The present invention relates to a diesel engine, and a fuel injection method for a diesel engine.
In a diesel engine, a fuel injection valve is usually arranged at a cylinder head and on an extension of an axis of a cylinder. An example of such conventional diesel engine is shown in
The fuel injection valve 5 has a lower end formed with 4-6 nozzle holes which are arranged circumferentially and substantially equidistantly. An axis L1 of the fuel injection valve 5 is substantially on an extension of an axis L2 of the cylinder 3.
In the above-mentioned diesel engine 1, when the piston 3 reaches a vicinity of an upper dead center during a compression stroke, fuel is injected from the fuel injection valve 5 radially in a plan view into atomization in a combustion chamber 6 to produce sprays 7. To inject the fuel radially in the plan view is for prevention of the produced sprays 7 from being interfered with each other into formation of excessively rich portions of the sprays 7 and thus for prevention of combustion failure.
The sprays 7 radially injected into the combustion chamber 6 take in air supplied from the suction valve into the cylinder 2 and advance to and strike against an inner periphery of the cylinder 2, so that the sprays 7 change their advancing directions to advance along the inner periphery of the cylinder 2 and collide with the sprays 7 from the opposite direction along the inner periphery of the cylinder 2 into a fuel-air mixture which burns by attaining its ignition temperature through compression of the combustion chamber 6.
There are various prior art literatures for a diesel engine. A diesel engine with an axis of a fuel injection valve being on an extension of an axis of a piston is shown, for example, in Patent Literatures 1 and 2.
In the diesel engine 1 shown in
However, when an axis L1 of the fuel injection valve 5 is on an extension of an axis L2 of the cylinder 2, a distance from the fuel injection valve 5 to the inner periphery of the cylinder 2 is short in length and the circumferentially advancing distances of the sprays 7 along the inner periphery of the cylinder 2 are also short in length. Thus, the sprays 7 of fuel injected from the fuel injection valve 5 and reaching and advancing along the inner periphery of the cylinder 2 fail in taking in sufficient air before the collision; as a result, the sprays 7 burn with insufficient oxygen to bring about combustion failure to thereby increase particulate matters (PM).
In the diesel engine 1 as shown in
Patent Literature 1 is to suppress production of soot and nitrogen oxides by sufficiently diffusing fuel sprays within a combustion chamber even if the fuel is injected in a vicinity of a top dead center. Patent Literature 2 is to prevent interference of sprays from main and auxiliary injection holes during a high load operation so as to prevent smoke degradation. Thus, both of the Patent Literatures 1 and 2 have no direct relevance to the invention.
The invention was made in view of the above and has its object to provide a fuel injection method for a diesel engine and a diesel engine capable of conducting sufficient intake of air in fuel sprays injected from a fuel injection valve so as to prevent combustion failure.
The invention is directed a fuel injection method for a diesel engine with fuel being injected from a fuel injection valve into a combustion chamber for production of sprays, comprising injecting the fuel to produce sprays by the fuel injection valve deviated radially outwardly of the cylinder into a position close to an inner periphery of the cylinder, the sprays advancing in a fan-like manner in a plan view to strike against the inner periphery of said cylinder on a side away from the deviated fuel injection valve.
In a fuel injection method for a diesel engine according to the invention, predetermined ones of the sprays striking against and advancing circumferentially along the inner periphery of said cylinder collide and interfere with the other sprays striking against and advancing along the inner periphery of the cylinder in the direction opposite to the first-mentioned sprays.
In a diesel engine according to the invention with fuel being injected from a fuel injection valve into a combustion chamber for production of sprays, said fuel injection valve is deviated radially of the cylinder into a position close to an inner periphery of said cylinder.
In a diesel engine of the invention, nozzle holes of said fuel injection valve are grouped into two groups with respect to a line connecting an axis of said injection valve with an axis of the cylinder in a plan view, the respective nozzle holes being arranged in a fan like manner in a plan view, tips of the respective nozzle holes being directed to the inner periphery of the cylinder on a side away from the fuel injection valve.
In a diesel engine according to the invention, an upper surface of a piston in said cylinder has a falling gradient from a side close to the fuel injection valve to a side away from the fuel injection valve.
