Apparatus and a procedure for shot-hood cleaning during the production of casting molds or core packets that are ready for casting

An apparatus for cleaning shot hoods during the manufacture of casting molds or core packets that are ready for casting, by means of core shooters or shooting stations, preferably in a linear arrangement, the core shooters in each instance incorporating a shot hood (3) that comprises a shot plate (1) and shot nozzles (2), it being possible to uncouple the shot hood (3) from the core shooter and lay it on a pallet (4) or the like with the shot nozzles (2) pointing downward, characterized by a delivery system (5), a transfer station (6), an emptying station (7), a flushing system (8), a drying system (9), an exit station (10), optionally an inspection station, and a removal system (11), the shot hood (3) that has been laid upon the pallet (4) being moveable from the core shooter to the transfer station (6) by means of the delivery system (5), it then being possible to raise it from the pallet (4) by means of a first manipulator (12) and pivot it through approximately 180.degree. about a horizontal axis (13) and then move it with the shot nozzles (2) pointing upward to the emptying station (7), in which it is emptied, to the flushing system (8), the drying system (9), and then to the exit station (10) where it is pivoted through approximately 180.degree. about a horizontal axis (13), when, with the shot nozzles (2) directed downward, it can be positioned upon a clean pallet (4) and then returned, optionally through the inspection station, by the removal system (11) to the core shooter or to a tool store.

BACKGROUND OF THE INVENTION 
The present invention relates to an apparatus for cleaning shothoods during 
the production of casting molds or core packets that are ready for 
casting, by means of core shooters or shooter stations that are preferably 
arranged in line, each of the core shooters incorporating a shot hood that 
comprises a shot plate and shot nozzles, it being possible to uncouple the 
shot hood from the core shooter and lay it on a pallet or the like, with 
the nozzles pointing downward. In addition, the present invention relates 
to a procedure for using the apparatus according to the present invention. 
In principle, the present invention relates to the field of casting 
technology. In order to cast shaped pieces, casting cores are in most 
instances manufactured in separate parts, combined, and then joined 
together to form a casting mold or a core packet. Then, in order to 
produce, for example, metal work pieces, these core packets are filled 
with molten metal, whereafter, in series production, the core packets that 
are to be filled with molten metal pass through the production line lined 
up one behind the other. 
Apparatuses to manufacture core packets of the type under discussion herein 
are already known from numerous publications. Solely as an example, 
reference is made herein to DE-OS 23 04 564. Also known from practice is 
the fact that the cores that are to be joined together to form a core 
packet are produced in a production line with a series of core shooters or 
shooting stations that incorporate a plurality of shot hoods, when the 
core packet has an additional core added to it at each shooting station 
that incorporates a shot hood. To this end, the cores are laid on a 
transit element that passes through the individual shooting stations when, 
in most instances, this transit element simultaneously serves as the tool 
lower section of the first shooting station. 
The sand that is used to shoot the cores or to make up the core packets is 
always mixed with binding agent, this causing on the one hand, 
considerable soiling of the tools--the tool upper section with the ejector 
blade and the tool lower section--and, on the other hand, the shot 
hoods--shot plates and shot nozzles. Accordingly, in addition to the 
tools, the shot hoods also have to be cleaned from time to time and to 
this end removed from the shooting stations and replaced. In the event 
that the type of core to be shot is changed, there will also be a tool 
change as well as a hood change so that the shot hoods that have been 
replaced will also have to be cleaned. Practice has shown that such a 
shot-hood change or the subsequent cleaning of the shot hoods is always 
problematic if fully automatic manufacture and thus fully automatic 
shot-hood cleaning is attempted. On the one hand, manipulation of the shot 
hoods is problematic and, on the other hand, the cleaning has to be 
carried out as quickly as possible, despite complicated handling 
procedures, although this has to be done without contaminating the 
environment with the core sand that remains in the shot hoods. 
For this reason, it is an object of the present invention to provide an 
apparatus of the type described in the introduction hereto, and an 
appropriate procedure, by which rapid and at the same time fully automatic 
shot-hood cleaning is made possible while avoiding environmental 
contamination. 
