DE6946457U - MEASURING ORGAN OF A FUEL INJECTION SYSTEM FOR MIXED COMPRESSING, EXTERNAL IGNITION ENGINE. - Google Patents

Description

^ J * »« · Ιι. ι ·. ·. S.

H. 9673

11/24/1969 Su / Kb

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ROBERT BOSCH GHBH, 7 Stuttnart 1, Breitschejdstr. 4-

Measurement range of a fuel injection system for mixed-compression, frcmd ^ eigned internal combustion engines

The invention relates to a measuring element for a fuel injection system for mixture-compressing, externally ignited internal combustion engines with continuous injection into the intake manifold, in which the measuring element and an arbitrarily actuatable throttle valve are arranged one behind the other and the measuring element as a valve disc arranged transversely to the direction of flow by the amount of air flowing through against a restoring force a corresponding section of the suction pipe which widens conically in the direction of flow proportional to the The amount of air flowing through the intake manifold is deflected and for metering an amount proportional to the amount of air Fuel quantity the passage cross-section of a fuel valve certainly.

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Robert Bosch GmbH Stuttgart

R. 9673 Su / Kb

The purpose of such fuel injection systems is for a gasoline engine automatically under all operating conditions to create a favorable fuel-air mixture ratio in order to burn the fuel as completely as possible and thus with the highest possible performance of the internal combustion engine or the lowest possible fuel consumption the emergence to avoid or greatly reduce the amount of toxic exhaust gases. It must therefore basically be the adjustment value Measuring element be approximately linearly proportional to the amount of air flowing through the intake manifold, so that with simple means a fuel quantity linearly proportional to this air flow rate can be metered at the metering valve. As soon However, deflection errors of the measuring element occur, for example, due to shaking movements of the motor, it is the measured value Fuel quantity is no longer linearly proportional to the air flow rate, so that an unfavorable fuel-air mixture ratio arises and, for example, the fuel does not burn completely, apart from one high fuel consumption the production of toxic exhaust gases has the consequence.

This desired proportionality is always given when the restoring force acting on the measuring element is constant is, the widening portion of the suction pipe is conical and the pressure in the suction pipe section remains constant between the measuring element and the throttle valve. In order to create these desired conditions, a known fuel injection system of this type (see USA Patent 2,937,858) the measuring element by a pneumatically controlled hydraulic servo motor adjusted

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j Robert Boooh GnbJI R- 9673 ^{Su / Kt}

: Stuttgart

^: namely in AbliänrJ C>'cit v-jii der. before and after the measuring organ

• The pressure prevailing in the intake manifold, which corresponds to the intake manifold ί Air flow. As is well known, this air throughput depends primarily on the engine speed

• and the degree of opening of the throttle valve. One of those

• However, the servo motor is relatively complex.

j With another fuel injection system, also with a measuring element and an arbitrarily actuatable throttle valve connected in series and with the ala reset ! force as soft a spring as possible engages the measuring element is

' _the measuring element air, designed to be pivotable about an axis

! det, whereby the working capacity of this measuring organ depends on the eccentric

• Tricity of the bearing of this axis depends. The eccentricity However, I is limited by the diameter of the suction pipe,

whereby the work capacity is also severely limited.

! However, to deflection errors of the measuring element, for example

to avoid friction on the fuel metering valve, must the working capacity of the measuring organ should be as large as possible.

i The invention is based on the object of a measuring element for

'' To develop a fuel injection system mentioned at the beginning

♦ wrap that works with less expensive resources than

_k in the aforementioned known fuel injection system and

t who has a sufficiently large working capacity

j adds.

j This object is achieved in that the

! Valve plate / a disc known per se is formed, ; ■ the one at one end of a stationary and possibly frictional] freely mounted pivot lever is attached,

594645729.4.71

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Robert Bosch Gnbi: R. 9675 .Su / ICb

Stuttgart

being advantageously used as a fuel valve Din slide valve serves, whose control slide can be actuated directly by the pivot lever and via a with the inflowing Fuel-related annular groove radial control slots leading to individual injection nozzles for a Fuel metering and distribution more or less steers up. Through this direct actuation of the control slide practically all mechanical play is switched off, which is particularly important when the engine is idling, as there are slight shifts in the control slide result in a relatively large change in speed.

About the influence of the pouring movements of the rotors on the movement d.es measuring organ to reduce to a minimum, is an advantageous embodiment of the invention such that the Swivel lever is two-armed and at the end of one arm Disc and a counterweight is arranged at the end of the other arm for mass balancing. Because the masses are compensated by the measuring element disk and pivot lever, the area of the disk of the measuring element can be proportionate can be chosen to be large, at least the area of the disk of the measuring element can be larger than the area of the throttle valve.

