US3848576A - Fuel injection pump for internal combustion engines - Google Patents

Fuel injection pump for internal combustion engines Download PDF

Info

Publication number
US3848576A
US3848576A US00411824A US41182473A US3848576A US 3848576 A US3848576 A US 3848576A US 00411824 A US00411824 A US 00411824A US 41182473 A US41182473 A US 41182473A US 3848576 A US3848576 A US 3848576A
Authority
US
United States
Prior art keywords
fuel
bore
piston
pump
bores
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.)
Expired - Lifetime
Application number
US00411824A
Other languages
English (en)
Inventor
G Hofer
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.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
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 Robert Bosch GmbH filed Critical Robert Bosch GmbH
Application granted granted Critical
Publication of US3848576A publication Critical patent/US3848576A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M41/00—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor
    • F02M41/08—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor and pumping elements being combined
    • F02M41/10—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor and pumping elements being combined pump pistons acting as the distributor
    • F02M41/12—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor and pumping elements being combined pump pistons acting as the distributor the pistons rotating to act as the distributor
    • F02M41/121—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor the distributor and pumping elements being combined pump pistons acting as the distributor the pistons rotating to act as the distributor with piston arranged axially to driving shaft

Definitions

  • the improvement resides in two coaxially 23 9 ED 13 AL, 40 B disposed blind bores in the piston and associated radial bores extending radially from the blind ends 5 References Cited thereof.
  • 123 139 BD from the Working chamber of the Pump includes a 2:965:087 12/1960 Bischoff a a1.
  • 123 139 BD Spring-loaded valve which Opens in the Pressure relief 3,023,705 3/1962 Heiser 123 139 BD x direction- 3,058,455 10/1962 Hofer et al.
  • the present invention relates to a fuel injection pump for internal combustion engines of the type having a simultaneously rotating and reciprocating pump piston actuated and controlled by a cam.
  • the fuel pump under consideration serves as a fuel distributor which distributes fuel through alternating ones of the supply channels disposed within the circumference of a cylinder of the pump, the number of supply channels corresponding to the number of the engine cylinders to be supplied.
  • the pump has a pressure relief apparatus which is operative in dependence on the rpm of the engine during the piston supply stroke and after interruption of the fuel supply to effect control of the fuel pressure in the supply channels and conduits leading to the fuel injection nozzles of the pump.
  • each injection line of the fuel injection pump contains a relief valve with a relief piston, and furthermore the connecting channel between this relief valve and the control point of the injection line is separated from the pump work chamber during the suction stroke and is relieved by a connecting line leading to the pump suction chamber.
  • a separate entry channel and an expensive relief valve for each injection line are required which results in considerable expense.
  • the pressure relief apparatus comprises two coaxially disposed blind bores and a radial bore for each of the two coaxially disposed blind bores formed within the pump piston.
  • the coaxially disposed blind bore and its associated radial bore closest to the working chamber of the pump serve as a passage through which fuel is distributed, while the coaxially disposed bore farthest from the working chamber of the pump includes a spring-loaded valve which opens in the pressure relief direction.
  • the improved pump according to the present invention has an advantage that during the suction stroke of the pump piston a reduced pressure can occur only in the region of the upper relief channel portion that is connected with the pump work chamber.
  • the pressure fluctuations occurring in the supply channel and in the injection lines connected thereto can be made to decay through the single central relief valve, and furthermore, the median pressure can be held constant there. Beyond this, even after the relief valve has opened and during the fuel supply or power stroke, a constant pressure can be maintained in the pump volume and in its connection to the central relief valve.
  • An advantageous embodiment of the present invention consists in that the distribution bore at the third control point can be closed shortly after the beginning of the suction stroke of the pump piston and earlier than the radial bore of the lower part of the relief channel at the second control point can be closed and in that both are operable at the same time.
  • Both the second and third control points are defined below.
  • Another advantageous embodiment of the present invention consists in that the driving cam for the pump piston has a flat portion at the top dead center. This also provides an advantageous possibility of achieving a further relief and pressure equalization in the supply channels prior to the beginning of the suction stroke when using the device according to the present invention.
