U.S. patent application number 09/429294 was filed with the patent office on 2002-01-24 for control member for a piezo-valve.
Invention is credited to HOFFMANN, MARKUS, JENTSCHKE, MICHAEL, WEINMANN, DR. MICHAEL.
Application Number | 20020008218 09/429294 |
Document ID | / |
Family ID | 8064968 |
Filed Date | 2002-01-24 |
United States Patent
Application |
20020008218 |
Kind Code |
A1 |
WEINMANN, DR. MICHAEL ; et
al. |
January 24, 2002 |
CONTROL MEMBER FOR A PIEZO-VALVE
Abstract
A control member for a piezo-valve having an elongated flexible
element, which at one of its two axial ends has a respective
sealing face on oppositely placed longitudinal side faces. The two
sealing elements are a common component of a sealing body, which
possesses a connecting section extending between the two sealing
elements and formed integrally with same, such connecting section
having an opening of the flexible element extending through it. The
two sealing elements overlap the marginal section, delimiting the
opening, of the flexible element and in the peripheral part of the
opening engage the respectively associated longitudinal side face
of the flexible element.
Inventors: |
WEINMANN, DR. MICHAEL;
(PLUDERHAUSEN, DE) ; JENTSCHKE, MICHAEL;
(AICHWALD, DE) ; HOFFMANN, MARKUS; (WOLFSCHLUGEN,
DE) |
Correspondence
Address: |
HOFFMANN & BARON LLP
6900 JERICHO TURNPIKE
SYOSSET
NY
11791
|
Family ID: |
8064968 |
Appl. No.: |
09/429294 |
Filed: |
October 28, 1999 |
Current U.S.
Class: |
251/129.06 ;
251/357 |
Current CPC
Class: |
F16K 31/006
20130101 |
Class at
Publication: |
251/129.06 ;
251/357 |
International
Class: |
F16K 001/226 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 6, 1998 |
DE |
298 19 856.8 |
Claims
1. A control member for a piezo-valve, comprising an elongated
flexible element, which at one of its two axial ends on opposite
longitudinal side face means possesses a sealing element having a
sealing face means, wherein the two sealing elements are common
components of a sealing body, which possesses a connecting section
extending between the two sealing elements and designed integrally
with the same, such connecting section extending through an opening
in the flexible element, the two sealing elements fitting around an
edge section, which delimits the opening, of the flexible element
and in the peripheral region of the opening resting against a
respectively associated longitudinal side face means of the
flexible element.
2. The control member as set forth in claim 1, wherein the opening,
through which the connecting section of the sealing body extends,
is open toward the edge of the flexible element to render possible
fitting by plugging in of the sealing body.
3. The control member as set forth in claim 2, wherein the opening
is directed toward the adjacent axially orientated end face means
of the flexible element.
4. The control member as set forth in claim 1, wherein the sealing
body is adhesively bonded to the flexible element.
5. The control member as set forth in claim 1, wherein the two
sealing elements engage the flexible element with an at least
slight bracing action.
6. The control member as set forth in claim 1, wherein the sealing
body possesses a surrounding annular groove, whose floor is
constituted by the peripheral face of the connecting section and
whose flanks are constituted by the sealing elements.
7. The control member as set forth in claim 1, wherein at least one
sealing face is formed directly on the associated sealing
element.
8. The control member as set forth in claim 1, wherein at least one
sealing face is provided on a separate sealing face part provided
on the associated sealing element.
9. The control member as set forth in claim 8, wherein the sealing
face part is secured on the associated sealing element by an
adhesive bond or by having material injected around it in the
course of production by injection molding of the sealing body.
10. The control member as set forth in claim 8, wherein the sealing
face part is at least partially embedded in the associated sealing
element.
Description
BACKGROUND OF THE INVENTION
[0001] The invention relates to a control member for a piezo-valve,
comprising an elongated flexible element, which at one of its two
axial ends on opposite longitudinal side faces respectively
possesses a sealing element having a sealing face.
THE PRIOR ART.
[0002] A control member of this type is for example disclosed in
the European patent publication 0 170 990 A1. Here it is part of a
piezo-valve belonging to a vacuum control device, it having an
elongated flexible element termed a flexure transducer held at one
axial end in a manner fixed in relation to the housing and at its
other axial end is provided on mutually opposite longitudinal side
faces with a respective sealing element, which is opposite to the
port or end of a fluid duct. By the application of a voltage to the
flexible element the latter is deformed so that a sealing face
provided on one of the two sealing elements is selectively brought
into contact with a valve seat surrounding the duct port or
end.
[0003] In the case of the known piezo-valve the two sealing
elements are mounted on the flexible element and probably bonded
thereto. This means that inaccuracies in manufacture and assembly
will make themselves felt at the two sealing elements and will be
cumulative in effect and will mean that the distances between the
two sealing faces may vary and this will impair operation of the
piezo-valve. Because the displacement of the flexible element
occurring in the course of operation is generally extremely small,
even small dimensional errors will have a disastrous effect and
will f. i. render necessary a complex resetting of the nozzles in
relation to the flexible element.
SHORT SUMMARY OF THE INVENTION
[0004] One object of the invention is to provide a control member
of the type initially mentioned, which renders possible simple but
nevertheless more accurate manufacture.
[0005] In order to achieve these and/or other objects appearing
from the present specification, claims and drawings, in the present
invention the two sealing elements are common components of a
sealing body, which possesses a connecting section extending
between the two sealing elements and designed integrally with the
same, such connecting section extending through an opening in the
flexible element, the two sealing elements fitting around an edge
section, which delimits the opening, of the flexible element and in
the peripheral region of the opening resting against a respectively
associated longitudinal side face of the flexible element.
[0006] It is in this manner that the two sealing elements are
collected together in a common sealing body, the elements being
connected together via the connecting section so that there is a
set distance between the two sealing faces, which may be
established even during the production of the sealing body. In this
respect there is also more especially the possibility of treating
the sealing body at its sealing faces, as required, mechanically
and/or thermally independently of the flexible element and without
the material of the flexible element being impaired. Since in the
mounted state (owing to the sealing elements overlapping the edge
section delimiting the opening) there is a mechanical anchoring of
the sealing body on the flexible element, and simple and accurate
assembly and fitting becomes possible, it is possible to ensure
that the distance present between the two sealing faces is not
changed and inaccuracy due to assembly is small. It will be clear
that the flexible element will be designed in accordance with the
opening, the position or layout of any electrodes necessary for
operation being more particularly a factor which facilitates
producing the opening.
[0007] Further advantageous developments of the invention are
defined in the claims.
[0008] It would in principle be possible to design the opening in
the form of a hole with a complete periphery, into which the
sealing body is thrust like a button which more especially in this
case should have rubber-like properties. An even simpler design is
however one in which the opening, through which the connecting
section of the sealing body extends, in the flexible element is
open or interrupted at its edge in order to permit plugging in of
the sealing body through the interruption in the edge or boundary
of the opening. In this respect it is an advantage for reasons of
symmetry for the edge interruption of the opening to be on the
axially orientated end face of the flexible element.
[0009] More particularly in cases in which no adequate, secure
attachment can be provided, it is recommended to have an additional
adhesive bond between the sealing body and the flexible
element.
[0010] The dimensions of the connecting section may be so selected
that the two sealing elements are braced against the flexible
element.
[0011] The sealing faces may be provided directly on the
respectively associated sealing element so that they constitute an
integral component of the sealing body. However as an alternative
in this respect a particularly advantageous design is one in which
the sealing faces are provided on separate sealing face parts and
such sealing face parts are on the integral sealing body. It is
then possible for the sealing body to be designed in an optimum
fashion as regards its holding functIon on the flexible element and
independently of this to select the best suited material for the
sealing faces.
[0012] Further advantageous developments and convenient forms of
the invention will be understood from the following detailed
descriptive disclosure of embodiments thereof in conjunction with
the accompanying drawings.
LIST OF THE SEVERAL VIEWS OF THE FIGURES
[0013] FIG. 1 shows a first design of the control member of the
invention in a plan view looking toward one of the longitudinal
side faces of the flexible element.
[0014] FIG. 2 shows a further design of the control member in a
view corresponding to that of FIG. 1, the direction of sight being
indicated in FIG. 3 by the arrow II.
[0015] FIG. 3 illustrates a longitudinal section taken through the
control member of FIG. 2 on the line III-III, housing components of
a piezo-valve provided with the control member and the sealing body
being illustrated in cross section prior to fitting and in a
lateral view following fitting.
[0016] FIG. 4 shows a further possible design of the control member
in a view corresponding to FIG. 2, the sealing elements having a
different configuration.
