DE2743170A1 - DEVICE FOR CONTROLLING THE THROTTLE FLAP IN A COMBUSTION ENGINE - Google Patents

Description

27A317U

'"irma A'hVii ;? Uk: A,> .υ.Λ., iiSiland (Italian).

"Sun device controlling the throttle valve in an internal combustion engine" .

The torque generated by an i-engine at a certain speed is an increasing function of the fuel-air mixture density in the intake manifold, after the same density with a rough approximation also in the engine cylinder at j ^; , walls of the intake stroke prevails: the Genischmeiiße that can burn in the cylinder (the cn during combustion, ^ walls of the pre-seal ENTV / ickelte amount of heat is utilized to obtain mechanical work in it / jhuo) depends namely on the weight of Forehand

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a mixture, i.e. from the product of the Ilubrauraes times the mixture density.

If the temperature of the air (and the mixture) is the same, the mixture density (and therefore the generated torque) depends on increasing Leave the one in the intake pipe (and thus also in the cylinder on the End of compression) from the prevailing absolute pressure. ^ s is also known dal. the vehicle driver the absolute value of this Pressure influenced by the fact that he depresses the accelerator pedal and thereby adjusts the Belasüungs loss that the sucked in Air in the area of the throttle valve is subject: the position of the throttle valve is in fact in operative connection with the accelerator pedal. In the vast majority of cases, this is the case urgan around a throttle; It consists of a thin disk that is non-rotatably connected to an axis that is in the suction line is mounted diametrically.

The plane of the disc of the throttle valve can be swiveled almost perpendicular to the axis of the intake line, to the smallest possible extent To achieve opening of the flow gap; of this In the off position, each turn increases this opening; is the plane of the disc of the throttle valve parallel to the Axis of the suction line, the flow opening is the largest.

When flowing through the opening regulated by the throttle valve, the sucked in air is forced to assume a speed which is greater, the higher the flow rate sucked in and the smaller the flow gap; with a rough approximation is the volume of the flow rate

C * η

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where η is the speed of the engine (a four-stroke engine) and G den

ilubraum denotes, and if ü the flow cross-section

(opalt) is the speed assumed by the air

Q G. η

(2) W =

S 2.3

The loss of load caused by the air flowing through the throttle valve suffers is equal to the kinetic energy corresponding to this speed (according to the throttle valve is namely, the recovery of the speed in printing is the same lmll); therefore, always with a rough approach, the loss of load is:

Ϊ '< ²

where J is the air weight and g is the acceleration due to gravity. Because of from (2) and (3) results

u ^{σ 2 n}

^P. Ig 1

where K represents a conscaate dependent on the engine displacement. v / enn Zip is expressed in atmospheres and the pressure in front of the throttle valve is equal to atmospheric pressure (i.e. = 1), the pressure after the throttle valve is the absolute supply pressure des hotors ρ,:

rr \ = 1 - 4p

(b) p _al

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from which due to

n ²
(") P _n π - 1 - K - 5

'al

from (ό) enbninub one that: l> .r, peisungsdruck (and somib ctas voia iiotoi · generated torque;) bsi a bos uiuMben iert des Guorschnibbes o, that is to say, on the accelerator pedal in certain cases exert pressure, depending on the engine speed fluctuates strongly; the value of the jubbraction expression or second term of the (6) goes over (with a rough approximation) like from 1 to 36, depending on the speed of the engine 1UOÜ or bc.Oü.

The repetitions that result from this can be seen in the purely explanatory diagrams of iVi ;;;. 1 and 2 represent: in both the pressure of the accelerator pedal is lower in the abscissa ;; give; depending on; ibb is the ordinate of Ji · ;. 1 the values of the flow cross-section O and the ·. rdinate from j'ig. 2 the ./wert of the motor supply pressure at different Kotor speeds from 1OÜÜ to bUUÜ rpm. In particular, one can see from the second diagram that at low Jrahsahlen only a section of the accelerator pedal stroke is to be regarded as active, in the sense that a certain positive displacement of the accelerator pedal corresponds to an actual increase in the feed pressure and therefore a real increase in the torque: especially at very low speeds, the torque in the very first section of the accelerator pedal stroke goes from the lowest to the highest speed; the remaining portion of the accelerator pedal stroke remains practically ineffective.

