Arrangement for measuring a fluid pressure

• US 20020046611A1
• Filed: 10/09/2001
• Published: 04/25/2002
• Est. Priority Date: 04/09/1999
• Status: Active Grant

• Current Assignee: Lucas Industries Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: Lucas Industries Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Gegalski, Helmut
• Granted Patent: US 6,722,204 B2
• Time in Patent Office: Days
• US Class Current: 73/716
• CPC Class Codes: B60T 8/3675 integrated in modulator units
• CPC Class Codes: F15B 11/028 for controlling the actuating force F15B11/024 takes precedence
• CPC Class Codes: F15B 13/0803 Modular units
• CPC Class Codes: F15B 2013/004 Cartridge valves
• CPC Class Codes: F15B 2211/25 Pressure control functions
• CPC Class Codes: F15B 2211/50554 the pressure control means controlling a pressure downstream of the pressure control means, e.g. pressure reducing valve
• CPC Class Codes: F15B 2211/526 electrically or electronically
• CPC Class Codes: F15B 2211/6313 the pressure being a load pressure
• CPC Class Codes: F15B 2211/6346 representing a state of input means, e.g. joystick position
• CPC Class Codes: F15B 2211/6653 Pressure control
• CPC Class Codes: F15B 2211/7052 Single-acting output members
• CPC Class Codes: F15B 2211/857 Monitoring of fluid pressure systems
• CPC Class Codes: G01L 19/0007 Fluidic connecting means
• CPC Class Codes: G01L 19/003 using a detachable interface or adapter between the process medium and the pressure gauge
• CPC Class Codes: G01L 19/0084 to the outside of the housing other details about the housing see G01L19/14
• CPC Class Codes: G01L 19/0645 using isolation membranes, specially adapted for protection
• CPC Class Codes: G01L 19/14 Housings G01L19/0007, G01L19/0084, G01L19/0092, G01L19/04, G01L19/06 take precedence
• CPC Class Codes: G01L 19/142 Multiple part housings
• CPC Class Codes: G01L 19/147 Details about the mounting of the sensor to support or covering means
• CPC Class Codes: G01L 19/148 Details about the circuit board integration, e.g. integrated with the diaphragm surface or encapsulation
• CPC Class Codes: G01L 9/0051 : using variations in ohmic resistance
• CPC Class Codes: G01L 9/0072 : using variations in capacitance

Abstract

An arrangement for measuring a fluid pressure, comprising a pressure sensor portion (10), which is devised for accommodation in a recess (12), which is open at least at one end, wherein the pressure sensor portion (10) in relation to the recess (12) is to be dimensioned in such a way that the pressure sensor portion (10) is surrounded by a gap (14) for receiving fluid, wherein first and second surfaces (16a, 16b, 18a, 18b), which are situated on the pressure sensor portion (10) and in contact with fluid, are so dimensioned and aligned that forces, which are exerted by the fluid pressure on the first surfaces (16a, 16b) and push the pressure sensor portion (10) in the direction of the open end of the recess, are equal to or lower than the forces, which are exerted by the fluid pressure on the second surfaces (18a, 18b) and push the pressure sensor portion (10) away from the open end of the recess (12).

Claims

1. An arrangement for measuring a fluid pressure, comprising

a portion (10) devised for accommodation in a recess (12), which is open at least at one end, wherein the portion (10) being so dimensioned in relation to the recess (12) that the portion (10) is surrounded by a gap (14) for receiving fluid, with which gap a fluid inlet disposed in a wall of the recess (12) is associated, the portion (10) including first and second surfaces (16a, 16b, 18a, 18b), which are situated on the portion (10) and in contact with fluid and are so dimensioned and aligned that forces, which are exerted by the fluid pressure on the first surfaces (16a, 16b) and push the portion (10) in the direction of the open end of the recess (12), are equal to or lower than forces, which are exerted by the fluid pressure on the second surfaces (18a, 18b) and push the portion (10) away from the open end of the recess (12);

and

a pressure sensor (26) carried by said portion (10).

