US4745898A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pre-injection apparatus for internal combustion engines
Assignee: Robert Bosch GmbH
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Filing: 1987-08-31
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Granted: 1988-05-24
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Expires: 2007-08-31
Abstract
Abstract In a pre-injection apparatus for Diesel engines, a pre-injection slide that generates a pronounced pressure intensification for the pre-injection in a pressure chamber closed off with respect to the high-pressure side and open toward the injection line is slidably supported in a stepped guide bore and is exposed to the injection pressure of a high-pressure pump. After the execution of a partial stroke (h v ), which is responsible for the pre-injection quantity, the pre-injection pressure chamber is opened with a backwards-oriented action toward the high-pressure side and thereby is intially relieved of pressure. The ensuing movement of the pre-injection slide until the complete end of its stroke forms a predeterminable capacity that enables an injection pause. The pre-injection pressure chamber communicates with an electrically triggerable magnetic valve with the low-pressure side or the high-pressure side, so that the shutoff of the pre-injection is possible under certain operating conditions.
Inventors
- 👤 Walter Egler
- 👤 Nestor Rodriquez-Amaya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:45
CPC Classifications
F; F02; F02M; F02M45/00; F02M45/02; F02M45/04; F02M45/06; F02B; F02B3/00; F02B3/06
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
257 words
A pre-injection apparatus for internal combustion engines comprising a housing, a high pressure fluid source, a low pressure fuel pump, a pre-injection slide that controls fuel flow to a pre-injection pressure chamber (20), said pre-injection slide having an enlarged area in said pre-injection pressure chamber said enlarged area forming first and second valve faces, said pre-injection pressure chamber having first and second valve seats, said pre-injection slide having an upper end subjected to a fuel pressure generated by said high-pressure fuel source and which undergoes a displacement determining a pre-injection quantity, a spring chamber (24) at a lower end of said pre-injection slide within said housing, a conduit connection between said spring chamber (24) and said fuel injection line, said pre-injection slide enabling a main injection by opening a fuel injection line leading to a nozzle, whereby during a first partial pre-injection stroke (h v ) of said pre-injection slide (12), a connection of the high-pressure side to the injection line (28) is kept sealed thereby forming a pressure intensification by means of a pressure stage (A 2 <A 1 ) at the pre-injection slide (12) from said spring chamber (24), which transfers a pre-injection quantity to the injection line (28), opening said pre-injection pressure chamber (20) toward the high-pressure side, causes a drop of the nozzle pressure, and the high-pressure side is relieved until a final stroke of the pre-injection slide and a magnetic valve (32, 32') is provided which communicates at least indirectly with the pre-injection pressure chamber (20) to shut-off control of said pre-injection.
Claim 2
Dependent Claim
257 words
A pre-injection apparatus for internal combustion engines comprising a housing, a high pressure fluid source, a low pressure fuel pump, a pre-injection slide that controls fuel flow to a pre-injection pressure chamber (20), said pre-injection slide having an enlarged area in said pre-injection pressure chamber said enlarged area forming first and second valve faces, said pre-injection pressure chamber having first and second valve seats, said pre-injection slide having an upper end subjected to a fuel pressure generated by said high-pressure fuel source and which undergoes a displacement determining a pre-injection quantity, a spring chamber (24) at a lower end of said pre-injection slide within said housing, a conduit connection between said spring chamber (24) and said fuel injection line, said pre-injection slide enabling a main injection by opening a fuel injection line leading to a nozzle, whereby during a first partial pre-injection stroke (h v ) of said pre-injection slide (12), a connection of the high-pressure side to the injection line (28) is kept sealed thereby forming a pressure intensification by means of a pressure stage (A 2 <A 1 ) at the pre-injection slide (12) from said spring chamber (24), which transfers a pre-injection quantity to the injection line (28), opening said pre-injection pressure chamber (20) toward the high-pressure side, causes a drop of the nozzle pressure, and the high-pressure side is relieved until a final stroke of the pre-injection slide and a magnetic valve (32, 32') is provided which communicates at least indirectly with the pre-injection pressure chamber (20) to shut-off control of said pre-injection.
Claim 3
Dependent Claim
26 words
A pre-injection apparatus as defined by claim 1, in which for shutoff control of the pre-injection, the pre-injection chamber (20) communicates with said low-pressure feed pump.
Claim 4
Dependent Claim
32 words
A pre-injection apparatus as defined by claim 1, in which for shutoff control of the pre-injection, the pre-injection chamber (20) communicates with said high-pressure pump via a bypass containing said magnetic valve.
Claim 5
Dependent Claim
99 words
A pre-injection apparatus as defined by claim 1, in which the pre-injection slide (12) is slidably supported is a stepped bore (13) of said housing (11) disposed between a high-pressure side and the nozzle, wherein an annular recess in the partial housing, in combination with the stepped bore, by means of different seat cross sections on both sides (A 2 , A 1 , with A 2 <A 1 ), forms the pressure chamber (20) for the pressure stage serving to effect the pressure intensification for the pre-injection, and the pressure chamber (20) communicates with the injection line (28).
