Note: Descriptions are shown in the official language in which they were submitted.
CA 02241822 1998-06-29
Method for blowing out and cleaning recesses in at least
one workpiece
The present invention relates to a method for
blowing out and cleaning recesses in at least one workpiece,
in particular blind holes, holes, drilled holes and threaded
holes, using a gas, in particular air, which originates from
a compressed-air source, the gas being compressed to a prede-
termined pressure in at least one container.
Nowadays, cast housings, which have a multiplicity
of passages, drilled holes, blind holes, threaded holes and
the like following machining in CNC machining centers, are
cleaned. The cleaning of the workpieces is carried out by
means of washing machines that are specifically suited for
this, it being subsequently necessary, following such
cleaning, for the machined workpieces to be reworked. In
particular, precise passages, blind holes, threaded holes and
the like must be freed from contaminants and, in particular,
swarf, which cannot be removed by the washing machine.
Hitherto, such blind holes, drilled holes and
passages were cleaned of swarf and contaminants by hand by
means of compressed air and compressed-air guns. Each
individual recess had to be blown out by hand. In the case of
this conventional cleaning method, it is disadvantageous that
AMENDED SHEET
CA 02241822 1998-06-29
during the process of blowing out using a nozzle and
compressed air, a very loud noise, which is damaging to the
health of persons in the adjacent environment, is produced
and, in addition, any remaining contaminants and, in par-
ticular, swarf are shot out of blind holes, and as a result
constitute a hazard to the operator, in particular to his
eyes.
A further disadvantage is that the blowing out of
recesses, such as blind holes, threaded holes or the like,
must be carried out very carefully in order, on the one hand,
to dispense with renewed subsequent testing and, on the other
hand, not to damage parts later during the assembly or in
operation as a result of residual contaminants, in particular
swarf. It has been shown that blowing out by hand is very
costly, since each individual recess has to be blown out by
hand by means of compressed air and a gun. It is often the
case that one or another recesses are forgotten, so that when
the fault appears, a complete series has to be checked again
and reworked.
US 5,054,155 discloses a device in which a
workpiece is clamped on a wheel which travels to individual
machining stations. At one station, the workpiece is shaken,
at the next station it is blown out using a plurality of
nozzles. In this case, the nozzles are connected to a common
AMENDED SHEET
CA 02241822 1998-06-29
compressed-air supply container.
According to DE 80 19 194, a device for cleaning
workpieces is known, a plurality of nozzles projecting from a
device above a conveyor belt and being aligned with
individual depressions, drilled holes or blind holes. These
individual nozzles are fed from a compressed-air source via a
common line.
DE 25 94 805 discloses a device for cleaning blind
drilled holes, a plurality of nozzles that are arranged in a
holder being fed via a common feed line in said holder. These
nozzles are then arranged above corresponding bores of blind
holes, in order to blow out the latter.
The present invention is based on the object of
eliminating the above-mentioned disadvantages and of provid-
ing a method and a device which permit the residue-free
cleaning and, in particular, blowing out of recesses, it also
being possible for a multiplicity of workpieces and recesses
in a workpiece to be worked on. In addition, time and costs
during the cleaning and blowing out of recesses in
workpieces, in particular castings, are to be reduced con-
siderably.
This object is achieved by the gas from a single
container or a plurality of containers, which are filled and
each connected to a single nozzle, subsequently being
AMENDED SHEET
CA 02241822 1998-06-29
-3a-
expanded into a recess in the workpiece in order to remove
contaminants, in particular swarf, from the recess.
This invention permits recesses, in particular
blind holes, holes or drilled holes in castings to be blown
out using higher pressure and cleaned of swarf and
contaminants via a multiplicity of nozzles that are arranged
in a perforated metal sheet.
In order that this high pressure is available for a
multiplicity of nozzles, individual containers, particularly
containers designed as pressure containers, are filled with
gas, in particular air, and the latter is compressed. Each
container, which is filled up via a control valve, is
preferably connected to a single nozzle, via a valve that is
assigned to the container.
In this arrangement, the nozzles are inserted in
any desired manner into a perforated metal sheet, which is
arranged in a housing via columns such that its height is
adjustable. A workpiece, which has recesses, in particular
drilled holes, threaded holes or the like, can be clamped on
the perforated metal sheet by means of workpiece holders.
This workpiece is intended to be cleaned of contaminants.
In order that the nozzles and, in particular, the
nozzle attachments are aligned with the recesses in the
workpiece, they may be constructed so as to be flexible and,
AMENDED SHEET
CA 02241822 1998-06-29
--4--
preferably, able to be bent. It is preferable if materials
such as aluminum, copper or the like are used for the nozzles
or nozzle attachments. In order that the alignment of the
nozzle attachments is carried out quickly and easily, the
recesses are located with the aid of a template, following
which the nozzle attachments can be aligned to said recesses
easily and quickly.