2. The arrangement for measuring a fluid pressure according to claim 1, wherein said first and second surfaces (16a, 18a), which are situated on the pressure sensor portion (10) and in contact with fluid, are so dimensioned and aligned that forces, which are exerted by the fluid pressure on the first surfaces (16a, 18a) and push the pressure sensor portion (10) in the direction of the open end of the recess (12), are equal to the forces, which are exerted by the fluid pressure on the second surfaces (16b, 18b) and push the pressure sensor portion (10) away from the open end of the recess (12).

3. The arrangement for measuring a fluid pressure according to claim 2, wherein said first surfaces (16a, 18a) and said second surfaces (16b, 18b) are, in relation to a centre plane (M), symmetrical to one another.

4. The arrangement for measuring a fluid pessure according to claim 3 wherein said pressure sensor portion (10) is secured in the recess (12) by a retaining means, preferably a snap ring (36).

5. The arrangement for measuring a fluid pressure according to claim 3 wherein said pressure sensor portion (10) has a shape, which in relation to its centre line (L) is rotationally symmetrical.

6. The arrangement for measuring a fluid pressure according to claim 1, wherein the pressure sensor portion (10) in a middle region includes a first collar (20) with a substantially closed lateral surface and a first end surface (16a) and a second end surface (18a), and wherein said first end surface (16a) and said second end surface (18a) and in relation to a centre plane (M) have substantially identical projected areas.

7. The arrangement for measuring a fluid pressure according to claim 6 wherein disposed at axial distances from said first and said second end surface (16a, 18a) of said first collar (20) are a second and a third collar (22, 24), the external dimensions of which are such that said second and the third collars help guide the pressure sensor portion (10) in the recess (12) and have end surfaces (16b, 18b), which each face said first collar (20) and in relation to a centre plane (M) have substantially identical projected areas.

8. The arrangement for measuring a fluid pressure according to claim 7 wherein said pressure sensor portion and/or at least individual portions of said first, second or third collars (20, 22, 24) have a cylindrical or conical, preferably circular cylindrical or circular conical shape.

9. The arrangement for measuring a fluid pressure according to claim 7 wherein disposed between the said collar (20) and said second collar (22) and/or between said first collar (20) and said third collar (24) there is in each case a seal (30, 32).

10. The arrangement for measuring a fluid pressure according to claim 9 wherein ambient atmospheric pressure prevails outside of at least one of said second and third collars (22, 24).

11. The arrangement for measuring a fluid pressure according to claim 9 wherein said seals (30, 32), which are disposed between the first collar (20) and the second collar (22) or between the first collar (20) and the third collar (24), are such that during operation they behave like a fluid when they are applied against the appropriate surfaces (16b, 18b) of said pressure sensor portion (10).

12. The arrangement for measuring a fluid pessure according to claim 9 wherein said pressure sensor portion (10) is secured in the recess (12) by a retaining means, preferably a snap ring (36).

13. The arrangement for measuring a fluid pressure according to claim 6 wherein the pressure sensor portion (10) is disposed in said recess (12) in such a way that said first collar (20) faces the fluid inlet disposed in the wall of said recess (12).

14. The arrangement for measuring a fluid pressure according to claim 6 wherein said pressure sensor portion (10) has a shape, which in relation to its centre line (L) is rotationally symmetrical.

15. The arrangement for measuring a fluid pressure according to claim 6 wherein said pressure sensor portion (10) said the pressure sensor (26) in the region of said first collar (20).

16. The arrangement for measuring a fluid pressure according to claim 1 wherein said pressure sensor portion (10) is an elongate body with, in relation to its longitudinal axis (L), laterally protruding surfaces (16a, 16b, 18a, 18b) and further wherein the sum of, relative to the longitudinal axis (L), orthogonal projections of surfaces (16a, 16b), which are oriented substantially in a first direction and during operation are wetted by fluid, the pressure of which is to be measured, is substantially equal to or less than the sum of, relative to the longitudinal axis, orthogonal projections of surfaces (18a, 18b), which are oriented substantially in a second direction opposed to the first direction and during operation are wetted by fluid, the pressure of which is to be measured.