EP0384870B1 - Foundry core shooter - Google Patents

Abstract

According to the invention, the foundry core shooter (1) comprises several shooting heads (203-202; 204-202). <IMAGE>

Description

• un dispositif de tir destiné au tir des noyaux,
• un moyen d'alimentation en sable destiné à fournir du sable audit dispositif de tir, et
• un moyen de support de boîtes à noyau muni d'organes de support qui peuvent recevoir simultanément plusieurs boîtes à noyau, et d'organes d'entraînement destinés notamment à amener lesdites boîtes à noyau successivement dans la zone de tir en regard du dispositif de tir.

The present invention relates to a machine for drawing foundry cores comprising in particular:

• a firing device intended for firing nuclei,
• sand supply means intended to supply sand to said firing device, and
• a means for supporting core boxes provided with support members which can receive several core boxes simultaneously, and with drive members intended in particular for bringing said core boxes successively into the firing zone opposite the firing device .

Such a machine for drawing foundry cores is described in EP-A-0 238 428. This known machine is particularly versatile and makes the production of cores relatively flexible.

Indeed, it should first of all be noted that it makes it possible to simultaneously produce different cores, so that if a part to be molded comprises several cores, the casting of the parts can begin substantially at the same time as the manufacture of the cores, while using only one machine.

In addition, this machine can be used to produce cores either in large series or in reduced series. The machine can thus be adapted exactly to the series of cores to be manufactured, which makes it possible to obtain, in each case, the lowest possible costs and production times. Indeed, in the case of mass production, it is possible to equip all the workstations of the machine with identical core boxes. The machine will thus manufacture the same core all the time. In the case of reduced series, it is possible to equip each work station of the machine with a different box. The machine will thus simultaneously manufacture several different cores, but in a smaller quantity. Any intermediate case, situated between these two extreme cases, is of course conceivable. Thus, in the case of medium series, only a few machine stations will be fitted with identical boxes. The machine is therefore, as has just been demonstrated, very flexible in use.

The object of the present invention is to make the use of this known machine or of a similar machine comprising a means for supporting core boxes provided with support members which can receive several core boxes simultaneously, and of organs of 'drive intended to bring said core boxes successively into the firing zone in particular, even more flexible, without making the construction thereof more complex and while limiting its increase in cost.

To this end, the machine according to the present invention is characterized in that the firing device comprises several firing heads which can be used interchangeably during the same production cycle and each having its own metering device, while a unit firing is common to at least some of said firing heads, and that the sand supply means also comprises several individual sand supplies intended for supplying sand to said metering devices.

Thanks to this characteristic, it is possible, during the same production cycle, to fire cores with different sands and / or to draw nuclei of very different shapes requiring sand outlet nozzles from the metering device for shooting heads of different shapes.

Being able to fire pits with different sands is extremely interesting. Indeed, in the machine of the prior art, a change of sand requires stopping the machine and cleaning the sand supply means, as well as the metering device of the firing device, which results in a time d relatively long installation. In the machine according to the present invention, on the other hand, it suffices simply to feed each core box with the appropriate firing head.

As it is moreover provided that each firing head comprises an individual metering device and that a firing unit is common to at least some of said firing heads, it is possible to obtain a relatively simple construction. Given the fact that the firing unit represents the noble element of a firing head, this also makes it possible to limit the increased cost of the machine generated by the arrangement of several firing heads.

In DE-C-31 48 461 there is described a machine for drawing foundry cores which in particular comprises a means for supporting core boxes provided with a support member having two fixings each intended to receive a single core box. This core box support member is capable of being pivoted about a horizontal axis. This known machine is moreover provided with a firing device provided with two firing tanks capable of being pivoted jointly around an axis. vertical. This known machine is finally still provided with a single sand supply. Thanks to this arrangement, it is possible to change the tooling and prepare the corresponding firing head without requiring the machine to stop. Indeed, while the machine produces cores with a tool and the respective firing head, the adjuster dismantles the tool that was used during the previous production and assembles the new tool intended to be operational for the production following that in progress . Similarly, while continuing the production in progress, the operator prepares the non-operational firing tank for the production of cores according to that in progress. Thus, when the production in progress is completed, the operator pivots the support member around the horizontal axis provided for this purpose, which has the effect of moving away from the work area the tooling just used and to set up the tools that will be used. Likewise, the operator pivots the fire tanks around the vertical axis which links them to the machine frame. In doing so, it moves the firing tank that has just been used and sets up the one that will be used. After that, the machine is again ready for operation, while the tools and the firing tank which have just been used, can be replaced, respectively prepared for the next production.

Thus, in this known machine, it is not intended that the support means for core boxes comprises support members which can receive several core boxes intended to be brought successively into the firing zone during the same production cycle. . Besides, it It is also not expected that this machine has multiple sand supplies. Finally, it is also not explained whether the two firing tanks of this machine each have an individual metering device and that a firing unit is common to these two firing tanks.