  • the disposition described above achieves in an advantageous manner that no reduced pressure occurs and therefore cavitation damage and unequal injection are avoided, even during higher supply performance.
  • FIG. 1 illustrates a longtudinal cross section of the fuel injection pump according to the present invention.
  • FIG. 2 is a timing diagram showing the opening times of the individual control points which are shown with respect to the stroke development of the pump piston.
  • FIG. 1 there is shown a pump having a housing 1 within which a cylinder 4 formed by a sleeve 3 is firmly mounted.
  • a piston 2 reciprocates within the cylinder 4.
  • the piston 2 which is embodied as a fuel distributor, sequentially supplies several cylinders of an internal combustion engine.
  • the piston 2 is mounted for simultaneous rotary and reciprocating motion according to the arrow shown in FIG. 1.
  • the rotary and reciprocating motion is achieved by a driven cam 6 which runs on rollers 7 which in turn are pressed against the cam 6 by means of a spring (not shown).
  • the transmission of rotary motion between the cam disc 6 and the piston 2 occurs by means of a pin 8 which engages a groove 9 at the bottom 10 of the piston 2.
  • a suction chamber 16 During each suction stroke of the piston 2, fuel is supplied from a suction chamber 16 to a working chamber 12 enclosed within the pump piston 2 and the cylinder 4 after passing through a supply channel 13, a supply bore 14 and one of the longitudinal grooves 15.
  • the suction chamber 16 is supplied with fuel by a delivery pump 34 drawing fuel from the tank 35.
  • the pressure in the suction chamber 16 is controlled in an rpm-dependent, known manner by means of a pressure control valve 36.
  • a relief channel consisting of an upper portion 17 which includes a blind bore.
  • the channel 17 starts at the working chamber 12 and extends to a radial bore 22.
  • a lower relief channel portion 18 also in the form of a blind bore is provided.
  • the channel portion includes an upper portion 20 and a lower portion 19.
  • the bottom portion of the piston 2 has a larger diameter than the terminal portion 10.
  • the radial bore 22 serves as a distribution bore, opening into the lower end of the relief channel portion 17 within the terminal portion 10'.
  • Another radial bore 23 opens into the upper portion of the lower relief channel 18.
  • a transverse bore 24 terminates in the lower portion 19 of the lower relief channel 18. The exit of this lateral bore 24 cooperates with a control sleeve 26 which can be axially displaced on the pump piston 2 in accordance with the load and the rpm of the engine.
  • a lever 37 which is pivotable about a pin 38 fixed in the housing 1.
  • the lever 37 carries a spherical head 39 which engages a complemental recess 40 provided in the control sleeve 26.
  • the lever 37 may be connected to a centrifugal governor and a regulator spring such as described e. g. in U.S. Pat. No. 3,635,603.
  • the relief channel portion 18 is closed from the bottom end of the piston 2 by a screwed-in stud 27.
  • a spring 28 can be adjustably pretensioned.
  • a suitable bolt can also be pressed in.
  • the spring 28 presses against a ball 30 which in turn presses against the seat formed between the portions 19 and 20 of the relief channel part 18 whereby the transition from the portion 19 to the portion 20 is sealed tightly.
  • the distribution bore 22 and the radial bore 23 can be connected with one another by means of a U-shaped connecting channel 32, which is formed in the sleeve 3.
  • connecting channel 32 there branches off one of a plurality of fuel supply lines 33 which leads to the injection nozzles (not shown).
  • These supply channels 33 and the connecting channels 32 are disposed around the circumference of the pump piston 2 depending on the number and the sequence of the cylinders of the internal combustion engine which are to be supplied.
  • a first control point (I) is defined by the control sleeve 26 and the lateral bore 24; a second control point (II) is defined by the radial bore 23 and the connecting channel 32; and a third control point (Ill) is defined by the radial bore 22 and the connecting channel 32.
  • the mode of operation of the fuel injection pump according to the present invention is as follows:
  • the cam plate 6 is driven and rotates over the rollers 7.
  • This causes the pump piston 2 to execute, as has already been described, a rotating and reciprocating motion, where during its downward motion or suction stroke, it aspirates fuel from the suction chamber 16 through the supply channel 13, the supply bore 14 and one of the longitudinal grooves 15 disposed at the upper circumference of the pump piston 2 and delivers it to the working chamber 12.
  • the connections between the distribution bore 22, the radial bore 23 and the connecting channel 32 are closed, but then the piston is rotated for the connections to be opened during the power stroke.