In order to keep the friction as low as possible, engages according to an additional embodiment of the invention, the pivot lever on a role on the control slide, wherein in particular, the role acts eccentrically and like a friction wheel on the rotatable control slide and this during the movement twisted of the swivel lever. According to a further embodiment of the invention, the pivot lever is in the touch section a cam track between the swivel lever and the control slide

Kobert BoschGmbll Stuttgart

it.

9G73 Su / Kb

arranged, whereby the assignment of external organ position and stem position changes with the pivoting movement (Fig. 2)
Sections of the intake manifold c. Supply / call to correct.

To accommodate the relatively long pivoting lever and the relatively large slice of desired, n ^ Iicßorgru constructively without dns rest of the suction tube in Durclmesser increased \: c.-ccn must ·, v :: .. rd. goniiß an advantage a \ cn Aunführuri ··; the Σ · fandung vorry ..sehen that o ^ ¹ ^ the Heßorg ntcllcr Suugrohrnbcchnitt receiving simultaneously a part of the
l ⁷ filter housing is so that the combustion air after flowing through the air filter at Ling: ui.- dos Z .ugrohros on the Heßorgantel! "he meets, v: o with" Ji chnrhcit a vibration node of the Baugj. ohrschvji 'gung [formed v.-ird, j also has the advantage that the valve timing and the exhaust pipe length achieved by matching the length of the intake manifold; I.uftsc '.viii η gun g (kamef fect) in the intake manifold is not disturbed.

Two exemplary embodiments of the subject matter of the invention sina is shown in simplified form in the drawing and is described in more detail below. Show it:

Fig. 1 the errte Ausfüüirungsbc _: game with a polio for power transmission from the pivot lever to the control slide of the fuel valve,

Fig. 2 the zvioite Ausführungsb ei game with a Kuivenbalm arn swivel lever in the section of its contact with your control slide of the fuel valve.

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Robert Bosch GmbH R. 9673 Su / Kb

Stuttgart

In the fuel injection system shown in FIG the combustion air flows in the direction of the arrow through an in an air filter 2 arranged in a housing 1, a suction section 3 »in which a measuring element 4 is arranged and to the

j a bend 5 is connected, a connecting hose 6

and a suction pipe section 7 with an arbitrarily operable Throttle valve 8. The intake manifold section 7 closes then a suction pipe section, not shown, of branch off the individual pipes to the cylinders of an internal combustion engine, also not shown.

As a Messorjan A- is used at right angles to the direction of flow A plate attached to a pivot lever 9, the pivot lever 9 being able to oscillate around a shaft 10 in a plane. Dps

'Measuring element ' \ plunges into the pivoting movement of the lever 9

a conical section that widens in the direction of flow of the suction pipe section 3. The path of the measuring element A- is linearly proportional to the amount flowing through the suction pipe Amount of air, with a constant on measuring element A- approaching Restoring force as well as a constant prevailing in front of the measuring element A Air pressure also of the second measuring elements A and Throttle valve 8 prevailing pressure! Remains constant.

To compensate for the hatred of the Hessorgan A and the pivot lever 9, d, h. In order not to have any influence of mass through the measuring element A and swiveling lever ') when the measuring element is being adjusted, the swiveling lever 9 has two arms and is at the end of the. one firm is the measuring element A-, at the end of the other arm a compensation '; ewicht 11 is arranged. This compensation weight 11 is attached to the pivot lever 9 by means of a screw 12 and is adjustable with the aid of an elongated hole 13.

Robert Bosch GmbH Stuttgart

R. 9675 Su / Kb

The Meßor ^ at 4 acts via the pivot lever 9 on one Control slide 15 of a flow divider valve 16. The dem The pivot lever 9 facing away from the end face 17 of the control slide 15 is driven by a fluid under constant pressure applied as the restoring force of the measuring element 4 serves.

The fuel supply to the flow divider valve 16 takes place Via a fuel pump 19 which, driven by an electric motor 20, sucks the fuel from a container 21 and feeds it to the flow divider valve 16 via a line 22. A return line 23 branches off from the line 22, into which a pressure relief valve (pressure holding valve) 24 is connected is.

From the line 22 the fuel arrives in an annular channel 25 running in the housing of the flow divider valve 16, the is connected on the one hand via channels 26 to an annular groove 27 of the control slide 15 and on the other hand to chambers 28, which are closed by a membrane 29. The membrane is thus acted upon by the fuel supplied. Depending on the position of the control slide 15, its annular groove is located

27 more or less in overlap with control slots 30, which each lead through channels 31 to a chamber 32, the through the membrane 29 from the previously described chambers

28 are separated.

The fuel passes from the chamber 32 via outlet pipes 33 to the individual not shown. old injectors, which are arranged near the engine cylinder in the intake manifold. The membrane 29 serves here as a movable valve part of flat seat valves, which by springs 3 ^ during normal operation be kept open. The chambers 28 and 32 form

Robert Bosch GmbH- R. 9673 Su / Kb

Stuttgart

Ilembrane doses through which is achieved that independently; from the one existing between the annular groove 27 and the slots 30 Coverage, i.e. independent of that of the injectors the amount of fuel flowing, the pressure gradient in front of and behind the metering parts 27, JO remains constant. This guarantees that the adjustment of the control slide 15 and the metered amount of fuel is linearly proportional are.

