Note: Descriptions are shown in the official language in which they were submitted.
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Accordinglv, the invention is based on the technical
problem of removing this disadvantage and creating
a straightway or multi-directional control valve of
the type mentioned at the beginning which is easy to
manufacture, simple in design and reliable in operation.
This objective has been successfully achieved owing
to the fact that the distance pieces and the control
plate are plane-parallel and each of the same thickness,
and that between the distance pieces and the cover
plates is located a lamination for forming a defined
gap between the control plate and the cover plates.
According to one design feature of the invention, the
lamination consists of an adhesive with particles of a
defined size having a maximum cross-sectional dimension
less than or equal to the requisite size of the gap between
the control plate and the cover plates, whereby the components
thus cemented together and the control plate form a proper
constructional element ready for assembly. According to a
further development of the invention, the cover plates, the
distance pieces and the control plate are all manufactured
from a ceramic material. Finally, as a further distinguishing
feature, claim is laid to a process for manufacturing a valve
in accordance with the invention, according to which process
the distance pieces and the control plate are manufactured from
one single piece which has been processed such that it is plane-
paralled and thus of uniform thickness, the distance pieces and
the control plate being subsequently separated from one another.
The lamination which forms the gap can be produced
in various ways. Coating on the distance pieces and/or
the cover plates are conceivable. In the case of a coating
on the cover plates, masks are required in the operating range
-- 2 --
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-- 3 --
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coating is applied in these areas. In the case of an ,-
alternative coating means for the distance pieces,
correlation between the control plate and the distance -
pieces which come from a common processed piece must
be ensured as the distance pieces or control plates
from other workpieces may differ considerably in
dimension, something which, incidentally, is quite
permissible. A combination of distance pieces and
control plates which were not subjected to this common i-~
process must, therefore, be avoided for the reasons
mentioned. t`
A cement layer in accordance with the invention,which -
cements the distance pieces and the cover plates
together, has proved particularly advantageous. The
cement lamination, once set, absorbs the forces
resulting from the subsequent pressure loading on the
cover plates. The resistance to pressure of these
cement laminations is quite considerable as they are
kept within the range of 0.5 - 2 microns, producing
a total gap at the controlp~e of approx. 1 - 4 microns
depending upon the~dcfincd ci~o of the particles added
to the cement. The components thus cemented together
can, if the cover plates are metallic and, at the same
time, constitute the valve body, be bolted together
after the cement has set. During the setting process,
only moderate force may be applied for displacing the
excess cement, otherwise there is the danger of the
particles being crushed. In cases where the cover
plates do not also constitute the valve body, the
cemented and proper constructional unit can be easily
inserted into a housing. The layer forming the gap
could, of course, also be manufactured by some other
method. Coatings on the distance pieces or on the
cover plates are also conceivable in the form of
chemical or electro-plating deposits, and also
deposits formed in the so-called PVD and CVD processes.
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of the control plate so that no coating is applied in these
areas. In the case of an alternative coating means for the
distance pieces, correlation between the control plate and
the distance pieces which come from a common processed piece
must be ensured as the distance pieces or control plates
from other workpieces may differ considerably in dimension,
something which, incidentally, is quite permissible. A
combination of distance pieces and control plates which were
not subjected to this common process must, therefore, be
avoided for the reasons mentioned.
A cement layer in accordance with the invention, which
cements the distance pieces and the cover plates together,
has proved particularly advantageous. The cement lamination,
once set, absorbs the forces resulting from the subsequent
pressure loading on the cover plates. The resistance to pressure
of these cement laminations is quite considerable as they are
kept within the range 0.5 - 2 microns, producing a total gap
at the control plate of approx. 1 - 4 microns depending upon the
maximum cross sectional dimension of the particles added to
the cement. The components thus cemented together can, if
the cover plates are metallic and, at the same time, constitute
the valve body, be bolted together after the cement has set.