  • the fuel flows from the working chamber 12 through the upper relief channel portion 17, the distribution bore 22, the connecting channel 32, and the supply channel 33 to the fuel injection nozzles (not shown).
  • the open connections permit fuel to flow through the relief valve 30 into the lower relief channel portion 18.
  • the first control point comprising the control sleeve 26 and the lateral bore 24
  • the first control point is closed so that the fuel is delivered exclusively to the nozzles.
  • the first control point is eventually opened prior to the pistons reaching its top dead center, so that the fuel drains through the relief valve 30, the lateral bore 24 and into the suction chamber 16.
  • the connection between the distribution bore 22 and the connecting channel 32 which together form the third control point, is closed by rotation of the piston 2.
  • FIG. 2 shows the stroke of the piston 2 as a function of its rotation.
  • the designation Ill represents the duration of the connection of the distribution bore 22 with the connecting channel 32 at the third control point.
  • the second control point designated by the reference ll and comprising the radial bore 23 and the connecting channel 32, remains open longer, for the same onset, than does the third control point and it remains open for nearly the entire suction stroke.
  • the closing of the third control point to begin the suction stroke assures that the motion of the piston 2 does not produce a reduced pressure in the connecting channel 32, the supply channel 33, or the second relief channel portion 18.
  • pressure pulses which are created in the injection lines can decay through the relief valve 30.
  • What is especially achieved, depending on the spring pressure in the relief valve 30, is that a uniform relief pressure is achieved in the supply channels and in the injection lines.
  • the central valve maintains a constant pressure in the pump chamber and the adjacent bores an instant after the lateral bore 24 is opened by the control sleeve 26.
  • the pressure which is to be maintained in the supply lines after closing the nozzles can be determined. With this disposition, reduced pressures which are caused by the suction process and which lead to unequal injections as well as reduced pressures which occur through pressure fluctuations in the supply channels and injection lines, and which lead to cavitation damage and to irregular injection, are avoided.
  • the cam which controls the motion of the pump piston 2 can have a short flat portion R at the top dead center, during which the piston stands still, by which means a pressure equalization and a decay of the pressure fluctuations in the supply system is also achieved.
  • a fuel injection pump for internal combustion engines including: (a) a housing; (b) a cylinder mounted within said housing and having a central bore and a plurality of fuel supplying bores formed about the circumference of said cylinder and extending substantially radially from said central bore; (c) a plurality of channel means within said housing, each extending between a fuel injection nozzle and a fuel supplying bore, said channel means and their operatively associated fuel supplying bores forming a plurality of fuel paths, one for each of the fuel injection nozzles, said plurality of fuel paths being equal in number to the number of engine cylinders supplied by said pump; (d) a piston,
  • said cylinder and said piston defining a work chamber; (e) cam means for rotating and reciprocating said piston within said central bore; said piston serving, as a result of its motion within said central bore, to distribute fuel through respective ones of said plurality of fuel paths; (f) relief channel means defining a first control point; (g) relief valve means operatively associated with said relief channel means, said relief valve means being adapted to open during the fuel supply stroke of said piston, as a function of engine rpm and after the fuel supply to said fuel paths has been interrupted to thereby control the fuel pressure of the fuel quantity within said fuel paths, the improvement wherein:
  • said relief channel means comprises two coaxially disposed blind bores within said piston and two radial bores one for each of said coaxially disposed blind bores, each said radial bore extending radially from the blind end of its respective blind bore;
  • said coaxially disposed blind bore closest to said work chamber and said third control point serving as a passage for supplying fuel to be distributed and as a passage through which fuel is distributed;
  • cam means includes a flat portion which is effective when said piston reaches its top dead center.
  • the first control point is defined by a control sleeve mounted to be axially slidable on said piston as a function of engine load and rpm, and a transverse bore formed in said piston and extending from the coaxially disposed blind bore farthest from said working chamber, said control sleeve controlling as a result of its sliding movement the opening and closing of said transverse bore.
US00411824A 1972-11-29 1973-11-01 Fuel injection pump for internal combustion engines Expired - Lifetime US3848576A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19722258309 DE2258309A1 (de) 1972-11-29 1972-11-29 Kraftstoffeinspritzpumpe fuer brennkraftmaschinen

