US3797756A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromagnetically actuated fuel injection valve for internal combustion engines
Assignee: Robert Bosch GmbH
•
Filing: 1973-03-05
•
Granted: 1974-03-19
•
Expires: 1993-03-05
Abstract
Abstract An electromagnetically actuated fuel injection valve for internal combustion engines, the valve needle of which, guided in a bore of the valve housing, is connected to the armature of an electromagnet and is lifted from a valve seat when the electromagnet is energized, against the force of a return spring and against the direction of flow of the fuel which is fed under pressure from an external pressure source, thereby establishing communication between a pressure chamber adjacent the valve seat and a discharge nozzle outlet is described, wherein the valve needle is coupled to a compensating piston which is guided coaxially with the valve needle and the armature, in a fluid tight manner in the said bore. The compensating piston has a first frontal face which is pressure-relieved and a second frontal face which is exposed to the fuel pressure, and a cross sectional area which is so large that, when the injection valve is closed, the hydraulic forces acting on the valve needle in the directions of opening and of closing, are equal or at least approximately equal.
Inventors
- 👤 W Voit
- 👤 K Ziesche
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:50
CPC Classifications
F; F02; F02M; F02M51/00; F02M51/06; F02M51/061; F02M51/0625; F02M51/0664; F02M51/0685; F02M61/00; F02M61/04
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
212 words
In an electromagnetically actuated fuel injection valve of the type that has a. a valve housing having a bore, a valve seat, a pressure chamber adjacent said valve seat, and at least one nozzle discharge outlet, b. a valve needle guided in said bore, c. return spring means for said needle, d. an electromagnet having an armatUre, and e. connecting means for connecting said armature to said valve needle, wherein, upon energization of said electromagnet, said armature lifts said valve needle from said valve seat against the force of said return spring means and against the direction of flow of fuel under pressure into said pressure chamber, thereby establishing communication between the latter and said nozzle discharge outlet, the improvement comprising a compensating piston guided in said bore in a fluid-tight manner and substantially coaxially with said armature and said valve needle, coupling means for coupling said piston to said valve needle, said piston having a pressure-relieved first frontal face and a second frontal face being exposed to fuel pressure and having a cross sectional area sufficiently large so that the hydraulic forces acting on said valve needle in the direction of its opening and in the direction of its closing, when said injection valve is closed, are at least approximately equal.
Claim 2
Dependent Claim
212 words
In an electromagnetically actuated fuel injection valve of the type that has a. a valve housing having a bore, a valve seat, a pressure chamber adjacent said valve seat, and at least one nozzle discharge outlet, b. a valve needle guided in said bore, c. return spring means for said needle, d. an electromagnet having an armatUre, and e. connecting means for connecting said armature to said valve needle, wherein, upon energization of said electromagnet, said armature lifts said valve needle from said valve seat against the force of said return spring means and against the direction of flow of fuel under pressure into said pressure chamber, thereby establishing communication between the latter and said nozzle discharge outlet, the improvement comprising a compensating piston guided in said bore in a fluid-tight manner and substantially coaxially with said armature and said valve needle, coupling means for coupling said piston to said valve needle, said piston having a pressure-relieved first frontal face and a second frontal face being exposed to fuel pressure and having a cross sectional area sufficiently large so that the hydraulic forces acting on said valve needle in the direction of its opening and in the direction of its closing, when said injection valve is closed, are at least approximately equal.
Claim 3
Dependent Claim
56 words
The improvement described in claim 1, further comprising a fuel supply chamber in said housing facing toward said armature and being limited by said second frontal face of said compensating piston, a fuel supply duct being the sole connection between said fuel supply chamber and said pressure chamber, and throttle means in said fuel supply duct.
Claim 4
Dependent Claim
77 words
The improvement as described in claim 2, wherein said throttle means has a throttling cross sectional area whereby, when the injection valve is open, the pressure in the pressure chamber is reduced so that the force acting in said pressure chamber on the valve needle in the direction of opening is at least approximately equal to the force acting in the same chamber on the valve needle in the opening direction when the injection valve is closed.
Claim 5
Dependent Claim
43 words
The improvement as described in claim 1, wherein the cross sectional area corresponding to the guiding diameter of said valve needle in said bore is at least ten times as large as the cross sectional area of fuel flow through the valve seat.
Claim 6
Dependent Claim
17 words
The improvement as described in claim 1, wherein said coupling means comprise an elastically bendable connecting member.
Claim 7
Dependent Claim
31 words
The improvement as described in claim 5, wherein said compensating piston and connecting member are arranged upstream of said armature and substantially coaxially aligned with said armature and said valve needle.