SUMMARY OF THE INVENTION 
The above and other objects and advantages of the present invention are 
achieved by the provision of an apparatus and method for cleaning shot 
hoods of the type comprising a shot plate and shot nozzles extending 
outwardly from one side of the shot plate, and which are adapted for use 
in the manufacture of casting molds or core pockets which are fabricated 
of sand and are ready for casting. The features set out in patent claim 1. 
According to this, the apparatus according to the present invention is 
characterized by a delivery system, a transfer station, an emptying 
station, a flushing system, a drying system, and an exit station, and 
optionally an inspection station and a removal system. The shot hood may 
be supported on a pallet which can be brought by means of the delivery 
system from the core shooter to the transfer station, raised from the 
pallet by means of a first manipulator and pivoted through approximately 
180.degree. about a horizontal axis and then, with the shot nozzles 
pointing upwards, emptied in the emptying station, brought into the 
flushing system and the drying system, pivoted through approximately 
180.degree. about a horizontal axis in the exit station and then, with the 
shot nozzles directed downwards, positioned on a pallet that has been 
cleaned and optionally returned via the inspection station to the core 
shooter or a tool store by means of the removal system. 
The present invention recognizes that completely automatic cleaning of shot 
hoods as part of the production of casting molds or core packages that are 
ready for casting is possible in every case if a delivery system, a 
transfer station, an emptying station, a flushing system, a drying system, 
an exit station, and optionally an inspection station and a removal system 
are provided which is to say if these, together, form the apparatus 
according to the present invention. The pallet, which is provided in order 
to avoid soiling or to avoid core sand from being scattered beyond the 
path of movement serves as a support for the shot hoods that are to be 
cleaned, the shot hoods being laid on the pallets in their working 
position, i.e., with the shot nozzles pointing downward. The shot hoods 
that have been laid on the pallets are now brought to the transfer station 
by means of the delivery system, where they are taken over by a 
manipulator, i.e., are raised from the pallet. This manipulator brings the 
shot hoods that are to be cleaned over the emptying station and rotates 
the shot hood through approximately 180.degree. about a horizontal axis so 
that, now, the shot nozzles are pointing upward and the opening of the 
shot hood is unobstructed and is directed downward. When this is done, the 
sand remaining in the shot hood is emptied into the emptying station. 
Then, the shot hood is brought to the next station by the same manipulator 
or is taken over by a second manipulator and subsequently brought to the 
next station, or, more precisely, to the flushing station. At the flushing 
station, any core sand adhering to the walls of the shot hood is blasted 
or flushed off. In the drying system that follows, the shot hood that has 
been wet by circulating water is dried. Next, using the same or a third 
manipulator, the shot hood is pivoted through approximately 180.degree. 
about a horizontal axis in the exit station so that the shot hood is then 
in the working position, with the shot nozzles directed downward. In a 
subsequent step, the shot hood is positioned on a pallet, which has been 
cleaned in a similar manner and, optionally, returned to the core shooter 
or a tool store, optionally via the inspection station, using the removal 
system. 
With respect to a particular configuration of the delivery system, it is an 
advantage if this comprise a roller conveyor in which individual rollers 
or groups of rollers are driven. Other known conveyor systems can also be 
used. 
The transfer station can be in the form of a transfer table that is 
incorporated between the roller conveyor and the emptying station. The 
manipulator that is used to grip or manipulate the shot hoods can be moved 
between the first station--the transfer station--and the last station--the 
exit station--horizontally as well as vertically. In order that it can 
rotate the shot hoods about a horizontal axis, preferably through 
180.degree., the manipulator incorporates a gripper system that can be 
rotated about a horizontal axis. This gripper system has, in its turn, 
gripper jaws that can be rotated about the horizontal, by means of which 
the shot hoods can be held, preferably on both sides. In addition, within 
the framework of a particularly advantageous configuration, the 
manipulator also incorporates a vibrator system in order to vibrate the 
shot hoods. This ensure that any sand remaining in the shot hood is 
loosened or shaken away from the inner wall of the shot hood to the 
largest possible extent. 