In CH-A-647 433 is described a machine for drawing foundry cores comprising a means for supporting core boxes provided with support members capable of receiving several core boxes used simultaneously during the same production cycle. This known machine also furthermore comprises a device for firing cores as well as a sand supply means intended to supply sand to said firing device. The firing device comprises two firing heads, each intended to supply a corresponding core box. The two firing heads each have their own firing unit. The metering device, on the other hand, is common to the two firing heads. This common metering device is mounted on a carriage which can, thanks to a driving device, be moved in one direction or the other along the horizontal slides. In this way, the metering device can be brought under the firing unit corresponding to the core box to be pulled, as well as under a single supply of sand.

An extremely simple embodiment of a machine for drawing foundry cores according to the invention is obtained when the common firing unit is fixed and the metering device, adapted to the core box to be drawn, is brought opposite said common firing unit by an operating device. Thanks to this feature, it is extremely easy to arrange the various sand supplies of the firing heads.

Advantageously, the various metering devices are brought opposite the common firing unit by displacement in an at least substantially horizontal plane.

According to a preferred embodiment, this displacement is a translation.

According to another additional characteristic of the invention, the metering devices, corresponding to a common firing unit, move together when the operating device brings one of these metering devices facing the common firing unit. In this case, a single operating device can control the movement of all of the metering devices corresponding to the same firing unit.

According to another additional characteristic of the invention, at least some of said metering devices, corresponding to the same firing unit, move jointly with the firing head which is operational, when the latter is moved towards or away from the core box located in the shooting area. This also greatly simplifies the construction of the machine.

According to another additional characteristic of the invention, at least some of said metering devices extend, in the position of non-use, under a supply of sand. Thus, the metering device which must be brought opposite the firing unit by the operating device, is already in place for filling before being brought opposite the firing unit. Unnecessary trips and wasted time are thus avoided.

In a particularly interesting construction, the sand supplies, intended to supply the metering devices, extend around the common firing unit.

• la figure 1 représente une vue de face schématique d'une machine à tirer des noyaux selon l'invention ;
• la figure 2 représente une vue suivant la flèche II (figure 1), partiellement en coupe, de la machine de la figure 1 ;
• la figure 3 représente une vue de face en coupe suivant III (figure 4) de la tête de gazage ;
• la figure 4 représente une vue de dessus de la tête de gazage de la figure 3, partiellement en coupe ;
• la figure 5 représente une vue de face de la tête de gazage des figures 3 et 4, en position de gazage ;
• la figure 6 représente une vue suivant la flèche VI (figure 2) du portique et du chariot du dispositif de tir ;
• la figure 7 représente le schéma du circuit hydraulique du vérin de descente et de montée du dispositif de tir ;
• la figure 8 représente une vue de face en coupe suivant VIII (figure 9) du moyen de support ;
• la figure 9 représente une vue de dessus partiellement en coupe suivant IX (figure 8) du moyen de support représenté sur la figure 8 ;
• la figure 10 représente une vue en coupe suivant X (figure 11) d'un appui de la table du moyen de support ;
• la figure 11 représente une vue suivant la flèche XI (figure 10) de l'appui représenté sur la figure 10 ;
• la figure 12 représente une vue partielle suivant XII (figure 13) partiellement en coupe des moyens de maintien des boîtes à noyau sur la table du moyen de support ;
• la figure 13 représente une vue de dessus partiellement en coupe suivant XIII (figure 12) des moyens de maintien de la figure 12 et de la table du moyen de support ;
• la figure 14 représente une vue en coupe suivant XIV (figure 1) du dispositif de tir ; et
• la figure 15 représente une vue de face partielle du dispositif de tir dans laquelle les dispositifs de dosage des têtes de tir ont été translatés.

The invention will be better understood on reading the following description of a nonlimiting exemplary embodiment made in the light of the appended drawing in which:

• FIG. 1 represents a schematic front view of a machine for drawing cores according to the invention;
• 2 shows a view along arrow II (Figure 1), partially in section, of the machine of Figure 1;
• 3 shows a front view in section along III (Figure 4) of the gassing head;
• 4 shows a top view of the gassing head of Figure 3, partially in section;
• 5 shows a front view of the gassing head of Figures 3 and 4, in the gassing position;
• 6 shows a view along arrow VI (Figure 2) of the gantry and the carriage of the firing device;
• FIG. 7 represents the diagram of the hydraulic circuit of the lowering and raising cylinder of the firing device;
• FIG. 8 represents a front view in section along VIII (FIG. 9) of the support means;
• Figure 9 shows a top view partially in section along IX (Figure 8) of the support means shown in Figure 8;
• 10 shows a sectional view along X (Figure 11) of a support of the table of the support means;
• Figure 11 shows a view along arrow XI (Figure 10) of the support shown in Figure 10;
• Figure 12 shows a partial view along XII (Figure 13) partially in section of the means for holding the core boxes on the table of the support means;
• Figure 13 shows a top view partially in section along XIII (Figure 12) of the holding means of Figure 12 and the table of the support means;
• Figure 14 shows a sectional view along XIV (Figure 1) of the firing device; and
• FIG. 15 represents a partial front view of the firing device in which the devices for dosing the firing heads have been translated.