A housing for the device preferably has rectangular
to square forms. For reasons of stability and costs, a
multiplicity of containers arranged alongside one another
form the frame of the housing, side and end walls projecting
from this frame. Toward the top, the housing is closed by a
lid, which may, in particular, have sound-insulating
materials or insulating elements on the inside. Furthermore,
four guide columns are arranged in the housing on the inside,
the perforated metal sheet preferably being arranged on these
guide columns so that it can be folded up in a manner
corresponding to the lid. A collecting tray located beneath
collects the swarf and contaminants that fall down and which,
after the perforated metal sheet has been folded up, can be
removed, for example by an industrial vacuum cleaner.
Furthermore, thought is given to constructing the guide
CA 02241822 1998-06-29
columns with the perforated metal sheet to be height-
adjustable for workpieces of different thicknesses.
However, it is also important that the housing can
be moved via rollers which, if appropriate, are arranged on
the frame in such a way that they can be rotated and fixed.
It is then possible for this device to be transported to
different machining centers and connected at any point to the
conventional compressed-air system, in order, for example, to
clean the machined workpieces, in particular castings.
A further significant advantage of the present
invention is that the device can be used universally and,
above all, can be equipped individually for all conceivable
parts.
However, it is also conceivable here for, for
example, the nozzles or nozzle attachments to be assigned to
the workpiece, in particular to the recesses of the latter,
via lateral vertical metal sheets. It is also possible for a
plurality of workpieces to be worked on at the same time, if
these are clamped on the perforated metal sheet in a
plurality of workpiece holders.
A particularly effective configuration of the
invention is provided if a plurality of control valves are
arranged on a central manifold in the interior of the
housing. It is possible for any number of containers to be
connected to each control valve, these containers being
CA 02241822 1998-06-29
filled with air via a specific valve that is assigned to the
container. Once the containers have been filled up, then on a
specific signal from the control valve the valve on the
container is opened and a connection between container and
nozzle is switched through, so that the entire compressed
content of air is abruptly output to the nozzle.
Since the individual nozzles, in particular their
nozzle attachments, are aligned toward the recesses in the
workpiece, the recesses are cleaned of swarf quickly in a
simple way. The swarf falls into the collecting tray through
the holes arranged in the perforated metal sheet. In the
tray, said swarf can then be removed.
While the containers that are connected to a
control valve are being discharged, or the air is flowing
out, it is possible for further containers that are connected
to a further control valve to be filled with air during this
time. When these containers are also filled, it is possible
for them likewise to be expanded on a further signal from the
control valve, and for the air to be abruptly output to
appropriately connected nozzles.
The advantage of the present invention is that any
number of containers can be connected to at least one or a
plurality of control valves, so that a precisely definable
and determinable number of nozzles feed air at high pressure
to the recesses abruptly and in different sequences.
CA 02241822 1998-06-29
It also lies within the scope of the present inven-
tion for a time progression or time sequence of the compres-
sion of air and discharge or expansion of the air from the
container to the nozzle to be regulated, for example via a
further control device, to which the control valves are
connected. Repeatedly charging up and outputting the air to
the individual nozzles is also possible here. This regulation
is preferably carried out pneumatically.
It is precisely in mass production that this inven-
tive device is used very economically, since the time during
which a workpiece is being machined by a machining center can
be used for the cleaning and decontamination and, in
particular, for blowing out recesses in parts already
produced.
Of course, it is also within the scope of the
invention for side parts, end walls and the lid to be lined
with insulating material, in order to attenuate machining
noises greatly.
The air discharged from the nozzles flows out
laterally and is led through the housing to the bottom, where
it emerges. Of course, it is also possible for insulating
mats and, in particular, filter mats to be provided there.
Thought should also be given here to safety mechan-
isms, so that, for example, when the lid is opened, blowing
out and expansion of air from a container or a nozzle is
CA 02241822 1998-06-29
prevented.
Further advantages, features and details of the
invention emerge from the following description of preferred
exemplary embodiments and with reference to the drawing, in
which:
Figure 1 shows a front view, illustrated schemati-
cally, of an inventive device for blowing out cavities;
Figure 2 shows a plan view of the device according
to Figure l;
Figure 3 shows a perspective illustration of the
device according to Figure l;
Figure 4 shows a block-diagram illustration of the
control of the device according to Figure l;
Figure 5 shows a block-diagram illustration of a
further exemplary embodiment of the control of the device
according to Figure 4.
