Capacitive pressure sensor with reduced sensitivity to temperature change

• US 10,288,509 B2
• Filed: 11/25/2014
• Issued: 05/14/2019
• Est. Priority Date: 11/25/2013
• Status: Active Grant

• Current Assignee: Horiba STEC, Co., Ltd. (Horiba Limited)
• Original Assignee: Horiba STEC, Co., Ltd. (Horiba Limited)
• Inventors: Kishida, Sotaro, Hataita, Takehisa, Kuwahara, Akira
• Primary Examiner(s): Allen, Andre J
• Application Number:
  US14/892,355
• Publication Number:
  US 20160169759A1
• Time in Patent Office: 1,631 Days
• Field of Search: 73724
• CPC Class Codes: G01L 19/0084 to the outside of the housing other details about the housing see G01L19/14
• CPC Class Codes: G01L 19/04 Means for compensating for effects of changes of temperature , i.e. other than electric compensation
• CPC Class Codes: G01L 19/147 Details about the mounting of the sensor to support or covering means
• CPC Class Codes: G01L 9/0072 using variations in capacitance

Abstract

Provided is a capacitive pressure sensor that prevents the position of an electrode face in the direction parallel to a diaphragm from deviating from the position of the diaphragm, and accurately measures pressure. The capacitive pressure sensor includes: the diaphragm that deforms under pressure; an electrode member having the electrode face opposed to the diaphragm with a gap between the diaphragm and the electrode face; a body having one end to which the diaphragm is joined, and accommodating at least a portion of the electrode member; an insulating positioning member that is provided in the body and positions at least the portion of the electrode member in the body; and a pressing mechanism that holds and presses the insulating positioning member or the electrode member in the direction parallel to the diaphragm.

Claims

1. A capacitive pressure sensor comprising:

a diaphragm that deforms under pressure;

an electrode having an electrode face opposed to the diaphragm with a gap between the diaphragm and the electrode face;

a body having one end to which the diaphragm is joined, and accommodating at least a portion of the electrode;

an insulating positioning member that is provided in the body, and that positions at least the portion of the electrode accommodated in the body; and

a pressing mechanism that is configured to hold and press the insulating positioning member or the electrode in a direction parallel to the diaphragm,

wherein the pressing mechanism includes a position adjuster that includes a contact surface that is in contact with the insulating positioning member, the position adjuster configured to press the insulating positioning member in a direction oblique to the diaphragm and

the position adjuster includes a cutout portion comprising a recess that extends transverse to the contact surface and through the position adjustor.

2. The capacitive pressure sensor according to claim 1,

wherein the position adjuster has a pressed surface to which a force is to be applied in a direction transverse to the diaphragm.

3. The capacitive pressure sensor according to claim 2,

wherein the contact surface is an inclined face inclined relative to the pressed surface.

4. The capacitive pressure sensor according to claim 2,

wherein the position adjuster is substantially ring-shaped, and has a top surface that is the pressed surface and an inner peripheral surface that is the contact surface.

5. The capacitive pressure sensor according to claim 2,

wherein the pressing mechanism further includes a pressing plate that is in contact with the pressed surface and screwed to the body in the direction transverse to the diaphragm.

6. The capacitive pressure sensor according to claim 1,

wherein the electrode includes:

a fixed electrode fixed to the insulating positioning member, and having the electrode face;

a signal extraction electrode fixed with an insulating seal sealing the other end of the body; and

a flexible connector that electrically connects the fixed electrode and the signal extraction electrode.

7. A capacitive pressure sensor comprising:

a diaphragm that deforms under pressure;

an electrode having an electrode face opposed to the diaphragm with a gap between the diaphragm and the electrode face;

a body having one end to which the diaphragm is joined, and accommodating at least a portion of the electrode;

an insulating positioning member that is provided in the body, and that positions at least the portion of the electrode accommodated in the body; and

a pressing mechanism that is configured to hold and press the insulating positioning member or the electrode in a direction parallel to the diaphragm,

wherein the pressing mechanism includes a position adjuster that includes a contact surface that is in contact with the insulating positioning member, the position adjuster configured to press the insulating positioning member in a direction oblique to the diaphragm and

the position adjuster includes a cutout portion comprising a cutout that extends transverse to the contact surface and through the position adjustor.

8. The capacitive pressure sensor according to claim 7,

wherein the position adjuster has a pressed surface to which a force is to be applied in a direction transverse to the diaphragm.

9. The capacitive pressure sensor according to claim 8,

wherein the contact surface is an inclined face inclined relative to the pressed surface.

10. The capacitive pressure sensor according to claim 8,

wherein the position adjuster is substantially ring-shaped, and has a top surface that is the pressed surface and an inner peripheral surface that is the contact surface.

11. The capacitive pressure sensor according to claim 8,

wherein the pressing mechanism further includes a pressing plate that is in contact with the pressed surface and screwed to the body in the direction transverse to the diaphragm.

12. The capacitive pressure sensor according to claim 7,

wherein the electrode includes:

a fixed electrode fixed to the insulating positioning member, and having the electrode face;

a signal extraction electrode fixed with an insulating seal sealing the other end of the body; and

a flexible connector that electrically connects the fixed electrode and the signal extraction electrode.