The core pulling machine (1) of the invention comprises a support means (2) for core boxes (3; 4; 5; 6). This support means (2) comprises support members which are, in the example shown, formed by a table (7) on the upper face (700) of which the core boxes (3; 4; 5; 6). This table (7) is substantially horizontal and can rotate around an axis of rotation (8) which extends substantially vertically.

The machine (1) also comprises a gantry (9) which supports a firing device (10). This shooting device (10) can move at least substantially vertically to be approached and distant from the table (7).

The machine (1) also further includes a bracket (11) which supports a gassing head (12). This gassing head (12) can also move at least substantially vertically to be approached and away from the table (7).

The support means (2), the gantry (9), as well as the bracket (11) are linked to a base (13) which makes it possible to seal the machine (1) on the floor of a core shop.

In FIG. 1, it can also be seen that the gantry (9) also supports two hoppers (198; 199) in each of which there is a core sand reserve. The hoppers (198; 199) can be fed from the central reserve of the core shop. The base of each hopper (198; 199) is provided with a hatch (200), the opening and closing of which are maneuvered by a corresponding jack (201).

The firing device (10) firstly comprises a firing unit (202) as well as two metering devices (203; 204) which can each be brought under the firing unit (202). Each assembly (203-202; 204-202) thus forms a firing head, so that the machine shown has two firing heads. The firing unit (202), as well as the metering devices (203; 204) are known (FOMES brand for example) and are therefore within the reach of ordinary skill in the art, so that they will not be described in detail. The only special feature of the metering devices (203; 204) is that they each have a removable outlet nozzle (205; 206). In this way, it is possible to mount on each metering device (203; 204) outlet nozzles (205; 206) having an outlet orifice (207; 208) of different shape. In FIG. 14, it can be seen that the outlet nozzle (205) equipping the metering device (203) has an outlet orifice (207) having a cross shape, while the outlet nozzle (206) equipping the dispensing device metering (204) has an outlet (208) having a substantially circular shape.

The two metering devices (203; 204) are mounted on two slides (209) extending under the firing unit (202) in a plane at least substantially horizontal and parallel to each other. The two metering devices (203; 204) are additionally linked to each other by means of a connecting member (210) so that they move together along said slides (209). The translation of the metering devices (203; 204) along the slides (209) is achieved by an actuating cylinder (211) which is connected on the one hand to one (204) of said metering devices (203; 204 ) And on the other hand to a carriage (32) which supports the firing device (10) and which will be described in detail below. To this end, said carriage (32) is provided with a console (212) on which is fixed the cylinder of the actuating cylinder (211).

In Figure 1, it is very clear that the two hoppers (198; 199) surround the firing unit (202) or more precisely extend on either side of said firing unit (202). It also appears, when one of the metering devices (203; 204) extends in its operational position under the firing unit (202), that the other of said metering devices (203; 204) extends under the corresponding hopper (198; 199). In FIG. 1, the metering device (204) is shown in the operational position under the firing unit (202) and the metering device (203) in the non-use position under the corresponding hopper (198). In FIG. 15, on the other hand, the actuating cylinder (211) has translated the metering devices (203; 204) so that it is the metering device (203) which extends in its operational position under the unit of shot (202) and the metering device (204) extends under the corresponding hopper (199).

The gassing head (12) is shown in more detail in Figures 3, 4 and 5. This gassing head (12) consists of a plate (20), which has on its underside (21 ) a cavity (22). On the outer edge (23) of the lower face (21) of the plate (20), which delimits the cavity (22), a counter plate (24) is fixed. This counter plate (24) is provided with a number of holes (25) which pass through the counter plate (24) right through and which open into the cavity (22). The counter plate (24) also has on its lower face (26) a seal (27). This seal (27) has holes (25 ') which correspond to the holes (25) of the counter plate (24) and which pass through the seal (27) right through. In the plate (20) is also arranged a threaded hole (28) which passes through the plate (20) right through and which opens into the cavity (22). In the threaded hole (28) is screwed the end piece (29) of a gas supply pipe (30) which is thus fixed on the upper face (31) of the plate (20).

As said above, the firing device (10) can be approached from the table (7) by automatically adapting to the size of the core boxes (3; 4; 5; 6). To this end, the firing device (10) is mounted on the carriage (32).

The carriage (32) appears in detail in Figures 1, 2 and 6. It consists of two beams (33; 34) which are connected to each other at their upper part by two crosspieces (35; 36). Each beam (33; 34) is provided at each of its ends with a roller (37; 38). The axes of rotation (39; 40) of these rollers (37; 38) extend substantially horizontally and are contained in a plane substantially parallel to the plane (41) of the carriage (32).