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27A3170

The higher the speeds, the longer the active section becomes the accelerator pedal stroke and at the highest speed, the entire accelerator pedal stroke can be regarded as active; i.e. at higher speeds lack the excessive initial speed that characterizes the curves for the low speeds.

The consequent disadvantage is the excessively rapid increase of the feed pressure and the torque even at low Displacement of the accelerator pedal while the engine is running at low or medium speeds: these small displacements cannot be measured precisely by the driver's foot, but on the other hand can also be the result of involuntary Adjustments of the foot in relation to the structure, e.g. during the temporary acceleration or deceleration processes or an evasive maneuver odor with a damaged road surface; but even when the accelerator pedal is not moving, sensitive fluctuations in the opening angle of the throttle valve (and thus dos Jpaltes ό) by relative adjustments of the springy Bearing built-up wotors enter opposite the chassis: The special effective connection between the accelerator pedal is not able to do this and Jros -3] flap such adjustments completely open.

Julie ... chv / aiikungen dos opeisungsdruckes are of course from itand-1-point of driving comfort from annoying, especially if unintentional er-Tül: .en; but with "poor" gassings, how they prey aimed at alleviating the exhaust poison and consumption abrupt, temporary phenomena, further instantaneous "depletion" of the fuel-air mixture

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and the associated weakening of the torque as a result to have. Iloch-effective auxiliary pumps that prevent such symptoms of decline are of course un ^ ünsti ^ in relation to Exhaust poison and consumption. However, the above conditions can also have negative effects from the point of view of safety: unmeasurable and therefore unmeasured fluctuations in the torque applied to the wheels can be violated the boundary friction between rubber tires and road surface and the slip of the drive wheels and the skidding of the vehicle lead, not only on slippery, wet or icy roads, but also on normal surfaces, especially when lower gears are engaged.

In order to prevent such dangers, the conventional active connection accelerator pedal / throttle valve is often constructed in such a way that a fairly flexible transmission ratio is available, allowing small swings of the throttle valve to match the movements of the accelerator pedal correspond during the first section of its stroke and larger swings in the second section of the accelerator pedal stroke. This measure improves the situation at low speeds, but practically the entire first section of the Accelerator pedal stroke ineffective at high speeds; this gives the driver the feeling of a slowly responding Ι- · ο tor with a weak one Power, as the desired acceleration can only be achieved by stepping flat on the accelerator pedal.

With this measure, too, there remains a different response of the motor at the individual speeds: this increases in considerable hatred the difficulties encountered by the normal

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Driver must overcome in order to be able to expect a not only comfortable but mainly safe journey.

To remedy the disadvantages described above (those for the conventional Active connection between the accelerator pedal and the throttle valve are characteristic) the device according to the invention is proposed, which is characterized by the fact that it enables the motor to respond (in relation to the supply pressure and thus to the Torque), which practically always remains the same at every heater speed, which at the same time optimizes the Shape of the attack curve is achieved.

With the device according to the invention - with reference to the diagram according to FIG. 2 - one and the same response curve can be achieved for all threat numbers ( e.g. similar to the curve for η = 5υυυ in the above-mentioned are closer to one another and their course is similar to that of the curve for n-6ü0ü in FIG.

This ILR ^r: ebnis, thanks to the proposed device achieved in that the throttle valve is not directly controlled by the accelerator pedal, but of a slightly biased by overcoming the effect by means of a i.embrane, compliant to the nainbrane acting spring;. this membrane is acted upon by a negative pressure, which is a fraction χ of the low pressure prevailing in the area downstream of the throttle valve: ie the force acting on the nem'oranc as the resultant of the low pressure effect χ. Λ- ρ is balanced by the preload on the spring.

If there is a certain flexibility inherent in this spring, it gives way

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their burden ί ·; during the movement of the diaphragm of theirs preload set during assembly does not decrease significantly; the diaphragm adjusts itself and controls it Throttle valve so that the pressure reduction z \ ρ through the throttle valve the equation

(7) χ. AP = h
enough.

The value of the ratio χ is namely influenced by the driver by pressing the accelerator pedal because the shut-off element of a modulation valve is in operative connection with the accelerator pedal; of the orientation of the obturator, the value depends at least on of a gap which is switched into the circuit, of the hembrane sets the chamber with the outside air and with the portion of the intake line after the throttle valve in combination; the value of the ratio χ and the value of the feed pressure thus depend on the fourth of the cross-section of this upaltes, which of course, taking into account (3) and (7)

What has been said so far is clarified with reference to FIG. 3, where a preferred embodiment of the device according to the invention is shown only for the purpose of explanation and not for limitation.

In Fig.; I the throttle device can be seen, which consists of the line 1, the flap 2, the pin 3, the throttle lever 4,

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tier Iienbrane 5 with counteracting, resilient spring 6, the Pull rod 7, which connects the j) rosette lever 4 and the l-.embrane 5 and the membrane chamber 8; also denotes 9 the stem of the accelerator pedal with its pivot 10 and the Lever arm 11 is firmly connected. The pin 10 is rotatably mounted in the frame 12, which by means of the sheet 13 on the wall of the The bodywork of the vehicle (not shown) is attached to the kit, the frame 12 is the housing 14 of the Lodulationsschieber firmly connected, in the interior of which the closure body 15 is displaceable is built in.

in the particular figurenraäJTigen embodiment of the shielding 15 appointed ^au s an approximately c indelfürmigen _> tift whose one portion is formed roller-shaped with straight-generating and also roller-shaped in a recessed also in jchiebergehäuse 14 guide bore back u-id reciprocates, a i ' End section 17 is designed with x-shape generators, and an end section 19 is also shaped, the first and last section engaging in the bores 18 and 20 recessed in the valve housing 14. The other iCni section of the shut-off element 15 is articulated on the lever arm 11 by means of a Langlochanlen '.;Un;: 16.

The ochiebs-i housing 14 also has a cavity 21, the is in communication with the outside air via a filter 22, as well as two small openings 25, 24; the opening 23 is in the area the hammer 27 downstream of the drill hole; 20 (in the sense of Air flow) and a pipe 25 is connected to it, that they are connected to the membrane 5 connected

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Chamber β connects; the opening 24 is located in the area downstream of the bore 18 (also in terms of air flow) and is in communication with the line 1 downstream of the throttle valve 2 via the pipe 26.

In Fig. 3 the device is in the idling state of the engine corresponding position shown: the accelerator pedal 9 is in its highest position and the closing body of the slide 14 is held by the lever arm 11 in its lowest (most retracted) position, in which the slide 14 the bore 18 (completely or almost completely) closes and the largest flow cross-section the bore 20 leaves free.

Passes through the cavity 21, the bore 20 and the tube 25 the atmospheric air pressure in the chamber 8 of the l-jembrane 5, and since the same atmospheric air pressure prevails on the outside of the membrane 5, the spring 6 pushes that of the dormant iiembrane 5 is not loaded, the throttle valve 2 (via tie rod 7 and throttle lever 4) in the position of the largest Closure, so that only the flow cross section in line 1 remains open, which is necessary to supply the required amount of air or mixture to the engine for idling operation. When the accelerator pedal is depressed, it rotates clockwise about the axis of the pivot 10 and pushes the closure body 15 over the i; ebclarm11 to the top; the shaped section 17 of the closing body 15 comes into the area of the bore 18 and lets you change depending on your profile Free flow cross-section; in the special case the free one takes Cross-section of the bore 18 gradually up to the end of the

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i the stroke of the accelerator pedal to the corresponding maximum
at the same time engages the frustoconical i ^ nd section 19 of the closure body 1? into the bore 20 and gradually reduces the free flow cross section of the same until the iiohj is completely or almost closed when the accelerator pedal is on
has reached its decline.

The accelerator pedal is always in an intermediate position; is located, experiences the through the simultaneously open cross-sections of the bores 20 and 18 as a result of the in the Leitun ;; 1 downstream of the
Throttle valve 2 prevailing negative pressure sucked in air flow a first pressure drop when flowing through bore 2ü
and an additional one when flowing through bore 18; the '»/ erte
these pressure drops and therefore downstream of the bore 20
and the vacuum prevailing in the chamber 8 of the liembrane 5
depend on the ratio between the cross-sections of the two bores 20 and 18 and on the value of the negative pressure in the line 1, which latter, as already said, is dependent on the degree of opening of the throttle valve 2 and the Iiotord speed; Who te of the negative pressure downstream of the bore 20 are the atmospheric air pressure more aligned, the greater the flow cross section of the bore 20 compared to that of the bore 18 is; on the other hand, the same values are more equal to the negative pressure prevailing in the line 1, the more the flow cross-section of the bore 18 increases and that of the bore 20 decreases; the law of variation of this negative pressure remains unchanged at the various engine speeds during the entire stroke of the accelerator pedal, because the maintenance of the ratio between

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see the holes 20 and 18 is solely from the location of the accelerator pedal and the fraction of the pressure difference depends on the value of this ratio before and after the throttle valve, which fraction is transferred into the cavity after the bore 18.

The negative pressure building up downstream of the bore 20 and in the chamber 3 of the Nebrane 5 creates a force acting on the membrane 5, the practically constant reaction of the spring 6 overcoming force, which is able to raise the tension beam 7 and the throttle valve 2 around the axis To turn your!, apfcns 3: the degree of opening of the throttle valve depends on the magnitude of this force and thus on the negative pressure values that are established in the chamber 3; Since the vacuum only depends on the accelerator pedal and not on the speed, and since the counteracting effect of the engine 6 is almost constant, the low pressure present downstream of the throttle valve depends practically on the pressure, ie the>poi:; ungsdruck always having the i.otors, only from the accelerator pedal on how high is the Kotordrehzahl, so that the Il Jpeisungsdruck corpse V / he te for the same layers of the accelerator pedal at the various notordrehzahlen ·

. • ei each Lotorcirehzahl the throttle valve has its largest flow cross-section when the bore: 20 is closed or narrowed the most and the bore 13 assumes its largest flow cross-section, ie when the accelerator pedal 9 is at the end of its stroke: la the mouth of the pipe 26 is provided in the area of the narrowest cross-section of the tapering line 1, a negative pressure arises in the chamber 8 even at full throttle,

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which is sufficient to balance the .. burden on the I ° eder.

ü, s follows from the fact that the entire üaspedal stroke for all rotor rotation ^, ahlen, and especially among the low, exploited is the amount by weight of the air sucked in by the engine or to measure the mixture via the throttle valve; the proportionality ratio between displacement of the accelerator pedal and corresponding angles of inclination of the throttle valve increases when increasing the engine speed.

Accordingly, a certain opening angle is used at low speeds the throttle valve achieved with a fraction of the accelerator pedal stroke, which fraction is greater than with the previously usual Active connections between the accelerator pedal and the throttle valve, which has the advantage of greater accuracy and regularity of the Bringing response of the engine to the control process on the part of the driver without affecting the proportionality between displacements of the accelerator pedal and the angle of inclination of the throttle valve over the entire course of the accelerator pedal stroke is impaired.