Claim 6
Dependent Claim
99 words
A pre-injection apparatus as defined by claim 2, in which the pre-injection slide (12) is slidably supported in a stepped bore (13) of said housing (11) disposed between a high-pressure side and the nozzle, wherein an annular recess in the partial housing, in combination with the stepped bore, by means of different seat cross sections on both sides (A 2 , A 1 , with A 2 <A 1 ), forms the pressure chamber (20) for the pressure stage serving to effect the pressure intensification for the pre-injection, and the pressure chamber (20) communicates with the injection line (28).
Claim 7
Dependent Claim
99 words
A pre-injection apparatus as defined by claim 3, in which the pre-injection slide (12) is slidably supported in a stepped bore (13) of said housing (11) disposed between a high-pressure side and the nozzle, wherein an annular recess in the partial housing, in combination with the stepped bore, by means of different seat cross sections on both sides (A 2 , A 1 , with A 2 <A 1 ), forms the pressure chamber (20) for the pressure stage serving to effect the pressure intensification for the pre-injection, and the pressure chamber (20) communicates with the injection line (28).
Claim 8
Dependent Claim
66 words
A pre-injection apparatus as defined by claim 4, in which said first and second valve seats have seat cross sections (A 1 , A 2 ) formed by the pre-injection pressure chamber (20) in a transition to a stepped bore (13) of the housing (11), and said first and second valve faces are, respectively, tapering stop and sealing faces (29a, 29b) on the pre-injection slide (12).
Claim 9
Dependent Claim
66 words
A pre-injection apparatus as defined by claim 5, in which said first and second valve seats have seat cross sections (A 1 , A 2 ) formed by the pre-injection pressure chamber (20) in a transition to a stepped bore (13) of the housing (11), and said first and second valve faces are, respectively, tapering stop and sealing faces (29a, 29b) on the pre-injection slide (12).
Claim 10
Dependent Claim
66 words
A pre-injection apparatus as defined by claim 6, in which said first and second valve seats have seat cross sections (A 1 , A 2 ) formed by the pre-injection pressure chamber (20) in a transition to a stepped bore (13) of the housing (11), and said first and second valve faces are, respectively, tapering stop and sealing faces (29a, 29b) on the pre-injection slide (12).
Claim 11
Dependent Claim
62 words
A pre-injection apparatus as defined by claim 7, in which a ratio of said seat cross sections (A 1 , A 2 ) is dimensioned such that with a long pre-injection stroke (h v ) of the pre-injection slide (12), a finely metered pre-injection quantity results, with a high pressure intensification (1:5-1:15) as a result of the pressure stage that is formed.
Claim 12
Dependent Claim
62 words
A pre-injection apparatus as defined by claim 8, in which a ratio of said seat cross sections (A 1 , A 2 ) is dimensioned such that with a long pre-injection stroke (h v ) of the pre-injection slide (12), a finely metered pre-injection quantity results, with a high pressure intensification (1:5-1:15) as a result of the pressure stage that is formed.
Claim 13
Dependent Claim
62 words
A pre-injection apparatus as defined by claim 9, in which a ratio of said seat cross sections (A 1 , A 2 ) is dimensioned such that with a long pre-injection stroke (h v ) of the pre-injection slide (12), a finely metered pre-injection quantity results, with a high pressure intensification (1:5-1:15) as a result of the pressure stage that is formed.
Claim 14
Dependent Claim
123 words
A pre-injection apparatus as defined by claim 1, in which said pre-injection slide (12), over the distance of the pre-injection stroke (h v ), closes an inflow from the high-pressure side to the injection line (20), and the pre-injection chamber (20) communicates with the injection line (28) leading onward to the nozzle, and that disposed on the lower end of the pre-injection slide (12) is the spring chamber (24) that enables the full stroke (H ges ) of the pre-injection slide until it comes to a stop on its lower conical ring face (29b) on said second valve seat cross section (A 2 ), and the spring chamber (24) communicates with a relief bore (25) to the spring chamber on the nozzle side.
Claim 15
Dependent Claim
123 words
A pre-injection apparatus as defined by claim 2, in which said pre-injection slide (12), over the distance of the pre-injection stroke (h v ), closes an inflow from the high-pressure side to the injection line (20), and the pre-injection chamber (20) communicates with the injection line (28) leading onward to the nozzle, and that disposed on the lower end of the pre-injection slide (12) is the spring chamber (24) that enables the full stroke (H ges ) of the pre-injection slide until it comes to a stop on its lower conical ring face (29b) on said second valve seat cross section (A 2 ), and the spring chamber (24) communicates with a relief bore (25) to the spring chamber on the nozzle side.
Claim 16
Dependent Claim
123 words
A pre-injection apparatus as defined by claim 3, in which said pre-injection slide (12), over the distance of the pre-injection stroke (h v ), closes an inflow from the high-pressure side to the injection line (20), and the pre-injection chamber (20) communicates with the injection line (28) leading onward to the nozzle, and that disposed on the lower end of the pre-injection slide (12) is the spring chamber (24) that enables the full stroke (H ges ) of the pre-injection slide until it comes to a stop on its lower conical ring face (29b) on said second valve seat cross section (A 2 ), and the spring chamber (24) communicates with a relief bore (25) to the spring chamber on the nozzle side.
