U.S. patent application number 14/926723 was filed with the patent office on 2016-05-12 for seat valve.
The applicant listed for this patent is Buerkert Werke GmbH. Invention is credited to Peter KRIPPNER, Cricia de Carvalho RODEGHERI, Ralf SCHEIBE, Stefan SEELECKE.
Application Number | 20160131275 14/926723 |
Document ID | / |
Family ID | 55803262 |
Filed Date | 2016-05-12 |
United States Patent
Application |
20160131275 |
Kind Code |
A1 |
RODEGHERI; Cricia de Carvalho ;
et al. |
May 12, 2016 |
SEAT VALVE
Abstract
A diaphragm actuator has a first frame part and a second frame
part, between which at least two diaphragm layers are disposed in a
stacked manner and formed as electro-active polymer layers.
Furthermore, a method for producing a diaphragm actuator is
described.
Inventors: |
RODEGHERI; Cricia de Carvalho;
(Mainz, DE) ; SCHEIBE; Ralf; (Kuenzelsau /
Garnberg, DE) ; KRIPPNER; Peter; (Karlsruhe, DE)
; SEELECKE; Stefan; (Saarbruecken, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Buerkert Werke GmbH |
Ingelfingen |
|
DE |
|
|
Family ID: |
55803262 |
Appl. No.: |
14/926723 |
Filed: |
October 29, 2015 |
Current U.S.
Class: |
251/129.06 ;
29/25.35 |
Current CPC
Class: |
H01L 41/293 20130101;
F16K 31/007 20130101; F16K 31/02 20130101; H01L 41/0474 20130101;
H01L 41/25 20130101; H01L 41/0536 20130101; H01L 41/193 20130101;
F16K 7/14 20130101; H01L 41/0973 20130101; F16K 25/005 20130101;
H01L 41/0986 20130101; H01L 41/083 20130101; Y10T 137/5196
20150401; H01L 41/338 20130101 |
International
Class: |
F16K 31/00 20060101
F16K031/00; H01L 41/193 20060101 H01L041/193; H01L 41/338 20060101
H01L041/338 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 7, 2014 |
DE |
102014116295.1 |
Claims
1. A diaphragm actuator which has a first frame part and a second
frame part, and having at least two diaphragm layers which are
disposed in a stacked manner and formed as electro-active polymer
layers and are arranged between said first frame part and said
second frame part.
2. The diaphragm actuator as claimed in claim 1 wherein said
diaphragm layers are arranged so as to be immediately adjacent.
3. The diaphragm actuator as claimed in claim 1 wherein said first
frame part contacts a first surface of said diaphragm layers and/or
said second frame part contacts a second surface of said two
diaphragm layers which is opposite to said first surface.
4. The diaphragm actuator as claimed in claim 1 wherein a first
connecting part is provided which mechanically contacts said first
surface of said diaphragm layers and/or wherein a second connecting
part is provided which mechanically contacts said second surface of
said diaphragm layers.
5. The diaphragm actuator as claimed in claim 4 wherein said first
connecting part and/or said second connecting part is/are arranged
centrally on said surface.
6. The diaphragm actuator as claimed in claim 1 wherein said
diaphragm layers each have an opening which is provided centrally
in said diaphragm layer.
7. The diaphragm actuator as claimed in claim 6 wherein said
opening is circular.
8. The diaphragm actuator as claimed in claim 1 wherein said
diaphragm layers have one of a circular or substantially
rectangular shape.
9. The diaphragm actuator as claimed in claim 1 wherein at least
one of said first and second frame parts has one of a circular or
substantially rectangular shape.
10. The diaphragm actuator as claimed in claim 1 wherein at least
one of said first and second frame parts is at least partially
flexible.
11. The diaphragm actuator as claimed in claim 1 wherein said
diaphragm layers each comprise at least one electrode.
12. The diaphragm actuator as claimed in claim 11 wherein said
electrodes of directly adjacent diaphragm layers are disposed
offset with respect to one another.
13. The diaphragm actuator as claimed in claim 1 wherein said first
frame part has a first terminal and/or said second frame part has a
second terminal.
14. The diaphragm actuator as claimed in claim 13 in combination
with claim 11 wherein said electrodes of said diaphragm layers are
electrically contacted, wherein said electrodes of every second of
said diaphragm layers are coupled to said first terminal and the
other of said diaphragm layers are coupled to said second
terminal.
15. A method for producing a diaphragm actuator comprising the
following steps: a) providing a first tool part, a first frame part
and a polymer film made from an electro-active material. b)
disposing said first frame part on said first tool part, c)
clamping said polymer film, d) mechanically expanding said polymer
film, e) fixing said polymer film on said first tool part, and f)
cutting said polymer film so that a diaphragm layer is
produced.
16. The method as claimed in claim 15 wherein a step g) is carried
out in which said electrode is attached to said diaphragm
layer.
17. The method of claim 16 wherein step g) is being carried out
after steps c) to e). 18, The method as claimed in claim 15 wherein
steps c) to g) are carried out repeatedly in order to form a
plurality of diaphragm layers.
19. The method as claimed in claim 15 wherein said electrodes of
directly adjacent diaphragm layers are disposed offset with respect
to one another.
20. The method as claimed in claim 15 wherein a second frame part
is provided which is disposed on a side of said diaphragm layer
which opposite to said first frame part.
21. The method as claimed in claim 15 wherein said polymer film is
expanded unidirectionally or radially in step d).
22. The method of claim 21 wherein said polymer film is being
expanded in a uniform manner.
23. The method as claimed in claim 15 wherein said first tool part
is moved in step d) in order to mechanically expand said polymer
film.
24. The method as claimed in claim 15 wherein a second tool part is
provided which is likewise moved in order to expand said polymer
film.
25. The method as claimed in claim 24 wherein said second tool part
has a structure which substantially corresponds to said first frame
part.
26. The method of claim 24 wherein said second tool part is
positioned opposite said first frame part.
27. The method as claimed in claim 15 wherein said first diaphragm
layer is fastened to said first frame part.
28. The method of claims 27 wherein said first diaphragm layer is
fastened to said first frame part by one of an adhesive or welding
method. 29, The method as claimed in claim 15 wherein said first
tool part is a working table or a working drum which has a
plurality of working surfaces.
30. The method as claimed in claim 15 wherein said first tool part
formed as a working drum is rotated about an axis of rotation and
so a polymer film portion of said polymer film allocated to a
working surface is supplied to different working stations.
Description
[0001] The invention relates to a diaphragm actuator and a method
for producing a diaphragm actuator.
BACKGROUND OF THE INVENTION
[0002] The term "actuator" as used herein designates a component or
an assembly with which electrical energy is converted into
mechanical energy, whereby a movement of a part of the actuator is
generated which can be transferred to an element to be actuated. An
actuator of this type can advantageously be used inter alia in
fluid valve technology, e.g. in order to actuate a valve.
[0003] A diaphragm actuator is characterised in that it has a
diaphragm layer which is used to convert the electrical energy into
mechanical energy. For this purpose, the diaphragm layer can
typically be formed from an electro-active polymer which e.g.
expands or contracts when a voltage is applied. In this way the
electrical energy applied by the application of voltage is
converted into mechanical energy, which leads to a movement of an
output part of the actuator.
[0004] Suitable electro-active polymers are e.g. silicone,
polyurethane and acrylate.
[0005] It is known from the prior art to stack such diaphragm
actuators on top of one another to form a stacked diaphragm
actuator in order to increase the available force thereof. For
example, a stacked diaphragm actuator of this type is known from WO
20081083325 A, in which each diaphragm layer is clamped in between
two frame parts. A plurality of these diaphragm actuators are
stacked one above the other in order to form the stacked diaphragm
actuator.
[0006] In stacked diaphragm actuators of this type it has proved to
be disadvantageous that they require a lot of space since the
individual diaphragm actuators each lie on top of one another via
their frame parts. However, the frames are of greater height than
the active regions of the diaphragm layers which generate the
movement, i.e. the regions of the diaphragm layers which are
disposed between electrode layers. Much space thereby is
wasted.
