Internal combustion engine

Patent metadata

Field	Value
Publication number	US-10738733-B2
Application number	US-201816229664-A
Country	US
Kind code	B2
Filing date	Dec 21, 2018
Priority date	Feb 14, 2018
Publication date	Aug 11, 2020
Grant date	Aug 11, 2020

Abstract

An internal combustion engine includes: a cylinder block including a bulkhead formed so as to separate adjacent cylinders; a crankshaft including a counterweight; and a gas-vent hole which is formed in the bulkhead within a radius of rotation of the counterweight when seen from below a piston bottom-dead-center position and an axial direction of the crankshaft, and which communicates between the adjacent cylinders. The counterweight includes at least one of a concave portion and a through-hole formed at at least a part of a region of the counterweight opposed to the gas-vent hole during rotation of the crankshaft. The concave portion hollows in a direction away from the gas-vent hole, the through-hole penetrating through the counterweight in a direction away from the gas-vent hole.

First claim

What is claimed is:

1. An internal combustion engine, comprising:
a cylinder block including a bulkhead formed so as to separate adjacent cylinders;
a crankshaft including a counterweight; and
a gas-vent hole which is formed in the bulkhead within a radius of rotation of the counterweight when seen from below a piston bottom-dead-center position and an axial direction of the crankshaft, and which communicates between the adjacent cylinders,
wherein the counterweight includes at least one of a concave portion and a through-hole formed at at least a part of a region of the counterweight opposed to the gas-vent hole during rotation of the crankshaft,
wherein, in a view along the axial direction of the crankshaft when the counterweight and the gas-vent hole overlap each other, the at least one of the concave portion and the through-hole is spaced radially inwardly from an outer edge of the counterweight, and
wherein the concave portion hollows in a direction away from the gas-vent hole, the through-hole penetrating through the counterweight in a direction away from the gas-vent hole.

2. The internal combustion engine according to claim 1 ,
wherein the internal combustion engine is an in-line three-cylinder engine,
wherein the internal combustion engine includes a cylinder A arranged at an end of the cylinder block in a cylinder row direction,
wherein the at least one of the concave portion and the through-hole is formed at the counterweight for the cylinder A, and
wherein the at least one of the concave portion and the through-hole is formed at the counterweight for the cylinder A in its region opposed to the gas-vent hole when a piston position of the cylinder A is within crank angle ranges of 20 to 175 and 220 to 325 degrees after bottom dead center.

3. The internal combustion engine according to claim 1 ,
wherein the internal combustion engine is an in-line three-cylinder engine,
wherein the internal combustion engine includes a cylinder A arranged at an end of the cylinder block in a cylinder row direction and a cylinder B arranged at a remaining end of the cylinder block in the cylinder row direction,
wherein the at least one of the concave portion and the through-hole is formed at the counterweight for the cylinder B, and
wherein the at least one of the concave portion and the through-hole is formed at the counterweight for the cylinder B in its region opposed to the gas-vent hole when a piston position of the cylinder B is within crank angle ranges of −110 to −15 and 75 to 200 degrees after bottom dead center.

4. The internal combustion engine according to claim 1 ,
wherein, when seen from the axial direction of the crankshaft, the at least one of the concave portion and the through-hole is formed so as to extend in an arc shape in a circumferential direction of the crankshaft.

5. The internal combustion engine according to claim 1 ,
wherein, with regard to a radial direction of the crankshaft, the at least one of the concave portion and the through-hole is formed so as to entirely overlap with the gas-vent hole when seen from the axial direction of the crankshaft.

Assignees

• Toyota Motor Co Ltd

Inventors

• Ikeda Naoya
• Okawa Makoto

Classifications

• F02F7/0007 Primary

  Crankcases of engines with cylinders in line · CPC title

• F02B2075/1812

  three · CPC title

• F01M13/00

  Crankcase ventilating or breathing · CPC title

• F02B75/20

  with cylinders all in one line · CPC title

• F02F7/0065 Primary

  Shape of casings for other machine parts and purposes, e.g. utilisation purposes, safety · CPC title