Each beam (33; 34) is provided with two other rollers (42; 43; 44; 45) which extend, as visible in FIG. 6, between the rollers (37; 38). The axes of rotation (46; 47; 48; 49) of the rollers (42; 43; 44; 45) also extend substantially horizontally, but are substantially perpendicular to the plane (41) of the carriage (32).

On the lower crosspiece (36) of the carriage (32) are fixed two beams (50; 51) substantially horizontal and whose longitudinal axis extends substantially perpendicular to the plane (41) of the carriage (32). At their end remote from the crosspiece (36), the two beams (50; 51) are linked together by a crosspiece (52). The two beams (50; 51) and the cross-member (52) serve to fix the firing unit (202) on the carriage (32), so that the axis (53) of the firing unit (202 ) extends at least substantially vertically.

The two beams (33; 34) of the carriage (32) are also provided with a frame (213) comprising in particular two beams (54; 55) which extend substantially parallel to the beams (50; 51). These two beams (54; 55) support the two slides (209) of the metering devices (203; 204) of the firing device (10), which slides (209) extend substantially parallel to the plane (41) of the carriage (32).

The carriage (32) which has just been described, is guided in translation in the gantry (9) thanks to the rollers (37; 38) and the rollers (42; 43; 44; 45). To this end, the gantry (9) has two substantially vertical uprights (56; 57) which are linked together at their upper end by a crosspiece (58). The gantry (9) thus formed is fixed on the base (13).

The two uprights (56; 57) of the gantry (9) are constituted by U-shaped profiles, the open part of which is directed towards the interior of the gantry (9). These two U-shaped uprights (56; 57) serve as a guide track for the rollers (37; 38) when the carriage (32) is moved in the gantry (9). The rollers (42; 43; 44; 45) meanwhile roll on the rear wing (59) of the U-shaped uprights (56; 57) and serve to guide the carriage laterally (32). The guide tracks of the rollers (37; 38) and (42; 43; 44; 45) can advantageously be equipped with a piece of hardened steel to prevent wear.

The uprights (56; 57) of the gantry (9) also have holes (60) blocked by removable covers (61). These holes (60) allow the assembly and disassembly of the rollers (37; 38) and therefore the assembly and disassembly of the carriage (32) of the gantry (9).

The movement of the carriage (32) with the firing device (10) in the gantry (9) is effected by a jack (62) which is advantageously a hydraulic jack. This jack (62) extends substantially in the plane (41) of the carriage (32) and is fixed on the one hand to the base (13) by means of a yoke (63) and on the other hand to the lower cross member (36) of the carriage (32) by means of another yoke (64).

The supply of this jack (62) is carried out by a hydraulic circuit (620) which is shown in FIG. 7.

This circuit is supplied by a pump (65) driven by a motor (66). The pressure of the oil delivered by the pump (65) is limited by a pressure relief valve (67). The circuit then comprises a distributor (68) with its four terminals (69; 70; 71; 72), its drawer with three compartments (73; 74; 75) and its two pushers (76; 77). The terminal (72) of the distributor (68) is linked to the chamber (78) of the jack (62) on the rod side of the jack by a pipe (79) comprising a piloted non-return valve (80) and a pressure switch (81). The terminal (71) of the distributor (68) is in turn linked to the other chamber (82) of the jack (62) by a line (83) comprising a piloted non-return valve (84) and a flow regulator ( 85).

The circuit which has just been described operates in the following manner. To approach the firing device (10) of the core box to be fired, the pusher (76) of the distributor (68) is excited, which brings the compartment (73) at the terminals (69; 70; 71; 72 ). The oil supplied by the pump (65) then enters via the terminal (69), exits through the terminal (72), passes through the valve (80) and enters the chamber (78) on the rod side of the jack (62). The oil contained in the chamber (82) is discharged when the pressure of the line (79) has opened the piloted valve (84). This oil discharged from the chamber (82) of the jack (62) passes through the flow regulator (85) which regulates the speed of retraction of the jack rod (62), that is to say the speed of descent of the carriage (32) and the firing device (10).

When the firing head (203-202; 204-202) comes into contact with the upper face (300; 400; 500; 600) of the core box (3; 4; 5; 6) to be fired, its descent is stopped as well as the retraction of the cylinder rod (62) in the cylinder of said cylinder (62). As the line (79) continues to be supplied, the oil contained in it increases in pressure until it reaches the setting pressure of the pressure switch (81). At this instant, the pressure switch (81) de-energizes the pusher (76), which has the effect of bringing the compartment (74) back to the terminals (69; 70; 71; 72). In doing so, the oil contained in the chambers (78; 82) of the jack (62) can no longer circulate because it is blocked by the valves (80 and 84) and the jack (62), that is to say the carriage (32) and the firing device (10) are locked. The oil that the pump (65) continues to flow, returns directly to the reservoir (86).

