Internal combustion engine and straddle-type vehicle equipped with the engine

Patent metadata

Field	Value
Publication number	US-9719405-B2
Application number	US-201213552669-A
Country	US
Kind code	B2
Filing date	Jul 19, 2012
Priority date	Jul 20, 2011
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

A single-cylinder internal combustion engine includes a knock sensor mounted thereto to suppress a temperature increase of the knock sensor and at the same time detect knocking with high accuracy. The engine includes a cylinder block having a cylinder provided therein, and a cylinder head connected to the cylinder block. On a surface of the cylinder block and the cylinder head, one or more fins protruding from the surface are provided. On the surface of the cylinder block, a sensor mounting boss protruding from the surface and being continuous with a portion of the one or more fins is provided. A knock sensor arranged to detect knocking is mounted to the sensor mounting boss.

First claim

What is claimed is:

1. A single-cylinder internal combustion engine for a vehicle, the single-cylinder internal combustion engine comprising:
a cylinder block including a cylinder provided therein;
a cylinder head connected to the cylinder block;
one or more air-cooled cooling fins protruding from an outside surface of at least one of the cylinder block and the cylinder head;
a sensor mounting boss protruding from the outside surface of the at least one of the cylinder block and the cylinder head and being continuous with the one or more air-cooled cooling fins at the outside surface of the at least one of the cylinder block and the cylinder head such that no gap is provided between the sensor mounting boss and the one or more air-cooled cooling fins; and
a sensor arranged to detect knocking of the single-cylinder internal combustion engine; wherein
the sensor is mounted to the sensor mounting boss; and
the sensor mounting boss and at least one of the one or more air-cooled cooling fins are integrally formed with each other.

2. The single-cylinder internal combustion engine according to claim 1 , wherein the sensor mounting boss protrudes in a direction parallel or substantially parallel to a direction in which the one or more air-cooled cooling fins protrude.

3. The single-cylinder internal combustion engine according to claim 1 , wherein the sensor mounting boss protrudes in a direction inclined with respect to a direction in which the one or more air-cooled cooling fins protrude.

4. The single-cylinder internal combustion engine according to claim 1 , wherein the sensor mounting boss protrudes in a direction parallel or substantially parallel to a virtual plane orthogonal or substantially orthogonal to a cylinder axis.

5. The single-cylinder internal combustion engine according to claim 1 , wherein a protruding amount of the sensor mounting boss from the outside surface is greater than a protruding amount of the one or more air-cooled cooling fins from the outside surface.

6. The single-cylinder internal combustion engine according to claim 1 , wherein the one or more air-cooled cooling fins includes a plurality of the air-cooled cooling fins, and the plurality of air-cooled cooling fins surround at least a portion of the sensor mounting boss or the sensor.

7. The single-cylinder internal combustion engine according to claim 1 , wherein:
each of the cylinder block and the cylinder head includes a top surface, a bottom surface, a left surface, and a right surface; and
the sensor mounting boss is provided on the top surface of the cylinder block or the top surface of the cylinder head.

8. The single-cylinder internal combustion engine according to claim 1 , wherein:
each of the cylinder block and the cylinder head includes a top surface, a bottom surface, a left surface, and a right surface; and
the sensor mounting boss is provided on the left surface of the cylinder block, the right surface of the cylinder block, the left surface of the cylinder head, or the right surface of the cylinder head.

9. The single-cylinder internal combustion engine according to claim 1 , wherein the sensor mounting boss is disposed at a position such that an extension line of a center of the sensor mounting boss passes through the cylinder.

10. The single-cylinder internal combustion engine according to claim 1 , wherein the sensor mounting boss is disposed at such a position that an extension line of a center of the sensor mounting boss intersects a cylinder axis.

11. The single-cylinder internal combustion engine according to claim 1 , wherein:
the one or more air-cooled cooling fins are provided at least on the outside surface of the cylinder block; and
the sensor mounting boss is provided at least on the outside surface of the cylinder block.

12. The single-cylinder internal combustion engine according to claim 1 , wherein:
the one or more air-cooled cooling fins include a plurality of air-cooled cooling fins; and
the sensor mounting boss is connected to the plurality of air-cooled cooling fins.

13. The single-cylinder internal combustion engine according to claim 1 , wherein a portion of the one or more air-cooled cooling fins that is connected to the sensor mounting boss has a larger cross-sectional area than portions of the one or more air-cooled cooling fins that are not connected to the sensor mounting boss.

14. The single-cylinder internal combustion engine according to claim 1 , wherein:
the sensor mounting boss includes a hole portion in which a bolt arranged to secure the sensor to the sensor mounting boss is inserted; and
the hole portion includes an internal thread portion in which a helical groove is formed, a non-threaded portion in which no helical groove is formed, and the non-threaded portion is positioned further inward than the internal thread portion.

15. A straddle-type vehicle comprising:
a single-cylinder internal combustion engine according to claim 1 .

Assignees

• Nakajima Akitoshi
• Inomori Toshinori
• Yamaha Motor Co Ltd

Inventors

• Nakajima Akitoshi
• Inomori Toshinori

Classifications

• F02B75/16

  Engines characterised by number of cylinders, e.g. single-cylinder engines (F02B75/26 takes precedence) · CPC title

• F02F1/30

  Finned cylinder heads · CPC title

• F02B61/02

  for driving cycles · CPC title

• F01P1/06 Primary

  Arrangements for cooling other engine or machine parts · CPC title

• F02B77/085

  with sensors measuring combustion processes, e.g. knocking, pressure, ionization, combustion flame · CPC title