With respect to a particular configuration of the emptying station, it is 
an advantage if this includes a collector container for core sand as well 
as an outlet for the core sand that has been collected. The collector 
container could be configured, at least for the most part, in a funnel 
shape so that the sand that has been emptied always collects at the lowest 
point of the collector container and can thus be removed and disposed of 
without a problem. 
The next station, which is in the form of a flushing system, incorporates 
spray heads that work on the shot hood both externally and internally. On 
the one hand, a plurality of spray heads that surround the shot hood could 
be provided outside the shot hood and, on the other hand, there could be a 
type of spray head provided within the hood so as to make optimal flushing 
or spraying of the shot head possible, both inside and outside. In a 
further advantageous manner, the spray heads are supplied with circulating 
water so that the consumption of fresh water is reduced to a minimum. 
With respect to the configuration of the flushing system, it also is 
advantageous if this incorporates a drain that runs into a collector basin 
and a return that runs from the collector basin to the spray heads, so 
that the circulating water can be recirculated. To this end, the collector 
basin in its turn incorporates at least a pump and a filter system to 
filter the circulating water. In the case of the filtering system, this 
can be a mechanical filter, for example, or a membrane-type filter. The 
drying system that follows the flushing system serves to dry the shot 
hoods that have been wetted with the circulating water and incorporates at 
least one fan to air-dry the shot hoods. In the event that a plurality of 
fans is provided, these can be positioned both outside and inside the shot 
hood so that drying can be effected both on the inside and on the outside. 
In a further advantageous manner, the air-drying is carried out at 
approximately 55.degree. C. In place of a single drying system, a total of 
two drying systems could be incorporated, these following each other in 
series in order that no super-critical cycle time is caused by the drying 
process. 
In order to provide a simple support or rest for the shot heads, both the 
flushing system and the drying systems incorporate framework or supporting 
elements. These framework or supporting elements are arranged and 
dimensioned in such a way that the shot hoods can be accommodated or held 
reliably and without the need for any particular centring operations, with 
the shot nozzles directed upward. 
With respect to effectively avoiding any unnecessary damage to the 
immediate environment around the systems described above, it is of a 
particular advantage if the flushing system and/or the drying systems can 
each be covered or closed off by means of a covering cowl. In order to 
permit loading or unloading the systems in question, it must be possible 
to remove the covering cowl as quickly as possible and close it prior to 
the beginning of the working process so that it is largely sealed. To this 
end, the covering cowls are articulated on pivot arms that are associated 
with the particular system, and can be operated or pivoted by means of a 
cylinder-piston arrangement. In other words, each of the covering cowls is 
operated by a special manipulator. The covering cowls can be pivoted out 
of the way to one side of the conveyor system for the shot hoods, so that 
they do not cause any interference. With respect to a particularly simple 
and, at the same time, space-saving checking of the shot hoods that have 
been cleaned, it is an advantage if the inspection station is associated 
with the exit station, especially since the actual cleaning process has 
already ended at that point. The inspection station that follows the 
drying system would serve to provide a visual check by an operator. In a 
particularly advantageous manner, and in particular with respect to 
completely automated cleaning and monitoring, the inspection station could 
preferably comprise sensors, preferably of the non-contact type, in order 
to provide for non-contact scanning of the surface of the shot hood. This 
sensing could be effected, for example, by visible light, by means of 
ultrasound, or by using induction processes. 
With respect to the pallet that remains once the shot hood has been raised 
into the transfer station, and with respect to a particularly simple 
cleaning of these pallets that are contaminated with sand, within the 
framework of a first alternative, these pallets could be moved to a 
separate pallet-cleaning path. This pallet-cleaning path could comprise a 
dedicated conveyor system, a pallet manipulator, and an emptying station, 
with the pallet being pivoted through approximately 180.degree. about a 
horizontal axis by means of the pallet manipulator, and then emptied in 
the emptying station with the load-bearing surface facing downward. The 
dedicated emptying station provided for the pallets could also incorporate 
brushes for brushing away any sand adhering to the load-bearing surface of 
the pallet. 