According to a fuel injection method for a diesel engine and a diesel engine of the invention, the fuel injection valve is deviated with respect to the cylinder, so that the distance from the fuel injection valve to the inner periphery of the cylinder and the circumferential distances along which the sprays flow can be made sufficiently prolonged, so that the sprays of fuel injected from the fuel injection valve reach and advance along the inner periphery of the cylinder, and take in and admix with sufficient air before the collision and the interference with each other. As a result, the combustion of the sprays is conducted in cooperation with an enough amount of evenly dispersed oxygen, so that combustion state becomes satisfactory to reduce particulate matters (PM).
In a diesel engine of the invention, the piston has a falling gradient in an advancing direction of the sprays, so that the sprays hardly adhere to the surface of the piston and enough distances can be afforded before the strike of substantially all of the sprays against the inner periphery of the cylinder, thereby attaining further favorable actions and effects.
Embodiments of the invention will be described in conjunction with the attached drawings.
The embodiment illustrated is characteristic in that an axis L1 of a fuel injection valve 5 is deviated with respect to an axis L2 of a cylinder 2 radially outwardly of the cylinder 2 by a distance S so that the injection valve 5 is positioned close to an inner periphery of the cylinder 2. Nozzle holes 5a of the fuel injection valve 5 are grouped into two with respect to line L3 connecting the axis L1 with the axis L2 as shown in
When the nozzle holes 5a of the fuel injection valve 5 are grouped into two groups each with three holes as shown in
In a side view, each of the axes L4 of the nozzle holes 5a has a falling gradient toward a side of the inner periphery of the cylinder 2 where the sprays 7 strike.
Next, a mode of operation of the above embodiment will be described.
In the diesel engine 1 shown, the sprays 7 of fuel injected from two grouped nozzle holes of the fuel injection valve 5 in two directions advance divergently in fan-like manner as shown in
In the embodiment shown, the fuel injection valve 5 is deviated with respect to the cylinder 2 by a distance S, so that a distance from the fuel injection valve 5 to the inner periphery of the cylinder 2 where the sprays 7 strike and circumferential distances along which the sprays 7 flow can be made sufficiently prolonged. Thus, the sprays 7 of fuel injected from the fuel injection valve 5 reach and advance along the inner periphery of cylinder 2 and can take in and admix with sufficient air before the collision. As a result, the sprays 7 burn in cooperation with an enough amount of evenly dispersed oxygen, so that the combustion state becomes favorable to reduce particulate matters (PM).
This embodiment shown can also attain effects and advantages similar to those in the embodiment illustrated previously in the above; moreover, the piston 3 has a falling gradient in the advancing direction of the sprays 7, so that the sprays 7 hardly adhere to the surface of the piston 3; it can afford enough distances for the strike of substantially all of the sprays 7 against the inner periphery of the cylinder 2, which brings about further favorable actions and effects.
It is to be understood that a fuel injection method for a diesel engine and a diesel engine according to the invention is not limited to the above-mentioned embodiments and that various changes and modifications may be made without departing from the scope of the invention.
Number | Date | Country | Kind |
---|---|---|---|
2007-324646 | Dec 2007 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/JP2008/003178 | 11/5/2008 | WO | 00 | 6/16/2010 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2009/078119 | 6/25/2009 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
2748757 | Morris | Jun 1956 | A |
7726282 | Ashizawa | Jun 2010 | B2 |
20040011324 | Arndt et al. | Jan 2004 | A1 |
20040244786 | Van Wyk | Dec 2004 | A1 |
Number | Date | Country |
---|---|---|
891 767 | Oct 1953 | DE |
857 909 | Oct 1940 | FR |
57-110718 | Jul 1982 | JP |
61-207816 | Sep 1986 | JP |
61-58649 | Dec 1986 | JP |
5-59352 | Sep 1993 | JP |
5-80566 | Nov 1993 | JP |
2570996 | Feb 1998 | JP |
10-227218 | Aug 1998 | JP |
10-252608 | Sep 1998 | JP |
2000-516687 | Dec 2000 | JP |
3191562 | May 2001 | JP |
2003-172144 | Jun 2003 | JP |
2004-92496 | Mar 2004 | JP |
2004-92586 | Mar 2004 | JP |
2007-255291 | Oct 2007 | JP |
2002-0042886 | Jun 2002 | KR |
WO 9213190 | Aug 1992 | WO |
WO 2008015536 | Feb 2008 | WO |
Entry |
---|
U.S. Appl. No. 12/747,646, filed Jun. 11, 2010, Marutani, et al. |
Extended European Search Report issued on Apr. 8, 2011 in Application No. 08861302.1. |
Number | Date | Country | |
---|---|---|---|
20110155101 A1 | Jun 2011 | US |