Pressure transducer with a sealed sensor

• US 4,866,989 A
• Filed: 11/07/1988
• Issued: 09/19/1989
• Est. Priority Date: 11/07/1988
• Status: Expired due to Fees

• Current Assignee: Chrysler Corporation (Stellantis NV)
• Original Assignee: Chrysler Corporation (Stellantis NV)
• Inventors: Lawless, Daniel F.
• Primary Examiner(s): Woodiel, Donald O.
• Application Number:
  US07/267,908
• Time in Patent Office: 316 Days
• Field of Search: 73/431, 73/756, 73/706, 73/707, 73/708, 73/115, 73/719, 73/720, 73/721, 73/DIG. 4, 73/725, 73/726, 73/727, 73/182, 73/754, 361/283, 338/4, 310/338, 26/622
• US Class Current: 73/756
• CPC Class Codes: G01L 19/14 Housings G01L19/0007, G01L19/0084, G01L19/0092, G01L19/04, G01L19/06 take precedence
• CPC Class Codes: G01L 19/143 Two part housings
• CPC Class Codes: Y10S 73/04 Piezoelectric

Abstract

A transducer for sensing fluid pressure including an enclosure forming housing, a cup-shaped rubber-like mount having an end wall and an annular side wall for supporting a pressure sensing electronic chip against the inner end wall surface of the mount. The chip is supported against the end wall in covering relation to a small opening in the end wall which connects one side of the chip with atmospheric pressure. A layer of non-hardening sealant gel extending between the inner side wall surface completely covers the chip and transmits fluid pressure to a second surface of the chip but inhibits fluid contact and leakage past the chip.

Claims

1. In an electronic transducer for sensing fluid pressure and using a sensing chip within an enclosure forming housing, an improved mounting means for the chip which isolates the chip from fluid pressure and is resistant to fluid leakage thereby, comprising:

a mounting member having a cup-shaped configuration and being molded of flexible rubber-like material, the mounting member having an end wall portion and an annularly shaped side wall portion thereby defining an open ended interior space adapted to be communicated with pressurized fluid;

the end wall portion of the mount having a small opening therethrough adapted to be communicated with atmosphere;

a substantially flat sensor chip supported within the mount'"'"'s interior against the inner surface of the end wall and positioned with a first surface in covering relation to the small opening, the size and the configuration of the sensor chip being sufficient to completely cover the small opening;

a non-hardening sealant gel filling a substantial portion of the mount'"'"'s interior and providing a relatively thick layer over the chip, whereby the gel is exposed to pressurized fluid and fluid pressure is transmitted through the gel to a second surface of the chip opposite the first surface.

2. An electronic transducer for sensing oil pressure in an engine, comprising:

a housing with an apertured end portion for securing the transducer to an engine in fluid communication with pressurized oil therein and defining an interior space therein, the housing having a cylindrical recess formed therein communicated with the pressurized oil;

a substantially cup-shaped member molded of flexible rubber-like material and having an end wall and an annularly extending side wall thereby defining an opening interior;

the recess and the side wall being so sized and configured that the side wall is tightly engaged in the recess thereby directly communicating the interior of the cup-shaped member and the interior of the housing;

the end wall of the cup-shaped member having a small opening therethrough for communication with the atmosphere therethrough;

a substantially flat sensor chip with opposite first and second surfaces being mounted in the interior the cup-shaped member against the inner surface of the end wall, the chip being so configured and positioned so that the first surface thereof covers the small opening in the end wall;

a non-hardening sealant gel filling a substantial portion of the interior of the cup-shaped member to provide a thick layer over the chip, whereby the sealant gel is exposed to pressurized oil so that oil pressure is transmitted to the second side of the chip through the gel.

3. The transducer set forth in Claim 2 in which a channel is formed between the housing recess and the side wall of the cup-shaped member and a resilient annularly shaped seal is tightly positioned therein to prevent leakage therebetween.

4. The transducer set forth in Claim 2 in which a channel is molded in the outer surface of the side wall and an O-ring type seal is located therein so that it engages the recess forming portions of the housing in a leak resistant manner.