CA1055336A - Automotive engine carburetor - Google Patents
Automotive engine carburetorInfo
- Publication number
- CA1055336A CA1055336A CA245,029A CA245029A CA1055336A CA 1055336 A CA1055336 A CA 1055336A CA 245029 A CA245029 A CA 245029A CA 1055336 A CA1055336 A CA 1055336A
- Authority
- CA
- Canada
- Prior art keywords
- air
- fuel
- internal combustion
- combustion engine
- air bleed
- 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
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D35/00—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for
- F02D35/0015—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for using exhaust gas sensors
- F02D35/0046—Controlling fuel supply
- F02D35/0053—Controlling fuel supply by means of a carburettor
- F02D35/0061—Controlling the emulsifying air only
-
- 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
- F02M7/23—Fuel aerating devices
- F02M7/24—Controlling flow of aerating air
Abstract
Abstract of the Disclosure A compensating member is provided in a conventional automotive engine carburetor, which is used with an electronic closed loop control system, in order to finely adjust a rate of air flow being delivered to a fuel passage extending between a discharge nozzle and a float bowl, and thereby performing a fine adjust-ment of an air-fuel mixture ratio to effectively reduce noxious components in exhaust gases.
Description
1~5S336 *he pre~ent invcrItic)rl re.late~ genernl:Ly to an a~Itomotive en~ine carhu.retor, and mor.e p~rticular.ly to atl improvement in such a carburetor which control~ ~;
the air-fuel mixture ratio in response to an electrical ~:ignal appLied thereto~
Variou~ ~ystems have been propo~ed to optimally control the air-fuel ratio of` an air-fuel mixture to an .internal combu~tion engine in dependence of mode~
of eslgine operation in order to effectively reduce nox.iou~ components (such as nitrogen oxides (NOx), cnr~)orI monoxide (CO), and hydrocarbons (}IC)) contained in exhaIlst gases, one of which syJtems is to utilize the concept of electronic closed loop ~y~tem based on a sen~ed concentration of a component in exhau~t ga~e~
of the engine. Each of the~e clo~ed loop ~ystems, -e~pecial:Ly when a ~o-called three-way catalytic con ~:
verter i~ employed for the reduction of the nox~ou~
component~ required to finely control the air- .;
.hIe.L mixture ratio to a considerable extent. This ~0 I~ because the erfect of the three-way catalytic converter i8 maximized when the air-fuel ratio is maintained in the vicinity of ~toichiometric air-fuel ..
ratlo. Therefore, a carburetor for u~e with the -~I.ectronic cLosed loop control Yy~tem is u~ually e(~ ipped with an electrical unit for the purpose of '~
the air-fuel mixture ratio in response to an electrical ~:ignal appLied thereto~
Variou~ ~ystems have been propo~ed to optimally control the air-fuel ratio of` an air-fuel mixture to an .internal combu~tion engine in dependence of mode~
of eslgine operation in order to effectively reduce nox.iou~ components (such as nitrogen oxides (NOx), cnr~)orI monoxide (CO), and hydrocarbons (}IC)) contained in exhaIlst gases, one of which syJtems is to utilize the concept of electronic closed loop ~y~tem based on a sen~ed concentration of a component in exhau~t ga~e~
of the engine. Each of the~e clo~ed loop ~ystems, -e~pecial:Ly when a ~o-called three-way catalytic con ~:
verter i~ employed for the reduction of the nox~ou~
component~ required to finely control the air- .;
.hIe.L mixture ratio to a considerable extent. This ~0 I~ because the erfect of the three-way catalytic converter i8 maximized when the air-fuel ratio is maintained in the vicinity of ~toichiometric air-fuel ..
ratlo. Therefore, a carburetor for u~e with the -~I.ectronic cLosed loop control Yy~tem is u~ually e(~ ipped with an electrical unit for the purpose of '~
- 2 ~
'. ~
. ~ .
10~533~;
fine control of the air-fuel ratio of the air-fuel mixture.
A three-way catalytic converter, as is well known, has a characteristic of deoxidizing NOX and oxidizing both CO and HC
at the same timeO
However, none of the conventional mass produced carburetors has a compensating or auxiliary element which serves to readily and finely adjust the air-fuel ratio to adequate set points in a manufacturing process. Furthermore, ready adjust-ments to compensate for changes of the set points with the passage of time are not possible. As a result, the conventional carburetors each, because of the absence of the compensating element, has not been suitable for mass-production and locked in reliability of proper operations in effective reduction of the noxious components due to the undesirable change of the set points with the passage of time.