The fluid acting as a constant restoring force on the control slide 15 is also fuel. For this purpose, a line 36 branches off from the line 22 and opens into the space 37 into which the control slide 15 protrudes with its end face 17. In the line 36 a throttle ⁷ -8 is arranged, through which the movement of the control slide is attenuated 15th The pressure of the fuel serving as the restoring force can be changed by means not shown, as a result of which the ratio between the metered amount of fuel and the amount of air flowing through the intake manifold changes.

The exemplary embodiments shown in FIGS. 1 and 2 differ only through the power transmission from the pivot lever 9 to the control slide 15. In the one shown in FIG For this purpose, an exemplary embodiment is used which is arranged on the pivot lever 9 Roller 40. This roller can also be mounted in such a way that it is eccentric on the end face of the control slide 15 engages and rotates the control slide 15 during the movement of the pivot lever 9 in addition to the axial movement, whereby possible Frictional forces are greatly reduced.

Since the Ileßorgan 4, as previously described, in a cone of the Suction pipe section 3 dips, with the between Keßorgan A- and cone-changing ring cross-section linearly proportional

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Robert BoschCmbII Stuttgart

R. 9673 Su / Kb

zxim the displacement of the Keßorgans 4- changes, there is in this embodiment also a linear proportionality between the adjusting movement of the measuring element 4- and the displacement of the control slide 15, so that the amount of air flowing through the intake manifold is always a linear proportional amount of fuel metered.

In the embodiment shown in Fig. 2 transmits the pivot lever 9 directly controls the actuating movements of the measuring element on the control slide, a cam track 4-1 being arranged in the contact section between the pivot lever and the control slide. Because of this curved path 41 is the proportionality between the adjusting movement of the measuring element 4 and the displacement movement of the control slide 15 is changed. This may be necessary, for example, to correct errors in the fuel-air mixture ratio that arise from throttling effects in the intake manifold, since a measuring device based on the flow resistance, such as the measuring element 4-, am Motor causes a loss of filling at higher speeds.

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Claims (8)

Expectations Λ. Measuring element for a fuel injection system for mixture-compressing, externally-ignited internal combustion engines with continuous injection into the intake manifold, in which the measuring organ and an arbitrarily "actuated are throttle valve are arranged one behind the other and the measuring element as a valve disk arranged transversely to the direction of flow through the air flow against a restoring force in a corresponding in The flow direction conically widening section of the intake manifold is deflected proportionally to the amount of air flowing through the intake manifold, the passage cross-section of a fuel valve is determined for the metering of an amount of fuel proportional to the amount of air, characterized in that the valve plate (4) is designed as a disk known to me which is attached to one end of a stationary pivot lever (9) mounted with as little friction as possible. 2. fuel injection! Age according to claim 1, characterized in that that a slide valve (16) is used as fuel serves, whose control slide (15) can be actuated directly by the pivot lever (9) and via a with the inflowing Fuel-related annular groove (2?) -11- Robert Bosch GmbH R. 9675 Su / Kb Stuttgart -adial control, leading to individual injection nozzles. slots (30) for fuel metering and distribution more or less steers up. 3. Fuel injection system according to claim 1 or 2, characterized characterized in that the pivot lever (9) has two arms and at the end of one arm the disc (A-) and on At the end of the other arm a counterweight (1 "O is arranged for mass balancing. A-. Fuel injection system according to one of the preceding Claims, characterized in that the area of the disc (A-) of the measuring element is larger than the area of the Throttle valve (8). 5. Fuel injection system according to one of claims 2 to A-, characterized in that the pivot lever (9) acts on the control slide (15) via a roller (AO). 6. fuel injection system according to claim 5i, characterized in that that the role (AO) is eccentric and like a friction wheel engages the rotatable control slide (15) and this at the Movement of the »swivel lever (9) twisted. -12- «■ β I Robert Bosch GmbH E. 9673 Bu / Kb Stuttgart 7. Fuel injection system according to one of claims 2 to 4, characterized in that a cam (41) is arranged on the pivot lever (9) in the section of contact between pivot lever (9) and control slide (15), whereby the assignment of the pivoting movement Measuring element position and control slide position changes (Fig. 2). 8. Fuel injection system according to claim 4, characterized in that the measuring element plate (4) receiving the suction pipe from section (5) at the same time a part of the filter housing (1) is so that the combustion air after. Flowing through the air filter (2) meets the measuring element plate (4) at the inlet of the suction pipe. .,, CO I. C /. C Ί η λ ι ιλ