After firing the core, the firing device (10) must be raised, that is to say that the rod of the jack (62) must come out of the cylinder. To do this, the pusher (77) is excited, which has the effect of bringing the compartment (75) to the level of the terminals (69; 70; 71; 72). The oil supplied by the pump (65) enters through the terminal (69), exits through the terminal (71), passes through the valve (84) and through the non-return valve (87) which short-circuits in this direction the flow regulator (85) to enter the chamber (82) of the jack (62), as soon as the pressure in the line (83) has piloted the opening of the valve (80) of the line (79) so that the oil contained in the chamber (78) of the jack (62) can return to the reservoir (86).

Thanks to this arrangement, it can therefore be seen that the firing device (10) can automatically adapt to core boxes (3; 4; 5; 6) of very different dimensions, since it is the core box itself which triggers the stopping of the descent of the firing device (10). It is also the core box which automatically locks the firing device (10) during the firing of the core. This is very important because it allows the machine to absorb the shock generated when firing the core.

We also see that the arrangement of this circuit also allows automatic unlocking of the firing device (10) before the ascent of said firing device (10).

The gassing head (12) can also be approached from the table (7) by automatically adapting to the size of the core boxes (3; 4; 5; 6). To this end, the gassing head (12) is fixed to the free end of the rod (88) of a jack (89) which is advantageously a pneumatic jack. The cylinder (90) of the jack (89) is fixed to the bracket (11). The connection between the free end of the rod (88) of the jack (89) and the gassing head (12) appears in more detail in FIGS. 3, 4 and 5. In these figures, it can be seen that the free end of the rod (88) of the jack ( 89) is screwed into a flange (91), the flange (92) of which extends substantially perpendicular to the longitudinal axis (93) of the rod (88). This flange (92) is provided with four holes (94) which are crossed by screws (95). These screws (95) are of special shape. Indeed, under their head (96), the rod of said screws (95) has a first part (97) of a certain diameter and a certain length, to which is then connected a second part (98) of a diameter smaller than the diameter of the first part (97), so that between these two parts (97; 98) there is a shoulder (99). The second part (98) of the screw rod (95) is threaded so that the screws (95) can be screwed into threaded holes (100) arranged in the upper face (31) of the plate (20), up to 'so that the shoulder (99) abuts on the upper face (31) of the plate (20). After locking the screws (95), the head (96) of the screws (95) is thus at a certain distance from the upper face (31) of the plate (20). In FIG. 3, it can also be seen that the diameter of the holes (94) of the flange (92) of the flange (91) is somewhat larger than the diameter of the first part (97) of the screws (95). It can also be seen that the thickness of the flange (92) is less than the distance which separates the lower face of the heads (96) from the screws (95) and the upper face (31) of the plate (20).

Furthermore, on the flange (92) of the flange (91) is fixed a known limit switch (101), so that the underside (102) of said limit switch (101) is slightly set back. relative to the lower face (103) of the flange (92) located opposite the upper face (31) of the plate (20).

In order to prevent the gassing head (12) from turning relative to the rod (88) of the jack (89), the plate (20) is provided with a guide (104) fixed on the plate (20) and which passes through a guide hole made in the stem (11). The longitudinal axis of the guide (104) is substantially parallel to the longitudinal axis of the rod (88) of the jack (89), that is to say substantially vertical.

The gassing head (12) and its adaptation means which allow the gassing head (12) to automatically adapt to the size of the core boxes (3; 4; 5; 6) operate in the following manner. When a core box (3; 4; 5; 6) is in the gassing position (the core box (6) for example in FIGS. 1 and 2), the jack (89) is supplied, which causes the lowering of the gassing head (12) towards the core box. When the seal (27) comes into contact with the upper face (300; 400; 500; 600) of the core box, the descent of the plate (20) stops. The cylinder (89) on the other hand continues to push on the flange (91) until the lower face (103) of the flange (92) of the flange (91) comes into contact with the upper face (31) of the plate (20). The thrust of the jack (89) on the upper face (31) of the plate (20) then compresses the seal (27) between the lower face (26) of the counter plate (24) and the upper face (300; 400 ; 500; 600) of the core box to prevent gas leakage. When the seal (27) is correctly compressed, the descent of the rod (88) of the jack (89) stops and the pressure is maintained in the jack (89) so that the seal (27) remains properly compressed throughout the gassing operation. This gassing operation only begins when the gassing head (12) is in place. It is triggered by the limit switch (101). Indeed, this detector (101) detects the upper face (31) of the plate (20) when the lower face (103) of the flange (92) of the flange (91) comes substantially close to the upper face (31) of the plate (20) (position shown in Figure 5 which shows the gassing position). Given the possible relative movement between the flange (92) of the flange (91) and the plate (20), this is effectively achieved only when the gassing head (12) is in contact with the upper face (300; 400; 500; 600) of the core box. During the approach phase, on the other hand, the detection of the upper face (31) of the plate (20) cannot take place since the upper face (31) of the plate (20) is too far from the lower face (102 ) of the detector (101) (position shown in Figure 3).

During the gassing, the gas is brought through the supply line (30) into the cavity (22) from where it is then distributed through the holes (25) of the counterplate (24) and the holes (25 ') of the seal (27) in the gas core box.