Claim 17
Dependent Claim
123 words
A pre-injection apparatus as defined by claim 4, in which said pre-injection slide (12), over the distance of the pre-injection stroke (h v ), closes an inflow from the high-pressure side to the injection line (20), and the pre-injection chamber (20) communicates with the injection line (28) leading onward to the nozzle, and that disposed on the lower end of the pre-injection slide (12) is the spring chamber (24) that enables the full stroke (H ges ) of the pre-injection slide until it comes to a stop on its lower conical ring face (29b) on said second valve seat cross section (A 2 ), and the spring chamber (24) communicates with a relief bore (25) to the spring chamber on the nozzle side.
Claim 18
Dependent Claim
123 words
A pre-injection apparatus as defined by claim 7, in which said pre-injection slide (12), over the distance of the pre-injection stroke (h v ), closes an inflow from the high-pressure side to the injection line (20), and the pre-injection chamber (20) communicates with the injection line (28) leading onward to the nozzle, and that disposed on the lower end of the pre-injection slide (12) is the spring chamber (24) that enables the full stroke (H ges ) of the pre-injection slide until it comes to a stop on its lower conical ring face (29b) on said second valve seat cross section (A 2 ), and the spring chamber (24) communicates with a relief bore (25) to the spring chamber on the nozzle side.
Claim 19
Dependent Claim
123 words
A pre-injection apparatus as defined by claim 10, in which said pre-injection slide (12), over the distance of the pre-injection stroke (h v ), closes an inflow from the high-pressure side to the injection line (20), and the pre-injection chamber (20) communicates with the injection line (28) leading onward to the nozzle, and that disposed on the lower end of the pre-injection slide (12) is the spring chamber (24) that enables the full stroke (H ges ) of the pre-injection slide until it comes to a stop on its lower conical ring face (29b) on said second valve seat cross section (A 2 ), and the spring chamber (24) communicates with a relief bore (25) to the spring chamber on the nozzle side.
Claim 20
Dependent Claim
35 words
A pre-injection apparatus as defined by claim 1, in which the pre-injection slide (12) has a fin-like structure (30) on the upper end for sliding guidance in the enlarged partial bore of the housing (11).
Claim 21
Dependent Claim
35 words
A pre-injection apparatus as defined by claim 2, in which the pre-injection slide (12) has a fin-like structure (30) on the upper end for sliding guidance in the enlarged partial bore of the housing (11).
Claim 22
Dependent Claim
35 words
A pre-injection apparatus as defined by claim 3, in which the pre-injection slide (12) has a fin-like structure (30) on the upper end for sliding guidance in the enlarged partial bore of the housing (11).
Claim 23
Dependent Claim
35 words
A pre-injection apparatus as defined by claim 4, in which the pre-injection slide (12) has a fin-like structure (30) on the upper end for sliding guidance in the enlarged partial bore of the housing (11).
Claim 24
Independent Claim
172 words
A method of pre-injection for internal combustion engines, in particular Diesel engines, which comprises influencing a pre-injection slide under the influence of a fuel pressure generated by a high-pressure side to undergo a displacement determining a pre-injection quantity, with an ensuing enabling of a main injection by opening of an injection line leading to a nozzle, producing a first partial stroke of a pre-injection stroke (h v ) of the pre-injection slide (12), connecting a high-pressure side of a fluid pressure to the injection line (28) while maintaining said pre-injection slide in a sealed position forming a pressure intensification by means of a pressure stage (A 2 <A 1 ) at the pre-injection slide (12), transfering the pre-injection quantity to the injection line (28), moving the pre-injection slide to open the pre-injection pressure chamber (20) uptoward the high-pressure side, with a drop of the nozzle pressure, and relieving the high-pressure side of said pre-injection slide until the final stroke of the pre-injection slide, and controlling the pre-injection quantity to a desired amount.
Claim 25
Independent Claim
172 words
A method of pre-injection for internal combustion engines, in particular Diesel engines, which comprises influencing a pre-injection slide under the influence of a fuel pressure generated by a high-pressure side to undergo a displacement determining a pre-injection quantity, with an ensuing enabling of a main injection by opening of an injection line leading to a nozzle, producing a first partial stroke of a pre-injection stroke (h v ) of the pre-injection slide (12), connecting a high-pressure side of a fluid pressure to the injection line (28) while maintaining said pre-injection slide in a sealed position forming a pressure intensification by means of a pressure stage (A 2 <A 1 ) at the pre-injection slide (12), transfering the pre-injection quantity to the injection line (28), moving the pre-injection slide to open the pre-injection pressure chamber (20) uptoward the high-pressure side, with a drop of the nozzle pressure, and relieving the high-pressure side of said pre-injection slide until the final stroke of the pre-injection slide, and controlling the pre-injection quantity to a desired amount.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-24 | 1991-11-23 | 1992-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-24 | 1995-11-23 | 1996-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-24 | 1999-11-23 | 2000-05-24 | $7700.00 | Window Closed / Lapsed |