Another advantage of the device is that the possibility . given is the closing of the throttle valve at the curtain to slow down the release of the accelerator pedal stroke, so dall the density of the engine used in this process sucked mixed charge increases and the combustion more complete ; It is made to reduce the proportion of unburned fuel in the exhaust gases.

When the accelerator pedal is released, the closing body of the slide V \ - is brought back by the accelerator pedal 9 to its starting position: the jjOhrun ;: 1u closes and the bore 2u opens by opening the

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leaves the largest flow cross-section free; through this cross-section the air enters the chamber 8 as a result of the negative pressure created during the previous operating conditions of the engine sucked in; the filling time of the chamber 8 depends on the suitability of the chamber 8, i.e. the time required for the pressure value inside it to reach the value of atmospheric pressure, so that the spring is no longer pushed back as a result 6 controls the throttle valve against the position of the largest opening. By appropriate measurement of the chamber 8 in relation to the dimension of the bore 20, or a particular one, in the "tubes 23 or 25 provided, not shown passage, the filling time of the chamber 8 can be set so that sets the closing law for the throttle valve, which is considered to be optimal.

The slide 14 shown in Fig. 3 has two bores 20 and 18 with a variable opening cross-section, but also only one of the two holes can optionally depending on the desired Services with variable opening cross-section are provided, while the other be fixed and one during the entire course of the accelerator pedal stroke can have a constant cross-section.

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Claims (1)

1.) Control device for throttling with eel dor fuel-T.uf0-mixture supply ein03 in oiaor.i. ./ahrzou "built-in combustion engine, which with at least one with the aforementioned restriction means provided jauglsitung is equipped, characterized in that it is used by the driver actuating controls on, pneumatically operated, with the Drive means that are operatively connected to the throttling leg includes, v / elche also with a pressure source through shut-off devices are in operative connection with which AbsDerrorgane are suitable are to modulate the actuation pressure for the drive means, the shut-off devices also with the oteuerungsmittel in v; irkverbindun ·: stand. 2. Apparatus according to claim 1, characterized in that the; Mieur.iatisch working drive means with Absoerrorgane : "ι3Γ outside air and at least with a mixture feed line of the motor downstream of the choke means are verounden, v / obei die Shut-off device with the control means to be actuated by the guardian stand in Jirkveroinuung. \ .. voi'riclitun: j according to claim 2, characterized in that the muumatically operating drive means consist of a single cylinder capsule, whose ..enbrane is connected to the oros.:elu>igsmittel in the mixture supply, \; above the carbon chamber of the capsule With my outside air a first open [; change if necessary 809816/0623 lic'.von '_uer schnittes, who through harvest Absoerror ^ nne οο vote will, and at least never genetically; Ues 1.0 tor downstream from the jrosselun ^ smitbein via a second ^ ffnimr. · changeable Cross-section through the second .vbsperrorgano oosti ^: ·: b is related stent, woboi the first and second: iboiierrorjane with the bobütijenden; Jeueru; i ,, 3i.iittüln in .; irkverüindun ;, standon. ^ I-. / orrichtunc uacn claim :), dadurcli ■ "■ eküuna'jiciineb, d? u lie first shut-off valve ^ ane eiit oiner.i in the essential ^ e ^ elif ^ from [; e: formed closing body, and that the second shut-off valve, ^rT ; ane are provided with an essentially frustoconical closure. 5. Apparatus according to claim 4, dadurcn gekennzeichnut, Jaß the Closing body of the first jibGperror; '; ane and the closing body of the second AbsperxOrtjane are related to each other in such a way that they form a single closure body. 6. The device according to claim 1, characterized in that the control means to be operated by the driver from a control device on the vehicle hinged foot pedal exist. ?. Device according to claim 5 and 6, characterized in that the closing body via a sliding joint with one on the accelerator pedal attached lever arm is connected » 809816/0623 BATH ORIGINAL