Claim 8
Dependent Claim
25 words
The improvement described in claim 6, wherein the diameter of the compensating piston is at least approximately equal to the diameter of said valve seat.
Claim 9
Dependent Claim
16 words
The improvement described in claim 5, wherein said connecting member is made of spring steel wire.
Claim 10
Dependent Claim
48 words
The improvement as described in claim 2, wherein said fuel supply duct extends essentially along the valve needle axis and has an enlarged portion, and said throttle means comprise a screw member having a throttling passage therein through which said enlarged duct portion communicates with said pressure chamber.
Claim 11
Dependent Claim
46 words
The improvement as described in claim 1, further comprising a guiding sleeve in said bore guiding, said compensating piston and socket means adapted for connection to a fuel return line, said socket means being located at the end of said bore remote from said valve needle.
Claim 12
Dependent Claim
38 words
The improvement as described in claim 1, wherein said compensating piston is arranged between said valve needle and said armature and is coupled to the latter, said coupling means to said valve needle comprising a rigid connecting member.
Claim 13
Dependent Claim
49 words
The improvement as described in claim 11, wherein the cross sectional area corresponding to the diameter of said compensating piston is smaller by the cross sectional area corresponding to the valve seat, than the cross sectional area corresponding to the guiding diameter of said valve needle in said bore.
Claim 14
Dependent Claim
22 words
The improvement described in claim 11, wherein said rigid connecting member has a collar acting as an abutment for said return spring.
Claim 15
Dependent Claim
36 words
The improvement described in claim 13, wherein said collar beaRs a spherically shaped supporting means and said return spring means comprises a return spring and a spring seat disc supporting one end of said return spring.
Claim 16
Dependent Claim
54 words
The improvement described in claim 11, wherein said rigid connecting member bears at each end thereof a spherical head, said compensating piston has a spherically shaped recess for receiving therein one of said heads, and said valve needle has a spherically shaped recess for receiving therein the other head, of said rigid connecting member.
Claim 17
Dependent Claim
47 words
The improvement described in claim 15, wherein the centers of said spherical heads and of said spherical recesses are located at least approximately on the central longitudinal axes of portions of said compensating piston and of said valve needle, respectively, which portions are guided in said bore.
Claim 18
Dependent Claim
28 words
The improvement described in claim 1, wherein said connecting means of said armature to said valve needle comprise a connecting rod having radial play relative to said armature.
Claim 19
Dependent Claim
58 words
The improvement described in claim 17, wherein said connecting means further comprise articulated joint means disposed between said connecting rod and said valve needle and comprising a pin extending through said valve needle and through said connecting rod traversely to the valve needle axis, said connecting rod having a traverse bore therethrough, both ends of which are beveled.
Claim 20
Dependent Claim
80 words
The improvement described in claim 1, further comprising a hollow guiding plug mounted fluid-tight in said discharge outlet, said plug having a cavity therein for guiding an end portion of said valve needle downstream of said valve seat, and wherein said compensating piston serves as said connecting means between said valve needle and said armature and has a diameter which is at least approximately equal to the diameter of said guiding plug and to the diameter of said valve seat.
Claim 21
Dependent Claim
87 words
The improvement described in claim 19, wherein said cavity in said guiding plug is closed toward the end of said valve needle facing toward said compensating piston, said plug having at least one substantially radially extending discharge orifice from said cavity to the outside of said valve, an annular groove about the periphery of said plug in the region of said valve seat and controllable by the latter, and at least one duct through the wall of said plug for connecting said cavity and said annular groove.
Claim 22
Dependent Claim
84 words
The improvement described in claim 1, further comprising a spray plug guided in said discharge outlet and being connected to the end of said valve needle downstream of said valve seat, and wherein said valve needle has a piston portion upstream of said valve seat and guided in said bore, and wherein said compensating piston serves as connecting said means between said valve needle and said armature and has a diameter which is at least approximately equal to the diameter of said valve seat.
Claim 23
Dependent Claim
108 words
An electromagnetically operable fuel injection valve as described in claim 21, wherein said spray plug forms a narrow annular gap together with said discharge outlet, which gap is laid out for only a partial amount of the total fuel quantity to be injected during operation under full load, and wherein said spray plug has at least one spray bore, fully cleaned by said valve seat after a preliminary stroke and laid out for the fuel amount to be injected under full load, or for a fuel amount to be injected under partial load, which latter fuel amount is larger than the partial amount injectable through said annular gap.
References Cited (Backward Citations)
US3623460A
Cited
US3680794A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |