GB2285096A - Formation of interconected high pressure passages - Google Patents

Formation of interconected high pressure passages Download PDF

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Publication number
GB2285096A
GB2285096A GB9423764A GB9423764A GB2285096A GB 2285096 A GB2285096 A GB 2285096A GB 9423764 A GB9423764 A GB 9423764A GB 9423764 A GB9423764 A GB 9423764A GB 2285096 A GB2285096 A GB 2285096A
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GB
United Kingdom
Prior art keywords
passage
longitudinal axis
poppet
intersection
point
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB9423764A
Other versions
GB2285096B (en
GB9423764D0 (en
Inventor
Brian J Murphy
Ronald D Shinogle
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Caterpillar Inc
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Caterpillar Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Caterpillar Inc filed Critical Caterpillar Inc
Publication of GB9423764D0 publication Critical patent/GB9423764D0/en
Publication of GB2285096A publication Critical patent/GB2285096A/en
Application granted granted Critical
Publication of GB2285096B publication Critical patent/GB2285096B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M55/00Fuel-injection apparatus characterised by their fuel conduits or their venting means; Arrangements of conduits between fuel tank and pump F02M37/00
    • F02M55/02Conduits between injection pumps and injectors, e.g. conduits between pump and common-rail or conduits between common-rail and injectors
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M57/00Fuel-injectors combined or associated with other devices
    • F02M57/02Injectors structurally combined with fuel-injection pumps
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M61/00Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/16Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fuel-Injection Apparatus (AREA)