With respect to an alternative configuration that is advantageous with 
respect, on the one hand, to requiring little space and, on the other 
hand, with respect to a smaller outlay for apparatus, the manipulator that 
is used to manipulate the shot hoods could also serve to pick up the 
pallets that remain on the transfer table once the shot hoods have been 
lifted. These pallets would then be taken by means of this manipulator to 
the same emptying station that is used to empty the shot hoods, where 
they, too, would be emptied. In order to provide for particularly simple 
cleaning of the pallets, this emptying station could also incorporate a 
brush, which is preferably moveable, in order to brush off the pallets. 
The brush could be moved, once again, by means of a cylinder-piston 
arrangement, so that the brush can move back and forth. 
In a particularly advantageous manner, the pallets that have been cleaned 
could be brought back to the transfer table by means of the manipulator 
and moved from there to the removal station and thus serve to receive the 
shot hoods that have been cleaned after the shot-hood cleaning process. To 
this end, the transfer table of the transfer station would be in the form 
of an elevator table, preferably as a scissor-leg elevator table. A return 
track that takes over the cleaned pallet from the transfer table in its 
lowered position and which leads to the exit station could be arranged 
beneath the delivery system that serves to deliver the soiled shot hoods 
on the pallets. The arrangement of the delivery track and the return track 
one above the other minimizes the amount of space that is required. 
The exit station that is adjacent to the last processing station, or the 
inspection station, could be in the form of a transfer table that acts 
between the last processing station, the drying system, and the return 
track, when this can be the same transfer table as the one ahead of the 
emptying station. The transfer table of the exit station could thus be in 
the form of an elevating table, in particular of a scissor-leg elevating 
table. 
In a lowered position, the transfer table of the exit station takes over 
the cleaned pallet from the return track and moves this to the exit 
station or inspection station, respectively. In a raised position, the 
shot hood that has been cleaned and which arrives there is then laid on 
the pallet or taken over by this so that the shot hood that has been 
cleaned and that is lying on the pallet can be moved off directly to the 
core shooter or a tool store on a removal track lying in the plane of the 
raised or lowered position. The removal system also incorporates a roller 
conveyor in the same way as the delivery system described heretofore. 
The shot hood that has been laid on the pallet is moved from the core 
shooter to the transfer station by means of the delivery system. There, 
the shot hood is raised from the pallet by the manipulator and brought 
into the area above the emptying station. At this point, the shot hood is 
pivoted about a horizontal axis through approximately 180.degree. in order 
to empty the shot hood that has its shot nozzles directed upward into the 
emptying station. Subsequently, the shot hood is moved into the flushing 
system by means of the manipulator and is flushed or blasted, this being 
done when it is sprayed or blasted with circulating water, both inside and 
outside. In a subsequent process step, the shot hood is moved by the 
manipulator into the drying system where the circulating water that is 
wetting its surfaces is removed. In the following process step, the shot 
hood is brought to the exit station, which optionally serves as the 
inspection station, and there pivoted about a horizontal axis through 
approximately 180.degree. by means of the manipulator so that the shot 
nozzles are once again directed downward. Thereafter, the shot hood is 
laid on a pallet that has been cleaned and made ready in the exit station 
and returned on the pallet--on the removal system--to the core shooter or 
to a tool store. With respect to particularly effective cleaning of the 
shot hoods, it is a great advantage if these can be placed in the flushing 
system by the manipulator with the shot nozzles directed upward. However, 
when this is done, it must be ensured that the shot hoods are blasted or 
sprayed on the inside as well. The arrangement of the shot hoods selected 
here is retained in the subsequent drying system so that the circulating 
water that is wetting the shot hoods can drip off without restriction. 