It is therefore an object of the present invention to provide a conventional automotive carburetor with a compensating or auxiliary element for fine adjustment of an air-fuel mixture ratio.
More specifically, it is an object of the invention to provide an internal combustion engine carburetor for use with an electronic closed loop air-fuel ratio control system to supply desired air-fuel mixture to the engine for effectively reducing noxious components in exhaust gases from the engine by a three-way catalytic converter. It comprises: an intake passage pro- ^~
vided with a venturi; a fuel-containing float bowl; a fuel pas-sage extending between the venturi and the bowl; a main air bleed passage connected to deliver air to the fuel passage; an auxiliary air bleed passage connected to the ~uel passage; an on/off type electromagnetic valve assembly serving as an actuator having a plunger arranged to move reciprocally in the -auxiliary air bleed passage for controlling the rate o~ air ~55336 !, .'.
flow in response to an electrical pulsating signal applied thereto from the electronic closed loop air-fuel ratio control system to supply a desired air-fuel mixture to the internal com-bustion engine; and manually adjustable means disposed in or adjacent to the auxiliary air bleed for calibrating the maximum rate of air flowing therethrough by varying the cross-sectional area of the auxiliary air bleed or by defining the maximum stroke of the plunger of the elec-tromagnetic valve. ~ -Embodiments of the invention will now be described with reference to the appended drawings, wherein:
Fig. l illustrates an example of a conventional auto-motive carburetor;
Fig. 2 illustrates an example of a conventional electro-nic ~losed loop control system for use with the Fig. 1 carburetor and several preferred embodiments of the present invention;
Fig. 3 shows various waveforms whlch demonstrate the basic control concept of the Fig. 2 system;
Fig. 4 shows a~first preferred embodiment of the present invention;
Fig. S shows a second preferred embodiment of the present invention;
Fig. 6a shows a third preferred embodiment of the present invention; and Fig. 6b is an enlarged fragmentary view of a part of ;
Fig. 6a. ;
Reference is no~ made to drawings, first to Fig. 1, ~ `
wherein there is schematically illustrated, in a cross-sectional ~ ;~
view, a conventional carburetor for use with an electronic closed loop air-fuel ratio control system. ~n electro- ;~
magnetic valve assembly lO is provided to control the rate of air delivered to a fuel passage 14 through an air passaye 12 in a manner to reciprocally __ _ _ _ ~055336 move a plun$er 11 thereof in response to an electrical E~lllsati~lg si~nal applied theretoO In other wordY~ the electromngnetic vaLve assembly 10 controls the air-f~el ratio of an alr-fuel mixture sucked into an intake ~)as~a$e 13 by moving the plunger 11 to R pO9itiQn which allow~ the air flow to pa~s therethrough or vice versa.
'I`he electrical signal is generated by a pu]L~e generator 10~ which forms part of the control sy~tem to be de-~cribed l~ter in detail in conjunction with ~igs. 2 and 3. The air passage 12 is opened at its one end to communicate with the intake passage 13 and connected at th0 other end to the fuel pa~age 14. The fuel sAge 1/~ is terminated at a dischar~ing nozzle 16 an(l extends between a f}oat bowl 18 and a ventnri 20.
~5 ~n air bleed hole 22 is located in the upper sectinn of an air bleed asYembly 24 for introduction of air to the fuel passage therethrough. ~ ' In the above-mentioned conventional carburetor, ;
when the aforementioned th~ee-wAy catalytic converter iq employed in order to effectively reduce noxious com~onent~ in exhaust gase~, the air-fue~ ratio of an ail-fuel mixture should be finely adjusted. Thi~ i8 becinllse, a~ is described at the outset of this specifi-Catiotl, the effect of the three-way catalytic converter '-~5 is maximized in reduction of the noxiou~ components : , . . ~ :
:.,. .: .. . . ............... . . ....... .. .
.. . : : . . ..
