US3734473A - Air valve type carburetor - Google Patents

Air valve type carburetor Download PDF

Info

Publication number
US3734473A
US3734473A US00104007A US3734473DA US3734473A US 3734473 A US3734473 A US 3734473A US 00104007 A US00104007 A US 00104007A US 3734473D A US3734473D A US 3734473DA US 3734473 A US3734473 A US 3734473A
Authority
US
United States
Prior art keywords
valve
air
fuel
orifice
nozzle
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
US00104007A
Other languages
English (en)
Inventor
H Moriya
Y Hosho
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.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
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 Hitachi Ltd filed Critical Hitachi Ltd
Application granted granted Critical
Publication of US3734473A publication Critical patent/US3734473A/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
    • F02M7/00—Carburettors with means for influencing, e.g. enriching or keeping constant, fuel/air ratio of charge under varying conditions
    • F02M7/12—Other installations, with moving parts, for influencing fuel/air ratio, e.g. having valves
    • F02M7/14—Other installations, with moving parts, for influencing fuel/air ratio, e.g. having valves with means for controlling cross-sectional area of fuel spray nozzle
    • F02M7/16—Other installations, with moving parts, for influencing fuel/air ratio, e.g. having valves with means for controlling cross-sectional area of fuel spray nozzle operated automatically, e.g. dependent on exhaust-gas analysis
    • F02M7/17—Other installations, with moving parts, for influencing fuel/air ratio, e.g. having valves with means for controlling cross-sectional area of fuel spray nozzle operated automatically, e.g. dependent on exhaust-gas analysis by a pneumatically adjustable piston-like element, e.g. constant depression carburettors

Definitions

  • ABSTRACT An air valve type carburetor in which a nozzle is disposed in an air passage between an air valve and a throttle valve, and said nozzle is communicated with a float chamber through a passage with a check ball disposed therein, whereby at the time of acceleration fuel is injected from the nozzle by making use of a negative pressure appearing in the vicinity of said nozzle.
  • This invention relates to an air valve type carburetor.
  • the negative pressure at a Venturi portion is constantly maintained at a substantially constant value by holding an air valve, which is operated by making use of said negative pressure, at a degree of opening proportional to the quantity of air supplied to an engine, whereby satisfactory atomization of fuel is obtained throughout the operation range of the engine, without lowering the efficiency of air suction.
  • the flow rate of fuel is varied by the axial position relative to a metering orifice of a needle valve which is operatively connected with the air valve.
  • the acceleration pump is provided in addition to the oil damper in the air valve type carburetor, so that the fuel will be supplied into the air passage not only at the initial stage but also at the latter stage of acceleration, so that the total quantity of fuel supplied at the latter stage of acceleration becomes too large, resulting in wasteful consumption of fuel which is uneconomical.
  • An object of the present invention is to provide an air valve type carburetor which is provided with means capable of supplying fuel during acceleration in such a quantity as will provide an optimum airfuel ratio.
  • Another object of the invention is to provide fuel supply means for use during acceleration, which is of simple construction not including a pump, piston or diaphragm which usually renders a carburetor expensive.
  • the present invention contemplates the provision of fuel supply means for use during acceleration, which makes use of a negative pressure variation between an air valve and a throttle valve.
  • a nozzle is disposed between the air valve and the throttle valve, while a check valve is provided in a passage communicating with a float chamber, whereby fuel is injected into an air passage by the effect of the negative pressure in the vicinity of said nozzle when the throttle valve is abruptly opened.
  • FIG. 1 is a vertical cross-sectional view of an embodiment of the air valve type carburetor according to the invention
  • FIG. 2 is a diagram illustrating a negative pressure in the vicinity of the nozzle varying with the passage of time after the throttle valve is opened, in the carburetor of the invention (with an oil damper means provided therein);
  • FIGS. 30 and 3b are a set of diagrams exemplifying the negative pressures at the respective points between the air valve and the throttle valve in the air passage, in the carbureter of the invention, when the engine is operating at 3,200 rpm. and the throttle valve is fully opened.
  • reference numeral 1 designates an air passage of the carburetor, 2 a throttle valve and 3 a variable Venturi portion.
  • An air valve 4 which constitutes a portion of the variable Venturi portion, is vertically movable within the air passage 1 according to the size of a negative pressure appearing between the throttle valve 2 and said air valve and acting into a suction chamber 5 through a channel 6.
  • An abrupt movement of the air valve 4 is controlled by oil damper means 9, including a piston rod 7 and a plunger 8, and a spring 10.
  • an orifice 13 communicating with a float chamber 12 is open into a bridge 11 which constitutes a portion of the variable Venturi portion 3, and a needle valve 14 integral with the air valve 4 extends into said orifice.
  • a nozzle 15 is open into the air passage 1 at a location intermediary of the air valve 4 and the throttle valve 2.
  • the nozzle 15 is communicated with the float chamber 12 through a channel 16 and a jet 17, and a check valve 20 consisting of a spring 18 and a ball 19 may be provided intermediary of said channel 16 as shown in FIG. 1.
  • This check valve 20 may be so constructed that it is opened when a negative pressure of a size larger than a predetermined value acts thereon from the air passage, compressing the spring 18.
  • the air valve type carburetor of the construction described above operates in the following manner.
  • the air valve 4 moves up and down according to the size of the negative pressure in that portion of the air passage between it and the throttle valve 2, to maintain the negative pressure at the variable Venturi portion 3 constant. Therefore, the position of the needle valve 14 integral with the air valve 4 is shifted relative to the orifice 13, whereby the fuel discharged into the air passage is controlled.
  • the oil damper means 9 acts to prevent a large variation in air-fuel ratio caused by variation in the opening and closing velocity of the throttle valve 2 due to the inertia differential between air and fuel.
  • the fuel is supplied into the air passage when the negative pressure has reached a predetermined value. It is only after the negative pressure has passed the peak in FIG. 2 that the quantity of air supplied to the engine increases. It will, therefore, be seen that by suitably selecting the strength of the spring 18, it becomes possible to inject the fuel into the air passage immediately after the negative pressure has passed its peak and thereby to supply a rich air-fuel mixture to the engine at the time of acceleration.
  • the absolute value of the negative pressure between the air valve 4 and the throttle valve 2, during the normal operation varies largely at locations, as shown in FIGS. 3a and 3b.
  • the nozzle 15 is provided preferably at a point downstream of the needle valve 14 and a negative pressure which enables the fuel to be supplied in a quantity suffi cient to accelerate the engine, can be obtained at said point.
  • a carburetor according to claim 4 wherein said channel extends uninterruptedly between said check valve and said float chamber.
  • An air valve type carburetor arrangement comprising:
  • a movable throttle valve arranged in said air passage means for controlling the flow of fuel and air mixture to said engine
  • a movable air valve extending into said air passage for controlling the opening in said air passage in response to the negative pressure at a location in said air passage between said throttle valve and said air valve
  • a float chamber for holding a supply of fuel
  • main fuel orifice control means for controlling the opening in said main fuel orifice in response to movement of said air valve
  • said main fuel orifice includes means for supplying sufficient fuel for optimizing said steady state high speed operation and acceleration once the fuel flow through the orifice has overcome the inertial lag related to the difference in weight of air and fuel and the response of said air valve which prevents sufficient immediate fuel flow through said orifice afteran abrupt movement of said air valve and corresponding abrupt adjustment of said orifice by said fuel orifice control means occurring immediately after said abrupt opening of said nozzle.
  • said check valve means includes a biasing means for closing said check valve means during steady state high speed operation and acceleration with an opened throttle due to a reduction in said high negative pressure at said nozzle which occurs shortly after said abrupt opening of said throttle valve.
  • said main fuel orifice includes means for supplying sufficient fuel for optimizing said steady state high speed operation and acceleration once the fuel flow through the orifice has overcome the inertial lag related to the difference in weight of air and fuel and the response of said air valve which prevents sufficient immediate fuel flow through said orifice after an abrupt movement of said air valve and corresponding abrupt adjustment of said orifice by said fuel orifice control means occurring immediately after said abrupt opening of said nozzle.
  • main fuel orifice control means is a needle valve attached to said air valve and extending into said main fuel orifice.
  • control passage is positioned intermediate said needle valve and said secondary fuel nozzle along the length of said air passage.
  • check valve means includes a spring biased ball controlling the opening in said channel.
  • said air valve includes an oil damper means for dampening the movement of said air valve.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Control Of The Air-Fuel Ratio Of Carburetors (AREA)
US00104007A 1970-01-16 1971-01-05 Air valve type carburetor Expired - Lifetime US3734473A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP45003832A JPS492801B1 (ja) 1970-01-16 1970-01-16