[0007] It is the object of the invention to form a diaphragm
actuator which can exert a high level of force but nevertheless
requires little installation space.
BRIEF DESCRIPTION OF THE INVENTION
[0008] The object is achieved in accordance with the invention by a
diaphragm actuator which has a first frame part and a second frame
part, between which at least two diaphragm layers are disposed in a
stacked manner and formed as electro-active polymer layers.
[0009] The fundamental idea of the invention is to reduce the space
required for the diaphragm actuator in that not every individual
diaphragm layer is damped in its own frame. It is much rather the
case that a plurality of diaphragm layers made from an
electro-active polymer (EAP diaphragms) are damped in between a
single frame. Thus a diaphragm actuator of this type can also be
termed a multi-layer diaphragm actuator since a plurality of
diaphragm layers are disposed in an actuator, in particular in a
frame of the actuator. Nevertheless the plurality of diaphragm
layers can provide a high level of force, whereby a diaphragm
actuator formed in this way can generate comparable forces to the
stacked diaphragm actuators known from the prior art but is of
lower construction height.
[0010] In particular the diaphragm actuator can be a dielectric
elastomeric actuator.
[0011] A dielectric elastomeric actuator is generally based on an
electrode with a large surface area being disposed on each of two
mutually opposing sides of a dielectric polymer film. If a
sufficiently strong electric voltage is applied to the electrodes,
the electrodes are drawn towards one another and so the polymer
film lying therebetween is compressed. Since the dielectric polymer
film used is almost incompressible, the reduction in the spacing
between the electrodes leads to a change in shape. In a diaphragm
e.g. the middle portion of a circular diaphragm can be deflected in
the axial direction with respect to the outer edge when an electric
voltage is applied to the electrodes on both sides of the
diaphragm; the reduction in the thickness of the dielectric polymer
film is, to put it simply, converted into a greater axial length
for the diaphragm.
[0012] One aspect of the invention makes provision for the at least
two active diaphragm layers to lie directly against one another. In
this way, the space requirement of the diaphragm actuator is
considerably reduced since the individual diaphragm layers are very
thin and no further component is disposed therebetween.
[0013] Furthermore, provision is made for the first frame part to
be able to lie against a first surface of the at least two
diaphragm layers and/or the second frame part to be able to lie
against a second surface of the at least two diaphragm layers,
which second surface is opposite to the first surface. The first
frame part can constitute a lower termination of the diaphragm
actuator, whereas the second frame part forms an upper termination
of the diaphragm actuator. The diaphragm layers lying between the
frame parts can thereby be held in a secure and fixed manner.
[0014] In accordance with a first embodiment of the diaphragm
actuator in accordance with the invention, a first connecting part
is provided which lies against the first surface of the at least
two diaphragm layers and/or a second connecting part is provided
which lies against the second surface of the at least two diaphragm
layers, wherein in particular the first connecting part and/or the
second connecting part lie(s) centrally on the respective surface.
By means of the first or the second connecting part the diaphragm
actuator can cooperate with the element to be actuated. This can
happen e.g. in that the diaphragm actuator is connected to the
respective part to be moved in each case via the first and/or the
second connecting part. Alternatively, the connecting parts can
also serve as stop elements which, upon movement of the actuator,
engage on an element to be actuated. Furthermore, a respective
element to be actuated can also be allocated to both connecting
parts. By means of the central arrangement of the first and/or of
the second connecting part it is ensured that the connecting parts
undergo a homogeneous displacement movement upon activation of the
diaphragm actuator.
[0015] In accordance with a second embodiment of the invention,
provision is made that the at least two diaphragm layers each have
an opening which is provided centrally in the respective diaphragm
layer and in particular is circular. In a diaphragm actuator of
this type provision can be made e.g. for the diaphragm layers to
expand or contract mechanically upon application of a voltage, such
that the opening within the diaphragm layers is changed. In this
connection, the opening can contract e.g. when an electric voltage
is applied, whereby the size of the opening is reduced. The opening
can be circular or substantially rectangular.
[0016] Furthermore, provision can be made for the at least two
diaphragm layers to be circular or substantially rectangular. By
means of the respective formation of the diaphragm layers,
different mechanical movements of the diaphragm actuator can be
achieved when it is electrically activated.
[0017] In particular the first frame part and/or the second frame
part can be circular or substantially rectangular. The frame parts
are formed to correspond to the respective diaphragm layers in
order to ensure that the frame parts can fixedly hold the diaphragm
layers at their outer edges in each case or are attached to the
diaphragm layers via the respective edges. The region of the
diaphragm layers which is not fixed by the frame parts serves as an
active region which converts movement when the diaphragm actuator
is energised.
[0018] A further aspect of the invention makes provision for the
first frame part and/or the second frame part to be at least
partially flexible. By reason of the partially flexible formation
of the frame parts, a diaphragm actuator can be created which is
able to adopt different shapes or can exert movements since the
frame itself can deform by reason of the at least partially
flexible frame parts. The diaphragm actuator can comprise a DEMES
structure or be formed therefrom. A DEMES structure (Dielectric
Elastomer Minimum Energy Structure) is a structure which adopts a
condition which is favourable in terms of energy (state of
equilibrium). By activation of the diaphragm layers, energy can
therefore be introduced into the diaphragm actuator at least
partially formed from a DEMES structure and so the actuator is
deformed out of its state of equilibrium which is favourable in
terms of energy. In particular, the diaphragm actuator can also be
completely flexible, i.e. consist entirely of a DEMES
structure.
[0019] Furthermore, the at least two diaphragm layers each comprise
an electrode. By means of the electrodes it is ensured that the
diaphragm layers can have electric voltage applied to them. The
electro-active diaphragm layers can therefore expand or contract
when an electric voltage is applied to them.
[0020] in particular, the electrodes of directly adjacent diaphragm
layers are disposed offset with respect to one another. In this way
it is possible to ensure in the case of a diaphragm actuator with
diaphragm layers disposed in a stack that an electric field is
formed between the directly adjacent diaphragm layers. For this
purpose, the mutually offset diaphragm layers are allocated to
different poles of a voltage source. Hence, a single voltage source
can suffice to apply electricity to all the diaphragm layers.
[0021] A further aspect of the invention makes provision for the
first frame part to have a first terminal and/or the second frame
part to have a second terminal. By means of the terminals the
diaphragm layers, in particular the electrodes thereof, have a
voltage applied to them. The frame parts which serve to fix the
individual diaphragm layers therefore simultaneously ensure the
indirect electrical supply of the individual diaphragm layers and
fixing of the diaphragm layers at the edge.
[0022] In particular, the electrodes of the at least two diaphragm
layers are electrically contacted, wherein the electrodes of every
second diaphragm layer are coupled to the first terminal and the
other diaphragm layers are coupled to the second terminal. This
results in asymmetrical contacting of the stacked diaphragm layers
since between every two adjacent diaphragm layers an electric field
is always formed, which is necessary in order to create a voltage
in the respective diaphragm layers.
[0023] The object of the invention is further achieved by a method
for producing a diaphragm actuator, comprising the following steps:
[0024] a) providing a first tool part, a first frame part and a
polymer film made from an electro-active material. [0025] b)
disposing the first frame part on the first tool part, [0026] c)
clamping the polymer film, [0027] d) mechanically expanding the
polymer film, [0028] e) fixing the polymer film, in particular on
the first tool part, and [0029] f) cutting the polymer film so that
a diaphragm layer is produced.
[0030] By means of the method in accordance with the invention it
is ensured that the required pretensioning of the diaphragm layer
can be achieved. By reason of the pretensioning, the available
force of the diaphragm actuator can be increased. By expansion or
stretching of the diaphragm layer a preferred direction of the
actuator is defined.
[0031] In accordance with one aspect of the invention a step g) is
carried out in which at least one electrode is attached to the
diaphragm layer, wherein in particular step g) is carried out after
steps c) to e). The attachment of the electrode is important in
order that a voltage can be applied to the diaphragm layer. The
electrode should in particular be attached after the mechanical
expansion in step d) in order to prevent damage to the electrode.
The at least one electrode can be attached by means of a wet
chemical process such as spraying, stamping, printing or screen
printing. In general, an extremely wide variety of electrode
patterns can thereby be achieved.
