Valves and valve actuation – Electrically actuated valve – Having element dimensionally responsive to field
Patent
1999-05-20
2000-11-07
Shaver, Kevin
Valves and valve actuation
Electrically actuated valve
Having element dimensionally responsive to field
137831, F16K 3102
Patent
active
061424447
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to micromechanically produced valves and especially to piezoelectrically operated microvalves.
2. Description of Prior Art
Microvalves can generally be used in the fields of pneumatics and fluidics for controlling the flow of gases and liquids, i.e. fluid flows. Such a valve can either have the function of a pilot valve or it can directly be used for controlling a volume flow or a pressure in a working piston or the like.
Piezoelectrically operated microvalves which are known at present and which are based on the inverse piezoelectric effect comprise a large piezoelectric ceramic which is fixed at one end in most cases and by means of which the fluid flow is controlled directly. Such a piezoelectrically operated silicon microvalve is described in R. Ro.beta.berg, B. Schmidt, S. Buttgenbach: "Micro Liquid Dosing System", Microsystem Technologies 2 (1995), pages 11 to 16, Springer-Verlag 1995. In such microvalves, either the piezoelectric ceramic itself can serve as a valve tappet or the valve tappet used is a tappet which is directly guided by the piezoelectric ceramic.
The microvalves described in the above publication are disadvantageous insofar as, for obtaining the deflection of the valve tappet over the valve seat which is necessary for a high flow rate, a very long piezoelectric ceramic is required, said valve tappet being also referred to as valve flap. For accommodating such a piezoelectric ceramic, it is, of course, also necessary to use a correspondingly large casing. It follows that the known piezo-operated microvalves, which are described e.g. in the above-mentioned publication, have, in comparison with their construction size, a comparatively small valve opening, i.e. nominal width.
From A. Dogan, J. F. Fernandez, J. F. Tressler, K. Uchino, R. E. Newnham: "Properties of piezoelectric actuators"; Proceedings 5th International Conference on New Actuators 1996; Bremen 26th to 28th June 1996, and J. F. Fernandez, A. Dogan, J. F. Tressler, K. Uchino, R. E. Newnham: "Tailoring performance of cymbal actuators", Proceedings 5th International Conference on New Actuators, Bremen 26th to 28th June 1996, piezoelectric actuators are known, which consist of a piezoelectric ceramic material as a drive element which is arranged between two end covers having their edges connected to the ceramic material. By means of this arrangement, a lateral movement of the piezoelectric ceramic is converted into a large axial displacement at right angles to said end covers and amplified. As has been described in the publication "Tailoring performance of cymbal actuators", metals or metal alloys, e.g. zirconium, brass, low-carbon steel, molybdenum or tungsten, are used as end covers.
U.S. Pat. No. 5529279 describes a microactuator in which a thermal actuator is provided for driving a tappet, which is formed in a first substrate and which is supported in a diaphragm-like manner, for leaving an opening open and for closing it. A second substrate is connected to the first substrate and to a carrier in such a way that the tappet closes an opening which extends through said second substrate and which is in In the Abstract of JP-A-0715 8757, a microvalve is described in which a carrier plate having a passage opening is provided, a silicon diaphragm with a tappet-like portion of increased thickness being connected to said carrier plate for leaving said passage opening open or for closing it. The diaphragm is driven by a piezocomponent arranged on said diaphragm.
DE-A-4417251 describes a microvalve in which one or a plurality of passage openings in a carrier component are adapted to be closed by a movement of a closure member which is connected to said carrier component via elastic connection elements, said movement taking place at right angles to said carrier component as well as parallel thereto.
It is the object of the present invention to provide a piezoelectrically operated microvalve, the construction size of which is substantially smaller than
REFERENCES:
patent: 3174716 (1965-03-01), Salter
patent: 4450375 (1984-05-01), Siegal
patent: 4581624 (1986-04-01), O'Connor
patent: 5340081 (1994-08-01), Wright
patent: 5529279 (1996-06-01), Beatty et al.
Rossberg et al., "Micro Liquid Dosing System", 1995, Microsystems Technoles.
Fernandez et al., "Properties of Piezoelectric Actuators", International Center for Actuators and Transducers.
Fernandez et al., "Tailoring Performance of Cymbal Actuators", International Center for Actuators and Transducers.
Fraunhofer-Gesellschaft zur Forderung der ange-wandten Forschung
Keasel Eric
Shaver Kevin
LandOfFree
Piezoelectrically actuated microvalve does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Piezoelectrically actuated microvalve, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Piezoelectrically actuated microvalve will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1633473