The gassing head (12) is raised after the gassing operation, the duration of which is programmed as a function of the size of the core. This programming is done on a computer (197) which will be discussed later.

Thanks to this arrangement, it can therefore be seen that the gassing head (12), as previously the firing device (10), can automatically adapt to core boxes (3; 4; 5; 6) of very large size. different since it is the core box itself which triggers the stop of the descent of the gassing head (12) and the triggering of the gassing operation.

The support means (2) is shown in Figures 1, 2, 8, 9, 10 and 11, and comprises as said above a table (7). This table (7) is preferably circular and as said above extends substantially in a horizontal plane and can rotate around a substantially vertical axis (8). The table (7) has for this purpose substantially at its center, a pivot (105) which extends downwards and whose longitudinal axis coincides with the axis of rotation (8). The pivot (105) engages in a bearing (106) which is fixed on the base (13). The pivot (105) in the bearing (106) is guided in rotation by means of a bearing (107) which extends to the upper part (108) of the bearing (106), and to the using a rolling stop (109) extending to the lower part (110) of said bearing (106). The rolling stop (109) also maintains the pivot (105) axially downward. The bearing (106) does not extend to the lower face (111) of the table (7), so that between the upper part (108) of the bearing (106) and the lower face (111) of the table (7), the pivot (105) can rotationally support a lever (112). The lever (112) is guided on the pivot (105) by two bearings (113; 114) housed in a hub (115) which includes the lever (112). A certain distance is maintained between the lever (112) and the bearing (106) by a spacer (116). The lever (112) has two arms (117; 118), one of which (117) extends on one side of the hub (115) and the other (118) of which extends on the other side of said hub (115).

At its free end (119), the arm (117) of the lever (112) is linked to the rod (120) of a jack (121) by means of an axis (122). The cylinder (123) of the jack (121) is in turn linked in an articulated manner using a pin (124) to an upright (125) integral with the base (13).

The arm (118) supports on its free end (126) a jack (127) whose cylinder (128) is fixed on the arm (118). The free end of the rod (129) of the jack (127) is integral with a V-shaped part (130) whose V is open towards the outside. When the rod (129) of the jack (127) is out, the V-shaped part (130) collaborates with an index (131) secured to the table (7). This index (131) is constituted by a cylindrical stud which, when it collaborates with the V-shaped part (130), extends between the wings of said V. In FIG. 9, it can be seen that the table (7) has four indexes (131). It will be noted that the number of indexes (131) that the table (7) comprises, corresponds to the number of core boxes (3; 4; 5; 6) intended to be supported simultaneously by the table (7). In the example shown, the table (7) can simultaneously support four core boxes. In (132) the disassembly, the extraction of the drawn and gassed cores and the reassembly of the core boxes are carried out. (133) corresponds to an intermediate position. In (134) the core is fired and in (135) the core is gassed.

Another cylinder (136) is also provided to collaborate with an index (131) of the table (7). The cylinder (137) of this jack (136) is fixed on an upright (138) integral with the base (13). The free end of the rod (139) of said cylinder (136) also includes a V-shaped part (140) similar to the V-shaped part (130) of the cylinder (127).

The jack (127) collaborates with an index (131) to rotate the table (7) around the axis of rotation (8) while the jack (136) collaborates with an index (131) during work to block the rotation of the table (7).

The mechanism which has just been described and used to rotate the table (7) (by quarter turn in the embodiment) and to block the table (7) during work, operates as follows. The drive cylinder (127) is actuated so that the V-shaped drive piece (130) is brought together with an index (131) of the table (7). It is then the blocking cylinder (136) which is actuated to separate the V-shaped blocking part (140) from the index (131) with which it collaborated. Then it is the actuator (121) which is actuated so as to bring out its rod (120). In doing so, the rod (120) pushes on the arm (117) of the lever (112) causing the rotation of the latter around the axis (8). As the V-shaped drive piece (130) of the drive cylinder (127) collaborates with an index (131) of the table (7), the rotation of the lever (112) will also cause the rotation of the table ( 7) around the axis (8). The stroke of the motor cylinder (121) is such that the table (7) performs in the example described a quarter turn. When the motor cylinder (121) is at the end of the elongation stroke, the lever (112) is in position (112 ') shown in phantom in Figure 9. At this time, the locking cylinder is actuated again. (136) for bringing out its rod (139) so that the V-shaped blocking piece (140) of said jack (136) can be secured to the index finger (131) which was brought in front of it during the rotation of the table (7). Then actuates the drive cylinder (127) to separate it from the index finger (131) with which it collaborated during the rotation of the table (7). Finally, the actuator (121) is actuated so that its rod (120) re-enters the cylinder (123). In doing so, the rod (120) pulls on the lever (112). When the motor cylinder (121) is at the end of the retraction stroke (position in strong lines in FIG. 9), the mechanism is again ready for a next rotation of the table (7).

In FIGS. 9, 10 and 11, it can be seen that the table (7) still rests on supports (141) at least one of which extends in the zone (134) of the firing device (10) substantially in the axis (53) of the firing unit (202). This support (141) allows the table (7) to absorb the shock generated during the firing of the core. (In Figure 1, the supports (141) have not been shown so as not to clutter the figure).

In the embodiment described, the supports (141) are three in number and are located equidistant from each other. They consist of rollers (142) which are fixed to the upper part of uprights (143) integral with the base (13), as shown in FIGS. 10 and 11. The rollers (142) rotate around axes ( 144) substantially horizontal and substantially cutting the axis of rotation (8) of the table (7). In the example, the uprights (143) are formed by U-shaped profiles. Each upright (143) is provided at its upper part with a roller-bearing arm (145) which extends between the two wings (146; 147) of the U-shaped profile. At its upper end, the roller support arm (145) rotatably supports the roller (142). Between its two ends, the roller support arm (145) is provided with an oblong hole (148) which is crossed by a bolt (149). This bolt (149) also also passes through a hole (150) in the core (151) of the upright (143). At its lower end, the roller arm (145) is in contact with a screw adjustment (152) which is screwed into a nut (153) integral with the upright (143).

Thanks to this arrangement, the position of each roller (142) can be adjusted relative to the table (7). To bring the roller (142) into contact with the table (7), loosen the bolt (149), then push on the lower end of the roller support arm (145) by means of the adjustment screw (152) , which will cause the roller arm (145) to slide in the upright (143). This sliding is possible, since the hole (148) provided in the roller support arm (145) and which is crossed by the bolt (149) is an oblong hole. When the roller (142) is in contact with the table (7), it will then suffice to tighten the bolt (149) to rigidly link the roller support arm (145) to its upright (143).

Figures 12 and 13 show an embodiment of holding means (154) of the core boxes (3; 4; 5; 6). These holding means (154) hold the core boxes during work. Since they are identical, we will only describe one of them. (In FIG. 12, for the sake of clarity of the figure, only the holding devices (154) of the stations (181 and 183) are shown).

The holding means (154) comprises a jaw holder (155) which is provided with two jaws (156; 157). Each jaw holder (155) comprises a bearing (158) integral with two wings (159; 160) so that, when viewed from above, the two wings (159; 160) form a U open towards the outside. At the rear, the bearing (158) is open so as to form a clamp (161) which can be tightened by a bolt (162). The bearing (158) of the jaw holder (155) is slid over a peg (163) fixed on the upper face of the table (7). The jaw holder (155) also comprises above the bearing (158) an actuating cylinder (164) which is fixed on top of the bearing (158) of the jaw holder (155). The operating cylinder (164) is closed at its upper part (165). This closed upper part (165) is crossed by an operating screw (166) which is screwed into a threaded hole (167) arranged in the longitudinal axis of the stud (163). The operating screw (166) is linked in translation to the operating cylinder (164) and on its part which protrudes from the operating cylinder (164), an operating handwheel (168) is fixed.

The device which has just been described makes it possible to adjust the position of the jaw holder (155) and consequently of the jaws (156; 157) relative to the dimension of the core box which they must maintain. To do this, simply loosen the bolt (162) to open the clamp (161), then turn the operating screw (166) using the handwheel (168) to enter or exit the operating screw (166) of the piton (163). When the jaws (156; 157) have reached the correct position relative to the core box, it will suffice to tighten the clamp (161) by blocking the bolt (162).

Between the two U-shaped wings (159; 160) extend two slides (169; 170) on which the jaws (156; 157) can slide. Between the two slides (169; 170) extends a jack (171) whose cylinder (172) is fixed on one (156) of the jaws and whose rod (173) is fixed on the other jaw (157 ).

One (169) of the slides has a number of holes (174), into which two pins (175) can be threaded on either side of one (156) of the jaws and which will be used to link in translation one (156) of the jaws to one (169) of the slides. In this way, the core box intended for this holding means (154) will always be substantially in the same place on the table (7), that is to say advantageously centered relative to the firing head (203 - 202; 204 - 202) and at the gassing head (12).

The jaws (156; 157) are closed by operating the jack (171) so as to bring its rod (173) into its cylinder (172). This will move the jaw (157) which can slide freely on the slides (169; 170) until it comes into contact with the core box to be maintained. Maintaining the core box is achieved by maintaining, for example, the pressure in the cylinder (171).

In FIG. 13, it can also be seen that the two jaws (156; 157) are different from each other. Indeed, the jaw (157) comprises a swiveling clamping plate (176). To this end, the jaw (157) comprises a yoke (177) fixed on its connecting part (178) to the slides (169; 170). At the end of this yoke (177) is linked the clamping plate (176) by means of a ball joint (179). In this way, the swiveling clamping plate (176) can well be positioned relative to the core box if the latter does not have parallel faces. This guarantees optimal maintenance of the core box.