With respect to effective cycling times, two shot hoods are dried 
simultaneously in two drying systems, in which connection the shot hoods 
and/or pallets can be cleaned in two or several parallel lines that 
incorporate apparatuses according to the present invention. 
The cleaning of the pallets that has been described heretofore with respect 
to the apparatus can be completed in two alternative process steps. On the 
one hand, after the shot heads have been raised, the pallets could be 
moved to a separate pallet-cleaning path. There, the pallets would be 
pivoted horizontally through approximately 180.degree. by means of a 
pallet manipulator and, with the load-bearing surface facing downwards, 
could be emptied in a dedicated emptying station. Within the emptying 
station, the sand adhering to the load-bearing surface could be brushed 
off by brushes. The cleaned pallet could then be moved to the exit station 
and used at that point to accommodate the cleaned shot hoods. 
Alternatively, and with respect to a particularly small space requirement, 
the pallet that remains on the transfer table after the shot hood has been 
lifted could also be gripped by the manipulator and moved to the emptying 
station used to empty the shot hoods so that it, too, can be emptied. The 
pallet that has been cleaned could be returned to the transfer table by 
means of the manipulator and moved from there to the exit station, where 
it could be used to receive the cleaned shot hood. In any case, what is 
important here is that the manipulator picks up a shot hood and a pallet 
in turn, so that the manipulation and cleaning of the shot hood and the 
pallet take place in an alternating sequence. A plurality of manipulators 
could be provided without any problem so that simultaneous manipulation of 
both shot hood and pallet is made possible. 
The return track that is arranged beneath the delivery system and which 
leads to the exit station takes over the cleaned pallet from the transfer 
table when this is in its lowered position and moves the cleaned pallet to 
the exit station to accept the cleaned shot hood. 
The exit station or the inspection station that is provided at that point 
could be formed between the drying system and the return track as a 
transfer table. The cleaned pallet would then be taken over from the 
transfer table of the exit station which is in a lowered position, moved 
to a return track or return system and then moved to the exit station or 
inspection station. With the transfer table in a raised position, the 
cleaned shot hood could be moved onto the pallet. The shot hood, lying on 
the pallet, would then be moved off together with the pallet to a removal 
track in the plane of the raised or lowered position, or else returned to 
the core shooter or a tool store.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The FIGS. 1 to 4 show, together, an apparatus for cleaning shot hoods 
during the manufacture of shells or core packets that are ready for 
casting, which are usually produced by means of core shooters or shooting 
stations that are in a linear arrangement. The core shooters incorporate a 
shot hood 3 that comprises a shot plate 1 and shot nozzles 2. The shot 
hoods 3 can be uncoupled from the core shooter (now shown in the drawings) 
and can be laid on a pallet 4 with the shot nozzles 2 pointing downward. 
According to the present invention, a delivery system 5, a transfer station 
6, an emptying station 7, a flushing system 8, a drying system 9, an exit 
station 10 that also serves as an inspection station, and a removal system 
11 are incorporated. With respect to the features set out above, it is 
important that the shot hood that is laid on the pallet 4 can be moved by 
means of the delivery system 5 from the core shooter (not shown in the 
drawings) to the transfer station 6, lifted from the pallet 4 and rotated 
through 180.degree. about a horizontal axis 13 by means of the manipulator 
12--with the shot nozzles 2 pointing upward--emptied in the emptying 
station 7, moved into the flushing system 8 and the drying system 9, 
pivoted through approximately 180.degree. about a horizontal axis 13 in 
the exit station 10--with the shot nozzles 2 pointing downward-and then 
positioned on a cleaned pallet 4 and returned via the inspection station 
with the removal system 11 to the core shooter (not shown herein) or a 
tool store (not shown herein). 
FIG. 1 makes it particularly clear that the delivery system 5 comprises a 
roller-type conveyor 14. The transfer station 6 is in the form of a 
transfer table 15 that works between the roller conveyor 14 and the 
emptying station 7. The manipulator 12 can move between the transfer 
station 6 and the removal station 10, both horizontally and vertically, 
which can be seen in FIG. 2. The manipulator 12 also incorporates a 
gripper system 16 that can traverse about a horizontal axis and which, in 
its turn, incorporates gripper jaws 17 that can be pivoted about a 
horizontal axis 13. 