[0032] Furthermore, the steps c) to e) are carried out repeatedly
in order to form a plurality of diaphragm layers. In dependence
upon the repetitions a multi-layer diaphragm actuator is created
which has diaphragm layers corresponding to the number of
repetitions. The available force of the diaphragm actuator is
thereby increased.
[0033] In particular, the electrodes of directly adjacent diaphragm
layers are disposed offset with respect to one another at least in
regions. In this way it is ensured that in each case directly
adjacent diaphragm layers can be supplied with or coupled to a
different voltage or a different terminal and so an electric field
can be created between directly adjacent diaphragm layers when a
voltage is applied to the diaphragm actuator.
[0034] Furthermore, a second frame part is provided which is
disposed on the side of the at least one diaphragm layer opposite
to the first frame part. Therefore, the second frame part forms the
termination of the diaphragm actuator opposite to the first frame
part, whereby it is ensured that the at least one diaphragm layer
is disposed between the two frame parts. The at least one diaphragm
layer is therefore clamped in securely.
[0035] Furthermore, provision is made for the polymer film to be
expanded unidirectionally or radially, in particular is expanded
uniformly, in step d). By means of the expansion a multi-layer
diaphragm actuator with pre-expanded diaphragm layers can be
provided which provides a large force with a compact structure. The
radial expansion is of significance in particular in diaphragm
layers which are circular. By means of the uniformly radial
expansion it is ensured that a circular diaphragm layer which is
clamped in a circular frame is compressed between the electrodes,
e.g. when the electrodes are acted upon in the active region
thereof, such that the wall thickness at that location is reduced.
Since the material of the diaphragm layers is incompressible, it
"elongates" and so the centre of the diaphragm can be deflected
with respect to the initial condition. If the voltage is withdrawn
from the electrodes, the actuator returns to the initial condition;
the wall thickness of the diaphragm layers increases, whereby the
centre is retracted into its original position. In general, the
pre-expansion means that a defined movement of the diaphragm
actuator can be achieved with a larger force.
[0036] In particular, the first tool part is moved in step d) in
order to expand the polymer film mechanically. The first tool part
therefore serves not only to fix the polymer film in order to form
the diaphragm layer but also in order to expand the polymer film.
In this way, a simple method is provided for producing the
diaphragm actuator, in particular a diaphragm actuator with
pre-expanded diaphragm layers.
[0037] Furthermore, a second tool part can be provided which is
likewise moved in order to expand the polymer film. This second
tool part can in particular be provided when a radial expansion of
the polymer film or of the diaphragm layer is to take place.
[0038] In accordance with one aspect of the invention, the second
tool part has a structure which substantially corresponds to the
first frame part and/or the second tool part is positioned opposite
to the first frame part. By reason of the positioning and/or design
of the second tool part, the radial expansion of the polymer film
can take place. For this purpose, the second tool part is in
particular able to move such that it can travel in the direction of
the first tool part on which the first frame part is disposed. The
correspondingly formed structure ensures that the radial expansion
of the polymer film takes place in order to form the radially
pre-expanded diaphragm layer.
[0039] In accordance with a further aspect of the invention, the
first diaphragm layer is attached to the first frame part, in
particular is adhered or welded thereto. This ensures that a firm
connection between the frame part and the edge of the first
diaphragm layer is provided and so a relative movement between the
first frame part and the first diaphragm layer cannot take
place.
[0040] Furthermore, the further diaphragm layers can also be
connected to the first frame part or the previous diaphragm layer.
The connection is effected at the edge.
[0041] In particular, the first tool part has a working table or a
working drum which has a plurality of working surfaces. In this way
an extremely economical production method can be achieved which can
be carried out in an very small space.
[0042] In particular, the first tool part formed as a working drum
rotates about an axis of rotation and so a polymer film portion of
the polymer film allocated to a working surface is supplied to
different working stations. In this way a multi-layer diaphragm
actuator can be produced in an extremely efficient manner since the
respective diaphragm layer to be processed passes through a
plurality of stations in succession. By reason of the expansion of
the working drum about its axis of rotation, the space requirement
is also slight. At the same time, further multi-layer diaphragm
actuators can be subjected to other method steps on the other
working surfaces.
[0043] In general, the working surfaces can be formed in such a way
that a plurality of diaphragm actuators can be formed
simultaneously. A batch of diaphragm actuators is accordingly
produced on one working surface. For this purpose, a matrix can be
disposed on the corresponding working surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] Further advantages and properties of the invention will be
apparent from the following description and the drawings to which
reference is made. In the drawings:
[0045] FIG. 1a shows a cross-sectional view through a first
embodiment of a diaphragm actuator in accordance with the
invention,
[0046] FIG. 1b shows a plan view of the diaphragm actuator
according to FIG. 1a,
[0047] FIG. 1c shows a cross-sectional view through the diaphragm
actuator of FIG. 1a in the case of a first electrode,
[0048] FIG. 1d shows a cross-sectional view through the diaphragm
actuator of FIG. 1a in the case of a second electrode,
[0049] FIGS. 2a to 2c show an illustration of the diaphragm
actuator of FIG. 1a in accordance with the invention, in a plan
view, a cross-sectional view in the initial condition and a
cross-sectional view in the activated condition,
[0050] FIGS. 3a to 3c show an illustration of a second embodiment
of the diaphragm actuator in accordance with the invention in a
plan view, a cross-sectional view in the initial condition and a
cross-sectional view in the activated condition,
[0051] FIG. 3d shows a plan view of the diaphragm actuator
according to the second embodiment,
[0052] FIG. 3e shows a cross-sectional view through the diaphragm
actuator of the second embodiment in the case of a first
electrode,
[0053] FIG. 3f shows a cross-sectional view through the diaphragm
actuator of the second embodiment in the case of a second
electrode,
[0054] FIGS. 4a to 4c show an illustration of a third embodiment of
a diaphragm actuator in accordance with the invention, in a plan
view, a cross-sectional view in the initial condition and a
cross-sectional view in the activated condition,
[0055] FIGS. 5a to 5c show an overview of a fourth embodiment of a
diaphragm actuator in accordance with the invention,
[0056] FIG. 6a shows a plan view of an electrode pattern of a fifth
embodiment of a diaphragm actuator in accordance with the
invention,
[0057] FIG. 6b shows a plan view of an electrode pattern of a sixth
embodiment of a diaphragm actuator in accordance with the
invention,
[0058] FIG. 6c shows a plan view of an electrode pattern of a
seventh embodiment of a diaphragm actuator in accordance with the
invention,
[0059] FIG. 6d shows a plan view of an electrode pattern of an
eighth embodiment of a diaphragm actuator in accordance with the
invention,
[0060] FIG. 7 shows a plan view of a matrix diaphragm actuator in
accordance with the invention,
[0061] FIGS. 8a to 8c show an illustration of a ninth embodiment of
a diaphragm actuator in accordance with the invention, in a plan
view in the activated condition, a cross-sectional view in the
initial condition and a cross-sectional view in the activated
condition,
[0062] FIGS. 9a to 9c show an illustration of a tenth embodiment of
a diaphragm actuator in accordance with the invention, in a plan
view in the activated condition, a cross-sectional view in the
initial condition and a cross-sectional view in the activated
condition,
[0063] FIG. 10a shows a plan view of an eleventh embodiment of a
diaphragm actuator in accordance with the invention,
[0064] FIG. 10b shows a plan view of a twelfth embodiment of a
diaphragm actuator in accordance with the invention,
[0065] FIG. 10c shows a plan view of a thirteenth embodiment of a
diaphragm actuator in accordance with the invention,
[0066] FIG. 10d shows a plan view of a fourteenth embodiment of a
diaphragm actuator in accordance with the invention,
[0067] FIG. 10e shows a plan view of a fifteenth embodiment of a
diaphragm actuator in accordance with the invention,
[0068] FIGS. 11a to 11c show an illustration of a sixteenth
embodiment of a diaphragm actuator in accordance with the
invention, in a plan view, a cross-sectional view in the initial
condition and a cross-sectional view in the activated
condition,
[0069] FIG. 12a shows a schematic illustration of a first method
step of the production method in accordance with the invention,
according to a first variation,
[0070] FIG. 12b shows a schematic illustration of a second method
step of a first variation of the production method in accordance
with the invention,
[0071] FIG. 12c shows a schematic illustration of a third method
step of a first variation of the production method in accordance
with the invention,
[0072] FIG. 12d shows a schematic illustration of a fourth method
step of a first variation of the production method in accordance
with the invention,
[0073] FIG. 12e shows a plan view of FIG. 12d,
[0074] FIG. 13a shows a schematic illustration during the
production method at a first moment in accordance with a first
embodiment variation,
[0075] FIG. 13b shows the illustration of FIG. 13a at a second
moment,
[0076] FIG. 14a shows a schematic illustration during the
production method at a first moment in accordance with a second
embodiment variation,
[0077] FIG. 14b shows the illustration of FIG. 14a at a second
moment,
[0078] FIG. 15a shows a schematic illustration of a first method
step during the production method in accordance with the invention,
according to a second variation,
[0079] FIG. 15b shows a schematic illustration of a second method
step during the production method in accordance with the invention,
according to a second variation,
[0080] FIG. 15c shows a schematic illustration of a third method
step during the production method in accordance with the invention,
according to a second variation,
[0081] FIG. 16 shows a detailed illustration of FIG. 15c,
[0082] FIG. 17 shows a method overview during the production method
in accordance with the invention, according to a second
variation,
[0083] FIG. 18 is a schematic overview of the production method in
accordance with the invention, according to a third variation,
[0084] FIG. 19 is a perspective illustration of the first tool part
formed as a tool drum, which is used in the method shown in FIG.
18,
[0085] FIG. 20a shows a first method step of the production method
in accordance with the invention, according to the third
variation,
[0086] FIG. 20b shows a second method step of the production method
in accordance with the invention, according to the third
variation,
[0087] FIG. 20c shows a third method step of the production method
in accordance with the invention, according to the third
variation,
[0088] FIG. 20d shows a fourth method step of the production method
in accordance with the invention, according to the third
variation,
[0089] FIG. 20e shows a fifth method step of the production method
in accordance with the invention, according to the third
variation,
[0090] FIG. 20f shows a sixth method step of the production method
in accordance with the invention, according to the third
variation,
[0091] FIG. 20g shows a seventh method step of the production
method in accordance with the invention, according to the third
variation,
[0092] FIG. 20h shows an eighth method step of the production
method in accordance with the invention, according to the third
variation,
[0093] FIG. 21a shows a first alternative embodiment of the first
tool part,
[0094] FIG. 21b shows a second alternative embodiment of the first
tool part,
[0095] FIG. 21c shows a third alternative embodiment of the first
tool part,
[0096] FIG. 22a shows an overview of a further diaphragm actuator
produced by the production method in accordance with the
invention,
[0097] FIG. 22b shows an overview of a further diaphragm actuator
produced by the production method in accordance with the
invention,
[0098] FIG. 22c shows an overview of a further diaphragm actuator
produced by the production method in accordance with the
invention,
[0099] FIG. 22d shows an overview of a further diaphragm actuator
produced by the production method in accordance with the
invention,
[0100] FIG. 22e shows an overview of a further diaphragm actuator
produced by the production method in accordance with the
invention,
[0101] FIG. 22f shows an overview of a further diaphragm actuator
produced by the production method in accordance with the
invention,
[0102] FIG. 22g shows an overview of a further diaphragm actuator
produced by the production method in accordance with the
invention,
DETAILED DESCRIPTION OF THE INVENTION
[0103] FIG. 1 a shows a diaphragm actuator 10 which has a first
frame part 12 and a second frame part 14.
[0104] Five diaphragm layers 16 are disposed between the two frame
parts 12, 14 in the illustrated embodiment. Accordingly the
diaphragm actuator 10 is a multi-layer diaphragm actuator which has
a plurality of diaphragm layers 16 in a frame 15 which is formed by
the frame parts 12, 14.
[0105] In general, the diaphragm layers 16 are produced from a
dielectric elastomer or an electro-active polymer and so they can
convert an electric excitation into a mechanical movement.
[0106] The individual diaphragm layers 16 can in particular be
pre-expanded as also explained later with the aid of FIGS. 12 to
20.
[0107] The diaphragm layers 16 lie directly against one another and
form a stack 17 which has a first surface 17a and a second surface
17b. The second surface 17b is disposed opposite to the first
surface 17a, wherein the first frame part 12 lies against the first
surface 17a and the second frame part 14 lies against the second
surface 17b.
[0108] The frame parts 12, 14 lie in a first edge region 18 and a
second edge region 19 respectively of the diaphragm layers 16
directly against the first diaphragm layer 16a and the last
diaphragm layer 16e.
[0109] Each of the diaphragm layers 16 are preferably allocated two
electrodes 20, 22 each, wherein a first electrode 20 and a second
electrode 22 are provided which differ in the correspondingly
allocated polarity thereof as explained hereinunder. In general,
the electrodes 20, 22 are allocated to the diaphragm layers 16 such
that two directly adjacent diaphragm layers 16 have a different
electrode sequence or a different electrode pattern.
[0110] The electrodes 20, 22 can be formed e.g. from metal.
Alternatively, the electrodes 20, 22 can be formed on the basis of
carbon, nano-particles or an ICP (intrinsically conducting
polymer).
[0111] In order to contact the electrodes 20, 22 the frame parts
12, 14 have a first terminal 24 which is allocated to the first
edge region 18, and a second terminal 25 which is allocated to the
second edge region 19. The two terminals 24, 25 differ in their
polarity.
[0112] Each diaphragm layer 16 accordingly has at least one
electrode 20, 22 which is allocated either to the first terminal 24
or the second terminal 25.
[0113] The through-contacting of the electrodes 20, 22 of the
diaphragm layers 16 and the contact with the terminals 24, 25 can
be effected via contact elements 26, 27 which are formed e.g. as
rivets, pressure pins and/or from an elastically-conductive
elastomer. The openings provided to receive the contact elements
26, 27 can be formed e.g. by stamping.
[0114] The terminals 24, 25 can be integrated in the respective
frame parts 12, 14 and also formed as plugs or bushings in order to
permit simple electric contacting of the diaphragm actuator 10.
[0115] By means of the terminals 24, 25 the diaphragm actuator 10
can be supplied with a voltage and so the electro-active diaphragm
layers 16 expand or contract, whereby the electrical energy is
converted into mechanical movement energy.
[0116] The structure of the individual diaphragm layers 16 is
explained hereinunder with the aid of FIGS. 1a to 1d:
[0117] For example, the first or lowermost diaphragm layer 16a,
which lies directly on the first frame part 12, has a first
electrode 20a which is provided on the upper side of the diaphragm
layer 16a. The first electrode 20a is electrically coupled to the
first terminal 24. An electrode 20a of this type is shown in FIG.
1c which shows a cross-sectional view.
[0118] In order to contact the first terminal 24 the first
electrode 20a has a lateral protrusion which is provided in the
first edge region 18.
[0119] In contrast, the second diaphragm layer 16b, which is
disposed directly on the side of the first diaphragm layer 16a
opposite to the first frame part 12, has a second electrode 22b on
its upper side. A second electrode 22 of this type is shown e.g. in
FIG. 1d.
[0120] The second electrode 22b extends to the second edge 19 and
so the second electrode 22b of the second diaphragm layer 16b is
electrically coupled to the second terminal 25.
[0121] This structure is repeated a number of times.
[0122] Accordingly, the third diaphragm layer 16c likewise has a
first electrode 20c on its upper side, which has a protrusion which
extends to the first edge region 18. In contrast, the fourth
diaphragm layer 16d has a second electrode 22d on its upper side,
which is coupled to the second terminal 25.
[0123] The terminating diaphragm layer 16e, in contrast, has a
first electrode 20e which is electrically coupled to the first
terminal 24.
[0124] In this way the stack 17 of the diaphragm layers 16 has an
asymmetrical electrode pattern in cross-section since a first
electrode 20 (FIG. 1 c) and a second electrode 22 (FIG. 1d) are
respectively provided in alternation.
[0125] Accordingly either a first or a second electrode 20, 22 is
attached to the respective upper side of each second diaphragm
layer 16 of the stack 17, wherein, a second or a first electrode
22, 20 is accordingly attached to the upper sides of the other
diaphragm layers 16.
[0126] It is thereby ensured that the diaphragm layers 16b to 16e
are each allocated a first electrode 20 and a second electrode 22
which have a different polarity. These diaphragm layers 16b to 16e
are then compressed in the direction of the electric field upon
application of a voltage and accordingly expand by reason of the
incompressibility of the diaphragm layers 16 perpendicularly to the
direction of the electric field in order to keep their volume
constant. The expansion of the diaphragm layers 16b to 16e is then
used to achieve the mechanical displacement movement.
[0127] In the illustrated cross-sectional view of figure I a, the
first diaphragm layer 16a also has a second electrode 22a on its
upper side, which, however, is optional. In this way it is merely
ensured that the first diaphragm layer 16a can also be used to
achieve the mechanical displacement movement.
[0128] Without the second electrode 22a on its underside the first
diaphragm layer 16a would function only as a support layer for the
first electrode 20a on its upper side, without making a
contribution to the displacement movement; it would be displaced
passively when the other diaphragm layers "work".
[0129] If the second electrode 22a were omitted from the underside
of the first diaphragm layer 16a then each diaphragm layer 16 would
have only one electrode 20, 22 on its respective upper side.
[0130] Alternatively, all the diaphragm layers 16 can have a
respective electrode 20, 22 on their upper side and their lower
side, wherein the electrodes 20, 22 have correspondingly different
polarity. For example, a first electrode 20 is provided on the
upper side whereas a second electrode 22 is provided on the lower
side. The diaphragm layer 16 disposed on the upper side must then
likewise have a first electrode 20 on its lower side and so no
isolation between adjacent diaphragm layers 16 is necessary.
[0131] However, in specific cases this can be provided.
[0132] From comparing FIGS. 1b to 1d it is clear that the two
electrodes 20, 22 differ only in their protrusions via which they
are coupled to the respective terminal 24, 26. Otherwise, they have
the same surface area which in particular corresponds almost to the
whole surface of the respective diaphragm layer 16, In this way the
electrodes 20, 22 lie opposite to one another over a large
area.
[0133] The diaphragm actuator 10 can in particular be installed in
a pretensioned manner and so e.g. the middle region of the
diaphragm layers 16 is pretensioned by means of a spring in a
deflected (conical) condition. The deflection of the middle region
can then be controlled extremely precisely in the desired manner by
application of a voltage.
[0134] Furthermore, the diaphragm actuator 10 shown in FIG. 1a then
has a first connecting part 28 and a second connecting part 30. The
first connecting part 28 is disposed like the first frame part 12
on the first surface 17a of the stack 17 whereas the second
connecting part 30 is disposed on the second surface 17b of the
stack 17.
[0135] The two connecting parts 28, 30 are each fastened centrally
on the stack 17 and have in particular a height which corresponds
to the two frame parts 12, 14. In this way a compact diaphragm
actuator 10 is created.
[0136] FIG. 1a also shows that the respective electrodes 20, 22 of
the diaphragm layers are formed in such a way that they do not
cover the middle region in which the connecting parts 28, 20 are
provided. The above-mentioned spring can engage on the connecting
parts 28, 30. The connecting parts can also be used as an output of
the actuator in order to transfer the generated stroke to another
component (e.g. a valve element).
[0137] FIG. 2 shows an overview of the diaphragm actuator 10 of
FIG. 1. The overview includes a plan view of the non-active
diaphragm actuator 10 (FIG. 2a) and a cross-sectional view of the
diaphragm actuator 10 in a non-active position (FIG. 2b) and a
deflected position (FIG. 2c).
[0138] As shown by FIG. 2a the diaphragm actuator 10 is circular
since both the first frame part 12 and also the second frame part
14 are circular. Furthermore, the individual diaphragm layers 16
are circular as are the connecting parts 28, 30.
[0139] In the initial condition (FIG. 2b), the diaphragm layers 16
are clamped taut between the frame parts and so the connecting
parts 28, 30 are located in an initial position in the middle
plane.
[0140] If a voltage is applied to the diaphragm actuator 10 via the
two electrical terminals 24, 25, not shown herein, an electric
field is created in each case between directly adjacent diaphragm
layers 16 of the stack 17 since the directly adjacent diaphragm
layers 16 are each contacted with one of the terminals 24, 25
alternately. The diaphragm layers 16 formed from electro-active
polymer are compressed by reason of the power of attraction between
the electrodes and so their wall thickness decreases.
[0141] However, since the material of the diaphragm layers is
(almost) incompressible, the material becomes "longer". In this way
the middle portion of the diaphragm layers 16 can be deflected with
respect to the initial condition. In FIG. 2c the middle portion is
deflected upwards in this case. This can be effected by means of a
spring (not shown) which can displace the connecting parts 28, 30
upwards when the diaphragm layers are compressed between the
electrodes 20, 22 and thus "lengthen".
[0142] If no spring or other component were provided which would
displace the middle portion upwards as in FIG. 2c, the middle
portion could also sag downwards under the effect of gravity when a
voltage is applied.
[0143] Irrespective of the respective installation position and an
element which pretensions the middle portion, it is clear that the
applied electrical energy is converted into mechanical energy which
leads to the deflection of the connecting parts 28, 30 as shown
from the lower illustration in the overview.
[0144] The connecting parts 28, 30 can cooperate in particular with
at least one element to be displaced and so, upon activation of the
diaphragm actuator 10, a mechanical displacement of the element to
be moved is achieved.
[0145] Provision can be made for the frame parts 12, 14 to have
means with which the diaphragm actuator 10 can be mechanically
fastened. The means can be bores or slits or fastening
elements.
[0146] FIGS. 3a to 3c also show an overview of a second embodiment
of the diaphragm actuator 10.
[0147] The second embodiment of the diaphragm actuator 10 differs
from the first embodiment in that the frame parts 12, 14, the
diaphragm layers 16 and the connecting parts 28, 30 are
substantially rectangular (see FIG. 3a). Only the corners are
rounded.
[0148] Otherwise the structure and mode of operation of the
diaphragm actuator 10 are the same, The advantage of the second
embodiment is that a plurality of actuators can be disposed closely
next to one another without space going to waste between them.
[0149] In FIGS. 3d to 3f the diaphragm actuator 10 of FIG. 3 is
shown in a plan view (FIG. 3d) and two transverse cross-sectional
views (FIGS. 3e and 3f) in different planes in order to clarify the
formation of the two electrodes 20, 22 in accordance with the
second embodiment.
[0150] FIGS. 3d to 3f are to be understood analogously to FIGS. 1b
to 1d and so the expansion of the respective electrode 20, 22 is
clear in particular from FIGS. 3e and 3f.
[0151] FIG. 4 shows an overview of a third embodiment of the
diaphragm actuator 10 which is similar to the first view of the
first embodiment.
[0152] However, the difference between the third embodiment and the
first embodiment is that each of the diaphragm layers 16 has an
opening 32 which is formed centrally in the respective diaphragm
layer 16 (see FIGS. 4a and 4b).
[0153] The openings 32 of the respective diaphragm layers 16 are
likewise circular in the illustrated embodiment.
[0154] As shown by the overview of FIG. 4, activation of the
diaphragm actuator 10 in accordance with the third embodiment
causes the individual diaphragm layers 16 to contract such that the
diameter of the openings 32 is reduced.
[0155] In the illustrated embodiment, the openings 32 can contract
so far that they close (see FIG. 4c) as compared with an initial
condition (see FIGS. 4a and 4b). In this way, e.g. a flow
cross-section can be directly controlled without the movement of
the actuator having to be transferred to a valve element.
[0156] FIG. 5 illustrates a fourth embodiment of the diaphragm
actuator 10 which substantially corresponds to the third
embodiment, wherein the frame parts 12, 14, the diaphragm layers 16
and the openings 32 are not circular but rather substantially
rectangular.
