (26) of a mould; means (14, 15, 16, 17) for feeding said moulds with slip; means for eliminating water from said slip during moulding; and means for handling the articles (35) to ensure their stripping and their evacuation from the installation.

Description

 Installation for die-casting of ceramic articles.

The invention relates to the mass production of ceramic parts, such as plates, by pressure casting.

Conventionally, the manufacture of plates in small series is carried out on machines comprising a plate carrying a number of halves of female molds, against which one comes to apply another plate carrying an identical number of halves of male molds coming in correspondence with the halves of female mussels. A slip is introduced through the female mold half, and the molds are pressed against one another to carry out the molding of the slip for the time necessary for the shaping and the extraction of the humidity. Then the tray carrying the male mold half is removed and the raw molding plates are extracted from the female mold halves to be conveyed to the processing stations ensuring the following stages of manufacture.

These machines require a waiting time during the shaping phase which limits their productivity. This process is therefore only used for the small series production of articles of relatively complex shape, difficult to produce by other means.

The object of the invention is to provide manufacturers of ceramic objects produced in series by pressure casting, such as plates - (but not exclusively), an installation allowing a gain in productivity compared to existing installations.

To this end, the subject of the invention is an installation for the pressure casting of ceramic articles, characterized in that it comprises two symmetrical treatment stations and comprises: - a frame;

- two rotary plates each arranged at one end of the frame, each of which can rotate around a horizontal axis between two positions:

* a position where the front face of the rotary plate is substantially vertical and turned towards the central part of the installation; * and a position where said front face is substantially horizontal and turned upwards,

- Two plates each attached to a front face of said rotary plates or merged with them and carrying the female part or parts of at least one mold for shaping an article; - two vertical plates located in the vicinity of the central part of the frame and means for moving them horizontally in the direction of said rotary plates between a molding position and a withdrawal position;

- Two plates each fixed on a front face of said vertical plates or merged with them, and carrying the male part or parts of at least one mold for shaping an article;

- Means for supplying said molds with a slip containing the material intended to constitute said articles;

- Means for discharging water from said slip during molding of said articles;

- And means for handling said articles to demold and evacuate them from the installation when said rotary plates have their front face substantially horizontal and facing upwards.

Said means for moving said vertical plates are preferably common to said vertical plates so as to move them simultaneously.

Said displacement means are preferably such that when one of said vertical plates is in the molding position, the other is in the withdrawal position. Said means for handling the articles are preferably common to the two treatment stations of the installation.

Said handling means may comprise a rotary vertical axis located substantially in the center of the installation, a bracket connected to said axis, a support carried by the end of the bracket, one or more suction cups attached to the support intended to come to bear against the article or articles, and a suction device making it possible to create a vacuum between said suction cups and said articles.

Preferably, the female parts and the male parts of said molds each comprise a core made of a non-porous material fixed on one of the plates and a covering made of porous material, said covering being fixed to said core by mechanical means, and said means for evacuating the water of said slip during molding comprises channels formed in said cores and one or more channels formed in the plates on which said cores are fixed. As will be understood, the invention essentially rests on an installation comprising two symmetrical treatment stations, one working in molding while the other works in demolding. This is made possible by the use of trays carrying the halves of female molds which can turn a quarter turn around a horizontal axis, the molding being carried out with the trays in vertical position and the demolding being carried out with the trays in horizontal position.

The invention will be better understood on reading the description which follows, given with reference to the following appended figures: FIG. 1 which schematically shows a side view of an example of installation according to the invention;

- Figures 2 to 13 which schematically represent in perspective this installation at the various stages of its operating cycle.

The installation according to the invention shown as an example in the figure mainly comprises the following elements:

- a frame 1 (the front part of which has not been shown in FIG. 1 for clarity) supporting the functional elements of the installation,

- two rotary plates 3, 4 each located towards one end of the frame 1; these rotary plates 3, 4 are arranged so that they can each rotate around a horizontal axis 5, 6 between at least two positions, such that the front faces 7, 8 of the rotary plates 3, 4 either are substantially vertical and turned towards the central part of the installation, either are substantially horizontal and turned upwards; in FIG. 1, the rotary plate 3 is shown in the first of these positions, and the rotary plate 4 in the second;

- two plates 9, 10 each fixed on a front face 7, 8 of the rotary plates 3, 4, and on the front faces 11, 12 of which are provided for construction or removably fixed female parts 13 of molds for plates which comprise each a hollow area; as a variant, these plates 9, 10 could be merged with the front faces 7, 8 of the corresponding rotary plates 3, 4;

- Two tanks 14, 15 containing a slip constituting the raw material of the plates to be manufactured, and pipes 16, 17 bringing the slip to the control inside the hollow areas of the female parts 13 of the molds before each molding operation;