Publications (1)

Publication Number Publication Date
US3848576A true US3848576A (en) 1974-11-19

Family

ID=5862943

Family Applications (1)

Application Number Title Priority Date Filing Date
US00411824A Expired - Lifetime US3848576A (en) 1972-11-29 1973-11-01 Fuel injection pump for internal combustion engines

Country Status (12)

Country Link
US (1) US3848576A (pl)
JP (1) JPS5815618B2 (pl)
AT (1) AT331572B (pl)
BR (1) BR7309345D0 (pl)
DE (1) DE2258309A1 (pl)
ES (1) ES420937A1 (pl)
FR (1) FR2208055B1 (pl)
GB (1) GB1455458A (pl)
IT (1) IT1002039B (pl)
PL (1) PL91160B1 (pl)
RO (1) RO64770A (pl)
SU (1) SU609486A3 (pl)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3942498A (en) * 1973-07-17 1976-03-09 Robert Bosch Gmbh Regulator for a fuel injection pump
US3999529A (en) * 1975-05-19 1976-12-28 Stanadyne, Inc. Multiple plunger fuel injection pump
US4271808A (en) * 1978-01-20 1981-06-09 Diesel Kiki Co., Ltd. Fuel injection pump for internal combustion engines
US4397280A (en) * 1979-05-21 1983-08-09 Nissan Motor Co., Ltd. Governor mechanism for a distributor-type fuel injection pump
US4583508A (en) * 1985-01-07 1986-04-22 Ford Motor Company Positive displacement electronic fuel injection pump
US4649883A (en) * 1983-07-27 1987-03-17 Robert Bosch Gmbh Fuel injection pump for internal combustion engines

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2528092B2 (ja) * 1985-01-17 1996-08-28 日産自動車株式会社 デイ−ゼルエンジンの分配型燃料噴射ポンプ
DE4137252A1 (de) * 1991-11-13 1993-05-19 Bosch Gmbh Robert Kraftstoffeinspritzpumpe fuer brennkraftmaschinen
US7962970B2 (en) 2003-08-12 2011-06-21 180S, Inc. Ear warmer having a curved ear portion

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2640419A (en) * 1950-05-23 1953-06-02 Cav Ltd Liquid fuel injection pump for internal-combustion engines
US2765741A (en) * 1953-01-19 1956-10-09 Bosch Arma Corp Fuel injection pump
US2775233A (en) * 1954-06-24 1956-12-25 Bosch Arma Corp Fuel injection pump
US2794397A (en) * 1952-04-19 1957-06-04 Bosch Arma Corp Fuel injection pump
FR69587E (fr) * 1956-05-25 1958-11-10 Prec Mecanique Perfectionnements apportés aux pompes à piston à débit variable, notamment pour l'injection du combustible dans les moteurs
US2965087A (en) * 1958-01-29 1960-12-20 Bosch Arma Corp Fuel injection pump
US3023705A (en) * 1958-09-24 1962-03-06 Bosch Gmbh Robert Injection pump
US3058455A (en) * 1960-02-24 1962-10-16 Bosch Gmbh Robert Injection pump

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB430663A (en) * 1933-12-22 1935-06-24 Simms Motor Units Ltd Improvements relating to liquid fuel injection pumps
DE1055878B (de) * 1954-07-29 1959-04-23 Bosch Gmbh Robert Kraftstoffeinspritzpumpe fuer mehrzylindrige Brennkraftmaschinen
DE1206205B (de) * 1962-03-30 1965-12-02 Bosch Gmbh Robert Kraftstoffeinspritzpumpe fuer mehrzylindrige Brennkraftmaschinen