16)55336 wh~n the air-fuel ratio i~ maintain~d in tlle vicinity of` Ytoichiometry. Therefore, as the air-fuel ratio is mfilrlly determined by the ratio of open to close dl~r.ltiorl of the electromMgnetic valve as~embly 10, the ratio ~hould be finely adju~ted in order to maiJItAin ;~
a richer and a leaner air-fuel mixture a little below and a little above stoichiometry, re~pectively. In the above, in order to ~ecure stable engine operation, the leaner air-fuel mixture i~, in ~enerAl, ~et at an air exce~ive ratio (viz., aetual air-fuel ratio:
Ytoichiometric air-fuel ratio~ nbout 1~05-l~lOo llow~ver, it i~ very dlrficult or impossible that alJ of the curburetors are flnely adjusted, with re~pect to de~ired ~et points of air-fuel ratio, to a considerably extent during ma~-production proce~s, ;~ ~;
ancl furthermore, even if finely adjusted~ there i# a possibility that the de~irable set point~ are liable ;
to change with the pa~sage of time. In the conventional carburetor for use with an electronic closa Joop alr~
~0 fuel control sy~tem, the above-described attention ha~
not been paid hitherto. ~-The present invention includes, therefore, an improved mean~ which is provided in the air passage 12 to readily and finely ad~ju~t the amount of air flowing '5 t~ere;hrollgh~ and thereby performing the aforementioned .
rl,oYe of the e~fect.ive reduction of the noxiou8 c.om~)onent~ especially when a three-w~ly catalytic converter :is emp.loyedO
.Ln the following, prior to de~cribing the embodi-ments of the present invention, exemplified i~ a corlventiorlal electronic closed loop contro.L ~y~tem l`or use with both the ~ig. 1 conventional carburetor alld als0 the embodiments of the present invention. .
~eference i~ now made to ~ig~. 2 and 3q wherein ~chematically illustrated are an example of a conven-tion.l.l electrical cl.osed loop air fuel control ~y~tem f`or IJ~e with an internal combu~tion engine 100 having the cnrburetor shown in Fig. 1 and several waveform~
deveLoped at or derived from different elements of the Fig. 2 system (Fig. 3). The purpo~e of the syste~ i~
to (?l ectrically control the air-fuel ratio of an air-f'ueL mixture ~upplied to the engine 100. A sen~or lOZ, ~UCil as an oxygcJI anAly~er, for ~en~ing the concen- ; `
tr(~tion Or oxygen in exhau~t gases i~ dispo~ed in an exhau.st pipe 101 in ~uch a manner as to be exposed to -the exhau~t gases. An electrical signal derived ; ~:
.from the sensor 102 i~ fed to a differential ~ignal generator 104 which generates an electrical signal .
.rep.re~entative of a difference value between the magni~
tlldes of the signal from the ~en~or 102 and a reference :~
1~ '.
~L~5533~i sixrlal. A portion of the wave~orm of the signal from th~ ~enqor 102 is depicted by reference character A
in l`ig. 3. The reference ~ignal magnitude, which i~
illu~trated by reference charncter ~ in Fig. 3, is previollsly determined in due con~iderution of optimum air-f`llel ratio of the air-fuel mixture supplied to the erlgine 100 for maximi~ing the efficiency of the three-way catalytlc converter (not shown) provided in the exhaust pipe 101 downstream of the senAor 102, etc. ~ -tO rhe ~ignal represerltative of the difference value from the dii`ferential ~igtlal generator 104 is then fed to contl~ol rnean~ ~o6 which u~ually include~ a conventional p~ )roportional-integral) controller. The provi~ion of the p-i controller, a~ is well known in the art, iY i~
to improYe the efficie~cy of the el~ctronic clo~ed loop control ~ystem, in other words, to ~acilitate a rapid tran~ient respon~e of the system. The output signal from the control means 106, which is depicted by refer-ence charncter C in Fig. 3, is fed to the next sta~e, ~0 viz., a pulse generator 108 which also receive~ a di-ther signal ~D in Fig. 3) from a dither signal generator 110 to generate a signal E consisting of a train of pulseY as shown in Fig. 3. Each pulse of the qignal E ha~ A width which corresponds to the duration wherl the signal D i9 larger than the signal C as ~05533~
~chematicnlly ~hown il~ Fig. 3. The train ot plllses of` the ~ignnl E 1Y then fed to the electromaglletic valve 10 in order to reg-llate the air-fuel mixture ratio as de~cribed in connection with Fig. 1.
~ef'ererlCe i9 now made to ~ig. 4, which schemat-icaLIy illu~tr~te~ a fir~t embodiment of the pre~ent invention. The first embodiment is analogou~ to the ,~
conventional one aY ~hown in Fig. 1 except that the ~ormer is equipped with a detachable membsr 150 with a .~llitable orifice (no numeral). The member 150 is ~nllgly fitted in the upper portion of the air paY~age 12 by, ~or example, being ~crewed into a portion ~rovided therein. Therefore, the fine adJu~tment of the air flow rate i~ readily carried out by replacing i5 the member 150 by the other one with a more appropriate orifice.