- two vertical plates 18, 19 located in the vicinity of the central part of the frame 1, movable horizontally and each carrying on their front face 20, 21 a plate 22, 23 itself carrying on its front face 24, 25 the male parts 26 of molds for plates which can be incorporated by construction into the tray or be detachably attached thereto; alternatively, these plates 12, 13 can be merged with the front faces 20, 21 of the vertical plates 18, 19; means for translational movement of the vertical plates

18, 19, preferably constituted, as shown, by a single actuator 27 and guides 28, 29, which cause the vertical plates 18, 19 to move between two positions:

* a position such that when one of the rotary plates 3, 4 has its front face 7, 8 in the vertical position, the male parts 26 of the molds carried by the plate 22, 23 of the vertical plate 18, 19 closest to the rotary plate 3, 4 penetrate into the female parts 13 of the molds carried by the plates 9, 10 of the rotary plate 3, 4 (molding position);

* and a position such that the vertical plate 18, 19 is substantially set back relative to the rotary plate 3, 4 which is closest to it (withdrawal position).

In the preferred example shown, the fact of having a single actuator 27 for the two vertical plates 18, 19 means that when one (18 in FIG. 1) is in the molding position, the other (19 in the Figure 1) is in the withdrawn position.

The installation also includes means, not shown, ensuring the evacuation of the water expelled from the material constituting the plates when the slip is pressurized.

Furthermore, the installation also includes means for handling the molded plates. In the example shown, they consist of a bracket 30 connected to a rotary vertical axis 31 located substantially in the center of the installation and enclosed in a casing 32 which also contains means for controlling the actuator 27. This bracket 30 carries at its end a support 32 to which is attached a series of suction cups 34 (not shown in Figure 1) intended to be applied by a downward movement of the axis 31 against the molded plates 35 when one of the rotary plates 3, 4 has its front face 8, 9 in a vertical position.

A suction device integrated into the casing 32, the axis 31, the bracket 30 and the support 33 makes it possible to create a vacuum between the suction cups 34 and the plates 35, so that the molded plates 35 are extracted from the female parts 13 and brought to the side of the installation to be discharged.

Figures 2 to 13 represent the various stages of an operating cycle of the installation of Figure 1: - stage 1 (figure 2): the installation is in a position where a series of plates finishes being molded between the plates 9 and 22 of the left part of the installation which are held one against the other by the actuator 27, while the plates 10 and 23 of the right part of the installation are both vertical but in their positions of maximum separation;

- step 2 (Figure 3): the actuator 26 has moved the vertical plates 22, 23 in their positions opposite to those of the previous step; the molding of the plates in the female molds 13 of the left plate 9 carried by the rotary plate 3 is completed, while the molding of the plates in the female molds 13 of the right plate 10 carried by the right rotary plate 4 can begin; for this purpose, once the position shown has been obtained, slip is introduced from the reservoir 15 via the line 17 between the male molds 26 of the vertical plate 23 and the female molds 13 of the plate 10;

- step 3 (FIG. 4): while the molding of the plates in the right part of the installation continues its course, the left rotary plate 3 is actuated so that its front face 7 is turned upwards;

- Step 4 (Figure 5): while the molding continues in the right part of the installation, the suction cups 34 take hold of the plates 35 which have just been molded in the left part; - step 5 (FIG. 6): while the molding continues in the right part of the installation, the bracket 30 is rotated to bring the plates 35 to the side of the installation, while the rotary plate on the left 3 is brought back to its vertical front face 7 position;

- step 6 (Figure 7): while the molding continues in the right part of the installation, the bracket 30 and the left rotary plate 3 have completed their movements initiated in step 5;

- Step 7 (Figure 8): while the molding ends in the right part of the installation, the plates 35 are released from the suction cups 34 on a support not shown, by cessation of the suction; - step 8 (Figure 9): the molding on the right side of the installation is now complete; the actuator 27 has, consequently, moved the vertical plates 22, 23 in their positions opposite to their previous positions to execute the molding of the plates in the female molds 13 of the left plate 9 of the left rotary plate 3; for this purpose, slip is introduced from the reservoir 14 through the pipe 16 between the male molds 26 of the left vertical plate 22 and the female molds 13 of the plate 9; simultaneously, the rotation of the right rotary plate 4 is started, the plate 10 of which carries a series of molded plates 35, and the bracket 30 is displaced so as to bring the support 33 of the suction cups 34 above the right rotary plate 4;

step 9 (FIG. 10): while the molding of the plates in the left part of the installation continues, the right rotary plate 4 completes its movement and its front face 8 is turned upwards;

- steps 10, 11 and 12 (Figures 11, 12 and _. 13): similar to what had happened during steps 5, 6 and 7, the plates 35 are extracted from the female molds 13 from the tray 10 by the suction cups 34 , moved to the side of the installation by a movement of the bracket 30 and deposited on the support, not shown; meanwhile, the molding of the plates on the left continues; then the installation is brought back to its state of step 1 shown in FIG. 2 and a new cycle begins.

The installation which has been described and shown in the figures has a high productivity, since it is possible to mold a series of plates while carrying out the demolding and unloading of another series of plates.