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2640419A (en) * 1950-05-23 1953-06-02 Cav Ltd Liquid fuel injection pump for internal-combustion engines
US2794397A (en) * 1952-04-19 1957-06-04 Bosch Arma Corp Fuel injection pump
US2765741A (en) * 1953-01-19 1956-10-09 Bosch Arma Corp Fuel injection pump
US2775233A (en) * 1954-06-24 1956-12-25 Bosch Arma Corp Fuel injection pump
FR69587E (fr) * 1956-05-25 1958-11-10 Prec Mecanique Perfectionnements apportés aux pompes à piston à débit variable, notamment pour l'injection du combustible dans les moteurs
US2965087A (en) * 1958-01-29 1960-12-20 Bosch Arma Corp Fuel injection pump
US3023705A (en) * 1958-09-24 1962-03-06 Bosch Gmbh Robert Injection pump
US3058455A (en) * 1960-02-24 1962-10-16 Bosch Gmbh Robert Injection pump

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3942498A (en) * 1973-07-17 1976-03-09 Robert Bosch Gmbh Regulator for a fuel injection pump
US3999529A (en) * 1975-05-19 1976-12-28 Stanadyne, Inc. Multiple plunger fuel injection pump
US4271808A (en) * 1978-01-20 1981-06-09 Diesel Kiki Co., Ltd. Fuel injection pump for internal combustion engines
US4327696A (en) * 1978-01-20 1982-05-04 Diesel Kiki Co., Ltd. Fuel injection pump for internal combustion engines
US4397280A (en) * 1979-05-21 1983-08-09 Nissan Motor Co., Ltd. Governor mechanism for a distributor-type fuel injection pump
US4649883A (en) * 1983-07-27 1987-03-17 Robert Bosch Gmbh Fuel injection pump for internal combustion engines
US4714412A (en) * 1983-07-27 1987-12-22 Robert Bosch Gmbh Fuel injection pump for internal combustion engines
US4583508A (en) * 1985-01-07 1986-04-22 Ford Motor Company Positive displacement electronic fuel injection pump

Also Published As

Publication number Publication date
DE2258309A1 (de) 1974-05-30
PL91160B1 (pl) 1977-02-28
SU609486A3 (ru) 1978-05-30
GB1455458A (en) 1976-11-10
IT1002039B (it) 1976-05-20
FR2208055B1 (pl) 1976-10-01
RO64770A (ro) 1980-06-15
ES420937A1 (es) 1976-05-01
JPS4982818A (pl) 1974-08-09
ATA994173A (de) 1975-11-15
FR2208055A1 (pl) 1974-06-21
DE2258309C2 (pl) 1987-05-14
AT331572B (de) 1976-08-25
JPS5815618B2 (ja) 1983-03-26
BR7309345D0 (pt) 1974-08-29

Similar Documents

Publication Publication Date Title
US4022165A (en) Fuel injection system for successively introducing multiple fuel quantities in an engine cylinder
EP0643221B1 (en) Fuel Supply Apparatus
US3699939A (en) Fuel injection pump for internal combustion engines and method of fuel control
US3837324A (en) Fuel injection system for internal combustion engines
US4449507A (en) Dual pressure metering for distributor pumps
US4083345A (en) Fuel injection pump
US4407250A (en) Fuel injection system
US4211203A (en) Fuel injection pump
GB1366048A (en) Fuel injection pump for multi-cylinder internal combustion engines
US3848576A (en) Fuel injection pump for internal combustion engines
US4398519A (en) Fuel injection apparatus for internal combustion engines, in particular for diesel engines
US4696271A (en) Fuel injection pump
US3910724A (en) Fuel injection pump for internal combustion engines
US3908619A (en) Fuel injection pumps for internal combustion engines
US4831986A (en) Fuel injection pump
EP0107894B1 (en) Method and apparatus for precisely controlled fuel injection in a diesel engine
JPH0325634B2 (pl)
US4059369A (en) Fuel injection pump
US6016786A (en) Fuel injection system
US4271805A (en) Fuel injection pump
US4440133A (en) Device for premetered pressure-time injection
US4662336A (en) Fuel injection pump for self-igniting internal combustion engines
US4537352A (en) Fuel injection apparatus
US3614944A (en) Engine apparatus
US4541789A (en) Fuel injection pump for internal combustion engines