In Fig. 5, there i~ illustrated a second preferred embodiment of the present invention wherein a member 152 :i~ added to the conventional carburetor of Fig. 1.
The member 152 i~ preferAbly an reguLating ~crew which adjll~tably protrude~ into the air p~sage 12 to con-tinuou~ly vary the cros~-~ectional area of part of the air pa~ge 12 for changing the amount of air flowing therethrough, and thereby performing the fine adju~tment of` the air-fuel ratiu. In Fig. 5, the member 152 i~
_ ~ _ 1~5~336 ,)rov.i~ed up~tream of the plunger 11, b~lt, alterrlAtively, i ~ cn~l t)e arranged down~tream thereof'. Furthermore, the member 152 îs not re~tr.icted to a needle typel but ally other type may be available on condition th~t the -at)ove-de~cribed continuous change of the cro~-sectional area can be obtained.
Finally, reference i8 now made to Figs- 6a and '.
~t:-, wherein a third preferred embodiment of the present ,-~ ~.
invention i~ schematica11y illu~trated. 1`he -third - '~
tO embodiment is equipped with an additional member 154 a~ compared with the conventional carburekor of Fig. 1. ' 'I`he member 154 i~ M regulating Ycrew which Yerve~ to chatlge the Ytroke of the plun~er 11 by means of a protruding member 156 a~ be~t Yeen in Fig. 6b, and t,hereby changing the opening at the open position of the plunger 11. ConYequently, the provi~ion of the ~ , e.lement 154 make~ po~sible the aforementioned fine ~'.' adju~tment of the air-fuel mixture ratio by changing the amount of the air flowing through the air pa~age 20' 12. ' ` ' In the last mentioned embodiment, another fine adju~tment of the air-fuel.~ixture ratio can be achieved by replacing the ~pring 158 by the other one ~ith a more appropriate ~pring constant ~o aQ to .' regulate the maximum ~troke of the plunger 11, in the - , _ ~ ~
- - .
: : .~ .: . , ' , `
~S5336 ~ `
cn~e of which the member 156 t~ omitted.
From the above, it i~ under~tood that, in ~ccor-(klllce with the preferred embodiments of the pre~*nt i nvention, the fine ad justment of the air-fuel mi~cture rat.. io of a carburetor, which i9 used with an electronic c.lo~ed loop control Yystem, can be readily performed in a ~imple man.ner, 80 that the above-deYcribed ~ .
advAntage~ are obtainable with ea~e.
,`, .~' " ' .
' .
;: ;' ~''' .
'' .
', ",.
;~
'. ~
. ~ .
10~533~;
fine control of the air-fuel ratio of the air-fuel mixture.
A three-way catalytic converter, as is well known, has a characteristic of deoxidizing NOX and oxidizing both CO and HC
at the same timeO
However, none of the conventional mass produced carburetors has a compensating or auxiliary element which serves to readily and finely adjust the air-fuel ratio to adequate set points in a manufacturing process. Furthermore, ready adjust-ments to compensate for changes of the set points with the passage of time are not possible. As a result, the conventional carburetors each, because of the absence of the compensating element, has not been suitable for mass-production and locked in reliability of proper operations in effective reduction of the noxious components due to the undesirable change of the set points with the passage of time.
It is therefore an object of the present invention to provide a conventional automotive carburetor with a compensating or auxiliary element for fine adjustment of an air-fuel mixture ratio.
More specifically, it is an object of the invention to provide an internal combustion engine carburetor for use with an electronic closed loop air-fuel ratio control system to supply desired air-fuel mixture to the engine for effectively reducing noxious components in exhaust gases from the engine by a three-way catalytic converter. It comprises: an intake passage pro- ^~
vided with a venturi; a fuel-containing float bowl; a fuel pas-sage extending between the venturi and the bowl; a main air bleed passage connected to deliver air to the fuel passage; an auxiliary air bleed passage connected to the ~uel passage; an on/off type electromagnetic valve assembly serving as an actuator having a plunger arranged to move reciprocally in the -auxiliary air bleed passage for controlling the rate o~ air ~55336 !, .'.