In FIG. 13, it can also be seen that each station (180; 181; 182; 183) is provided with an index (184; 185; 186; 187) which is fixed on the table (7). These indexes (184; 185; 186; 187) are arranged on circles (188; 189; 190; 191) of different radius and are centered on the axis of rotation (8) of the table (7). These indexes (184; 185; 186; 187) pass during the rotation of the table (7) which is always done in the same direction (192), above sensors (193; 194; 195; 196) which are fixed on the base (13) and which therefore do not rotate with the table (7). Each sensor (193; 194; 195; 196) is located at a distance from the axis of rotation (8) of the table (7) equal to the radius of the circle (188; 189; 190; 191) on which the corresponding index (184; 185; 186; 187).

The passage of an index (184; 185; 186; 187) on its sensor (193; 194; 195; 196) is transmitted to a programmable computer (197) and will indicate for example to said computer (197) the start of the cycle carried out by each core box (3; 4; 5; 6) for which the firing head (203-202; 204-202) to be used, the number of shots and the duration of gassing required.

Thus when a core box (3; 4; 5; 6) is in the zone (134) where the firing operation is carried out, the computer (197) controls the jack (211) which brings, under the firing unit (202), the metering device (203; 204) intended to supply said core box (3; 4; 5; 6) and which will have been previously supplied with sand by the hopper (198; 199) corresponding.

In the example shown, the nozzles (205; 206) of the metering devices (203; 204) have outlet orifices (207; 208) of different shape. It will however be understood that in the invention, these outlet orifices (207; 208) can be of the same shape.

Moreover, the hoppers (198; 199) may contain different sands.

These different characteristics reinforce the flexibility of the machine. Indeed, if the user has to simultaneously manufacture several cores of very different shape requiring outlet nozzles (205; 206) with different outlet orifice (207; 208), and moreover having to be produced using sands different, it will supply the two hoppers (198; 199) with different sands and mount the appropriate outlet nozzle on each of the metering devices (203; 204). If, on the other hand, the user has to manufacture several cores of very different shape, but in the same sand, he will mount on each of the metering devices (203; 204) the appropriate outlet nozzle (205; 206) and will supply the two hoppers (198; 199) with the same sand. If finally the user has to simultaneously manufacture cores of similar shape, but in different sands, he will mount the same outlet nozzles (205; 206) on the metering devices (203; 204) and will supply the hoppers (198; 199) with different sands.

It is also possible to have more than two firing heads (203-202; 204-202).

Finally, it is quite possible that the machine is equipped to support a number of core boxes other than four.

Claims (8)

1. A machine for shooting foundry cores (1) comprising particularly:

   - a shooting device (10) intended to shoot cores,

   - a sand supply device (198, 200, 201, 199, 200, 201) intended to supply sand to the said shooting device (10), and

   - a support device (2) for core boxes (3; 4; 5; 6) equipped with support means (7) which can simultaneously receive several core boxes (3; 4; 5; 6), and drive means (112, 121, 127, 130) intended particularly to bring the said core boxes (3; 4; 5; 6) successively into the shooting area (134) opposite to the shooting device (10),

   characterised in that the shooting device (10) comprises several shooting heads (203-202; 204-202) which may be utilised equally well during the same production cycle and each having its own dosing device (203; 204), while a shooting unit (202) is common to some at least of the said shooting heads (203-202; 204-202), and that the sand supply device (198, 200, 201, 199, 200, 201) also have several individual sand supplies (198, 200, 201; 199, 200, 201) intended for the supply of sand to the said dosing devices (203; 204).
2. A machine for shooting foundry cores in accordance with claim 1, characterised in that the common shooting unit (202) is fixed and that the dosing device (203; 204) adapted to the core box (3; 4; 5; 6) to be shot, is brought opposite to the said common shooting unit (202) by a manoeuvring device (211).
3. A machine for shooting foundry cores in accordance with claim 2, characterised in that the dosing devices (203; 204) are brought opposite to the said common shooting unit (202) by displacement in an at least approximately horizontal plane.
4. A machine for shooting foundry cores in accordance with claim 3, characterised in that the dosing devices (203; 204) are brought opposite to said common shooting unit (202) by translation in the said at least approximately horizontal plane.
5. A machine for shooting foundry cores in accordance with at least one of the claims 2 to 4, characterised in that the dosing devices (203; 204), corresponding to a common shooting unit (202), are jointly displaced when the manoeuvring device (211 ) brings one of the dosing devices (203; 204) opposite to the said common shooting unit (202).
6. A machine for shooting foundry cores in accordance with at least one of claims 1 to 5, characterised in that some at least of the said dosing devices (203; 204), corresponding to a common shooting unit (202), are jointly displaced with the shooting head (203-202; 204-202) which is operational, when this is displaced towards or away from the core box (3; 4; 5; 6) which is in the shooting area (134).
7. A machine for shooting foundry cores in accordance with at least one of claims 1 to 6, characterised in that in the non-use position, some at least of the said dosing devices (203, 204) extend under a sand supply (198; 199).
8. A machine for shooting foundry cores in accordance with at least one of claims 1 to 7, characterised in that the sand supplies ( 198; 199) extend around the common shooting unit (202).

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