According to Figure 1, an inventive device R has a
housing 1 with side walls 2, 3 and end walls 2.1, 3.1 (Fig.
2). The side walls 2, 3 and the end walls 2.1, 3.1 form a
preferably cuboidal housing 1, which can be closed at the top
by a lid 4 that can be folded open. In order that the lid 4
remains in an opened position, it is assigned at least one
gas spring 5, which at the other end is connected to the
housing 1. When the lid 4 is moved downward, it closes an
opening 6. The lid 4 can be fixed with respect to the housing
CA 02241822 1998-06-29
_ g_
1 by means of a bolt 7.
Toward the bottom, the housing 1 is opened within a
frame 8, as illustrated in Figure 3. The frame 8 comprises a
multiplicity of individual containers 9, which are connected
to one another, for example welded, and which in each case
are constructed as pressure containers. Of course, it is also
within the scope of the invention for the containers 9 to be
inserted into the housing 1 in a different arrangement. The
containers 9 are preferably constructed to be like cubes and
partitioned off from one another. They have an opening, not
shown specifically here, into which a valve 10 is inserted in
each case.
Compressed air from a compressed-air source lla is
fed to the device R from the outside via a line 11 and, as
illustrated in Figures 2 and 3, said air is led into the
interior of the housing 1 through a dewatering unit 12 and
adjacent filter 13. In the interior of the housing, the line
11 reaches a manifold 14, which distributes the air to a
plurality of control valves 15. A plurality of containers 9
are connected to each control valve 15 via valves 10.
Furthermore, each container 9 or each valve 10 is connected
to at least one nozzle 17 via a line 16.
The nozzles 17 can be inserted in any desired
manner into a perforated metal sheet 18, which is inserted
into the housing 1 in the manner illustrated. The perforated
CA 02241822 1998-06-29
--1 0 -
metal sheet 18 is preferably fixed via a hinge 19 to guide
columns 20 so that it can be folded and, at the other end,
rests on a further guide column 21 and can be fixed there by
means of a fastening element 22. In order to fold the
perforated metal sheet 18 upward, said sheet being mounted on
the guide columns 20 so that it can rotate about the hinge
19, it is necessary for the fastening elements 22 to be
released. Here, too, thought is given to holding the
perforated metal sheet 18 in an upwardly folded position,
corresponding to the lid 4, via gas springs, which are not
illustrated here.
Underneath the perforated metal sheet 18, a
collecting tray 23 is arranged in a similar way in the
housing 1. The perforated metal sheet 18 and the collecting
tray 23 are arranged on the guide columns 20, 21 so that
their height can be adjusted.
It is possible to fasten to the perforated metal
sheet 18 any number of workpiece holders 24, which are able
to hold a workpiece 25, preferably at a distance from the
perforated metal sheet 18. Via clamping devices, clamping
brackets or similar elements, not shown here, the workpiece
25 can be rereleasably fixed to the workpiece holders 24.
In order that the device R can be used flexibly
with respect to location, said device is preferably assigned
rotatable and fixable rollers 26 on the frame 8 of the
CA 02241822 1998-06-29
housing 1.
In order that the device R operates with low noise
levels, sound insulation 27, indicated by dashed lines, is
provided within the lid 4. It is also possible for sound-
insulating materials to be provided on the inside on the side
walls 2, 3 and end walls 2.1, 3.1.
The functioning of the present invention is as
follows.
Air is fed to the device R from the outside via the
line 11, the air being dewatered in the dewatering device 12
and subsequently being cleaned by the very fine filter 13.
From the filter 13, the compressed air is fed to the manifold
14 and, uniformly distributed, passed on to a plurality of
control valves 15. This can be seen, in particular, in Figure
4.
The control valve 15 is connected to a multiplicity
of containers 9 and, in particular, to their valves 10, each
valve 10 being connected in each case via a line 16 to a
nozzle 17 that is inserted into the perforated metal sheet
18. The nozzles 17 can be inserted in any desired
distribution in any holes in the perforated metal sheet 18.
The compressed air is distributed from the control
valve 15 to all the containers 9 that are connected to the
control valve 15, and is compressed in said containers, until
a specific pressure ha~ been built up. During the charging of
CA 02241822 1998-06-29
the containers 19 with compressed air, the connection between
valve 10, line 16 and nozzle 17 remains closed. When the
containers 9 have reached a specific pressure after a
specific time, then, in response to a specific signal from
the control valve 15, for example by means of a vacuum, the
valve 10 can be shut off in the direction of the control
valve 15, at the same time a connection between container 9
and nozzle 17 via the line 16 being opened and the compressed
air emerging from the nozzles 17 at a high velocity.