DETAILED ACCOUNT OF WORKING EMBODIMENTS OF THE INVENTION
[0017] All figures of the drawing show a control member 1, which is
able to be employed in piezo-valves. FIG. 3 shows as an example
some further components of such piezo-valve 2, which as a rule has
a housing 3 defining an inner space 4, wherein the control member 1
extends.
[0018] The control member 1 contains an elongated tabular flexible
element 5 with a preferably rectangular outline which at one of its
two axial ends--in the following referred to the rear end 6--is
clamped in relation to the housing. Its two mutually opposite
longitudinal side faces 7 and 7' which are represented by large
longitudinal plate faces turned away from each other, are contacted
by electrical conductors 8 and 8' so that by means of a power
source 12 as indicated in chained lines a voltage may be applied,
which causes a pivotal movement 12, indicated by a double arrow, in
relation to the point 13 of fixation on the housing, of the
flexible element.
[0019] At the other axial end, opposite to the rear end 6, of the
flexible element 5--such end being referred to in the following as
the front end 14--a sealing body 15 is secured. Such body contains
two disk- or plate-like sealing elements 16 and 16', which from
opposite sides abut the two longitudinal side faces 7 and 7' of the
flexible element 5. Each sealing element 16 and 16' comprises a
sealing face 17 and 17' turned away from the flexible element 5,
such face being opposite an annular valve seat 18 and 18' on the
housing and which surrounds the opening or port of a fluid duct 19
and 19' extending in the housing 3.
[0020] By pivoting the control member 1 it is possible for the one
or the other of the sealing faces 17 and 17' to be applied to the
valve seat 18 and 18' opposite to it so that the port of the
associated fluid duct 19 and 19' is closed. Simultaneously with
this the oppositely oriented other sealing face is moved clear of
the valve seat facing same so that the port of the associated fluid
duct is cleared and fluid flow may take place. If the piezo-valve 2
is a 3/2 way valve, it is possible for a further fluid duct (not
illustrated) to open into the inner space 4, such duct being able
to be connected with one of the two above mentioned fluid ducts 19
and 19' in a manner dependent on the pivotal setting of the control
member. It would also be possible to have a design with a 2/2 way
valve, a switching position as indicated FIG. 3 being possible, in
which both sealing faces 17 and 17' are moved clear of the
associated valve seat 18 and 18' so that a fluid, as for example
compressed air, may be transferred through the inner space 4
between the two fluid ducts 19 and 19'. In order to interrupt the
fluid connection in this case the one of the sealing faces 17 and
17' sealing body 15 is thrust against one of the valve seats 18 and
18'.
[0021] The two sealing elements 16 and 16' are connected integrally
by means of a connecting section 22 arranged between them of the
sealing body 15, the cross section of the connecting section 22
being smaller than that of the two sealing elements 16 and 16' so
that sealing body 15 on the whole possesses a block- or disk-like
shape and has an surrounding annular groove 23. The floor 24 of the
groove 23 is constituted by the peripheral face of the connecting
section 22 and the two groove flanks are formed by the marginal
region, overlapping connecting section 22, of the sealing elements
16 and 16'. The width, as measured l between the groove flanks 25
and 25', of the annular groove 23 is best made the same as the
thickness, as measured between the longitudinal side faces 7 and
7', of the flexible element 5 at the attachment point of the
sealing body 15.
[0022] At the attachment point of the sealing body 15 the flexible
element 5 possesses a through opening 26 between the longitudinal
side faces 7 and 7'. When the sealing body 15 is mounted the
connecting section 22 extends through the opening 26, whereas the
two sealing elements 16 and 16' overlap the marginal section 27
(which peripherally delimits the opening 26) of the flexible
element 5 and furthermore in the peripheral region of the opening
26 rest against the respectively associated longitudinal side faces
7 and 7' of the flexible element 5.
[0023] In the working embodiment of FIG. 1 the opening 26 is in the
form of a hole which is peripherally complete and without any slot
opening into it and into which the sealing body 15 is buttoned or
snap fitted, such body 15 preferably consisting of a material with
rubber-like properties.
[0024] As a departure from this in the case of the working examples
of FIGS. 2 such 4 there is the provision that the opening 26 is
open or interrupted at the relatively narrow edge of the flexible
element 5, the marginal interruption 28 preferably being on the
axially orientated end face 32 of the front end 14 of the flexible
element 5. The opening 26 is in this case thus produced as a sort
of cut or recess in the front end face 32.
[0025] The production of the opening 26 is furthermore preferably
facilitated in all embodiments because the electrodes (which are in
electrical contact with the conductors 8 and 8' and are not
illustrated in detail in the drawing) of the flexible element
possess a suitably adapted configuration .
