Pressure measurement unit in a pressure measurement system

• US 20030070488A1
• Filed: 09/05/2002
• Published: 04/17/2003
• Est. Priority Date: 09/10/2001
• Status: Active Grant

• Current Assignee: First Sensor Technology GmbH (TE Connectivity Ltd. (United Kingdom))
• Original Assignee: First Sensor Technology GmbH (TE Connectivity Ltd. (United Kingdom))
• Inventors: Ante, Johannes, Gilch, Markus
• Granted Patent: US 6,877,384 B2
• Time in Patent Office: Days
• US Class Current: 73/715
• CPC Class Codes: G01L 9/0044 Constructional details of non-semiconductive diaphragms

Abstract

Pressure measurement unit in a pressure measurement system A pressure measurement unit in a pressure measurement system has a housing section (8) which has an internal space (9) with internal surfaces, and a ceramic unit (1) which has a pressure diaphragm (2) and at least one external surface, with the ceramic unit (1) held in the press fit in the housing section (8) and with radial holding stresses operating between the external surface of the ceramic unit (1) and the internal surfaces of the housing section (8). In a method for manufacturing a corresponding pressure measurement unit with a housing section (8) and with a ceramic unit (1) which has a pressure diaphragm (2) and at least one external surface, with holding stresses built up between the housing section (8) and the ceramic unit (1), which hold the ceramic unit (1) in the internal space of the housing section (8).

Claims

1. Pressure measurement unit in a pressure measurement system, with a housing section (8), which has an internal space (9) with an internal surface, and with a ceramic unit (1) which has a pressure diaphragm (2) and at least one external surface,

characterized in that

the ceramic unit (1) is held in the housing section (8) in the press fit, resulting in radial holding stresses between the external surface of the ceramic unit (1) and the internal surface of the housing section. (8).

2. Pressure measurement unit according to claim 1, characterized in that the internal surface of the housing section (8) is of a softer material than that of the ceramic unit (1), specifically metal, and the press fit results from the displacement of the material of the internal surface due to the insertion of the ceramic unit (1) into the internal space (9) of the housing section (8).

3. Pressure measurement unit according to claim 1 or 2, characterized in that the ceramic unit (1) and the internal space (9) of the housing section (8) have cylindrical portions.

4. Pressure measurement unit according to claim 3, characterized in that in each area in which holding stresses occur, the external surface of the ceramic unit (1) is flattened off to a polygon and the internal space (9) of the housing section (8) is circular in section.

5. Pressure measurement unit according to claim 4, characterized in that the maximum diameter of the internal space (9) of the housing section (8) is smaller in the area in which holding stresses occur than the external diameter of the polygon formed by the contact surfaces (7) of the ceramic unit (1) and the minimum diameter of the internal space (9) of the housing section (8) is larger in the area in which holding stresses occur than the internal diameter of the polygon formed by the contact surfaces (7) of the ceramic unit (1).

6. Pressure measurement unit according to one of the preceding claims, characterized in that the internal surfaces of the housing section (8), on which the holding stresses act, are grooved.

7. Pressure measurement unit according to one of claims 1 to 4, characterized in that a corrugated sleeve (25) is positioned between the internal surfaces of the housing section (8) and the external surface of the ceramic unit (1).

8. Pressure measurement unit according to one of the preceding claims, characterized in that the ceramic unit (1) is not held in the press fit in the housings section (8) in a portion (5) in which the pressure diaphragm (2) is located.

9. Pressure measurement unit according to the preceding claim, characterized in that the ceramic unit (1) has a conical or stepped portion (6) on its external surface(s).

10. Pressure measurement unit according to claims 6 and 9, characterized in that the grooving is formed by a thread, the thread runout (24) of which serves as the transition area (11).

11. Pressure measurement unit according to one of the preceding claims, characterized by a support unit (17), which supplies pressure to the ceramic unit (1), with a seal (18) positioned between the ceramic unit (1) and the support unit (17).

12. Method for manufacturing a pressure measurement unit with a housing section (8), which has an internal space (9) with internal surfaces, and with a ceramic unit (1), which has a pressure diaphragm (2) and at least one external surface, characterized in that radial holding stresses are built up between the housing section (8) and the ceramic unit (1), which hold the ceramic unit (1) in the internal space (9) of the housing section (8).

13. Method according to claim 12, characterized in that the holding stresses are built up by the displacement of housing section material during insertion of the ceramic unit (1) into the internal space (9) of the housing section (8).

14. Method according to claim 12, characterized in that, when the ceramic unit (1) is already inserted into the internal space (9) of the housing section (8), the holding stresses are generated by the displacement of the housing section material due to forces acting on the external surfaces of the housing section (8).

15. Method according to claim 12, characterized in that a corrugated sleeve (25) is inserted into the internal space (9) of the housing section (8), the ceramic unit (1) then being pressed into said sleeve.

16. Method according to claim 12, characterized in that the press fit of the ceramic unit (1) in the housing section (8) is manufactured by heat shrinking of the housing section (8).