During the setting process, only moderate force may be applied
for displacing the excess cement, otherwise there is the danger
of the particles being crushed. In cases where the cover plates
do not also constitute the valve body, the cemented and proper
constructional unit can be easily inserted into a housing.
The layer forming the gap could, of course, also be manufactured
by some other method. Coatings on the distance pieces or on the
cover plates are also conceivable in the form of chemical or
electro-plating deposits, and also deposits formed in the
so-called PVD and CVD processes.
_ 4 _ 1 ~54 10 7
A valve according to the invention of wafer construction
can, in contrast to piston valves, be simply manufactured
owing to the flat, undercut-free shape of the plates
and distance pieces, employing sintered materials
which are processed by pressing, firing and subsequent
flat working. Of particular interest in this connection
is the applicability of aluminium oxide ceramics or
other ceramics. These materials undergo little or no
wear owing to their considerable hardness, and can
be manufactured cheaply with flat surfaces of very
low peak-to-valley values. The surface quality depends
upon the required gap tolerance. Where tolerances are
close, the peak-to-valley height can be easily
maintained below Ra = 0.1 ~m. In the event that the
distance pieces and the control plate are, in accordance
with the invention, manufactured from a single piece
which has been processed for plane-parallelity with
uniform thickness throughout, the subsequent separation
of the components from one another can be carried out
by means of saws or laser cutting. No distortion of
the components will take place owing to the sintered
structure which is completely - stress-free.
A valve in accordance with the invention is, of course,
suitable for other applications apart from the hydraulics
sector. For example, applications in pneumatic systems,
and particularly high-pressure pneumatic systems is
quite conceivable. Likewise, a valve of this kind can
also be employed as a mixer valve for the sanitary
valves and fittings sector.
The drawing illustrates the subject matter in the
form of an example embodiment as a multi-directional
high-pressure gate valve, whereby:
. .. ~, . .
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Fig. 1 shows a longitudinal section of the valve,
Fig. 2 shows an enlarged illustration of a constructional
unit consisting of cover plates, distance
pieces and the control plate with a larger-
scale detail, shown in Fig. 2A.
Fig. 3 shows a section in accordance with the line s-B
of Fig. 2,
and
Fig. 4 shows a section in accordance with the line A-A
of Fig. 2.
The stationary external cover plates are designated
in the figures with 3, and the distance pieces witn 4.
As can be seen, the cover plates 3 and the distance
pieces 4 together form a receptacle chamber for a
moving control plate 5. As is particularly obvious
from the detail enlargement, a lamination 6 is located
between the distance pieces 4 and the cover plates 3
in order to form a defined gap 7 between the control plate
5 and the cover plates 3. The distance pieces 4 and the
control plate 5 were processed together in a common workpiece
for plane-parallelity, each being of the same thickness. The
lamination 6 comprises a cement with particles 8 of a defined
size, this size corresponding to the gap 7 (1.5 - 2 ~m), such
that the particles have a maximum cross-sectional dimension less
than or equal to the size of the gap 7 as shown in Fig. 2A.
The components 3 and 4 thus cemented together form, with the
control plate, a proper construction unit ready for testing and
assembly. As is fur~her demonstrated, the cover plates 3 and
the distance pieces 4 are additionally connected together by
means of centering pins 9. The distance pieces 4 and the
control plate 5 were manufactured from one single plane-parallel
piece of uniform thickness. setween the distance pieces and
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the control plate, separating grooves were preformed on the
single-piece sintered material, and the subsequent cutting
process could be carried out without great expense by means
of saws or laser cutting.
As regards the mode of operation of the embodiment
shown in Fig. 1, the following may be said:
The unit shown by way of example is a three-way brake
valve, whereby the third connection is located at
the flange face 10 on the right hand side. With the
control plate 5 in mid-position, both the high-pressure
side P and the return from the valve chamber to the
tank are shut off. If the control plate 5 is moved
to the right, the pressure medium flows into the
chamber and passes from there to the consumer. If,
on the other hand, the control plate is moved to
the left, the oil received by the consumer can be
fed back into the tank.
