Piston and cylinder features for enhanced squish flow

Patent metadata

Field	Value
Publication number	US-10316734-B2
Application number	US-201615286334-A
Country	US
Kind code	B2
Filing date	Oct 5, 2016
Priority date	Oct 5, 2016
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

An internal combustion engine includes an engine block having a cylinder, a cylinder head disposed on one end of the cylinder, a piston disposed within the cylinder, and a rim. A piston crown of the piston defines a piston bowl. The rim depends from at least one of the cylinder head and piston and is located radially inward from the piston crown. At least one of the piston crown and cylinder head defines a passageway that is configured to guide a squish flow from between the piston crown and cylinder head to the piston bowl to interact with a plurality of flames within the piston bowl to enhance combustion.

First claim

What is claimed is:

1. An internal combustion engine comprising:
an engine block having a cylinder disposed therein, an end of the cylinder being closed by a cylinder head;
a piston disposed in reciprocating engagement with an internal surface of the cylinder,
the piston including a piston crown that faces the cylinder head, the piston crown defining a piston bowl,
the piston crown including an outer circumferential surface that directly faces the internal surface of the cylinder along a radial direction, and a top surface that extends from the outer circumferential surface to an inner circumferential surface of the piston bowl along the radial direction,
the piston and the cylinder head defining a combustion chamber therebetween;

a fuel injector disposed in fluid communication with the combustion chamber for delivering a fuel into the combustion chamber, the fuel creating a plurality of flames within the combustion chamber when ignited; and
an annular rim extending beyond the top surface of the piston crown and toward the cylinder head along a longitudinal direction, the longitudinal direction extending from the piston toward the cylinder head and being perpendicular to the radial direction,
the annular rim being disposed inside the piston bowl along the radial direction,
at least one of the piston crown and cylinder head defining a plurality of flow passageways, the plurality of flow passageways being configured to guide a squish flow from between the top surface of the piston crown and the cylinder head to the piston bowl to enhance combustion by interacting with the plurality of flames within the piston bowl.

2. The internal combustion engine of claim 1 , wherein the plurality of flow passageways includes a first flow passageway and a second flow passageway,
the first flow passageway is defined by the piston crown, and
the second flow passageway is defined by the cylinder head.

3. The internal combustion engine of claim 1 , wherein the annular rim is in direct contact with the piston crown.

4. The internal combustion engine of claim 1 , wherein each passageway of the plurality of passageways is disposed entirely within the piston crown.

5. The internal combustion engine of claim 1 , wherein the top surface of the piston crown includes a topland groove.

6. The internal combustion engine of claim 5 , wherein the plurality of passageways is in direct fluid communication with with the topland groove.

7. The internal combustion engine of claim 1 , wherein at least one passageway of the plurality of passageways extends from an inlet that is defined by the top surface of the piston crown to an outlet that is defined by the piston bowl, and
the inlet is disposed outside the outlet along the radial direction.

8. The internal combustion engine of claim 1 , wherein at least one passageway of the plurality of passageways extends from an inlet that is defined by the cylinder head to an outlet that is defined by the cylinder head,
the inlet directly faces the top surface of the piston crown,
the outlet directly faces the piston bowl, and
the inlet is disposed outside the outlet along the radial direction.

9. A piston comprising:
a cylindrical base; and
a crown disposed on the cylindrical base, the crown defining a piston bowl,
the crown including an outer circumferential surface that faces away from an inner circumferential surface of the piston bowl along a radial direction, and a top surface that extends from the outer circumferential surface to the inner circumferential surface of the piston bowl along the radial direction,
an annular rim extending beyond the top surface of the crown along a longitudinal direction, the longitudinal direction extending from the cylindrical base toward the crown and being perpendicular to the radial direction,
the annular rim being disposed inside the piston bowl along the radial direction,
the crown defining a flow passageway that is configured to guide a squish flow from the top surface of the crown to the piston bowl.

10. The piston of claim 9 , wherein the passageway has a converging flow area between the top surface of the crown and the piston bowl to accelerate the squish flow between the top surface of the crown and the piston bowl.

11. The piston of claim 9 , wherein the passageway extends from an inlet that is defined by the top surface of the crown to an outlet that is defined by the piston bowl, and
the inlet is disposed outside the outlet along the radial direction.

12. A method for operating an internal combustion engine, the method comprising:
providing a piston within a cylinder, and closing an end of the cylinder with a cylinder head, the piston and the cylinder head defining a combustion chamber therebetween, the piston including
a cylindrical base; and
a crown disposed on the cylindrical base, the crown defining a piston bowl,
the crown including an outer circumferential surface that faces away from an inner circumferential surface of the piston bowl along a radial direction, and a top surface that extends from the outer circumferential surface to the inner circumferential surface of the piston bowl along the radial direction,
an annular rim extending beyond the top surface of the crown along a longitudinal direction, the longitudinal direction extending from the cylindrical base toward the crown and being perpendicular to the radial direction,
the annular rim being disposed inside the piston bowl along the radial direction,
the crown defining a flow passageway that is configured to guide a squish flow from the top surface of the crown to the piston bowl;

driving the piston to a top dead center position;
driving a squish flow from the top surface of the crown to the piston bowl via the passageway while the piston is located at the top dead center position; and
interacting the squish flow with a plurality of flames within the combustion chamber.

13. The method of claim 12 , wherein the passageway is configured to follow at least one of a curved path and a straight path.

14. The method of claim 12 , wherein a velocity of the squish flow is accelerated along the passageway before interacting with the plurality of flames.

15. The method of claim 12 , further comprising effecting a plurality of mixing zones to mix the squish flow with the plurality of flames in the combustion chamber.

16. The method of claim 12 , wherein the passageway extends from an inlet that is defined by the top surface of the crown to an outlet that is defined by the piston bowl, and
the inlet is disposed outside the outlet along the radial direction.

Assignees

• Caterpillar Inc

Inventors

• Svensson Kenth
• Koci Chad Palmer

Classifications

• F02F3/24

  having means for guiding gases in cylinders, e.g. for guiding scavenging charge in two-stroke engines · CPC title

• F02B23/0696 Primary

  W-piston bowl, i.e. the combustion space having a central projection pointing towards the cylinder head and the surrounding wall being inclined towards the cylinder wall · CPC title

• F02B2275/40

  Squish effect · CPC title

• Y02T10/125

  Cross-Sectional Technologies · mapped topic

• F02B23/0621

  Squish flow · CPC title