flow in response to an electrical pulsating signal applied thereto from the electronic closed loop air-fuel ratio control system to supply a desired air-fuel mixture to the internal com-bustion engine; and manually adjustable means disposed in or adjacent to the auxiliary air bleed for calibrating the maximum rate of air flowing therethrough by varying the cross-sectional area of the auxiliary air bleed or by defining the maximum stroke of the plunger of the elec-tromagnetic valve. ~ -Embodiments of the invention will now be described with reference to the appended drawings, wherein:
Fig. l illustrates an example of a conventional auto-motive carburetor;
Fig. 2 illustrates an example of a conventional electro-nic ~losed loop control system for use with the Fig. 1 carburetor and several preferred embodiments of the present invention;
Fig. 3 shows various waveforms whlch demonstrate the basic control concept of the Fig. 2 system;
Fig. 4 shows a~first preferred embodiment of the present invention;
Fig. S shows a second preferred embodiment of the present invention;
Fig. 6a shows a third preferred embodiment of the present invention; and Fig. 6b is an enlarged fragmentary view of a part of ;
Fig. 6a. ;
Reference is no~ made to drawings, first to Fig. 1, ~ `
wherein there is schematically illustrated, in a cross-sectional ~ ;~
view, a conventional carburetor for use with an electronic closed loop air-fuel ratio control system. ~n electro- ;~
magnetic valve assembly lO is provided to control the rate of air delivered to a fuel passage 14 through an air passaye 12 in a manner to reciprocally __ _ _ _ ~055336 move a plun$er 11 thereof in response to an electrical E~lllsati~lg si~nal applied theretoO In other wordY~ the electromngnetic vaLve assembly 10 controls the air-f~el ratio of an alr-fuel mixture sucked into an intake ~)as~a$e 13 by moving the plunger 11 to R pO9itiQn which allow~ the air flow to pa~s therethrough or vice versa.
'I`he electrical signal is generated by a pu]L~e generator 10~ which forms part of the control sy~tem to be de-~cribed l~ter in detail in conjunction with ~igs. 2 and 3. The air passage 12 is opened at its one end to communicate with the intake passage 13 and connected at th0 other end to the fuel pa~age 14. The fuel sAge 1/~ is terminated at a dischar~ing nozzle 16 an(l extends between a f}oat bowl 18 and a ventnri 20.
~5 ~n air bleed hole 22 is located in the upper sectinn of an air bleed asYembly 24 for introduction of air to the fuel passage therethrough. ~ ' In the above-mentioned conventional carburetor, ;
when the aforementioned th~ee-wAy catalytic converter iq employed in order to effectively reduce noxious com~onent~ in exhaust gase~, the air-fue~ ratio of an ail-fuel mixture should be finely adjusted. Thi~ i8 becinllse, a~ is described at the outset of this specifi-Catiotl, the effect of the three-way catalytic converter '-~5 is maximized in reduction of the noxiou~ components : , . . ~ :
:.,. .: .. . . ............... . . ....... .. .
.. . : : . . ..
16)55336 wh~n the air-fuel ratio i~ maintain~d in tlle vicinity of` Ytoichiometry. Therefore, as the air-fuel ratio is mfilrlly determined by the ratio of open to close dl~r.ltiorl of the electromMgnetic valve as~embly 10, the ratio ~hould be finely adju~ted in order to maiJItAin ;~
a richer and a leaner air-fuel mixture a little below and a little above stoichiometry, re~pectively. In the above, in order to ~ecure stable engine operation, the leaner air-fuel mixture i~, in ~enerAl, ~et at an air exce~ive ratio (viz., aetual air-fuel ratio:
Ytoichiometric air-fuel ratio~ nbout 1~05-l~lOo llow~ver, it i~ very dlrficult or impossible that alJ of the curburetors are flnely adjusted, with re~pect to de~ired ~et points of air-fuel ratio, to a considerably extent during ma~-production proce~s, ;~ ~;
ancl furthermore, even if finely adjusted~ there i# a possibility that the de~irable set point~ are liable ;
to change with the pa~sage of time. In the conventional carburetor for use with an electronic closa Joop alr~
~0 fuel control sy~tem, the above-described attention ha~
not been paid hitherto. ~-The present invention includes, therefore, an improved mean~ which is provided in the air passage 12 to readily and finely ad~ju~t the amount of air flowing '5 t~ere;hrollgh~ and thereby performing the aforementioned .
rl,oYe of the e~fect.ive reduction of the noxiou8 c.om~)onent~ especially when a three-w~ly catalytic converter :is emp.loyedO
.Ln the following, prior to de~cribing the embodi-ments of the present invention, exemplified i~ a corlventiorlal electronic closed loop contro.L ~y~tem l`or use with both the ~ig. 1 conventional carburetor alld als0 the embodiments of the present invention. .
~eference i~ now made to ~ig~. 2 and 3q wherein ~chematically illustrated are an example of a conven-tion.l.l electrical cl.osed loop air fuel control ~y~tem f`or IJ~e with an internal combu~tion engine 100 having the cnrburetor shown in Fig. 1 and several waveform~
deveLoped at or derived from different elements of the Fig. 2 system (Fig. 3). The purpo~e of the syste~ i~
to (?l ectrically control the air-fuel ratio of an air-f'ueL mixture ~upplied to the engine 100. A sen~or lOZ, ~UCil as an oxygcJI anAly~er, for ~en~ing the concen- ; `
tr(~tion Or oxygen in exhau~t gases i~ dispo~ed in an exhau.st pipe 101 in ~uch a manner as to be exposed to -the exhau~t gases. An electrical signal derived ; ~:
.from the sensor 102 i~ fed to a differential ~ignal generator 104 which generates an electrical signal .
.rep.re~entative of a difference value between the magni~
tlldes of the signal from the ~en~or 102 and a reference :~
1~ '.
~L~5533~i sixrlal. A portion of the wave~orm of the signal from th~ ~enqor 102 is depicted by reference character A
in l`ig. 3. The reference ~ignal magnitude, which i~
illu~trated by reference charncter ~ in Fig. 3, is previollsly determined in due con~iderution of optimum air-f`llel ratio of the air-fuel mixture supplied to the erlgine 100 for maximi~ing the efficiency of the three-way catalytlc converter (not shown) provided in the exhaust pipe 101 downstream of the senAor 102, etc. ~ -tO rhe ~ignal represerltative of the difference value from the dii`ferential ~igtlal generator 104 is then fed to contl~ol rnean~ ~o6 which u~ually include~ a conventional p~ )roportional-integral) controller. The provi~ion of the p-i controller, a~ is well known in the art, iY i~
to improYe the efficie~cy of the el~ctronic clo~ed loop control ~ystem, in other words, to ~acilitate a rapid tran~ient respon~e of the system. The output signal from the control means 106, which is depicted by refer-ence charncter C in Fig. 3, is fed to the next sta~e, ~0 viz., a pulse generator 108 which also receive~ a di-ther signal ~D in Fig. 3) from a dither signal generator 110 to generate a signal E consisting of a train of pulseY as shown in Fig. 3. Each pulse of the qignal E ha~ A width which corresponds to the duration wherl the signal D i9 larger than the signal C as ~05533~
~chematicnlly ~hown il~ Fig. 3. The train ot plllses of` the ~ignnl E 1Y then fed to the electromaglletic valve 10 in order to reg-llate the air-fuel mixture ratio as de~cribed in connection with Fig. 1.
~ef'ererlCe i9 now made to ~ig. 4, which schemat-icaLIy illu~tr~te~ a fir~t embodiment of the pre~ent invention. The first embodiment is analogou~ to the ,~
conventional one aY ~hown in Fig. 1 except that the ~ormer is equipped with a detachable membsr 150 with a .~llitable orifice (no numeral). The member 150 is ~nllgly fitted in the upper portion of the air paY~age 12 by, ~or example, being ~crewed into a portion ~rovided therein. Therefore, the fine adJu~tment of the air flow rate i~ readily carried out by replacing i5 the member 150 by the other one with a more appropriate orifice.
In Fig. 5, there i~ illustrated a second preferred embodiment of the present invention wherein a member 152 :i~ added to the conventional carburetor of Fig. 1.
The member 152 i~ preferAbly an reguLating ~crew which adjll~tably protrude~ into the air p~sage 12 to con-tinuou~ly vary the cros~-~ectional area of part of the air pa~ge 12 for changing the amount of air flowing therethrough, and thereby performing the fine adju~tment of` the air-fuel ratiu. In Fig. 5, the member 152 i~
_ ~ _ 1~5~336 ,)rov.i~ed up~tream of the plunger 11, b~lt, alterrlAtively, i ~ cn~l t)e arranged down~tream thereof'. Furthermore, the member 152 îs not re~tr.icted to a needle typel but ally other type may be available on condition th~t the -at)ove-de~cribed continuous change of the cro~-sectional area can be obtained.
Finally, reference i8 now made to Figs- 6a and '.