It is also advantageous (although not compulsory in the spirit of the invention) for the plates handling members constituted by the bracket 30, the support 33 and the suction cups 34 to be common to the two halves of the installation.

The fact that the displacement means 27 are unique and act simultaneously on the two vertical plates 18, 19 is also advantageous, in that such an arrangement is more economical than the use of means for moving the separate vertical plates 18, 19 and independent. This also makes it possible to guarantee good synchronization of the respective displacements of the vertical plates 18, 19. It would however remain in the spirit of the invention to provide such separate displacement means.

An advantage of the installation according to the invention is that the demolding operation takes place in a vertical position. This prevents the accumulation of mold water in the part during the opening of the mold.

A necessary condition for the proper functioning of the installation is that the duration of the demolding operations does not exceed the duration of the molding operations and vice versa.

For this purpose, it is advantageous to use, for the molding of the plates, pairs of half-molds with core, the cores of which intended to be fixed on the plates 1, 10, 22, 23 are made of a particularly resistant non-porous material. , such as a metal not corrodible by humidity (stainless steel, aluminum ...) and whose porous coatings (for example in polymethacrylate methyl) which are brought into contact with the slip during the pressure casting operation consist of removable elements fixed to the corresponding core by purely mechanical means (undercut means, screws, bonding ...). The channels formed in the cores ensure the evacuation of water when the slip is pressurized after this water has passed through the porous coatings. These channels open into one or more channels formed in the plates 9, 10, 22, 23 and open to the outside of the installation which are preferably connected to a suction installation to assist the evacuation of the water. This suction device can also be used to inject air into the channels if its operation is reversed. This makes it possible to clean the canals and also to assist in demolding the plates, the duration of which can be shortened. This gives more assured perfect coordination of molding and demolding operations. In this configuration, all the fluid connections are automatically made during the clamping of the molds on the plates 9, 10, 22, 23 of the machine.

The example described and shown relates to the manufacture of plates, but it is understood that the invention is applicable to the pressure casting of other types of ceramic articles. Likewise, the example was taken of an installation capable of producing a plurality of articles of small dimensions during the same molding operation, but it goes without saying that the installation could be adapted to the casting of a single large item in each of its parts. Finally, instead of a single article handling device, which can act on the two parts of the installation as described and shown, it can be provided that each part of the installation has its own handling means.

Claims

1. Installation for die-casting of ceramic articles (35), characterized in that it comprises two symmetrical treatment stations and comprises: - a frame (1); - two rotary plates (3, 4) each disposed at one end of the frame (1), each of which can rotate around a horizontal axis (5, 6) between two positions: * a position where the front face (7, 8) of the rotary plate (3, 4) is substantially vertical and turned towards the central part of the installation; * and a position where said front face (7, 8) is substantially horizontal and turned upwards, - two plates (9, 10) each fixed on a front face (7, 8) of said rotary plates (3, 4) or merged with them and carrying the female part (s) (13) of at least one mold for placing in the form of an article; - two vertical plates (18, 19) located in the vicinity of the central part of the frame (1) and means (27, 28, 29) for moving them horizontally in the direction of said rotary plates (3, 4) between a molding position and a withdrawal position; - Two plates (22, 23) each fixed on a front face (20, 21) of said vertical plates (18, 19) or merged with them, and carrying the male part or parts (26) of at least one mold for the shaping of an article (35); - Means (14, 15, 16, 17) for supplying said molds with a slip containing the material intended to constitute said articles; - Means for removing water from said slip during the molding of said articles (35); - And means for handling said articles (35) for demolding and evacuating them from the installation when said rotary plates (3, 4) have their front face (7, 8) substantially horizontal and turned upwards. 2. Installation according to claim 1, characterized in that said displacement means (27, 28, 29) of said vertical plates (18, 19) are common to said vertical plates (18, 19) so as to move them simultaneously. 3. Installation according to claim 2, characterized in that said displacement means (27, 28, 29) are such that when one of said vertical plates (18, 19) is in the molding position, the other is in position withdrawal. 4. Installation according to one of claims 1 to 3, characterized in that said means for handling the articles (35) are common to the two treatment stations of the installation. 5. Installation according to claim 4, characterized in that said handling means comprise a rotary vertical axis (31) located substantially in the center of the installation, a bracket (30) connected to said axis (31), a support (33) carried by the end of the bracket (30), one or more suction cups (34) attached to the support (33) intended to be applied against the article or articles (35), and a suction device making it possible to make the vacuum between said suction cups (34) and said articles (35). 6. Installation according to one of claims 1 to 5, characterized in that the female parts (13) and the male parts (26) of said molds each comprise a core made of a non-porous material fixed on one of the plates ((9, 10, 22, 23) and a coating made of a porous material, said coating being fixed to said core by mechanical means, and in that said means for removing water from said slip during molding comprise channels formed in said cores and one or more channels formed in the plates (9, 10, 22, 23) on which said cores are fixed.