[0026] The marginal interruption 28 into the opening 26 renders
possible simple assembly by plugging in of the sealing body 15 from
the axial front side of the flexible element 5. In this case there
is preferably a provision such that the width, as measured in the
plane of extension of the flexible element 5 athwart its
longitudinal direction, of the marginal interruption 28 corresponds
to the transverse dimensions of the connecting section 22. The
arrangement should as far as possible be such that on introduction
of the sealing body 15 into the opening 26 in the flexible element
5, the distance "a" present before fitting between the two sealing
face 17 and 17' remains unchanged. Thus in the case of manufacture
of the sealing body 15 taking place separately from that of the
flexible element 5 it is possible to ensure an accurate distance
"a", which even after fitting to the flexible element 5 will not be
changed so that one the whole exact manufacture is possible with
extremely small inaccuracies.
[0027] During fitting of the sealing body 15 by plugging into the
opening 26 the flexible element's marginal section 27, which
delimits the opening 26, fits into the annular groove 23 on
opposite sides so that the sealing body 15 may be readily slipped
on in the correct setting. Once the sealing body 15 has reached its
terminal position, it is both mechanically interlocked and held in
the transverse direction of the flexible element 5 and also in the
thickness direction thereof and is relatively securely fixed in
place just by this. In this respect conventionally used rubber-like
material for the sealing body 15 will permit dimensions such that
the two sealing elements 16 and 16' engage the flexible element 5
with an at least slight bracing or biasing effect so that there is
also a certain degree of non-positive or frictional holding action
as well. It is however convenient to have an additional adhesive
bond between the sealing body 15 and the flexible element 5 for
final attachment.
[0028] In the working embodiments illustrated in FIGS. 1 through 3
the connecting section 22 possesses a cylindrical shape and
furthermore the sealing elements 16 and 16' as well have a circular
outline. In the case of the design of FIG. 1 the diameter of the
opening 26 is the same as that of the connecting section 22. In the
working embodiment of FIGS. 2 and 3 the opening 26 possesses a
U-like shape, the marginal interruption 28 being located in the
U-like region and the radius of the U-like region being the same as
that of the connecting section 22 so that same may make snug
engagement with the edge of the interruption 26.
[0029] In the working embodiment of FIG. 4 both the interruption 26
and also the connecting section 22 is rectangular and more
especially square in shape. Furthermore the sealing elements 16 and
16' possess a rectangular and more particularly square outline.
[0030] FIGS. 2 through 4 furthermore serve to make it clear that
the depth as measured in the longitudinal direction of the flexible
element 5 may readily be selected so that in its fitted state the
sealing body 15 has a portion of its periphery extending past the
front end face 32 of the flexible element 5 axially.
[0031] The sealing faces 17 and 17' can be directly formed on the
respectively associated sealing element 16 and 16', as is indicated
by way of example with reference to FIG. 1. In this case the
sealing body 15 including the sealing faces 17 and 17' constitutes
a preferably integral body, which is preferably made of plastic
material and more especially has rubber-like properties.
[0032] In the case of an alternative design as is indicated with
reference to FIGS. 2 through 4, the sealing faces 17 and 17' are a
component of separate sealing face parts 33 and 33', which are
secured in a permanent manner on the sealing body 15 adjacent to
the sealing elements 16 and 16'. The attachment of the sealing face
parts 33 and 33' may for instance be by adhesive bonding, or more
preferably, in the case of production by injection molding of the
sealing body 15, by having material of the sealing body injected
partly around same. In any case it is preferred to use a design in
the case of which the sealing face parts 33 and 33' are flat disk
bodies, which are embedded or let into the external face, turned
toward valve seat 18 and 18', in the associated sealing element 16
and 16' at least partially. In the case of the embodiments of FIGS.
2 through 4, the sealing faces 17 and 17' provided on the sealing
face parts 33 and 33' are in a common plane with the region
surrounding the sealing face parts 33 and 33', of the sealing body
15.
[0033] The separate design of the sealing faces 17 and 17' does
offer the advantage that the material of the sealing body 15 may be
selected as regards its holding function and the material of the
sealing face parts 33 and 33' 15 may be selected as regards its
sealing function to be performed without having to make any
compromise. It is convenient for both the sealing body and also the
sealing face parts 33 and 33' to be manufactured of plastic
material, whose hardness and elasticity may be selected as
desired.
* * * * *