Description

A L 1 2285096 BREAKOUT OF A HIGH-PRESSURE FLUID PASSAGE INTO A
HIGH-PRESSURE FLUID CAVITY This invention relates generally to high-pressure apparatus and, more particularly, to a fuel injector having first and second high-pressure passages.
Fuel injectors generally include a valve body having a poppet valve inlet passage that converges with a poppet bore formed in the valve body. The poppet valve inlet passage and the poppet bore are typically formed in the valve body by electrochemical machining (ECM), electrical discharge machining (EDM), or drilling. In the prior art, the poppet valve inlet passage of a fuel injector normally has a circular cross-section viewed perpendicular to the central longitudinal axis of the poppet valve inlet passage.
In operation, fuel is delivered to a poppet bore through the poppet valve inlet passage at high pressure, e.g., of the order of 138 MPa (20,000 p.s. i) or greater.
This pressure exerts a force on the walls defining the poppet bore and the poppet valve inlet passage that tends to radially expand or stretch those walls producing an internal stress (known as a hoop stress) therein. At the convergence of the walls of the poppet valve inlet passage with the walls of the poppet bore, the hoop stress tends to elongate the cross-section of the poppet valve inlet passage in a direction perpendicular to a longitudinal axis of the poppet bore and reduce the cross-section of the inlet passage in a direction parallel to the longitudinal axis of the poppet bore. Consequently, upper and lower margins of the poppet valve inlet passage, which have a small radius of curvature, are subjected to a high concentration of tensile stress. This tensile stress tends to weaken the valve body and can eventually cause structural fatigue, failure or fracture thereof.
In accordance with one aspect of the present invention, a method of producing first and second high- 1 A L 2 pressure passages which meet at a point of intersection includes the steps of forming a first wall defining the first passage and forming a second wall defining the second passage such that at the point of intersection the second passage has an elongate cross-section having a major dimension transverse to a longitudinal axis of the first passage in an unpressurised condition.
The second passage preferably has an oval crosssection at the point of intersection and a longitudinal axis that is substantially perpendicular to the longitudinal axis of the first passage.
Further, a portion of the second passage extending from the point of intersection also preferably has an elongate cross-section having a major dimension transverse to the longitudinal axis of the first passage in the unpressurised condition.
In accordance with a further aspect of the present invention, a highpressure apparatus includes a first wall defining a first passage having a longitudinal axis; and a second wall defining a second passage converging with the first passage at a point of intersection; wherein in an unpressurised condition the second passage has an elongate cross-section proximate the point of intersection having a major dimension substantially transverse to the longitudinal axis of the first passage.
Preferably, the major dimension of the elongate crosssection of the second passage is substantially perpendicular to the longitudinal axis of the first passage. Also preferably, the second passage has a longitudinal axis that is substantially perpendicular to the longitudinal axis of the first passage and has an oval cross-section proximate the point of intersection.
In accordance with yet another aspect of the present invention, a fuel injector includes a first wall defining a poppet bore having a circular cross-section in an unpressurised condition; and a second wall defining a poppet valve inlet passage converging with the poppet bore A 1 3 at a point of intersection and having an oval cross-section with a major dimension transverse to a longitudinal axis of the poppet bore proximate to the point of intersection in the unpressurised condition.
The poppet valve inlet passage preferably has a longitudinal axis that is substantially perpendicular to a longitudinal axis of the poppet bore.
In the accompanying drawings:- Fig. 1 comprises an elevational view partly in section of a fuel injector in which the present invention can be used; Fig. 2 comprises a fragmentary perspective view of a prior-art valve body having a circular poppet valve inlet passage in an unpressurised condition; Fig. 3 comprises a fragmentary perspective view of the valve body of Fig. 2 in a pressurized condition; Fig. 4 comprises a fragmentary elevational view of the inlet passage of the valve body of Fig. 2 shown in unpressurised and pressurized conditions; Fig. 5 comprises a generalized fragmentary perspective view of a valve body incorporating the present invention; Fig. 6 comprises a sectional view of the valve body taken generally along the lines 6-6 of Fig. 5; Fig. 7 comprises a fragmentary perspective view of a valve body in accordance with the present invention in an unpressurised condition; Fig. 8 comprises a fragmentary perspective view of the valve body of Fig. 7 in a pressurized condition; and Fig. 9 comprises a fragmentary elevational view of the inlet passage of the valve body of Fig. 7 shown in unpressurised and pressurized conditions.
Referring initially to Fig. 1, a fuel injector 20 includes a three-way poppet valve 22 comprising a valve body 24 and a valve element or poppet 26 disposed within a cylindrical poppet bore 28 formed within the valve body 24. The poppet 26 is coupled to and actuated by an armature 30 of a solenoid 32. The armature 30 is normally biased A h 4 downward (as shown in Fig. 1) by a spring 34. When the solenoid 32 is electrically energized, the poppet 26 moves upward within the poppet bore 28.
Referring now to Fig. 2, the poppet bore 2 8 is def ined by a wall 40 in the centre of the valve body 24 and has a longitudinal axis 42. The valve body 24 also includes a poppet valve inlet passage 44 defined by a wall 46. Fuel is supplied to the poppet bore 28 through the poppet valve inlet passage 44 at high pressure, e.g., of the order of 138 MPa (20,000 p.s.i.) or greater. The poppet bore 28 and the poppet valve inlet passage 44 are conventionally formed in the valve body 24 using, for example, electrochemical machining (ECM) or electrical discharge machining (EDM) techniques.
Figs. 2-4 depict a conventional design known in the prior art, in which the poppet bore 28 and the poppet valve inlet passage 44 of a valve body 24 have circular cross sections when the valve body 24 is in an unpressurised condition. When fuel is delivered to the poppet bore 28 under high pressure, the fuel exerts a force on the wall 40 defining the poppet bore 28 and on the wall 46 defining the poppet valve inlet passage 44. Arrows 48 show the directions of the forces exerted on the wall 40. These forces tend to produce tensile stress in the walls 40 and 46. The tensile stress is most concentrated in the upper and lower portions 50 and 52 (as shown in Figs. 2-4) of the intersection of the poppet valve inlet passage 44 with the poppet bore 28. This high stress concentration tends to cause structural fatigue and even fracture of the valve body 24 when fuel is delivered to the poppet bore 28 under high pressure.
The effect of the stress exerted on the walls of the poppet valve inlet passage 44 during a high-pressure condition is best seen in Fig. 3 wherein the normally circular cross-section of the poppet valve inlet passage 44 is elongated into a noncircular shape having a major dimension perpendicular to the longitudinal axis 42 of the A k poppet bore 28. Elongation of the poppet valve inlet passage 44 produces a deflection of the walls defining the poppet valve inlet passage 44 adjacent to a point of intersection of the poppet bore 28 and the poppet valve inlet passage 44 at the top and bottom portions of the poppet valve inlet passage 44 as shown in Fig. 3. The effect of this elongation on the shape of the cross-section of the inlet passage 44 is illustrated in Fig. 4 which depicts the cross-section of the inlet passage 44 in the unpressurised condition (solid outline) as well as in the pressurized condition (broken outline). This undesirable effect is diminished, but not eliminated, by forming the poppet valve inlet passage 44 so that the longitudinal axis thereof is substantially perpendicular to the longitudinal axis 42 of the poppet bore 28.
Referring now to Figs. 5-9, a valve body 60 in accordance with the present invention includes a poppet bore 62 defined by a wall 64 and having a longitudinal axis 66 and a poppet valve inlet passage 68 defined by a wall 70 and having a longitudinal axis 72. As shown in Fig. 6, the poppet valve inlet passage 68 converges gradually into the poppet bore 28 at a smooth, curved transition region 74.
The poppet valve inlet passage 68 has an elongate cross section having a major dimension which is preferably substantially perpendicular to the longitudinal axis 66 of the poppet bore 62 when the valve body 60 is in an unpressurised condition. As a result, upper and lower portions 76 and 78 of the poppet valve inlet passage 68, as shown in Fig. 7, have a radius of curvature which is substantially infinite, and the concentration of stress in those portions of the poppet valve inlet passage 68 is lower than in comparable portions of the poppet valve inlet passage 44 of the prior-art valve body 24. This reduction in stress concentration in the upper and lower portions of the poppet valve inlet passage 68 is enhanced by forming the poppet valve inlet passage 68 so that it converges with the poppet bore 62 at an angle of substantially ninety A hL 6 degrees. In other words, the longitudinal axis 72 of the poppet valve inlet passage 68 is substantially perpendicular to the longitudinal axis 66 of the poppet bore 62. This reduction in stress concentration, in turn, reduces the likelihood of structural fatigue, failure or fracture of the valve body 60 when fuel is delivered to the poppet bore 62 under high pressure.
Preferably, a portion of the poppet valve inlet passage 68 extending from the point of intersection of the poppet valve inlet passage 68 with the poppet bore 62 has an elongate cross-section so that the stress concentration in the valve body 60 is reduced suf f iciently to avoid fracture thereof. Industrial APR1icability Referring now to Fig. 8, while the high-pressure fuel periodically delivered to the poppet bore 62 through the poppet valve inlet passage 68 does exert forces which produce pulsating hoop stress in the walls of the valve body 60, the stress concentration factor of the oval-shaped poppet valve inlet passage 68 is lower than that of the prior-art circular passage. Thus, the flattened portions 76, 78 of the poppet valve inlet passage 68 do not tend to deflect appreciably as a result of the hoop stress created during the pressurized condition, and the valve body 60 is less prone to fatigue failure or failure. Arrows 80 show the directions of the forces exerted on the wall 64. Fig.
9 depicts the cross-section of the inlet passage 68 in the unpressurised condition (solid outline) and in the pressurized condition (broken outline) to illustrate the reduced tendency of the valve body 60 to deflect as compared to the prior-art valve body 24.
The foregoing description relates to the present invention as embodied in a fuel injector. However, the present invention may be embodied in any application where one high-pressure passage converges with another. Because the adverse effects of hoop stress are reduced by the present invention, high-pressure apparatus can be designed a L 7 to withstand greater pressures, or can be made smaller or fabricated with materials which are less strong, and therefore less expensive, without sacrificing durability of the apparatus.
A)h 8