[0157] However, the remainder of the structure and the mode of
operation of the diaphragm actuator 10 do not differ from the third
embodiment; the openings 32 can also in this case be closed (see
FIG. 5c) from an initial condition (see FIGS. 5a and 5b) in that a
voltage is applied to the electrodes.
[0158] FIGS. 6a to 6e show further embodiments of the diaphragm
actuator 10, wherein the arrangement of the electrodes 20, 22 or
the electrode pattern are shown.
[0159] By means of the arrangement and design of the electrodes 20,
22, different movements of the diaphragm actuator 10 in accordance
with the invention can be achieved. In particular asymmetric
deformations of the diaphragm layers can be obtained by asymmetric
electrodes.
[0160] FIG. 7 shows a plan view of a matrix diaphragm actuator
34.
[0161] The matrix diaphragm actuator 34 has a peripheral frame 35
with intermediate webs 36 disposed therebetween and forming a
matrix 37.
[0162] A plurality of segments 38 are provided in this matrix 37,
in which a respective diaphragm actuator 10 is disposed. The
diaphragm actuators 10 are each formed in accordance with the
second embodiment shown in FIG. 3.
[0163] Furthermore, the terminals 24, 25 are allocated to each
individual segment 38 and so the individual diaphragm actuators 10
of the matrix diaphragm actuator 34 can be electrically actuated
independently of one another.
[0164] The matrix diaphragm actuator 34 can also be formed with the
diaphragm actuators 10 of the other embodiments. In particular
mixtures of the embodiments can also be provided in one matrix
diaphragm actuator 34.
[0165] FIG. 8 shows an overview of a ninth embodiment of the
diaphragm actuator 10, wherein the plan view (FIG. 8a) and the
lower cross-sectional view (FIG. 8c) now show the electrically
excited position of the diaphragm actuator 10.
[0166] In contrast to the previous embodiments, the frame parts 12,
14 of the diaphragm actuator 10 are flexible. For this purpose, the
diaphragm actuators 10 and in particular the frame parts 12, 12 can
be formed from a DEMES structure.
[0167] As shown by the overview in FIG. 8, the individual diaphragm
layers 16 and therefore the stack 17 contract upon application of a
voltage.
[0168] In this way the diaphragm actuator 10 and in particular the
frame 15 thereof are transferred from an equilibrium condition
which is favourable in terms of energy (FIG. 8b) to an excited
condition (FIG. 8c).
[0169] In this way in the illustrated embodiment, the height of the
diaphragm actuator 10 is reduced as shown in particular by a
comparison with FIGS. 8b and 8c.
[0170] The frame parts 12, 14 and the diaphragm layers 16 are each
circular in the illustrated embodiment.
[0171] FIG. 9 shows a further embodiment of the diaphragm actuator
10 in which the frame parts 12, 14 are flexible in a manner
analogous to the previous embodiment.
[0172] However, in contrast to the previous embodiment, the frame
parts 12, 14 and the diaphragm layers 16 are substantially
rectangular.
[0173] Furthermore, a comparison of the two embodiments shown in
FIGS. 8 and 9 makes it clear that the frame parts 12, 14 can be
formed differently with respect to their basic condition in terms
of energy. This is manifested in that, when no voltage is applied,
the frame parts contract to different extents (and accordingly
deform to different extents when a voltage is applied).
[0174] The frame 15 in the embodiment of FIG. 9 contracts more
strongly in the relaxed condition than the frame 15 of the
embodiment of FIG. 8.
[0175] FIGS. 10a to 10e show further embodiments of the diaphragm
actuator 10 which are each shown in a plan view.
[0176] In this way both the geometry of the flexible frames 15 and
also that of the electrode pattern can be formed in a corresponding
manner in order to achieve an extremely wide range of movements of
the diaphragm actuator 10.
[0177] FIG. 11 shows an overview of a further embodiment of the
diaphragm actuator 10 in which the plan view (FIG. 11a) shows the
excited position of the diaphragm actuator 10 (FIG. 11c).
[0178] In this embodiment, features of the third embodiment are
combined with features of the ninth embodiment: the actuator has a
central opening 32, and DEMES structures are used.
[0179] In the initial condition (FIG. 11b), the central opening 32
is between quadrant-shaped diaphragm layers. These are bent in the
same direction by reason of the pretensioning of their frame parts
and so their tips are at a distance from one another.
[0180] If a voltage is applied to the electrodes, they deform into
a stretched condition (see FIG. 11c) in which their tips (almost)
lie against one another. The opening 32 is now (almost) closed.
[0181] This is possible since the frame 15 is partially flexible,
The frame 15 has a flexible frame part 14a which has an annular
portion and four portions surrounding the quadrant-shaped diaphragm
layers which protrude inwards from the annular portion.
[0182] The partially flexible frame part 14a is fixedly disposed on
the rigid frame part 14 via its annular portion, whereas the
inwardly protruding portions are free and so they can deform by
reason of their flexible formation as a comparison of FIGS. 11a to
11c shows.
[0183] Different mechanical movement patterns and also extremely
different geometries of the diaphragm actuators 10 can generally be
achieved by means of the partially flexible frame 15.
[0184] Instead of the second frame part 14 and in particular of the
portion 14a, a first or a second connecting part can also be used
which is correspondingly flexible.
[0185] With the aid of FIGS. 12a to 12e, the production method in
accordance with the invention is described, by which the diaphragm
actuator 10 in accordance with the invention can be produced.
[0186] In order to produce the diaphragm actuator 10 a polymer film
40 is provided which is clamped between a first roller pair 42 and
a second roller pair 44.
[0187] Furthermore, a first tool part 46 is provided which is
formed as a working table in the illustrated embodiment. The first
frame part 12 is disposed on a first surface 46a of the first tool
part 46, which frame part, however, is not shown in the figures for
reasons of clarity.
[0188] The polymer film 40 is passed via the first roller pair 42,
which rotates at a first speed, to the second roller pair 44 which
rotates at a second speed. If the two roller pairs 42, 44 are
rotated at the same speed, no pretensioning of the polymer film 40
is provided and so only a clamping effect is present.
[0189] However, if the second roller pair 44 is at a higher
rotational speed than the first roller pair 42, the polymer film 40
is already mechanically pretensioned between the two roller pairs
42, 44.
[0190] The first tool part 46 with the first frame part 12 disposed
thereon is moved in a linear and translatory manner in the
direction of the polymer film 40 (see FIG. 12b) and so the polymer
film 40 clamped in between the two roller pairs 42, 44 is
mechanically expanded.
[0191] In this way a uniaxial expansion of the polymer film 40
takes place, i.e. a mechanical expansion in one direction.
[0192] An alignment grid can be provided which has previously been
applied to the non-expanded polymer film 40. By means of the
deformation of the alignment grid it is possible to see whether the
desired expansion of the polymer film 40 has been achieved. The
alignment grid can e.g. be electronically detected and
monitored.
[0193] Furthermore, openings can be provided in the first surface
46a of the tool part 46, via which openings an overpressure or a
negative pressure can be generated and so the polymer film 40
either slides well over the first surface 46a, namely when air or
gas is blown between the film and the tool, or adheres thereto when
the film is sucked against the surface by negative pressure.
[0194] The tool 46 can be formed from a sintered metal or at least
comprise a sintered metal plate which forms the first surface 46a
and so the first surface 46a is air-permeable.
[0195] The first surface 46a generally has a high surface quality
since it comes into contact with the polymer film 40.
[0196] The two roller pairs 42, 44 are then moved about the first
tool part 46, in particular moved in a translatory manner, until
they are opposite to the second surface 46b of the first tool part
46 which is opposite to the first surface 46a (see FIG. 12c). The
first tool part 46 has thereby become surrounded by the polymer
film 40.
[0197] The polymer film 40 is now attached to the first tool part
46, in particular to the second surface 46b of the first tool part
46.
[0198] The polymer film 40 is then cut in the region of the two
roller pairs 42, 44 by cutting means 48, in particular in a region
between the fastened points on the first tool part 46 and the
roller pairs 42, 44 (see FIG. 12d). The cutting means 48 can be
blades or metal plates.
