Combustion pressure sensor

Patent metadata

Field	Value
Publication number	US-9841356-B2
Application number	US-201314424502-A
Country	US
Kind code	B2
Filing date	Aug 27, 2013
Priority date	Aug 29, 2012
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

A combustion pressure sensor is formed of a ring-shaped cylindrical body. The combustion pressure sensor detects combustion pressure in a combustion chamber of an engine by being attached to an outer periphery of a tip of a functional component attached to the combustion chamber. The cylindrical body forms sealed space sealed with a ring-shaped diaphragm on one side and with a ring-shaped support member on an opposite side. The sealed space is defined by an external cylindrical member and an internal cylindrical member coaxial with each other. The diaphragm has a ring-shaped pressure receiving part formed on a side near the combustion chamber to receive pressure from outside and a ring-shaped transmitting part formed on a rear surface of the diaphragm. A pressure transmitting member and a pressure detecting element are provided in the sealed space. Tight abutting contact is formed between the transmitting part of the diaphragm and the pressure transmitting member, between the pressure transmitting member and the pressure detecting element, and between the pressure detecting element and the support member.

First claim

The invention claimed is:

1. A combustion pressure sensor formed of a ring-shaped cylindrical body, the combustion pressure sensor detecting combustion pressure in a combustion chamber of an engine by being attached to an outer periphery of a tip of a functional component attached to the combustion chamber, comprising:
the ring-shaped cylindrical body forming a sealed space sealed with a ring-shaped diaphragm on one side and with a ring-shaped support member on an opposite side, the sealed space being defined by an external cylindrical member and an internal cylindrical member coaxial with respect to each other,
the ring-shaped diaphragm having a ring-shaped pressure receiving part formed on a side closest to the combustion chamber to receive pressure from outside and a ring-shaped transmitting part formed on a rear surface of the ring-shaped diaphragm,
a pressure transmitting member and a pressure detecting element being provided in the sealed space, and
abutting contact being formed between the ring-shaped transmitting part of the ring-shaped diaphragm and the pressure transmitting member, between the pressure transmitting member and the pressure detecting element, and between the pressure detecting element and the ring-shaped support member,
wherein opposite sides of an end of the ring-shaped pressure receiving part on the side closest to the combustion chamber includes an external end portion and an internal end portion of the ring-shaped pressure receiving part wherein the external end portion of the ring-shaped pressure receiving part is fixed to an internal peripheral end portion of the external cylindrical member and the internal end portion is fixed to an external peripheral end portion of the internal cylindrical member,
wherein:
at least any one of that the external cylindrical member has a distal end with an annular recess formed on the internal peripheral end portion and that the internal cylindrical member has a distal end with an annular recess formed on the external peripheral end portion,
at least any one of that the external end portion of the ring-shaped pressure receiving part is fixed to the annular recess formed on the internal peripheral end portion of the external cylindrical member and that the internal end portion of the ring-shaped pressure receiving part is fixed to the annular recess formed on the external peripheral end portion of the internal cylindrical member, and
the ring-shaped pressure receiving part extends from the distal end of the external end portion and the distal end of the internal end portion.

2. The combustion pressure sensor according to claim 1 , wherein the ring-shaped transmitting part and the ring-shaped pressure receiving part are formed integrally, a ring thickness is smaller at the ring-shaped transmitting part than at the ring-shaped pressure receiving part, and the ring-shaped transmitting part is provided in a central part of a thickness direction of the ring-shaped pressure receiving part, thereby forming a T-shape cross section.

3. The combustion pressure sensor according to claim 1 , wherein the ring-shaped transmitting part is formed so as to become smaller gradually in a ring thickness relative to the ring thickness adjacent to the pressure transmitting member as the ring-shaped transmitting part extends from a side near the pressure transmitting member toward a side near the ring-shaped pressure receiving part.

4. The combustion pressure sensor according to claim 1 , wherein the ring-shaped pressure receiving part is formed so as to become smaller gradually in a ring width from opposite sides toward a center in a thickness direction thereof.

5. The combustion pressure sensor according to claim 1 , wherein opposite sides of the ring-shaped pressure receiving part in a thickness direction thereof are fixed to an end portion of the external cylindrical member and an end portion of the internal cylindrical member.

6. The combustion pressure sensor according to claim 1 , wherein the ring-shaped pressure receiving part has a flat pressure receiving surface.

7. The combustion pressure sensor according to claim 1 , wherein the ring-shaped pressure receiving part has a flat pressure receiving surface and a groove is formed in a central part of the pressure receiving surface in a thickness direction thereof so as to extend along an entire circumference.

8. The combustion pressure sensor according to claim 1 , wherein the pressure detecting element includes a plurality of pressure detecting elements that are each formed as a rectangular parallelepiped and the pressure detecting elements are arranged at an interval in a circumferential direction of the sealed space.

9. The combustion pressure sensor according to claim 8 , wherein a spacer is arranged in the interval between the pressure detecting elements.

10. The combustion pressure sensor according to claim 2 , wherein the ring-shaped transmitting part is formed so as to become smaller gradually in the ring thickness from a side near the pressure transmitting member toward a side near the ring-shaped pressure receiving part.

11. The combustion pressure sensor according to claim 2 , wherein the ring-shaped pressure receiving part is formed so as to become smaller gradually in a ring width from opposite sides toward the center in a thickness direction thereof.

12. The combustion pressure sensor according to claim 3 , wherein the ring-shaped pressure receiving part is formed so as to become smaller gradually in a ring width from opposite sides toward the center in a thickness direction thereof.

13. The combustion pressure sensor according to claim 2 , wherein opposite sides of the ring-shaped pressure receiving part in a thickness direction thereof are fixed to an end portion of the external cylindrical member and an end portion of the internal cylindrical member.

14. The combustion pressure sensor according to claim 3 , wherein opposite sides of the ring-shaped pressure receiving part in a thickness direction thereof are fixed to an end portion of the external cylindrical member and an end portion of the internal cylindrical member.

15. The combustion pressure sensor according to claim 2 , wherein the ring-shaped pressure receiving part has a flat pressure receiving surface.

16. The combustion pressure sensor according to claim 3 , wherein the ring-shaped pressure receiving part has a flat pressure receiving surface.

17. The combustion pressure sensor according to claim 4 , wherein the ring-shaped pressure receiving part has a flat pressure receiving surface.

18. The combustion pressure sensor according to claim 1 , wherein the external cylindrical member has the annular recess.

19. The combustion pressure sensor according to claim 1 , wherein the internal cylindrical member has the annular recess.

20. The combustion pressure sensor according to claim 1 , wherein the external cylindrical member and the internal cylindrical member have the annular recess.

Assignees

• Citizen Finetech Miyota Co Ltd
• Citizen Holdings Co Ltd
• Citizen Finedevice Co Ltd
• Citizen Watch Co Ltd

Inventors

• Takahashi Kazuo
• Hayashi Takayuki

Classifications

• G01M15/08 Primary

  by monitoring pressure in cylinders · CPC title

• G01L23/26

  Details or accessories · CPC title

• G01L23/08 Primary

  operated electrically {(G01L23/22 takes precedence)} · CPC title