Claims (12)

1. A method of producing first and second high-pressure f luid passages which meet at a point of intersection, comprising the steps of forming a first wall defining the f irst passage; and f orming a second wall def ining the second passage such that at the point of intersection the second passage has an elongate cross-section having a major dimension transverse to a longitudinal axis of the f irst 10 passage in an unpressurised condition.
2. A method according to claim 1, wherein the second passage has an oval cross-section at the point of intersection.
3. A method according to claim 1 or claim 2, wherein the second passage has a longitudinal axis that is substantially perpendicular to the longitudinal axis of the first passage.
4. A method according to any one of the preceding claims, wherein a portion of the second passage extending from the point of intersection has an elongate cross-section having a major dimension transverse to the longitudinal axis of the first passage in the unpressurised condition.
5. A method according to claim 4, wherein the portion of the second passage has an oval cross-section.
6. A high-pressure apparatus, comprising a first wall defining a first passage having a longitudinal axis; and a second wall defining a second passage converging with the first passage at a point of intersection; wherein in an unpressurised condition the second passage has an elongate cross-section proximate the point of intersection having a major dimension substantially transverse to the longitudinal axis of the first passage.
9
7. An apparatus according to claim 6, wherein the major dimension is substantially perpendicular to the longitudinal axis of the first passage.
8. An apparatus according to claim 6 or 7, wherein the second passage has a longitudinal axis that is substantially perpendicular to the longitudinal axis of the first passage.
9. An apparatus according to any one of claims 6 to 8, wherein the second passage has an oval cross-section proximate the point of intersection.
10. A fuel injector comprising a first wall defining a poppet bore having a circular cross-section in an unpressurised condition; and a second wall defining a poppet valve inlet passage converging with the poppet bore at a point of intersection and having an oval cross- section with a major dimension transverse to a longitudinal axis of the poppet bore proximate to the point of intersection in the unpressurised condition.
11. A fuel injector according to claim 10, wherein the poppet valve inlet passage has a longitudinal axis that is substantially perpendicular to a longitudinal axis of the poppet bore.
12. A high pressure apparatus substantially as described with reference to Figs. 5 to 9 of the accompanying drawings.
GB9423764A 1993-12-27 1994-11-16 Method of operating a high-pressure apparatus such as a fuel injector Expired - Fee Related GB2285096B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US17427693A 1993-12-27 1993-12-27