~t:-, wherein a third preferred embodiment of the present ,-~ ~.
invention i~ schematica11y illu~trated. 1`he -third - '~
tO embodiment is equipped with an additional member 154 a~ compared with the conventional carburekor of Fig. 1. ' 'I`he member 154 i~ M regulating Ycrew which Yerve~ to chatlge the Ytroke of the plun~er 11 by means of a protruding member 156 a~ be~t Yeen in Fig. 6b, and t,hereby changing the opening at the open position of the plunger 11. ConYequently, the provi~ion of the ~ , e.lement 154 make~ po~sible the aforementioned fine ~'.' adju~tment of the air-fuel mixture ratio by changing the amount of the air flowing through the air pa~age 20' 12. ' ` ' In the last mentioned embodiment, another fine adju~tment of the air-fuel.~ixture ratio can be achieved by replacing the ~pring 158 by the other one ~ith a more appropriate ~pring constant ~o aQ to .' regulate the maximum ~troke of the plunger 11, in the - , _ ~ ~
- - .
: : .~ .: . , ' , `
~S5336 ~ `
cn~e of which the member 156 t~ omitted.
From the above, it i~ under~tood that, in ~ccor-(klllce with the preferred embodiments of the pre~*nt i nvention, the fine ad justment of the air-fuel mi~cture rat.. io of a carburetor, which i9 used with an electronic c.lo~ed loop control Yystem, can be readily performed in a ~imple man.ner, 80 that the above-deYcribed ~ .
advAntage~ are obtainable with ea~e.
,`, .~' " ' .
' .
;: ;' ~''' .
'' .
', ",.
;~
Claims (6)
1. An internal combustion engine carburetor for use with an electronic closed loop air-fuel ratio control system to supply desired air-fuel mixture to an internal combustion engine for effectively reducing noxious components in exhaust gases from the engine by a three-way catalytic converter, comprising:
an intake passage provided with a venturi;
a float bowl for containing fuel therein;
a fuel passage extending between said venturi and said float bowl;
a main air bleed passage connected to said fuel pas-sage for delivering air flow to the same;
an auxiliary air bleed passage connected to said fuel passage;
an on/off type electromagnetic valve assembly serving as an actuator having a plunger arranged to move reciprocally in said auxiliary air bleed passage for controlling the rate of air flow in response to an electrical pulsating signal applied thereto from said electronic closed loop air-fuel ratio control system to supply a desired air-fuel mixture to said internal com-bustion engine; and manually adjustable means disposed in or adjacent to said auxiliary air bleed for calibrating the maximum rate of air flowing therethrough by varying the cross-sectional area of said auxiliary air bleed or by defining the maximum stroke of said plunger of said electromagnetic valve.
an intake passage provided with a venturi;
a float bowl for containing fuel therein;
a fuel passage extending between said venturi and said float bowl;
a main air bleed passage connected to said fuel pas-sage for delivering air flow to the same;
an auxiliary air bleed passage connected to said fuel passage;
an on/off type electromagnetic valve assembly serving as an actuator having a plunger arranged to move reciprocally in said auxiliary air bleed passage for controlling the rate of air flow in response to an electrical pulsating signal applied thereto from said electronic closed loop air-fuel ratio control system to supply a desired air-fuel mixture to said internal com-bustion engine; and manually adjustable means disposed in or adjacent to said auxiliary air bleed for calibrating the maximum rate of air flowing therethrough by varying the cross-sectional area of said auxiliary air bleed or by defining the maximum stroke of said plunger of said electromagnetic valve.
2. An internal combustion engine carburetor as claimed in claim 1, wherein said means is an interlayable member disposed in said auxiliary air bleed passage, said interlayable member having an orifice providing said calibration by substitu-tion same with a different interlayable member having a dif-ferent size orifice.
3. An internal combustion engine carburetor as claimed in claim 1, wherein said means is a member adjustably protruding into said auxiliary air bleed passage to vary a cross-sectional area of part of said auxiliary air bleed passage, thereby achieving said calibration.
4. An internal combustion engine carburetor as claimed in claim 3, wherein said member is a regulating screw.
5. An internal combustion engine carburetor as claimed in claim 1, wherein said on/off type electromagnetic valve including a plunger which serves to control the rate of the air flow by its reciprocating motion within said auxiliary air bleed passage, and said means is a member for adjusting the stroke of said plunger so as to achieve said calibration.
