Direct injection fuel injector and internal combustion engine mounting the same

• US 6,345,601 B1
• Filed: 07/20/2000
• Issued: 02/12/2002
• Est. Priority Date: 12/15/1999
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Togashi, Shigenori, Ishikawa, Tohru, Miyajima, Ayumu, Okamoto, Yoshio, Kadomukai, Yuzo
• Primary Examiner(s): SOLIS, ERICK R
• Application Number:
  US09/620,584
• Time in Patent Office: 572 Days
• Field of Search: 123/295, 123/305, 123/472, 239/467, 239/483, 239/533.12
• US Class Current: 123/305
• CPC Class Codes: F02B 2075/125 Direct injection in the combustion chamber for spark ignition engines, i.e. not in pre-combustion chamber
• CPC Class Codes: F02M 51/0675 the valve body having cylindrical guiding or metering portions, e.g. with fuel passages
• CPC Class Codes: F02M 51/0682 the body being hollow and its interior communicating with the fuel flow F02M51/0675 takes precedence
• CPC Class Codes: F02M 61/162 Means to impart a whirling motion to fuel upstream or near discharging orifices
• CPC Class Codes: F02M 61/1806 characterised by the arrangement of discharge orifices, e.g. orientation or size
• CPC Class Codes: F02M 69/045 for injecting into the combustion chamber F02M69/046 takes precedence
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

In a spray characteristic in a direct injection system gasoline engine use electromagnetic system fuel injector, to a piston cavity a mixture of fuel and air having a combustible concentration is converged and making rich the mixture having the combustible concentration at a side of ignition plug, then an ignition performance is improved and making thin the mixture of fuel and air to a piston direction a combustion performance is improved, namely it is necessary to generate a flat inclined spray. A part of a wall face for forming the injection hole at an outlet portion of the injector is formed with V groove according to two inclination faces with optional angles against a center axial line of the injection hole or a substantially recess shape step-wise rectangular groove having different cut-off depths.

Claims

1. A fuel injector having an injection hole, a valve seat arranged at an upstream end of said injection hole, a swirl passage for imparting a swirl force to fuel at an upstream side of said valve seat, a valve body for carrying out an opening operation and a closing operation of a fuel passage at said valve seat, and driving means for driving said valve body in an axial direction thereof, wherein at an outlet portion of said injection hole, a part of the wall face forming said injection hole is cutoff so as to have a groove shape.

2. A fuel injector having an injection hole, a valve seat arranged at an upstream end of said injection hole, a swirl passage for imparting a swirl force to fuel at an upstream side of said valve seat, a valve body for carrying out an opening operation and a closing operation of a fuel passage at said valve seat, and driving means for driving said valve body in an axial direction thereof, wherein at a nozzle tip end face on which an outlet opening face of said injection hole is formed, a groove extending on both sides of said outlet opening is formed in said outlet opening face, and the respective distances from a center axial line of said injection hole to each of the side walls forming said groove are different.

3. A fuel injector having an injection hole, a valve seat arranged at an upstream end of said injection hole, a swirl passage for imparting a swirl force to fuel at an upstream side of said valve seat, a valve body for carrying out an opening operation and a closing operation of a fuel passage at said valve seat, and driving means for driving said valve body in an axial direction thereof, wherein a V groove is formed with two faces which are inclined at optional angles relative to a center axial line of said injection hole.

4. A fuel injector having an injection hole, a valve seat arranged at an upstream end of said injection hole, a swirl passage for imparting a swirl force to fuel at an upstream side of said valve seat, a valve body for carrying out an opening operation and a closing operation of a fuel passage at said valve seat, and driving means for driving said valve body in an axial direction thereof, wherein a groove-shaped cut-off face is formed by a substantially recess-shaped step-wise groove having different cut-off depths.

5. In a fuel injection apparatus having a fuel injector for injecting fuel directly into a cylinder, a pump for supplying the fuel to said fuel injector by pressurizing the fuel, and a control apparatus for controlling said fuel injector to control fuel injection, said fuel injector having an injection hole, a valve seat arranged at an upstream end of said injection hole, a swirl passage for imparting a swirl force to fuel at an upstream side of said valve seat, a valve body for carrying out an opening operation and a closing operation of a fuel passage at said valve seat, and driving means for driving said valve body in an axial direction thereof, wherein at a nozzle tip end face on which an outlet opening face of said injection hole is formed, a groove extending on both sides of said outlet opening is formed in said outlet opening face, and the respective distances from a center axial line of said injection hole to each of the side walls forming said groove are different.

6. In an internal combustion engine having a cylinder, a piston which reciprocates in said cylinder, an air intake means for introducing air into said cylinder, an air exhaust means for exhausting combustion gas from said cylinder, a fuel injector for injecting fuel directly into said cylinder, a fuel supply means for supplying fuel to said fuel injector from a fuel tank, a piston in said cylinder and having a cavity for catching a mixture of air introduced into said cylinder from said air intake means and fuel injected into said cylinder by said fuel injector, and an ignition apparatus for igniting said mixture of fuel and air, said fuel injector having an injection hole, a valve seat arranged at an upstream end of said injection hole, a swirl passage for imparting a swirl force to fuel at an upstream side of said valve seat, a valve body for carrying out an opening operation and a closing operation of a fuel passage at said valve seat, and driving means for driving said valve body to in axial direction thereof, wherein at an outlet portion of said injection hole, a part of the wall face for forming said injection hole is cut off so as to have a groove shape.

8. In an internal combustion engine according to claim 6 or claim 7, wherein:

a flat inclined spray is produced by said fuel infector such that in the vicinity of said ignition apparatus, the spray concentration is high, and in the vicinity of said piston, the spray concentration is formed thin; and

by converging said flat inclined spray to said cavity, said flat inclined spray is induced toward said ignition apparatus.

7. In an internal combustion engine having a cylinder, a piston which reciprocates in said cylinder, an air intake means for introducing air into said cylinder, an air exhaust means for exhausting combustion gas from said cylinder, a fuel injector for injecting fuel directly into said cylinder, a fuel supply means for supplying fuel to said fuel injector from a fuel tank, a piston in said cylinder and having a cavity for catching a mixture of air introduced into said cylinder from said intake air means and fuel injected into said cylinder by said fuel injector, and an ignition apparatus for igniting said mixture of fuel and air, said fuel injector having an injection hole, a valve seat arranged at an upstream end of said injection hole, a swirl passage for imparting a swirl force to fuel at an upstream side of said valve seat, a valve body for carrying out an opening operation and a closing operation of a fuel passage at said valve seat, and driving means for driving said valve body in an axial direction thereof, wherein a part of a wall face for forming said injection hole at an outlet portion of said injection hole is formed with a substantially recess-shaped step-wise rectangular groove having different cut-off depths, and a side where said cut-off depth of a face of said step-wise groove is large is directed toward said ignition apparatus and a side where said cut-off depth of said face of said step-wise groove is small is directed toward said piston.