FIG. 2 shows particularly clearly that the emptying station 7 comprises a 
collecting container 18 for core sand as well as an outlet 19 for the core 
sand 20 that has been collected. The collecting container 18 is formed in 
the shape of a funnel. 
In the same way, according to FIG. 2, the flushing system 8 incorporates 
spray heads 21 that act on the shot hood 3 both externally and internally. 
These spray heads 21 are supplied with circulating water, which is only 
indicated in FIG. 2. With respect to these details, reference is made to 
the general portion of the description. 
The drying system 8 incorporates a fan 22 for air-drying the shot hood 3. A 
total of two drying systems 9, which are arranged adjacent to each other, 
is provided. 
FIG. 2 also shows that the flushing system 8 and the drying systems 9 
incorporate frame or supporting elements 23 that are used to receive the 
shot hoods 3. These frame or supporting elements 23 serve to simplify 
positioning of the shot hoods 3 that are to be processed, so that no 
particular centring operation is required. 
FIG. 5 shows particularly clearly and in detail that the flushing system 8 
can be covered or closed off by means of a covering cowl 24. The same 
applies to the drying system 9, which is not shown in FIG. 5. The covering 
cowl 24 is articulated onto the pivot arms 25 that are associated with the 
flushing system 8 and can be activated or pivoted by means of a 
cylinder-piston arrangement 26. 
FIG. 1 shows that the inspection station, referred to heretofore, is 
associated with the exit station 10. The inspection station, which is thus 
adjacent to the drying system 9, is used to check the quality of cleaning 
as it applies to the shot hoods 3, on the one hand, and for a basic check 
of the shot hoods 3, on the other. 
In the embodiment selected here, the manipulator 12 that is shown in FIG. 2 
is also used to grip the pallet 4 that remains on the transfer table 5 
once the shot hood 3 has been lifted. The pallet 4 can be moved to the 
same emptying station 7 that is used to empty the shot hood 3 in order 
that it, too, can be emptied, and is moved by means of the manipulator 12. 
As can be seen from FIGS. 3 and 4, the emptying station 7 has an 
associated and moveable brush 27 that is used to brush off the pallet 4. 
The pallet 4 that has been cleaned in this way is returned by the 
manipulator 12 to the transfer table 15 and from there is moved to the 
exit station 10, where it is used to accept the shot hood that has been 
cleaned. 
FIGS. 1 and 2 show that the transfer table 15 of the transfer station 6 is 
configured as a scissor-leg elevator table. Beneath the delivery system 5 
there is a return track 28 that takes over the pallet 4 from the transfer 
table 5 when this is in its lowered position and which leads to the exit 
station 10. The exit station 10, or the inspection station that is 
associated with the exit station 10, is in the form of a transfer table 29 
that works between the drying system 9 and the return track 28. The 
transfer table 29 of the exit station 10, like the transfer table 15 in 
the transfer station 6, is in the form of a scissor-leg elevator table. 
The transfer table 29 of the exit station 10 takes over the clean pallet 4 
from the return track 28 when it is in its lowered position and moves this 
to the exit station 10 or to the inspection station that is provided 
there. In a raised position, the cleaned shot hood 3 is then moved onto 
the pallet 4 so that the shot hood 3 that is lying on the pallet 4 can be 
moved off or returned by way of a removal track 30 that is located in the 
plane of the raised or lowered position. The removal system 11 that 
incorporates the removal track 30 comprises a roller conveyor 31 in the 
same way as the delivery system 5. 
With respect to the procedure according to the present invention, reference 
is made to the general portion of the description in order to avoid 
unnecessary repetition. 
In conclusion, it should be noted that the preceding example of the 
teachings according to the present invention, which are referred to only 
as an example, simply explain these teachings without necessarily being 
restricted thereto.