Valve including a step-up piston for controlling fluids

Details Valve including a step-up piston for controlling fluids Valve including a step-up piston for controlling fluids

1999-07-08

2001-09-18

Shaver, Kevin (Department: 3754)

Valves and valve actuation

Fluid actuated or retarded

Fluid link or column actuator

C251S129190, C251S054000

Reexamination Certificate

active

06290204

ABSTRACT:

PRIOR ART
The invention relates to a valve for controlling liquids. One such valve is known from European Patent Disclosure EP 0 477 400. There, the actuating piston of the valve member is disposed, tightly displaceably, in a smaller-diameter portion of a stepped bore, while conversely a larger-diameter step-up piston, which is moved with the piezoelectric actuator, is disposed in a larger-diameter portion of the stepped bore.
Between the two pistons, a hydraulic chamber is enclosed in such a way that when the step-up piston is moved a certain distance by the actuator, the actuating piston of the valve member is moved by a distance that is increased by the step-up ratio of the stepped bore diameters. The valve member, actuating piston, larger-diameter step-up piston, and piezoelectric actuator are all located on the same axis.
In such valves, the problem exists of compensating for changes in length of the piezoelectric actuator, the valve, or the valve housing, by means of the hydraulic coupling chamber. Since the piezoelectric actuator, for opening the valve, generates a pressure in the coupling chamber, this pressure also leads to a loss of coupling chamber liquid. To prevent the coupling chamber from being pumped dry, it must be refilled. A device that is intended to accomplish such refilling is already known from the prior art named at the outset, but this prior art has the disadvantage that a connection between the coupling chamber and a supply container that is constantly open in both possible flow directions is provided, which significantly affects the operating performance of the piezoelectric actuator. In particular, a thus increased volume leads to a compressibility that reduces the transmission rigidity of the hydraulic column formed by the coupling chamber.
ADVANTAGES OF THE INVENTION
The valve of the invention has an advantage over the prior art that filling of the coupling chamber is attained in a simple way via a valve function, and thus the step-up piston and the piston that actuates the valve always remain at the same spacing from one another. It is also advantageous that filling of the coupling chamber can be attained by simple means.


REFERENCES:
patent: 4320778 (1982-03-01), Baumann
patent: 4762300 (1988-08-01), Inagaki et al.
patent: 5186151 (1993-02-01), Schwerdt et al.
patent: 6067955 (1993-02-01), Boecking
patent: 6089529 (2000-07-01), Boecking
patent: 6142443 (2000-11-01), Potschin et al.
patent: 6155532 (2000-12-01), Heinz et al.

Affiliated with

Also associated with

Rating

Valve including a step-up piston for controlling fluids does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Valve including a step-up piston for controlling fluids, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Valve including a step-up piston for controlling fluids will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2454394