Publications (3)

Publication Number Publication Date
GB9423764D0 GB9423764D0 (en) 1995-01-11
GB2285096A true GB2285096A (en) 1995-06-28
GB2285096B GB2285096B (en) 1997-12-03

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Family Applications (1)

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GB9423764A Expired - Fee Related GB2285096B (en) 1993-12-27 1994-11-16 Method of operating a high-pressure apparatus such as a fuel injector

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JP (1) JP3020535U (en)
DE (1) DE4446071A1 (en)
GB (1) GB2285096B (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1927751A1 (en) * 2006-11-27 2008-06-04 Delphi Technologies, Inc. Housing with intersecting passages
EP2018925A2 (en) * 2005-06-06 2009-01-28 Delphi Technologies, Inc. Machining Method
US20120234403A1 (en) * 2009-11-06 2012-09-20 Daniel Jeremy Hopley Housing with intersecting passages for high pressure fluid applications
EP2808532A1 (en) * 2013-05-30 2014-12-03 Delphi International Operations Luxembourg S.à r.l. Fuel injector
WO2015086560A1 (en) * 2013-12-10 2015-06-18 Robert Bosch Gmbh Connection region between a high-pressure duct and a high-pressure chamber, and fuel injection component having a connection region

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10220320A (en) * 1996-12-07 1998-08-18 Usui Internatl Ind Co Ltd Common rail
DE10002715A1 (en) * 2000-01-22 2001-07-26 Bosch Gmbh Robert Fuel injection valve for internal combustion engine; has central spring chamber and fuel supply channel with larger cross-section in circumferential direction than in radial direction
DE102008040383A1 (en) 2008-07-14 2010-01-21 Robert Bosch Gmbh High pressure resistant fuel injector
DE102008040381A1 (en) 2008-07-14 2010-01-21 Robert Bosch Gmbh High pressure resistant fuel injector

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1472125A (en) * 1974-05-07 1977-05-04 Yanmar Diesel Engine Co Fuel-injection pump for an internal combustion eingine
EP0449662A1 (en) * 1990-03-29 1991-10-02 Cummins Engine Company, Inc. A fuel injector and a method of relieving stress concentration within a fuel injector bore

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1472125A (en) * 1974-05-07 1977-05-04 Yanmar Diesel Engine Co Fuel-injection pump for an internal combustion eingine
EP0449662A1 (en) * 1990-03-29 1991-10-02 Cummins Engine Company, Inc. A fuel injector and a method of relieving stress concentration within a fuel injector bore

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2018925A2 (en) * 2005-06-06 2009-01-28 Delphi Technologies, Inc. Machining Method
US8313636B2 (en) 2005-06-06 2012-11-20 Delphi Technologies Holding S.Arl Machining method
EP1927751A1 (en) * 2006-11-27 2008-06-04 Delphi Technologies, Inc. Housing with intersecting passages
US7607458B2 (en) 2006-11-27 2009-10-27 Delphi Technologies, Inc. Housing with intersecting passages
US20120234403A1 (en) * 2009-11-06 2012-09-20 Daniel Jeremy Hopley Housing with intersecting passages for high pressure fluid applications
US9234511B2 (en) * 2009-11-06 2016-01-12 Delphi International Operions Luxembourg S.A.R.L. Housing with intersecting passages for high pressure fluid applications
EP2808532A1 (en) * 2013-05-30 2014-12-03 Delphi International Operations Luxembourg S.à r.l. Fuel injector
WO2015086560A1 (en) * 2013-12-10 2015-06-18 Robert Bosch Gmbh Connection region between a high-pressure duct and a high-pressure chamber, and fuel injection component having a connection region

Also Published As

Publication number Publication date
GB2285096B (en) 1997-12-03
GB9423764D0 (en) 1995-01-11
DE4446071A1 (en) 1995-06-29
JP3020535U (en) 1996-02-02

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PCNP Patent ceased through non-payment of renewal fee

Effective date: 20031116