Method and apparatus for detecting the liquid level in a liquid reservoir

Patent metadata

Field	Value
Publication number	US-2018356271-A1
Application number	US-201816104710-A
Country	US
Kind code	A1
Filing date	Aug 17, 2018
Priority date	Feb 17, 2016
Publication date	Dec 13, 2018
Grant date	—

Abstract

A valve for connecting and disconnecting two fluid ports, that has a valve member which is movable between an open position, where the ports are in fluid communication and a first closed position where the first and second ports are not in fluid communication can be used to alter the volume of a gas being confined in a reservoir being connected to the valve, if the valve member can be moved into a second closed position in which the valve remains closed and the volume of a chamber being in fluid communication with the reservoir is altered.

First claim

What is claimed is:

1 . An apparatus for altering a gas volume in a reservoir, the apparatus comprising:
at least one valve having at least a first port being in fluid communication with the reservoir, a second port, and a conduit for enabling a liquid communication between the first port and the second port; and a valve member movable between at least an open position in which the first port and the second port are in fluid communication via said conduit, and a first closed position, in which the fluid communication between the first port and the second port is blocked by the valve member, wherein the valve member is movable into at least a second closed position, in which the fluid communication between the first port and the second port is blocked, and wherein a volume of a chamber that is in liquid communication with the first port is altered when moving the valve member from the first closed position to the second closed position and/or from the second closed position to the first position.

2 . The apparatus of claim 1 , wherein the apparatus further comprises a sensor providing a signal being representative for the force F required to move the valve member against the pressure in the reservoir from the first to the second closed position and/or from the second to the first closed position.

3 . The apparatus claim 1 , wherein the reservoir is a fuel tank and wherein the valve is:
a Fuel Tank Isolation Valve for controlling a fluid communication between the reservoir and the environment; a Fuel Tank Vent valve for controlling a fluid communication between the reservoir and an engine air intake and/or a canister being in fluid communication with the environment; a Fuel Tank Separation Valve for isolating the reservoir from the engine, a canister and environment during canister purging; an Atmospheric Isolation Valve for isolating a canister and/or the reservoir from the atmosphere to prevent gas emissions after shutoff; or a Fuel Tank Shutoff Valve for controlling fluid communication between a combustion engine and the reservoir.

4 . The apparatus of claim 1 , wherein the conduit comprises a valve seat and the valve member closes the valve seat in its first closed position and second closed positions and opens the valve seat in its open position, wherein an elastic gasket is positioned between the valve seat and the valve member, and wherein the elastic gasket is compressed when moving the valve member from its first closed position to its second closed position and decompressed when moving the valve member from its second closed position to its first closed position.

5 . The apparatus of claim 1 , wherein the valve member comprises at least a section of the conduit, wherein the conduit has at least a first opening being positioned in front of the first port and a second opening being positioned in front of a second port if the valve member is in its open position to thereby provide the fluid communication, wherein the first port is in fluid communication with a chamber into which the valve member protrudes when the valve member is moved from the first closed position to the second closed position, and wherein a boundary of the chamber closes at least one of the first and/or second openings of the conduit when moving the valve member from the open position into the first closed position and/or second closed position.

6 . A method for measuring a change in pressure due to change of a volume of a reservoir confining a gas, the method comprising:
altering the volume of the reservoir according to a first initial signal by a first change in volume; obtaining a pressure signal that is representative of the pressure in the reservoir as function of time; and demodulating the pressure signal using the first initial signal as a reference signal.

7 . The method of claim 6 , wherein the liquid reservoir is in fluid communication with a first port of an apparatus, the apparatus comprising:
at least one valve having at least a first port being in fluid communication with the reservoir, a second port, and a conduit for enabling a liquid communication between the first port and the second port; and
a valve member movable between at least an open position in which the first port and the second port are in fluid communication via said conduit, and a first closed position, in which the fluid communication between the first port and the second port is blocked by the valve member,
wherein the valve member is movable into at least a second closed position, in which the fluid communication between the first port and the second port is blocked, and
wherein a volume of a chamber that is in liquid communication with the first port is altered when moving the valve member from the first closed position to the second closed position and/or from the second closed position to the first position, and
wherein, altering the volume is obtained by altering the position of the valve member between at least two of said closed positions according to the first initial signal

8 . The method of claim 6 , wherein the step of demodulation comprises multiplying the reference signal with the pressure signal thereby obtaining a demodulated pressure signal.

9 . The method of claim 6 , wherein the step of demodulation comprises multiplying a phase shifted reference signal with the pressure signal thereby obtaining a second demodulated pressure signal.

10 . The method of claim 8 , wherein the demodulated pressure signal is given by p d,1 (t)=√{square root over (p d,1 X 2 (t)+p d,1 γ 2 (t))}.

11 . The method of claim 9 , wherein the demodulated pressure signal is integrated or wherein the pressure signal is amplified prior to its demodulation.

12 . The method of claim 6 , further comprising:
altering the volume of the reservoir according to a second initial signal by a second change in volume; obtaining a second pressure signal being representative for the pressure in the reservoir as function of time; and demodulating the pressure signal using the second initial signal as the reference signal thereby obtaining a second demodulated pressure signal.

13 . The method of claim 6 , wherein the step of altering the volume of the reservoir according to an initial signal comprises altering the volume by a first change in volume according to a first initial signal and at substantially a same time by a second change in volume according to a second initial signal at a substantially same time by modulating the volume with a superposition of the first and second changes in volume, and wherein the step of demodulating the pressure signal using the first initial signal as the reference signal thereby obtaining a first demodulated pressure signal and demodulating the pressure signal uses the second initial signal as the reference signal thereby obtaining a second demodulated pressure signal.

14 . The method of claim 13 , wherein a gas volume inside the reservoir follows:
V g ( t )= V 0 +ΔV 1 ·S 1 ( t )+Δ V 2 ( t )· S 2 ( t ),
wherein V 0 is a constant, ΔV 1 ,ΔV 2 are said first and second changes in volume and S 1 (t),S 2 (t) are the first and second initial signals.

15 . The method of claim 13 , wherein, for the first and second signals the equation S 1 (t)≠γ·S 2 (t) holds true for any constant γ and/or in that at least the first initial signal (S 1 (t)) is periodic and has an angular frequency, wherein the method is repeated with different angular frequencies, the resonance frequency is determined where the absolute value of the change in pressure becomes maximum and in that the volume of t

Assignees

• Hella Gmbh & Co Kgaa

Inventors

• Henning Irle
• Niemeyer Ingo

Classifications

• G01F22/02 Primary

  involving measurement of pressure · CPC title

• G01F23/18

  Indicating, recording or alarm devices actuated electrically · CPC title

• G01F23/14

  by measurement of pressure · CPC title

• G01F17/00

  Methods or apparatus for determining the capacity of containers or cavities, or the volume of solid bodies (measuring linear dimensions to determine volume G01B) · CPC title

• G01F23/80

  Arrangements for signal processing · CPC title