US4976244A — Fuel injection device for internal combustion eng…

Claim 1

Independent Claim 449 words

A fuel injection device for internal combustion engines, comprising a housing, a cylinder bore (2) in said housing a pump piston (1) in said cylinder bore, a pump chamber (4) in said cylinder bore related to said pump piston (1) that has a constant working stroke, an intermediate piston (5) in said cylinder bore, a pressure chamber (6) in said cylinder bore relative to said intermediate piston, said intermediate piston (5) hydraulically separating said pump chamber (4) from said pressure chamber (6), a valve needle (11)that controls injection openings (9), a nozzle pressure chamber (8) relative to said valve needle and said injection openings, a pressure line (7) that extends from said pressure chamber (6) to said nozzle pressure chamber (8), a supply onset means for determining an injection onset of fuel for said pressure chamber (6) to said nozzle pressure chamber (8) as a function of a fuel volume containable in said pump chamber (4), for this purpose, said pressure chamber (6) functioning to pre-store a fuel volume therein for injection of a required supply quantity, via said nozzle pressure chamber (8), a diversion conduit (22) connected to said pressure chamber (6) and to a fuel supply container, said diversion conduit determining an end of supply by opening a one-way valve therein to permit fuel flow from said pressure chamber (6) near an end of a compression stroke due to movement of said intermediate piston (5), wherein said intermediate piston (5) always attains a predetermined end position at an end of a compression stroke, a low-pressure fuel source (15), a feed line (17) which can be connected from said low pressure fuel source to a fill line (28) leading to said pressure chamber (6), a fill valve (32) connected in said fill line (28), a control valve (19) in said feed line (17) for controlling a flow of a fuel volume into the pressure chamber (6) via said feed line (17) and said fill line (28), a reservoir (35) connected with said pump chamber (4) and connectable with said feed line (17) via said cylinder bore, said reservoir including a piston (43) separating a reservoir chamber (41) from a control chamber (42), a compensation line (45) connected from said pump chamber (4) to said reservoir chamber (41) of said reservoir (35) and a control line (34) which leads from said cylinder bore to said control chamber (42), whereby a volumetric capacity of said reservoir (35) is variable in order to determine an enclosable fuel volume in said pump chamber (4) and thus to define a supply onset, and that a volumetric capacity of said reservoir is determined by a stroke of said reservoir piston (43) within said reservoir.

Claim 2

Dependent Claim 449 words

A fuel injection device for internal combustion engines, comprising a housing, a cylinder bore (2) in said housing a pump piston (1) in said cylinder bore, a pump chamber (4) in said cylinder bore related to said pump piston (1) that has a constant working stroke, an intermediate piston (5) in said cylinder bore, a pressure chamber (6) in said cylinder bore relative to said intermediate piston, said intermediate piston (5) hydraulically separating said pump chamber (4) from said pressure chamber (6), a valve needle (11)that controls injection openings (9), a nozzle pressure chamber (8) relative to said valve needle and said injection openings, a pressure line (7) that extends from said pressure chamber (6) to said nozzle pressure chamber (8), a supply onset means for determining an injection onset of fuel for said pressure chamber (6) to said nozzle pressure chamber (8) as a function of a fuel volume containable in said pump chamber (4), for this purpose, said pressure chamber (6) functioning to pre-store a fuel volume therein for injection of a required supply quantity, via said nozzle pressure chamber (8), a diversion conduit (22) connected to said pressure chamber (6) and to a fuel supply container, said diversion conduit determining an end of supply by opening a one-way valve therein to permit fuel flow from said pressure chamber (6) near an end of a compression stroke due to movement of said intermediate piston (5), wherein said intermediate piston (5) always attains a predetermined end position at an end of a compression stroke, a low-pressure fuel source (15), a feed line (17) which can be connected from said low pressure fuel source to a fill line (28) leading to said pressure chamber (6), a fill valve (32) connected in said fill line (28), a control valve (19) in said feed line (17) for controlling a flow of a fuel volume into the pressure chamber (6) via said feed line (17) and said fill line (28), a reservoir (35) connected with said pump chamber (4) and connectable with said feed line (17) via said cylinder bore, said reservoir including a piston (43) separating a reservoir chamber (41) from a control chamber (42), a compensation line (45) connected from said pump chamber (4) to said reservoir chamber (41) of said reservoir (35) and a control line (34) which leads from said cylinder bore to said control chamber (42), whereby a volumetric capacity of said reservoir (35) is variable in order to determine an enclosable fuel volume in said pump chamber (4) and thus to define a supply onset, and that a volumetric capacity of said reservoir is determined by a stroke of said reservoir piston (43) within said reservoir.

Claim 3

Dependent Claim 33 words

A fuel injection device as defined by claim 1, in which said control valve (19) in said feed line (17) controls the volumetric capacity of the reservoir chamber (41) for the supply onset.

Claim 4

Dependent Claim 34 words

A fuel injector as defined by claim 1, in which fuel flow via said feed line (17) is controllable additionally by means of said intermediate piston driven in synchronism with the pump piston (1).

Claim 5

Dependent Claim 34 words

A fuel injector as defined by claim 2, in which fuel flow via said feed line (17) is controllable additionally by means of said intermediate piston driven in synchronism with the pump piston (1).

Claim 6

Dependent Claim 43 words

A fuel injector as defined by claim 2, whereby in an intake stroke of the pump piston (1), a control of the fuel volumes into the pressure chamber (6) is effected first, and a control of the volumetric capacity is effected after that.

Claim 7

Dependent Claim 43 words

A fuel injector as defined by claim 3, whereby in an intake stroke of the pump piston (1), a control of the fuel volumes into the pressure chamber (6) is effected first, and a control of the volumetric capacity is effected after that.