[0199] After cutting off the polymer film 40, the two roller pairs
42, 44 can move freely and return to their initial position.
[0200] In this way, the first diaphragm layer 16a is disposed on
the first frame part 12. The first electrode 20 or the second
electrode 22 can then be applied to the first diaphragm layer
16a.
[0201] The above-described steps can now be carried out again in
order to apply further diaphragm layers 16 in an analogous manner,
wherein the electrodes 20, 22 are each applied in an alternating
manner so that a mull-layer diaphragm actuator 10 is formed.
[0202] Provision can additionally be made for the first diaphragm
layer 16a to be fastened, in particular adhered or welded, to the
first frame part 12. For this purpose, a UV-hardened silicone or a
thermal ultrasonic compression welding process can be used.
[0203] FIG. 12e shows a plan view of the illustration shown in FIG.
12d. The plan view shows that a batch of diaphragm actuators 10 has
been produced simultaneously. For this purpose, a plurality of
first frame parts 12 or a continuous part has been disposed on the
first tool part 46 which includes a plurality of first frame parts
12 in a matrix-like manner. This can be e.g. an injection moulded
matrix.
[0204] After all the diaphragm layers 16 have been disposed on the
respective diaphragm actuator 10, the second frame part 14 is
placed onto the respective last or uppermost diaphragm layer 16.
All the diaphragm layers 16 are therefore disposed between the
first frame part 12 and the second frame part 14 which form the
frame 15.
[0205] The individual diaphragm layers 16 are then
through-contacted, wherein this can take place by means of a
contact element such as a rivet or a pressure pin. The contact
element used can also be formed from an elastically conductive
elastomer. In this case it is advantageous additionally to dispose
rigid fastening elements between the two frame parts and so the
diaphragm layers are reliably held. Otherwise, the contact elements
can be used to fix the diaphragm layers to the frame parts 12, 14
in the radial direction.
[0206] In general the contacting can be effected by stamping or by
pressing in contact elements.
[0207] If the first diaphragm layer 16a is to have an electrode 20,
22 on its underside, this electrode can be attached before the
first diaphragm layer 16a is disposed on the first frame part 12 or
even subsequently, this rendering contacting more difficult.
[0208] Therefore, a diaphragm actuator 10 in accordance with the
invention, which is a multi-layer diaphragm actuator, is
created.
[0209] By means of such a production method, a unidirectional or
uniaxial pre-expansion of the polymer film 40 can be produced which
is of significance in particular in the case of a substantially
rectangular diaphragm actuator 10.
[0210] FIG. 13a shows the two roller pairs 42, 44 in their initial
position in which the polymer film 40 is supplied to the first
roller pair 42. Since the first roller pair 42 rotates, the
introduced polymer film 40 is advanced to the second roller pair 44
and so the polymer film 40 is clamped between the two roller pairs
42, 44.
[0211] Then the second roller pair 44 moves away from the first
roller pair 42, wherein, in dependence upon the movement of the
second roller pair 44 and the rotational speed thereof, a
pre-extension of the polymer film 40 may or may not take place.
[0212] The roller pairs 42, 44 can in particular be driven and
controlled individually in order to ensure defined movements.
[0213] Furthermore, the roller pairs 42, 44 can have a surface
hardening or coating and so they have anti-adhesion properties.
Alternatively, a rubber coating can also be provided.
[0214] FIGS. 14a to 14b show an alternative embodiment variation of
the production method in which the second roller pair has been
replaced by a gripper 50 which is moved linearly at a defined
speed.
[0215] A pre-expansion of the polymer film 40 can be set depending
on how high the speed of the gripper 50 is.
[0216] FIGS. 15a to 15c show an alternative embodiment variation of
the production method in which a radial expansion of the polymer
film 40 and therefore of the individual diaphragm layers 16 is
produced.
[0217] In a manner analogous to the first production variation, the
polymer film 40 is clamped, in particular pretensioned, between the
first roller pair 42 and the second roller pair 44.
[0218] Furthermore, the first tool part 46 is likewise formed as a
working table on which the first frame part 12 is disposed, which
is not illustrated for reasons of clarity.
[0219] However, the first tool part 46 differs from that of the
first embodiment variation in that protrusions 52 are provided
which protrude from the first surface 46a of the tool part 46. The
protrusions 52 are arranged on the outer edges of the tool part
46.
[0220] The function of these protrusions 52 is clarified with the
aid of FIG. 15b since the fixedly clamped polymer film 40 comes to
lie on the protrusions 52 when the first tool part 46 has been
moved in a linear and translatory manner in the direction of the
polymer film 40 in order to mechanically tension or expand the
polymer film 40.
[0221] The protrusions 52 protrude from the first surface 46a of
the first tool part 46 such that the polymer film 40 does not
contact the first frame part 12 disposed on the first surface
46a.
[0222] As shown by FIG. 15c, the mechanically expanded polymer film
40 is now acted upon by a second tool part 54 which contacts the
side of the polymer film 40 opposite to the first tool part 46. The
second tool part 54 can likewise move in a linear and translatory
manner in order to contact the polymer film 40.
[0223] FIG. 16 shows in detail the region circled with a broken
line in FIG. 15.
[0224] FIG. 16 shows that the second tool part 54 has at least one
stamp arrangement 56 on its side facing the polymer film 40. By
means of the stamp arrangement 56 the second tool part 54 has a
structure which corresponds to the first frame part 12 and the
first connecting part 28 which are both disposed on the first
surface 46a of the first tool part 46.
[0225] The stamp arrangement 56 accordingly has a middle pin 58
which is allocated to the first connecting part 28, and two outer
pins 60, 62 which can co-operate with the first frame part 12.
[0226] However, before the stamp arrangement 56 is activated, the
polymer film 40 is fastened to the first tool part 46 in a manner
analogous to the previously described embodiment. For this purpose,
the two roller pairs 42, 44 are moved around the tool part 46 and
so they lie opposite to the second surface 46b.
[0227] At that location, the polymer film 40 is fastened in an
analogous manner and so now the stamp arrangement 56 can be
activated.
[0228] As shown by the progression of FIG. 17, by means of the
stamp arrangement 56 the desired symmetrical and radial expansion
of the polymer film 40 is achieved since the middle pin 58 of the
stamp arrangement 56 is displaced first, whereby the polymer film
40 is pressed down onto the first connecting part 28.
[0229] The two outer pins 60, 62 are then likewise linearly
displaced and so the polymer film 40 is pressed onto the first
frame part 12.
[0230] The stamp arrangement 56 therefore constitutes a
displaceable structure with which the symmetrical and radial
expansion of the polymer film 40 is ensured.
[0231] Furthermore, provision can be made for the polymer film 40
additionally to be fastened to the second tool part 54 in order to
achieve additional fixing. The fastening to the second tool part 54
can also take place as an alternative to the fastening to the first
tool part 46.
[0232] The polymer film 40 can then be fastened to the first frame
part 12, wherein this can happen by adhesion using e.g. UV-hardened
silicone or by thermal ultrasonic compression welding. The second
tool part 54 can comprise the corresponding instruments for
fastening purposes.
[0233] In general, the second tool part 54 has a plurality of such
stamp arrangements 56 and so a plurality of diaphragm actuators 10
can be produced simultaneously. This is significant in particular
in the case of batch-wise production of the diaphragm actuators
10.
[0234] After the mechanical expansion of the polymer film 40 has
taken place, the polymer film 40 fastened to the first tool part 46
can be cut off in a manner analogous to the first embodiment
variation of the production method and so the first diaphragm layer
16a is formed.
[0235] If the polymer film 40 should now have been fastened to the
second tool part 54, the polymer film 40 is correspondingly cut off
at that location.
[0236] The first electrode 20 or the second electrode 22 are
likewise subsequently attached to the first diaphragm layer
16a.
[0237] The above-described steps are now repeated and so a
plurality of diaphragm layers 16 are attached in order to form the
multi-layer diaphragm actuator 10. The electrodes 20, 22 attached
to the upper sides of the diaphragm layers 16 are respectively
alternated in this process and so each diaphragm layer 16 is
allocated a first electrode 20 and a second electrode 22.