6. An internal combustion engine carburetor as claimed in claim 5, wherein said member is a screw arranged so as to limit the maximum stroke of said plunger.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP50015129A JPS5189939A (en) | 1975-02-05 | 1975-02-05 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1055336A true CA1055336A (en) | 1979-05-29 |
Family
ID=11880201
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA245,029A Expired CA1055336A (en) | 1975-02-05 | 1976-02-04 | Automotive engine carburetor |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS5189939A (en) |
| AU (1) | AU474901B2 (en) |
| CA (1) | CA1055336A (en) |
| DE (1) | DE2603858A1 (en) |
| FR (1) | FR2300224A1 (en) |
| GB (1) | GB1529591A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5618049A (en) * | 1979-07-20 | 1981-02-20 | Hitachi Ltd | Electronic control method for internal combustion engine |
| JPS5623531A (en) * | 1979-08-02 | 1981-03-05 | Fuji Heavy Ind Ltd | Air-fuel ratio controller |
| JPS5623533A (en) * | 1979-08-02 | 1981-03-05 | Fuji Heavy Ind Ltd | Air-fuel ratio controller |
| JPS58175159U (en) * | 1982-05-20 | 1983-11-22 | 富士重工業株式会社 | Air fuel ratio control device |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5118023B2 (en) * | 1972-04-14 | 1976-06-07 | ||
| JPS4919229A (en) * | 1972-06-17 | 1974-02-20 | ||
| DE2246625C3 (en) * | 1972-09-22 | 1982-02-18 | Robert Bosch Gmbh, 7000 Stuttgart | Fuel metering system |
| JPS5316853B2 (en) * | 1973-03-19 | 1978-06-03 |
-
1975
- 1975-02-05 JP JP50015129A patent/JPS5189939A/ja active Pending
-
1976
- 1976-01-27 GB GB304476A patent/GB1529591A/en not_active Expired
- 1976-02-02 DE DE19762603858 patent/DE2603858A1/en not_active Withdrawn
- 1976-02-03 AU AU10757/76A patent/AU474901B2/en not_active Expired
- 1976-02-04 CA CA245,029A patent/CA1055336A/en not_active Expired
- 1976-02-05 FR FR7603189A patent/FR2300224A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| DE2603858A1 (en) | 1976-08-19 |
| FR2300224B1 (en) | 1980-11-21 |
| AU474901B2 (en) | 1976-08-05 |
| GB1529591A (en) | 1978-10-25 |
| AU1075776A (en) | 1976-08-05 |
| JPS5189939A (en) | 1976-08-06 |
| FR2300224A1 (en) | 1976-09-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4342443A (en) | Multi-stage fuel metering valve assembly | |
| US3960118A (en) | Air-fuel ratio adjusting device in an internal combustion engine having a carburetor | |
| US4508091A (en) | Fuel metering apparatus with multi-stage fuel metering valve assembly | |
| US4539960A (en) | Fuel pressure regulator | |
| CA1156525A (en) | Fuel injection apparatus and system | |
| CA1044093A (en) | Air/fuel ratio control system in internal combustion engine | |
| US4149376A (en) | Internal combustion engine equipped with exhaust gas purifying device | |
| GB2093229A (en) | Air-fuel ratio control system | |
| US4107920A (en) | Method of and apparatus for controlling air/fuel ratio in internal combustion engine | |
| US4480606A (en) | Intake system of an internal combustion engine | |
| US4086890A (en) | Carburetor with altitude compensation assembly | |
| CA1055336A (en) | Automotive engine carburetor | |
| US4085716A (en) | Internal combustion engine with air-fuel ratio control device | |
| US4043305A (en) | Control device for regulating the compositions of the inlet and exhaust gases of an internal combustion engine | |
| US4187805A (en) | Fuel-air ratio controlled carburetion system | |
| US4111170A (en) | Air-fuel ratio control system | |
| US4335693A (en) | Fuel injection apparatus and system | |
| US4311126A (en) | Fuel injection apparatus and system | |
| US4079714A (en) | Air-fuel mixture supply device of internal combustion engine | |
| CA1155015A (en) | Electronic controlled carburetor | |
| US4291658A (en) | Automotive engine carburetor | |
| US4091781A (en) | Air-fuel ratio control system in an internal combustion engine | |
| US4364357A (en) | Air-fuel ratio control system | |
| GB2060213A (en) | Automatic control of air fuel ration in ic engines | |
| US4637366A (en) | Fuel injection apparatus and system |