Publications (1)

Publication Number Publication Date
US3734473A true US3734473A (en) 1973-05-22

Family

ID=11568156

Family Applications (1)

Application Number Title Priority Date Filing Date
US00104007A Expired - Lifetime US3734473A (en) 1970-01-16 1971-01-05 Air valve type carburetor

Country Status (3)

Country Link
US (1) US3734473A (ja)
JP (1) JPS492801B1 (ja)
GB (1) GB1307501A (ja)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4074661A (en) * 1975-02-14 1978-02-21 Nippon Soken, Inc. Fuel reforming system for an internal combustion engine
US4086885A (en) * 1973-12-13 1978-05-02 Nippon Soken, Inc. Carburetor for stratified internal combustion engine
US4202303A (en) * 1977-03-26 1980-05-13 Lucas Industries Limited Fuel systems for compression ignition engines
US4250125A (en) * 1979-07-16 1981-02-10 Borg-Warner Corporation Slide valve carburetor idle fuel delivery system

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2363223A (en) * 1941-05-15 1944-11-21 Bonnier Claude Etienne Carburetor
US2732193A (en) * 1956-01-24 Carburetor
GB752339A (en) * 1953-01-08 1956-07-11 Pieter Hendrikus Wiegel Improvements in and relating to carburettors
GB917130A (en) * 1960-06-13 1963-01-30 Soichiro Honda Control devices for internal combustion engines
US3320937A (en) * 1963-02-14 1967-05-23 Tillotson Mfg Co Charge forming and fuel feeding method and apparatus for internal combustion engines

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2732193A (en) * 1956-01-24 Carburetor
US2363223A (en) * 1941-05-15 1944-11-21 Bonnier Claude Etienne Carburetor
GB752339A (en) * 1953-01-08 1956-07-11 Pieter Hendrikus Wiegel Improvements in and relating to carburettors
GB917130A (en) * 1960-06-13 1963-01-30 Soichiro Honda Control devices for internal combustion engines
US3320937A (en) * 1963-02-14 1967-05-23 Tillotson Mfg Co Charge forming and fuel feeding method and apparatus for internal combustion engines

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4086885A (en) * 1973-12-13 1978-05-02 Nippon Soken, Inc. Carburetor for stratified internal combustion engine
US4074661A (en) * 1975-02-14 1978-02-21 Nippon Soken, Inc. Fuel reforming system for an internal combustion engine
US4202303A (en) * 1977-03-26 1980-05-13 Lucas Industries Limited Fuel systems for compression ignition engines
US4250125A (en) * 1979-07-16 1981-02-10 Borg-Warner Corporation Slide valve carburetor idle fuel delivery system

Also Published As

Publication number Publication date
GB1307501A (en) 1973-02-21
JPS492801B1 (ja) 1974-01-23

Similar Documents

Publication Publication Date Title
US3243167A (en) Constant vacuum type carburetor
US3493217A (en) Carburettors
US4075294A (en) Carburetor accelerating fuel circuit means
US3642256A (en) Fuel supply system
US4007721A (en) Fuel metering apparatus for a carburetor
US3181843A (en) Carburetor
US3077341A (en) Carburetor
US5843345A (en) Pneumatic accelerator for low emission charge forming devices
US3994268A (en) Internal combustion engine
GB875277A (en) Improvements in or relating to diaphragm carburettors
US5240649A (en) Accelerating device for carburetor
US3734473A (en) Air valve type carburetor
US4092380A (en) Carburetors for internal combustion engines
US3016889A (en) Fuel injector
US2649290A (en) Carburetor
US3672339A (en) Fuel injection apparatus
US4495112A (en) Variable venturi-type carburetor
US3329413A (en) Carburetor
US4146594A (en) Fuel flow control device
US2943849A (en) Carburetor attachment for motor vehicles
US3198497A (en) Carburetors for internal combustion engines
US2460528A (en) Carburetor
US4542726A (en) Deceleration enrichment fuel system for an internal combustion engine
US3943205A (en) Internal combustion engine
US4152375A (en) Fuel supply apparatus for externally ignited combustion engines with continuous fuel addition to the suction pipe