# US 2017/0254262 A1 · Internal combustion engine

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- Number: US 2017/0254262 A1
- Document ID: US20170254262A1
- Status: Published application
- Kind: A1
- Application number: 15/446,604
- Filed: 2017-03-01
- Published: 2017-09-07
- Earliest claimed: 2016-03-03
- Assignees: Toyota Jidosha Kabushiki Kaisha
- Applicants: Toyota Jidosha Kabushiki Kaisha
- Inventors: Keisuke SASAKI; Hajime TAKAGAWA; Yoichiro GOYA
- Web page: https://patentgrep.com/patent/US20170254262A1

## CPC

- F02B 77/085: {with sensors measuring combustion processes, e.g. knocking, pressure, ionization, combustion flame}
- F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G)

## Abstract

An engine includes a cylinder pressure sensor inserted into a through-hole of a cylinder head. A sealing member that seals between a hole wall surface and a body-side wall surface. A dimension relationship of D1<D3×(D4/D2) is satisfied where: D1 is a distance in a direction of a central axis from a reference position of the sealing member to a first given position; D2 is a distance between the hole wall surface and the body-side wall surface at the first given position; D3 is a distance in the direction of the central axis from the reference position to a second given position; and D4 is a distance between the hole wall surface and the body-side wall surface at the second given position.

## Claims

### Claim 1

An internal combustion engine comprising:
a cylinder head having a through-hole;
a cylinder pressure sensor including a sensor body and a pressure receiving portion,
the sensor body including a fixed portion abutting with a head wall surface of the cylinder head on an opposite side to a combustion chamber of the internal combustion engine,
the sensor body having a bar shape,
the sensor body being placed inside the through-hole,
the pressure receiving portion being provided in an end portion of the sensor body on a combustion-chamber-side;
a sealing member that seals between a hole wall surface as a wall surface of the through-hole and a body-side wall surface as a side wall surface of the sensor body; and
a fixing member configured to fix the fixed portion such that the fixed portion is pressed against the head wall surface, wherein
the sealing member is placed in a middle of the sensor body in a direction of a central axis of the sensor body, when the sensor body is placed inside the through-hole,
the sensor body and the through-hole in a reference state are configured such that at least one combination of values that are taken as D1, D2, D3, and D4 satisfies a dimension relationship of D1<D3×(D4/D2),
D1 is a distance in a direction of a central axis of the through-hole from a reference position of the sealing member to a first given position, the first given position being a position of one of the hole wall surface and the body-side wall surface placed on a side closer to the combustion engine than the sealing member,
D2 is a distance between the hole wall surface and the body-side wall surface at the first given position where the hole wall surface and the body-side wall surface face each other;
D3 is a distance in the direction of the central axis of the through-hole from the reference position to a second given position, the second given position being a position of one of the hole wall surface and the body-side wall surface placed on a side farther from the combustion engine than the sealing member;
D4 is a distance between the hole wall surface and the body-side wall surface at the second given position where the hole wall surface and the body-side wall surface face each other, and
the reference state is a state where the central axis of the through-hole is aligned with the central axis of the sensor body.

### Claim 2 (depends on 1)

The internal combustion engine according to claim 1, wherein
in the through-hole, a diameter of a part distant from an end on the combustion-chamber-side is larger than a diameter of a part closer to the end.