Physical quantity sensor

• US 20060112766A1
• Filed: 11/15/2005
• Published: 06/01/2006
• Est. Priority Date: 12/01/2004
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Ohta, Tameharu
• Granted Patent: US 7,464,592 B2
• Time in Patent Office: Days
• US Class Current: 73/526
• CPC Class Codes: G01P 1/006 used for thermal compensation
• CPC Class Codes: G01P 1/023 for acceleration measuring devices
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 15/13 by measuring the force required to restore a proofmass subjected to inertial forces to a null position

Abstract

The angular velocity sensor includes a container, a sensing element in the container and a viscous fluid between the container and the sensing element. The sensing element is supported by the viscous fluid such as an ER fluid or an MR fluid. The angular velocity sensor detects acceleration of the body in which the angular velocity sensor is installed. The angular velocity sensor controls the viscosity of the viscous fluid depending on the acceleration of a body, by changing a voltage applied to the viscous fluid.

Claims

1. A physical quantity sensor, comprising:

a container; and

a sensor element installed in the container for detecting a physical quantity; and

a viscous fluid;

wherein;

the sensing element is supported by the viscous fluid; and

viscosity of the viscous fluid is controllable.

2. The physical quantity sensor according to claim 1, wherein the viscous fluid is an electrorheological fluid, wherein the viscosity of the electrorheological fluid changes in accordance with the electric field applied to the electrorheological fluid, and the physical quantity sensor further comprises an electrode for applying the electric field to the electrorheological fluid.

3. The physical quantity sensor according to claim 1, wherein the viscous fluid is a magnetorheological fluid, wherein the viscosity of the magnetorheological fluid changes in accordance with the magnetic field applied to the magnetorheological fluid, and the physical quantity sensor further comprises an electrode for generating the magnetic field to apply to the electrorheological fluid.

4. The physical quantity sensor according to claim 2, wherein the electrode is installed in the container.

5. The physical quantity sensor according to claim 1, wherein the sensing element is supported by the viscous fluid which is confined in the container.

6. The physical quantity sensor according to claim 1, further comprising a holding body for absorbing the viscous fluid, wherein the sensing element is fixed to the container through the holding body.

7. The physical quantity sensor according to claim 2, further comprising:

a holding body for absorbing the viscous fluid; and

a circuit board supported by the container through the holding body, wherein;

the sensing element is fixed to the circuit board; and

the electrode is installed in the container.

8. The physical quantity sensor according to claim 2, further comprising:

a holding body for absorbing the viscous fluid; and

a circuit board fixed to the container, wherein;

the sensing element is supported by the circuit board through the holding body; and

the electrode is formed on the circuit board.

9. The physical quantity sensor according to claim 6, wherein the holding body is a polymer.

10. The physical quantity sensor according to claim 1, further comprising:

an acceleration detecting unit for detecting the acceleration at the sensing element; and

a controller for controlling the viscosity of the viscous fluid depending on the detected acceleration.

11. The physical quantity sensor according to claim 1, further comprising:

an electrode for applying the electric field to the viscous fluid;

a holding body for absorbing the viscous fluid; and

a circuit board supported by the container through the holding body, wherein;

the sensing element is fixed to the circuit board; and

the electrode is installed in the container.

12. The physical quantity sensor according to claim 1, further comprising:

an electrode for applying the electric field to the viscous fluid;

a holding body for absorbing the viscous fluid; and

a circuit board fixed to the container, wherein;

the sensing element is supported by the circuit board through the holding body; and

the electrode is formed on the circuit board.