[0238] As a concluding step, the second frame part 14 is placed
onto the last diaphragm layer 16 and the individual diaphragm
layers 16 are through-contacted in order to produce an electrical
connection and to mechanically couple the individual diaphragm
layers 16 to the frame parts 12, 14.
[0239] Furthermore, the second tool part 54 can have cutting means
64 with which the polymer film 40 fastened to the first tool part
46 can be cut off directly in the region of the first frame part 12
or of the diaphragm actuator 10. This can take place after
fastening the respective diaphragm layer 16 or after all diaphragm
layers 16 have been disposed.
[0240] The first tool part 46 formed as a working table can be
formed analogously to the embodiment previously depicted in FIGS.
12a to 12e.
[0241] The radial expansion of the polymer film 40 is suitable in
particular for the diaphragm actuators 10 which are circular.
[0242] FIG. 18 schematically shows a third embodiment variation of
the production method in accordance with the invention for
producing the diaphragm actuator 10 in accordance with the
invention.
[0243] In this alternative embodiment of the production method, a
working drum is used as the first tool part 46 and is shown in a
perspective view in FIG. 19.
[0244] In the illustrated embodiment, the first tool part 46 formed
as a working drum has eight working surfaces 66 which are each
allocated to one of eight working stations 68 as shown in FIG.
18.
[0245] As already indicated by the arrows in FIG. 18, the first
tool part 46 formed as a working drum can be moved rotationally and
in a linearly translatory manner, whereby one of the eight working
surfaces 66 lies opposite to one of the working stations 68 in a
step-by-step manner. For this purpose, the tool part 46 rotates by
45.degree. each time about its axis of rotation A.
[0246] The working stations 68 generally likewise have at least one
degree of freedom and so they can be linearly displaced.
[0247] The production of the diaphragm actuator 10 is described
with the aid of FIGS. 20a to 20h and with reference to the third
embodiment variation of the production method in accordance with
the invention.
[0248] In the first process step, the polymer film 40 is inserted
between the two roller pairs 42, 44 into a unit 70 formed by the
working stations 68 and the first tool part 46. The polymer film 40
is in this process damped between the two roller pairs 42, 44, in
particular it is slightly pretensioned.
[0249] The first tool part 46 is located in a position which is
displaced in a translatory manner from the centre.
[0250] The first working station 68a is moved in the first process
step in a translatory and linear manner towards the polymer film 40
and so it almost comes into contact with the polymer film 40. The
first working station 68a can measure the thickness of the polymer
film 40, wherein the thickness of the polymer film 40 can be
adjusted according to the movement of the roller pair 42, 44. In
particular, a greater pretensioning of the polymer film 40 can be
produced with the different speeds of the roller pairs 42, 44 and
the stretching resulting therefrom.
[0251] The thickness can be measured in particular by means of
optical techniques such as white light interferometry, transmission
spectroscopy or laser profilometry.
[0252] If the desired thickness of the polymer film 40 is achieved,
the second process step is carried out (see FIG. 20b).
[0253] In this process step, the first tool part 46 formed as a
working drum is moved in a translatory manner, wherein it is moved
with a first working surface 66a against the polymer film 40 and
expands said film mechanically. The first frame part 12 is placed
on the first working surface 66a and so this frame part is disposed
between the first working surface 66a and the polymer film 40.
[0254] The polymer film 40 can slide along the first working
surface 66a of the first tool part 46 provided that the surface of
the first working surface 66a is formed appropriately.
[0255] In this position the first working station 68a measures the
thickness of the polymer film 40 again and fastens the polymer film
40 to the first tool part 46. The polymer film 40 is then cut off
in a region between the second roller pair 44 and the fastening
point, as schematically illustrated by the arrow.
[0256] In order to fasten the polymer film 40 to the first tool
part 46, the first working station 68a can be formed substantially
analogously to the second tool part 54 in accordance with the
second embodiment variation of the production method.
[0257] The first tool part 46 formed as a working drum is now
rotated about its axis of rotation A by 45.degree. and so the first
working surface 66a lies opposite to the second working station 68b
(FIG. 20c). This constitutes the beginning of the third process
step.
[0258] In the second working station 68b a surface treatment of the
polymer film 40 is carried out. This can be e.g. a plasma
activation which increases the adhesion of the electron layer.
[0259] At the same time, in the first working station 68a, a second
batch of diaphragm actuators 10 is prepared since the same steps as
in FIG. 20b are carried out.
[0260] In general, the expansion of the polymer film 40 should
remain constant, for which reason the thickness of the polymer film
40 is constantly monitored in the first working station 68a.
[0261] After the surface treatment has been carried out, the first
tool part 46 formed as a working drum rotates again by 45.degree.
and so the first working surface 66a lies opposite to the third
working station 68c (see FIG. 20d).
[0262] In the third working station 68c, the first electrode 20 or
the second electrode 22 is attached to the treated surfaces of the
polymer film 40 and so the corresponding electrode 20, 22 is later
attached to the upper side of the diaphragm layer 16.
[0263] At the same time a third batch of diaphragm actuators 10,
which is disposed on the third working surface 66c, is prepared in
the first working station 68a, wherein the second batch undergoes a
surface treatment in the second working station 68b.
[0264] In a fourth process step, the first tool part 46 formed as a
working drum is again rotated by 45.degree. (see FIG. 20e) and so
the first working surface 66a of the first tool part 46 lies
opposite to the fourth working station 68d.
[0265] In the fourth working station 68d, a surface treatment is
again carried out, wherein this can be a corona treatment which
should avoid bubbles occurring during lamination.
[0266] The further batches of the diaphragm actuators 10 are
correspondingly treated in the working stations 68a to 68c.
[0267] The first tool part 46 now rotates further in 45.degree.
steps, wherein the fifth to eighth working surfaces 66e to 66h are
provided with a batch and the process steps provided in the first
four working stations 68a to 68d have been carried out.
[0268] When the first working surface 66a reaches the first working
station 68a, a second diaphragm layer 16 is then attached.
[0269] The steps are now repeated multiple times and so each batch
of diaphragm actuators 10 is provided with a plurality of diaphragm
layers 16 (see FIG. 20f). The individual diaphragm layers 16 are
laminated together to form a composite.
[0270] The working stations 5 to 8 only come into use when the
diaphragm actuators 10 comprise all the diaphragm layers 16.
[0271] When this is the case, the second frame part 14 is disposed
onto the uppermost diaphragm layer 16 in the fifth working station
68e, and is fastened thereto (see FIG. 20g).
[0272] At the same time, the polymer film 40 is severed in the
region of the first working station 68a. The further batches of
diaphragm actuators 10 continue to be processed in the preceding
working stations 68a to 68d.
[0273] The first tool part 46 then rotates again by 45.degree.,
wherein the individual diaphragm layers 16 of the diaphragm
actuators 10 are through-contacted in the sixth working station
68f.
[0274] After renewed rotation of the first tool part 46 by
45.degree., the batch of finished diaphragm actuators 10 is tested
in the seventh working station 68g.
[0275] After a further rotation by 45.degree., the diaphragm
actuator 10 reaches the eighth working station 68h in which the
batch of diaphragm actuators 10 is stamped or cut out in order to
form the individual diaphragm actuators 10.
[0276] In FIGS. 21a to 21c alternative embodiments of the first
tool part 46 are illustrated which can be used in the production
method in accordance with the third embodiment variation.
[0277] The illustrated tool parts 46 have fewer working surfaces 66
and so a working surface 66 can be allocated a plurality of working
stations 68.
[0278] Furthermore, FIGS. 22a to 22g show different embodiments of
the diaphragm actuator 10 which can likewise be produced with the
production method in accordance with the invention according to one
of the three alternative embodiments.
[0279] These correspond substantially to the previously described
embodiment with the difference that the diaphragm actuators 10 are
formed as single-layer diaphragm actuators.
[0280] In general, with the production method in accordance with
the invention a diaphragm actuator 10 in accordance with the
invention is created which can provide greater forces but is of a
small structure.
* * * * *