Cylinder block and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-9353701-B2
Application number	US-201214002603-A
Country	US
Kind code	B2
Filing date	Feb 17, 2012
Priority date	Mar 9, 2011
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

A cylinder block ( 100 ) of the invention includes a coolant passage ( 115 ) that guides coolant inside of a water jacket ( 120 ), inside of an inter-bore partition wall ( 111 ). The coolant passage ( 115 ) is formed by a head-side drill hole ( 115 a ) that opens at a position away from a center portion of a top surface of the inter-bore partition wall ( 111 ) and is formed inclined with respect to an extending direction (L 2 ) of an axis of a cylinder bore so as to come closer to the center portion of the inter-bore partition wall ( 111 ) farther away from the top surface, and a jacket-side drill hole ( 115 b ) that is communicated with a tip end portion of the head-side drill hole ( 115 a ) and opens into the water jacket ( 120 ) and is formed inclined with respect to the extending direction (L 2 ) of the axis toward the opening so as to gradually come closer to the top surface.

First claim

The invention claimed is:

1. A cylinder block comprising:
a plurality of cylinder bores;
a water jacket surrounding the plurality of cylinder bores;
an inter-bore partition wall being positioned between adjacent cylinder bores;
a coolant passage, disposed inside the inter-bore partition wall, for guiding coolant from the water jacket without passing through a center portion that is a thinnest portion of the inter-bore partition wall,
the coolant passage having i) a head-side hole that opens at a position away from the center portion of a top surface on a cylinder head side of the inter-bore partition wall and is formed inclined with respect to an axial direction of the cylinder bore so as to come closer to the center portion farther away from the top surface, and having ii) a jacket-side hole that is communicated with a tip end portion of the head-side hole and opens into the water jacket and is formed inclined with respect to the axial direction from a portion that is communicated with the head-side hole toward the opening so as to gradually come closer to the top surface, wherein an extension line of the jacket-side hole that extends to outside of the water jacket is set such that the extension line does not contact a head bolt boss that forms an outer peripheral side end portion of the water jacket.

2. The cylinder block according to claim 1 , wherein a depth, in the axial direction from the top surface of the inter-bore partition wall, of a portion where the head-side hole is communicated with the jacket-side hole is set based on a height of a top ring when a piston is at top dead center.

3. The cylinder block according to claim 1 , wherein the tip end portion of the head-side hole is located such that the tip end portion of the head-side hole does not interfere with a cylinder liner that forms an inner peripheral surface of the cylinder bore.

4. The cylinder block according to claim 1 , wherein a shortest length between an opening of the head-side hole in the top surface of the inter-bore partition wall and the cylinder bore is set such that the opening does not overlap with a seal portion of a cylinder bore peripheral edge of a head gasket.

5. The cylinder block according to claim 1 , wherein an angle between the head-side hole and the jacket-side hole is an acute angle.

6. The cylinder block according to claim 1 , wherein a pair of the coolant passages is formed in the inter-bore partition wall so as to sandwich the center portion of the inter-bore partition wall.

7. The cylinder block according to claim 6 , wherein the two coolant passages are provided axisymmetrical about the center portion inside the inter-bore partition wall.

8. The cylinder block according to claim 1 , wherein the head-side hole and the jacket-side hole are both holes that are in straight lines.

9. A manufacturing method of a cylinder block provided with a water jacket formed surrounding a plurality of cylinder bores, and a coolant passage that is inside of an inter-bore partition wall positioned between adjacent cylinder bores and that guides coolant inside of the water jacket without passing through a center portion that is a thinnest portion of the inter-bore partition wall, the method comprising:
drilling a head-side hole, in the inter-bore partition wall, at an angle inclined with respect to an axial direction of the cylinder bore so as to come closer to the center portion farther away from a top surface on a cylinder head side of the inter-bore partition wall, from a position away from the center portion of the top surface; and
drilling a jacket-side hole, in the inter-bore partition wall, at an angle inclined with respect to the axial direction from a wall surface of the inter-bore partition wall that faces the water jacket toward a tip end of the head-side hole so as to gradually come closer to the top surface, and communicating the head-side hole with the jacket-side hole,
wherein an extension line of the jacket-side hole that extends to outside of the water jacket is set such that the extension line does not contact a head bolt boss that forms an outer peripheral side end portion of the water jacket.

Assignees

• Yamamoto Toshiaki
• Toyota Motor Co Ltd

Inventors

• Yamamoto Toshiaki

Classifications

• F01C21/06

  Heating; Cooling (of machines or engines in general F01P); Heat insulation (heat insulation in general F16L) · CPC title

• F02F7/00 Primary

  Casings, e.g. crankcases · CPC title

• F01P2003/021

  Cooling cylinders · CPC title

• F02F1/10 Primary

  for liquid cooling · CPC title

• Y10T29/49231

  I.C. [internal combustion] engine making · CPC title