Operating fluid container with capacitive detection of filling levels

Patent metadata

Field	Value
Publication number	US-11754430-B2
Application number	US-201916979384-A
Country	US
Kind code	B2
Filing date	Feb 15, 2019
Priority date	Mar 9, 2018
Publication date	Sep 12, 2023
Grant date	Sep 12, 2023

Abstract

An operating fluid tank includes a capacitor. The capacitor includes a first electrode and a second electrode. Between the first electrode and the second electrode, a clearance is formed which is fluid-connected to an operating fluid tank interior. The fluid tank also includes an evaluator electrically connected to the capacitor for determining a capacity of the capacitor by means of measurement signals determined by the capacitor. The first electrode and the second electrode include an electrically conductive plastic material.

First claim

The invention claimed is:

1. An operating fluid tank with a capacitive determination of a fill level of the operating fluid tank, the operating fluid tank comprising:
a capacitor comprising a first electrode and a second electrode, wherein between the first electrode and the second electrode a clearance is formed which is fluid-connected to an operating fluid tank interior; and
an evaluator electrically connected to the capacitor for determining a capacitance of the capacitor by means of measurement signals determined by the capacitor, wherein the capacitance of the capacitor indicates a measure of the fill level,
wherein the first electrode and the second electrode comprise an electrically conductive plastic material,
wherein:
the first electrode is multi-layered, and
an electrode layer of the first electrode, which adjoins a clearance of the capacitor, is formed from the electrically conductive plastic material, and

wherein the first electrode has an outer layer, a recyclate layer adjacent to the outer layer, a first adhesion promoting layer adjacent to the recyclate layer, a barrier layer adjacent to the first adhesion promoting layer, a second adhesion promoting layer, and an electrode layer adjacent to the barrier layer, and
wherein the electrode layer is adjacent to the second adhesion promoting layer.

2. The operating fluid tank according to claim 1 , wherein the capacitor is connected to a tank wall of the operating fluid tank.

3. The operating fluid tank according to claim 1 , wherein:
the operating fluid tank has a reserve fluid-connected connected to the operating fluid tank interior which is connected to a tank base wall of the operating fluid tank; and
at least one part of a wall of the reserve forms a first electrode and/or a second electrode.

4. The operating fluid tank according to claim 1 , wherein:
the operating fluid tank interior is filled with operating fluid via a filler tube through an opening;
the filler tube forms the capacitor, wherein the first electrode forms a first partly hollow cylinder and the second electrode forms a second partly hollow cylinder;
the first partly hollow cylinder is connected through longitudinal edges thereof with longitudinal edges of the second partly hollow cylinder to form a clearance, wherein the clearance forms a cavity; and
an electrically insulating plastic material is arranged between the longitudinal edges of the first partly hollow cylinder and the longitudinal edges of the second partly hollow cylinder.

5. The operating fluid tank according to claim 1 , wherein the capacitor is arranged in a liquid separator of a venting device of the operating fluid tank via which the operating fluid tank interior is at least indirectly fluid-connected to the atmosphere, so that an operating fluid in the liquid separator is detectable via the capacitor.

6. The operating fluid tank according to claim 1 , wherein the electrically conductive plastic material includes electrically conductive particles dispersed therein.

7. The operating fluid tank according to claim 6 , wherein the electrically conductive particles comprise conductive soot particles.

8. The operating fluid tank according to claim 6 , wherein the first electrode and/or the second electrode comprise a high-density polyethylene plastic material in which the electrically conductive particles are dispersed.

9. The operating fluid tank according to claim 1 , wherein:
the second electrode is multi-layered; and
an electrode layer of the second electrode, which adjoins a clearance of the capacitor, is formed from electrically conductive plastic material.

10. The operating fluid tank according to claim 9 , wherein the second electrode has an outer layer, a recyclate layer adjacent to the outer layer, a first adhesion promoting layer adjacent to the recyclate layer, a barrier layer adjacent to the first adhesion promoting layer, a second adhesion promoting layer, and an electrode layer adjacent to the barrier layer, and
wherein the electrode layer is adjacent to the second adhesion promoting layer.

11. The operating fluid tank according to claim 1 , wherein at least one part of a tank wall of the operating fluid tank forms the first electrode and/or as the second electrode.

12. The operating fluid tank according to claim 11 , wherein the tank wall is an exterior wall and the first electrode and/or the second electrode face the operating fluid tank interior.

13. The operating fluid tank according to claim 1 , wherein the first electrode forms a first partly hollow cylinder and/or the second electrode forms a second partly hollow cylinder.

14. The operating fluid tank according to claim 12 , wherein:
the first partly hollow cylinder is connected via longitudinal edges thereof to the second electrode to form a clearance, wherein the clearance forms a cavity; and
the first partly hollow cylinder is connected to the second electrode by means of an electrically insulating plastic material.

Assignees

• Kautex Textron Gmbh & Co Kg

Inventors

• Wind Stefan
• Barkow Axel

Classifications

• G01F23/263 Primary

  by measuring variations in capacitance of capacitors · CPC title

• D06F39/087

  Water level measuring or regulating devices · CPC title