Pressure sensor with a membrane applied on a pressure chamber side and use thereof

Patent metadata

Field	Value
Publication number	US-11002636-B2
Application number	US-201615045857-A
Country	US
Kind code	B2
Filing date	Feb 17, 2016
Priority date	Feb 20, 2015
Publication date	May 11, 2021
Grant date	May 11, 2021

Abstract

A pressure sensor for measuring pressures in combustion chambers of internal combustion engines includes a sensor housing with a longitudinal axis and an interior space, a measuring element in the interior space, and a rotation-symmetrically designed membrane with a peripheral edge section connected with an end of the sensor housing at the pressure chamber side to seal off the interior space of the sensor housing on the pressure chamber side. The membrane has a flexible annular membrane segment and a central plunger that interacts with the measuring element and the flexible annular membrane segment. The annular membrane segment connects the plunger with the peripheral edge section. The annular membrane segment is designed as a convex circular arc of constant material thickness on the pressure chamber side.

First claim

The invention claimed is:

1. A pressure sensor that has a pressure chamber side for being exposed to a pressure chamber for measuring pressures in the pressure chamber, the pressure sensor comprising:
a sensor housing defining an end on the pressure chamber side of the sensor, the sensor housing defining an interior space having an opening at the pressure chamber side of the sensor, the sensor housing having a virtual longitudinal axis disposed extending in an axial direction symmetrically through said interior space;
a measuring element arranged in the interior space of the sensor housing and including a piezoelectrical element or a piezoresistive element;
a membrane shaped symmetrically with respect to the virtual longitudinal axis and having a peripheral edge section that connects the membrane with the end of the sensor housing and seals off the opening of the interior space of the sensor housing, the membrane defining a pressure chamber side facing away from the interior space and an interior side facing toward the interior space;
wherein the interior side of the membrane includes a central plunger having a portion maintaining mechanical contact with the measuring element in the interior space;
wherein the membrane includes a flexible, annular membrane segment which connects the plunger to the peripheral edge section, wherein the cross-section taken through the annular membrane segment by a plane that includes the virtual longitudinal axis has a convex circular arc of constant material thickness, the central plunger being thicker measured along the virtual longitudinal axis than the thickness of the annular membrane segment; and
wherein the membrane is made of metal and the metal comprises steel, nickel-based alloy, iron-based alloy, cobalt-based alloy, or titanium-based alloy.

2. The pressure sensor according to claim 1 , wherein on the pressure chamber side of the membrane there is a radial inner end point of the circular arc and a radial outer end point of the circular arc, wherein the radial distance between the virtual longitudinal axis and the radial inner end point of the circular arc is less than the radial distance between the virtual longitudinal axis and the radial outer end point of the circular arc, wherein the radial inner end point of the circular arc is disposed set back in the axial direction closer to the interior space as compared to the disposition of the radial outer end point of the circular arc.

3. The pressure sensor according to claim 1 , wherein the circular arc of the peripheral edge section defines on the pressure chamber side of the membrane, a vertex of that projects away from interior space in the axial direction.

4. The pressure sensor according to claim 3 , wherein the circular arc encloses an angle of 30 to 120 degrees.

5. The pressure sensor according to claim 4 , wherein the circular arc encloses an angle of 55 to 90 degrees.

6. The pressure sensor according to claim 1 , wherein on the pressure chamber side of the membrane, a circumferential recess is formed at the transition of the annular membrane segment to the peripheral edge section.

7. The pressure sensor according to claim 6 , wherein at its radial outer edge the recess forms an obtuse angle of 90 to 160 degrees to the pressure chamber side surface of the peripheral edge section.

8. The pressure sensor according to claim 7 , wherein the obtuse angle is 120 to 130 degrees.

9. The pressure sensor according to claim 1 , wherein in the interior space the tangent at the outer end point of the prolongation of the circular arc forms an opening angle of 10 to 80 degrees with the virtual longitudinal axis of the sensor housing.

10. The pressure sensor according to claim 9 , wherein the opening angle is 30 to 40 degrees.

11. The pressure sensor according to claim 1 , wherein in the interior space the plunger has an undercut in the inner prolongation of the circular arc.

12. The pressure sensor according to claim 1 , wherein in the direction of the virtual longitudinal axis of the membrane the plunger is thicker than the material thickness of the circular arc.

13. The pressure sensor according to claim 1 , wherein in the direction of the virtual longitudinal axis of the membrane the peripheral edge section is thicker than the material thickness of the circular arc.

14. The pressure sensor according to claim 1 , wherein in the direction of the virtual longitudinal axis of the membrane, each of the plunger and the peripheral edge section is thicker than the material thickness of the circular arc.

15. The pressure sensor according to claim 1 , wherein delimited by the annular membrane segment on the pressure chamber side of the membrane there is disposed centrally above the plunger, a central trough formed with an essentially flat base.

16. The pressure sensor according to claim 1 , wherein delimited by the annular membrane segment on the pressure chamber side of the membrane there is disposed centrally above the plunger, a central trough formed with an essentially rounded base.

17. A method of monitoring pressure within a combustion chamber of a ballistic missile, the method comprising the steps of:
installing within the combustion chamber of the ballistic missile, a pressure sensor according to claim 1 with the membrane exposed to the combustion chamber;
connecting the pressure sensor to a monitoring device; and
using the monitoring device to receive from the pressure sensor, signals indicative of the pressure at the location of the membrane within the combustion chamber of the ballistic missile.

18. The pressure sensor according to claim 1 , wherein the cross-section taken through the annular membrane segment by a plane that includes the virtual longitudinal axis defines a concave circular arc exposed to the interior space.

19. The pressure sensor according to claim 1 , wherein the peripheral edge section of the membrane and the sensor housing that connects to the peripheral edge section of the membrane are not formed as a unitary element.

Assignees

• Kistler Holding Ag

Inventors

• Brunner Simon
• Giger Martin

Classifications

• G01L23/10 Primary

  by pressure-sensitive members of the piezoelectric type · CPC title

• G01L9/08

  by making use of piezoelectric devices {, i.e. electric circuits therefor} · CPC title

• G01L23/18

  by resistance strain gauges · CPC title

• G01L9/06

  of piezo-resistive devices · CPC title

• G01L7/08 Primary

  of the flexible-diaphragm type · CPC title