Since the compressed air, which is supplied via the
line 11 via a conventional compressed-air system, is not
available in such great quantities, air is compressed in each
container 9 that is connected to the control valve 15. While
air is flowing out of the container 9, via the line 16 and
out of the nozzle 17, no air is supplied to the container 9
via the control valve 15.1. In this case, while the air is
flowing out, a further control valve 15.2 is supplied with
air in a manner corresponding to that described above,
further valves 10 with containers 9 being connected to said
further control valve 15.2 and likewise being able to supply
nozzles 17 with compressed air following its compression in
the container 9.
However, it is also significant in the present
invention that the air that is compressed in the container 9
flows out of the nozzle 17 abruptly via the line 16, the air
CA 02241822 1998-06-29
-13-
being guided into recesses 29 in the workpiece 25 via a
nozzle attachment 28, if appropriate a flexible nozzle
attachment 28, which is placed onto the nozzle 17. The
blowing out of these recesses 29 is thus performed under very
high pressure using a large volume of air. If a plurality of
containers are filled with air, it is possible for a
multiplicity of recesses, in particular blind holes, threaded
holes or the like, to be freed from contaminants and, in
particular, swarf.
The alignment of the nozzles 17 and, in particular,
of the nozzle attachments 28 is carried out by means of a
template, which, for example, can be produced from Plexiglas,
on which the recesses 29 in a workpiece are drawn and with
which the corresponding nozzle attachments can then be
aligned. After this, a multiplicity of recesses 29 in a
workpiece 25 can be cleaned of contaminants in one operation.
These contaminants fall through the perforated metal sheet 29
and remain in the collecting tray 23. After the perforated
metal sheet 18 has been folded up, it is possible for swarf
and cont~;n~nts to be removed from the collecting tray 23 by
means of a vacuum cleaner or the like.
However, the scope of the invention is also
intended to include the possibility of providing lateral
perforated metal sheets, which are, if appropriate, placed
onto the perforated metal sheet 18 and in which further
CA 02241822 1998-06-29
nozzles 17 engage and, by means of nozzle attachments 28,
blow out lateral recesses 23 in a workpiece 25 in the manner
described above.
In a further exemplary embodiment of the present
invention according to Figure 5, compressed air is fed via
the line 11 to the manifold 14, from which a plurality of
control valves 15, 15.1 to 15.3 branch off. As described
above, it is possible for a plurality of containers 9 with
valves 10 to be connected to each control valve 15, 15.1 to
15.3, being connected to the nozzles 17 and, if appropriate,
nozzle attachments 28 via lines 16. As distinct from the
exemplary embodiment according to Figure 4, each control
valve 15 is connected to a pneumatic control device 30, which
regulates a series of consecutive sequences, in particular
compression of air in the containers 9 and expansion
processes of individual control valves 15, 15.1, 15.2, also
as a function of time. Thus, it is possible, for example, for
the control valve 15.1 to fill the containers 9 with
compressed air and subsequently feed the air to the nozzle 17
upon a signal. While the air is flowing out of the containers
9 that are connected to the control valve 15.1, it is
possible, for example, for further containers 9 that are
connected to the control valve 15.2 to be filled with
compressed air.
CA 02241822 1998-06-29
-15-
The duration of the filling of the containers 9 can
also be regulated by the control device 30, thought being
given to filling the containers 9 for a determinable time or
regulating a filling process as a function of pressure. These
regulating processes are preferably carried out
pneumatically, so that no power connection is necessary.
A repeated filling process of the containers 9
following expansion can also be performed by the control
device 30, as desired.
A further significant advantage of the present
invention is that any number of control valves 15, 15.1, 15.2
can be connected to a manifold 14, any number of containers 9
with valves 10 in turn being connected to said control
valves. The greater the number of containers 9 that are
connected to a control valve 15, the longer the duration of
the filling process until a spècific pressure is reached.
If, for example, workpieces 25 having only a few
recesses 29 are clamped into the workpiece holders 24, then
only a low number of containers 9 and, in particular, nozzles
17 with nozzle attachments 28 are required for blowing out
and cleaning. The workpiece 25 is processed correspondingly
quickly.
Furthermore, a plurality of workpieces 25 can also
be clamped onto the perforated metal sheet 18, a relatively
large number of control valves 15, 15.1 to 15.3 with separ-
CA 02241822 1998-06-29
ately connected containers 9 in each case being expedient for
this purpose, since, during a recharging process or
compression process, for example, a new workpiece to be
cleaned can be clamped in workpiece holders 24.
A device R, which can be adapted in a versatile
manner and form to workpieces 25 of different constructions,
in particular castings, is provided here.
