US6161518A
Expired / Lapsed
US
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Direct-injection diesel engine and combustion method for the same
Assignee: Toyota Motor Corp
•
Filing: 1999-03-26
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Granted: 2000-12-19
•
Expires: 2019-03-26
Abstract
Abstract A direct-injection diesel engine in which a shallow-dish type piston cavity is formed on a top surface of a piston; wherein in the vicinity of the top dead center, a squish area is defined mainly by the top surface of the piston and an inner surface of a cylinder head opposite the top surface; when a velocity of a reverse squish flow from the shallow-dish type piston cavity to the squish area, generated due to a movement of the piston and is represented by Vs, and a fuel spray velocity in the vicinity of a lip portion of the shallow-dish type piston cavity is represented by Vsp, the distance between opposite wall portions of the shallow-dish type piston cavity is set such that the ratio Vs/Vsp is not greater than 1.25; and the squish area constitutes a part of the combustion chamber.
Inventors
- 👤 Kiyomi Nakakita
- 👤 Minaji Inayoshi
- 👤 Kazuhisa Inagaki
- 👤 Yoshihiro Hotta
- 👤 Takayuki Fuyuto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:55
CPC Classifications
F; F02; F02B; F02B23/00; F02B23/02; F02B23/06; F02B23/0645; F02B23/0648; F02B23/0651; F02B23/0618; F02B23/0621; F02B23/0672; F02B23/0696; F02B2275/00; F02B2275/14; F02B3/00; F02B3/06; F02F; F02F1/00; F02F1/24; F02F2001/244; F02F2001/245; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
177 words
A direct-injection diesel engine comprising: a combustion chamber defined by a piston, a cylinder head, and a cylinder liner; a shallow-dish type piston cavity formed on a top surface of said piston; a squish area defined by said top surface of said piston and said cylinder head in the vicinity of a compression top dead center; a fuel injector for injecting fuel into said combustion chamber to combust in a fuel-air mixture state; wherein; a distance between opposite wall surfaces of said shallow-dish type piston cavity is set such that ratio Vs/Vsp is not greater than 1.25, in order to use said squish area effectively as a part of said combustion chamber by dispersing and burning a fuel uniformly within said shallow-dish type piston cavity and said squish area; where: Vs is a velocity of the reverse squish flow flowing from said shallow-dish type piston cavity to said squish area due to a movement of said piston; and Vsp is a fuel spray velocity in the vicinity of a lip portion of said shallow-dish type piston cavity.
Claim 2
Dependent Claim
177 words
A direct-injection diesel engine comprising: a combustion chamber defined by a piston, a cylinder head, and a cylinder liner; a shallow-dish type piston cavity formed on a top surface of said piston; a squish area defined by said top surface of said piston and said cylinder head in the vicinity of a compression top dead center; a fuel injector for injecting fuel into said combustion chamber to combust in a fuel-air mixture state; wherein; a distance between opposite wall surfaces of said shallow-dish type piston cavity is set such that ratio Vs/Vsp is not greater than 1.25, in order to use said squish area effectively as a part of said combustion chamber by dispersing and burning a fuel uniformly within said shallow-dish type piston cavity and said squish area; where: Vs is a velocity of the reverse squish flow flowing from said shallow-dish type piston cavity to said squish area due to a movement of said piston; and Vsp is a fuel spray velocity in the vicinity of a lip portion of said shallow-dish type piston cavity.
Claim 3
Dependent Claim
19 words
A direct-injection diesel engine according to claim 1, wherein a specific power is set to 40 KW/l or higher.
Claim 4
Dependent Claim
39 words
A direct-injection diesel engine according to claim 1, wherein a ratio of a minimum diameter of an inlet of the shallow-dish type piston cavity to a depth of the shallow-dish type piston cavity is set to 3.3 or higher.
Claim 5
Dependent Claim
39 words
A direct-injection diesel engine according to claim 1, wherein a ratio of a minimum diameter of an inlet of the shallow-dish type piston cavity to a depth of the shallow-dish type piston cavity is set to 3.5 or higher.
Claim 6
Dependent Claim
35 words
A direct-injection diesel engine according to claim 1, wherein a ratio of a minimum diameter of the shallow-dish type piston cavity inlet to a bore diameter of the cylinder is set to 0.5 or higher.
Claim 7
Dependent Claim
35 words
A direct-injection diesel engine according to claim 1, wherein a ratio of a minimum diameter of the shallow-dish type piston cavity inlet to a bore diameter of the cylinder is set to 0.52 or higher.
Claim 8
Dependent Claim
24 words
A direct-injection diesel engine according to claim 1, wherein a nozzle hole diameter of said fuel injector is set to 0.2 mm or less.
Claim 9
Dependent Claim
24 words
A direct-injection diesel engine according to claim 1, wherein a nozzle hole diameter of said fuel injector is set to 0.15 mm or less.
Claim 10
Dependent Claim
21 words
A direct-injection diesel engine according to claim 1, wherein the squish velocity Vs is a maximum value of the squish velocity.
Claim 11
Dependent Claim
40 words
A direct-injection diesel engine according to claim 1, wherein the fuel spray velocity Vsp is calculated as a fuel spray velocity for a case where a radius of the lip portion is regarded as the fuel spray reach distance S.
Claim 12
Dependent Claim
22 words
A direct-injection diesel engine according to claim 1, wherein the ratio Vs/Vsp is a value which is obtained at a maximum output.
Claim 13
Dependent Claim
55 words
A direct-injection diesel engine according to claim 1, wherein said lip portion of said shallow-dish type piston cavity comprises a small lip formed by the difference of maximum diameter and minimum diameter of said shallow-dish type piston cavity in order to cause the reverse squish flow from said shallow-dish type piston to said squish area.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-12-19 | 2004-06-19 | 2004-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-12-19 | 2008-06-19 | 2008-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-12-19 | 2012-06-19 | 2012-12-19 | $7700.00 | Window Closed / Lapsed |