Claim 8

Dependent Claim 98 words

A fuel injector as defined by claim 5, in which said feed line (17) is opened by said control valve (19) and a control slide (101) at the onset of the intake stroke, and after metering of the injection quantity the control valve (19) closes again, after which, during the continuing intake stroke, the control slide disconnects the feed line (17) from the pressure chamber (4) and connects it to said control chamber (42) of said reservoir (35), so that subsequently the control valve (19) opens, and then for the supply onset closes again, in a quantity-determining manner.

Claim 9

Dependent Claim 98 words

A fuel injector as defined by claim 6, in which said feel line (17) is opened by said control valve (19) and a control slide (101) at the onset of the intake stroke, and after metering of the injection quantity the control valve (19) closes again, after which, during the continuing intake stroke, the control slide disconnects the feed line (17) from the pressure chamber (4) and connects it to said control chamber (42) of said reservoir (35), so that subsequently the control valve (19) opens, and then for the supply onset closes again, in a quantity-determining manner.

Claim 10

Dependent Claim 22 words

A fuel injector as defined by claim 1, which includes stops (51) that determine the end positions of the intermediate piston (5).

Claim 11

Dependent Claim 22 words

A fuel injector as defined by claim 2, which includes stops (51) that determine the end positions of the intermediate piston (5).

Claim 12

Dependent Claim 22 words

A fuel injector as defined by claim 3, which includes stops (51) that determine the end positions of the intermediate piston (5).

Claim 13

Dependent Claim 32 words

A fuel injector as defined by claim 1, which includes a spring (46) that loads said intermediate piston (105), and said spring (46) acts in a direction toward the pump chamber (4).

Claim 14

Dependent Claim 32 words

A fuel injector as defined by claim 2, which includes a spring (46) that loads said intermediate piston (105), and said spring (46) acts in a direction toward the pump chamber (4).

Claim 15

Dependent Claim 32 words

A fuel injector as defined by claim 3, which includes a spring (46) that loads said intermediate piston (105), and said spring (46) acts in a direction toward the pump chamber (4).

Claim 16

Dependent Claim 38 words

A fuel injector as defined by claim 1, in which said pump chamber (4) in the intake stroke end position of the pump piston (1) communicates via a refill line (39) with said fuel source of low pressure.

Claim 17

Dependent Claim 38 words

A fuel injector as defined by claim 2, in which said pump chamber (4) in the intake stroke end position of the pump piston (1) communicates via a refill line (39) with said fuel source of low pressure.

Claim 18

Dependent Claim 38 words

A fuel injector as defined by claim 3, in which said pump chamber (4) in the intake stroke end position of the pump piston (1) communicates via a refill line (39) with said fuel source of low pressure.

Claim 19

Dependent Claim 42 words

A fuel injector as defined by claim 1, in which said reservoir piston (43) operates as a deflection piston, which at a beginning of the compression stroke and on receiving fuel from the pump chamber (4), is deflected by a controllable stroke.

Claim 20

Dependent Claim 42 words

A fuel injector as defined by claim 2, in which said reservoir piston (43) operates as a deflection piston, which at a beginning of the compression stroke and on receiving fuel from the pump chamber (4), is deflected by a controllable stroke.

Claim 21

Dependent Claim 42 words

A fuel injector as defined by claim 3, in which said reservoir piston (43) operates as a deflection piston, which at a beginning of the compression stroke and on receiving fuel from the pump chamber (4), is deflected by a controllable stroke.

Claim 22

Dependent Claim 99 words

A fuel injector as defined by claim 18, in which said reservoir piston (43) is loaded in a deflection direction by a reservoir spring (44), and that on said control chamber (42) side of the reservoir piston (43), said reservoir piston can be acted upon via a control line (34) by fluid pressure that is higher than the pressure prevailing in the pump chamber (4) during the intake stroke and resting phase of the pump piston (1), which via pressure in said control chamber (42), said reservoir piston (43) is displaceable by a distance corresponding to the deflection stroke.

Claim 23

Dependent Claim 27 words

A fuel injector as defined by claim 21, in which said control line (34) can be connected by said intermediate piston (5) to the feed line (17).

Claim 24

Dependent Claim 23 words

A fuel injector as defined by claim 7, in which a portion of the pump piston (1) serves as the control slide (101).

Claim 25

Dependent Claim 22 words

A fuel injector as defined by claim 3, in which a portion of said intermediate piston (5) serves as a control slide.

Claim 26

Dependent Claim 86 words

A fuel injector as defined by claim 21, in which said control valve (19) includes a one-way valve (21) embodied in a closed position as a check valve through which a counter current flow is possible, so that during a first phase of a compression stroke of the pump piston (1), fuel from the control chamber of reservoir (35) can be positively displaced back to the fuel source via not only the control line (34) and the feed line (17) but also said control valve (19).

Claim 27

Dependent Claim 49 words

A fuel injector as defined by claim 1, in which said control valve (19) is a magnetic valve that is preferably opened when without current and is triggered by an electronic control unit (24), in which engine parameters such as rpm (n), temperature (T) and the like are processed.

Claim 28

Dependent Claim 49 words

A fuel injector as defined by claim 1, in which said pump piston (1) is a drive cam (13), which has a long, flatly descending intake stroke segment (intake stroke edge III), a short resting segment (base circle IV), and a steep compression stroke segment (compression stroke edge V).

Claim 29

Dependent Claim 21 words

A fuel injector as defined by claim 27, in which a curve of the intake stroke edge follows an Archimedes spiral.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1993-12-10	1994-06-11	1994-12-11	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1997-12-10	1998-06-11	1998-12-11	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2001-12-10	2002-06-11	2002-12-11	$7700.00	Window Closed / Lapsed

Fuel injection device for internal combustion engines, in particular unit fuel injection

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag