DE2529178A1 - PROCEDURE AND ARRANGEMENT FOR CONTROLLING THE FUEL-AIR MIXTURE SUPPLIED TO A COMBUSTION ENGINE - Google Patents

Description

© im ei 2 F 02 M 23/04 ^

© FEDERAL REPUBLIC OF GERMANY ^

GERMAN ^ gj ^ PATENTAMT * ™

__ IA

Offenlegungsschrift 25 29178

File number: P 25 29 178.5

Registration date: 1. 7.75

Disclosure date: 3. 2.77

Union priority:

Designation: Method and arrangement for the regulation of an internal combustion engine

supplied fuel-air mixture

Applicant: Robert Bosch GmbH, 7000 Stuttgart

Inventor: Zeller, Hans, Dipl.-Ing., 7031 Grafenau;

Latsch, Reinhard, Dipl.-Ing. Dr., 7143 Vaihingen; Brettschneider, Johannes, Dipl.-Ing. Dr., 7140 Ludwigsburg; Bianchi, Valerio, Dr., 7147 Hochdorf

© 1.77 609 885/21 10/60

June 23, 1975 Bö / Ml * ~ ^ϋΔΌ '' ^ö

Attachment to

Patent and

Utility model registration

Method and arrangement for regulating the fuel-air mixture supplied to an internal combustion engine

The invention relates to a method for regulating the mixture supplied to an internal combustion engine, in the case of which
Fuel-air mixture of certain composition additional air is supplied.

In a common way with known methods of influencing the composition of the fuel-air mixture, the amount of air sucked in by the internal combustion engine is assigned the corresponding amount of fuel. This has the advantage that the metering of fuel is easy to control insofar as the amount of fuel introduced can be influenced far less by pressure and temperature than is the case, for example, with the
Metering of air is the case.-Eei internal combustion engines,
whose fuel-air mixture should be regulated precisely to certain Λ values, in lean operation with the air ratio -Λ - 1, the dependency of the torque achieved on the amount of fuel introduced is particularly disruptive, since there the change in torque is related to the change in the air ratio λ is particularly large. Operating modes with -A = I are particularly interesting in terms of fuel consumption, but

609885/0021 _ ₂ _

In this area, the aforementioned disadvantage is particularly evident when using the smoothness of the internal combustion engine as The controlled variable is noticeable in a disturbing manner, since when there is a change in the fuel supplied to the internal combustion engine in a controlled manner through this smoothness of operation me age new torque fluctuations are generated.

The object of the invention is to provide a method for influencing of the fuel-air mixture supplied to an internal combustion engine to develop in which the aforementioned disadvantages are avoided and a fast and precise control is possible is G.

This object is achieved in that the metering of the additional air volume depending on the position of the mixture quantity control device takes place and this dependence on a parameter of the internal combustion engine detecting control device can be influenced multiplicatively between the value 0 and 1.

It is known to influence the fuel-air mixture by supplying additional air, but this is done at known solutions either directly dependent on operating parameters or e.g. directly dependent on the Main throttle position. The supply of additional air to a fuel-air mixture of a certain composition, that is generated e.g. by a carburetor, has especially with a mixture control according to the smoothness of the internal combustion engine the great advantage that in the lean operating range the change in the air supply to the mixture compared with the change in the fuel supply to the mixture causes significantly smaller changes in torque and the regulation not adversely affected by excessive torque fluctuations will. The regulation by additional air is also much faster because of the lower inertia of the air and because there are no such great delays or dead times as occur when controlling the fuel metering, partly caused by pilm evaporation effects

609885/0021

on the walls that come into contact with the mixture. Furthermore, the regulation is much faster and more accurate by a coarse influence preceding the actual regulation according to the position of the mixture-tightness control device Subsequent multiplicative intervention in the transmission between the control device and the metering of the additional air. The mixture quantity control device can, for example, be the usual main throttle valve which, when in operation, corresponds to the load is adjusted.

It is a further object of the invention to provide an arrangement for implementation of the above method, which enables rapid multiplicative intervention.

This object is achieved in that the adjustment of the throttle member takes place by means of a transmission device from the main throttle valve and the transmission factor of Device can be changed multiplicatively by a certain parameters of the internal combustion engine detecting control device.

An advantageous embodiment of the arrangement according to the invention consists in the fact that a by-pass throttle valve is used as a throttle body is used, which is coupled to the main throttle valve via a linkage that consists of an intermediate link lever, one end of which can be pivoted about a pivot point, which can be adjusted by an actuator connected to the control device is and of which the other end is connected to a lever of the throttle valve shaft and a sliding block in its setting an operating lever of the main throttle valve is displaceable. In this way, the transmission ratio can be changed without much effort between the adjustment of the main throttle valve and the adjustment of the by-pass throttle valve in the range from 0 to 1 adjusted will. In any position of the main throttle valve, the by-pass throttle valve can also be activated by the control intervention in Be brought to the closed position.

There is an anlere embodiment of the arrangement according to the invention in that a by-pass throttle valve is used as a throttle body

609885/0031

which is used with the main throttle valve via a parallelogram linkage is coupled, which consists of a stationary articulated lever, the operating lever of the by-pass throttle valve and one there is an intermediate rod connecting both levers, on which a sliding sleeve is arranged, which is attached to an adjusting piece on a is articulated with the main throttle shaft connected lever on which the adjusting piece by means of one of the control device controlled actuator is adjustable between two end points. This can also be done in this way transmission ratio between by-pass throttle valve and main throttle valve can be changed in the range from 0 to 1, the adjustment being carried out in an advantageous embodiment, that the adjusting piece is a screw sleeve and the lever is designed as a threaded shaft driven by an electric motor is driven. Above all, this has the advantage that the electric motor has an integrating effect in the control loop and that the adjustment is quick and accurate.

Further refinements of the invention are set out in the subclaims in connection with the description below and the in Refer to the drawing illustrated embodiments. Show it:

Fig. 1 shows a first embodiment of the invention Arrangement with an intermediate link lever as a transmission link between the main throttle valve and by-pass throttle j

Fig. 2 shows a second embodiment with a parallelogram linkage as a transfer element between the main and by-pass throttle valve,

3 shows a section through the arrangement according to FIG. 2,

FIG. 4 shows a partial section through a further embodiment of the arrangement according to FIG. 2,

Fig. 5 is a schematic circuit diagram of the drive control of the embodiment of Fig. H and

609 8 8 5/0021

Pig. 6 shows a third exemplary embodiment of the arrangement according to the invention with electrical tracking of a Throttle element in the by-pass air line corresponding to the main throttle position.

In the exemplary embodiment shown in FIG. 1, an internal combustion engine 10 is supplied by a mixture generator via an intake manifold 11 13 is supplied with a fuel-air mixture, which is supplied with fresh air via an air intake pipe provided with a filter 15 receives. The mixture generator 13 can be a carburetor of conventional design or some other mixture generator such as, for example, one of an air flow meter or a pressure gauge or similar controlled fuel metering device. In the by-pass to the mix producer 13 is a by-pass air line 17 between the air intake pipe 14 and Suction pipe 11 is provided. Downstream of the mixture generator 13, a main throttle valve 18 is arranged in the suction line 11, which can be actuated in the usual way via a linkage 19 by an accelerator pedal 20 against a spring 21. The shaft 23 of the main throttle valve is firmly connected to an actuating lever 24, at the free end of which a sliding block 25 is movably attached. The sliding block 25 is guided in a circular arc-shaped recess 26 of an intermediate link lever 27, on one of the outer ones At the end of a connecting lever 29 engages an actuating lever 30. The operating lever 30 is fixed to the shaft of a by-pass throttle valve 32 connected in the by-pass air line 17. At the other outer end of the intermediate link lever 27 engages in the pivot point 34 a connecting rod 35 to the armature of an actuating magnet 36. The actuating magnet is controlled by a schematically illustrated control device 37 in accordance with the parameters detected by it Internal combustion engine supplied with power. This control device can, for example, be a known A. control or smooth running control. However, other operating parameters of the internal combustion engine such as the motor temperature can also be used as Control signal can be used for this control device.

In the arrangement described in FIG. 1, the internal combustion engine 10 corresponding to the position of the throttle valve l8

609885/0021 - 6 -

A certain amount of a fuel-air mixture supplied, which is provided by the mixture generator 13. As long as the control device 37 does not supply the solenoid 36 with power, the pivot point 34 of the intermediate link lever 27 is in the rest position corresponding to a control stroke 0. In this position of the intermediate lever, the sliding block 25 follows the recess when the main throttle valve l8 is actuated, without the position of the intermediate link lever to change, so that the by-pass throttle valve remains in the drawn closed position. If, however, the actuating magnet 36 is activated in accordance with a corresponding signal from the internal combustion engine via the control device 37, the pivot point 34 is moved out of its zero position, so that when the main throttle valve 18 is actuated, the intermediate link lever 27 performs a pivoting movement which is controlled via the levers 29, 30 is transferred to the by-pass throttle valve 32 and moves it in the opening direction. This movement takes place at the same time as the main throttle valve with a transmission factor that is determined on the one hand by the transmission ratio of the intermediate levers and, on the other hand, primarily by the control stroke of the actuating magnet J> 6 . The maximum Fegelhub of the solenoid 36 corresponding to a value is designed together with the transmission ratio of the transmission linkage to the bypass throttle valve 32 so that at control stroke 1 the bypass throttle valve 32 is guided parallel to the main throttle valve 18. The movement of both throttle valves can be approximately determined by the following equation:

* ■ DB ^ * DH ^{% X} ' ^{WHERE bei}

0 £ χ £ 1.

In the case of the present arrangement, the supply of additional air can thus be effected by the intervention via the control device 37 each position of the main throttle valve l8 between a maximum value corresponding to the main throttle valve position and the Value 0 can be set. This device has the advantage

S098gS / 0021

that, regardless of the type of mixture, the one supplied in the by-pass Additional air corresponding to the main throttle valve adjustment very quickly via the pilot control 24, 27, 29, 30 can be changed and then, in addition, a corrective control intervention that superimposes this precontrol in a multiplicative manner is, can be done. This ensures fast and precise regulation.

In the embodiment of FIG. 2 is the same as in the embodiment after Pig. 1 an internal combustion engine 10 is provided, which via the intake manifold 11 from the Gemisoherzeußer 13 a fuel-air mixture the amount of which is influenced by the position of the throttle valve 18. From the air intake pipe l4 leads the by-pass to the mixture generator 13, the by-pass air line 17 into the intake manifold. The 3y-pass air line is through the by-pass throttle 32 controlled, the actuation of which takes place via the actuating lever 30, which in this embodiment Is part of a parallelogram linkage. The parallelogram linkage also consists of a stationary articulated lever 39 same length as the operating lever 30. Both levers are connected by an intermediate rod 40 on which a sliding sleeve

41 is displaceable. Articulated with the sliding sleeve 4l is a Adjusting piece 42 connected, which is designed as a screw sleeve. The screw sleeve 42 is located on a threaded shaft 43, with the axis 46 of a main throttle valve shaft on the angled part 44 23 seated electric motor 45 is connected. The throttle valve 18 is operated in the usual way via a linkage 19 actuated by the accelerator pedal 20.

As can be seen in more detail from Fig. 3, the threaded shaft 43 is through the angular part 44, which is fixed to the main throttle shaft 23 is connected, led. For the screw socket

42 limit switches 47 and 48 are provided on the threaded shaft, which are part of an engine control unit 50. the The electric motor 45 is supplied with power via the lines 51, 52 from this engine control unit 50. The engine control unit is activated by the regulating device 37.

609885/0021 - B -

Even with this arrangement, the transmission ratio can be between the rotary movement of the main throttle valve and the rotary movement of the by-pass throttle valve in a ratio of 0 to 1 the control intervention can be changed. In the case of a minimum position corresponding to control intervention 0, the motor 45 driven has Threaded shaft 43 moves the screw socket so far in the direction of the electric motor that the pivot point between the screw socket and sliding sleeve 4l is aligned with the axis of rotation of the main throttle valve 18, so the connecting rod 40 is in the Alignment line between the axis of rotation of the by-pass throttle valve and the main throttle valve shaft 23 lies. When turning the main throttle valve, there is no adjustment of the parallelogram linkage in this case. At the maximum position accordingly a control stroke 1, the screw sleeve 42 has been brought into the other extreme position by the threaded shaft 43, see above that now the actuating lever 30, the stationary lever 39 and the threaded shaft 43 are parallel to one another. Likewise the main throttle valve 18 is parallel to the by-pass throttle valve 32. If the main throttle valve 18 is now rotated from the accelerator pedal 20, the bypass throttle valve 32 takes over the parallelogram linkage 30, 39 and 40 carried along, the same angular position as the main throttle valve. The respective end positions of the screw sleeve 42 corresponding to control stroke 0 or control stroke 1 are set by the limit switches 47 and 48, which can be seen even more clearly in the example according to FIG are determined.

With this arrangement, just like in the first exemplary embodiment according to FIG. 1, a rapid multiplicative control intervention can be carried out the additional air control. This version also offers the advantage that the set control stroke is independent of any frictional forces when the main throttle valve 18 is actuated is also safely retained.

An improved embodiment of the embodiment of FIG. 2 is shown in FIG. 4, where the electric motor 45 is arranged so that

- 9 609885/0021

does not have to be moved when changing the throttle valve position. As in the embodiment according to Pig-2, a threaded shaft 43 'is also provided here, on which the screw sleeve 42 is arranged. The screw sleeve 42 is articulated to the sliding sleeve 4l, which is displaceable on the intermediate rod 40. At its ends, the threaded shaft 43 'is mounted in a rectangular frame 54 so that it lies in one plane with the throttle valve. The frame 54 is firmly connected on its one longitudinal side 53 to the main throttle valve shaft 23 and also serves to support the electric motor shaft 46, which is aligned with the main throttle valve shaft 23. A bevel gear 55, which engages in a corresponding bevel gear 56, is placed on the motor shaft 46. The bevel gear 56 is firmly connected to the threaded shaft 43 'and is used to drive it. The limit switches 47 and 48, which can be actuated by a nose 57 of the screw sleeve 42, are also attached to a longitudinal side of the frame that is parallel to the threaded shaft. The nose 57 and the limit switches 48 are associated with each other _a that the axis of the intermediate rod cut upon actuation of the switch 48 4ü the axis of the main throttle shaft 23 so that 48 no height adjustment of the intermediate rod can be performed 40 more at a rotation of the main throttle valve. The position of the upper limit switch 47 corresponds to a position of the intermediate rod 40 in which the threaded shaft 43 ′ lies parallel to the actuating lever 30 or the lever 39. In this position, the by-pass throttle valve 32 performs the same angular movements as the main throttle valve due to the height adjustment of the parallelogram brought about by the main throttle valve 18.

This embodiment has the advantage that the electric motor 45 can be fixed in place and thus less Dimensional forces have to be used when adjusting the throttle valves. The control of the servomotor in connection with the limit switches 47 and 48 takes place in the same way as in the embodiment of FIG. 2 via the Motorsteuergei-ät 50.

609885/0 021

In Pig. 5, the circuit of the engine control unit 50 is shown schematically. The input signal of the control device 37 is fed via the line 60 to the electric motor 45, from which a further line 61 _3, into which a line branch 62, 63 is connected, leads to an inverting stage 64. The inverting stage is controlled by a line 65 branching off from line 60. In the line 62 of the line branching, the limit switch 48 is in series with a diode 66, which blocks in the direction of the electric motor. In the line 63 of the line branching, the limit switch 47 is in series with a diode 67, which blocks in the direction of Ir.vertierstufe 64.

If there is a positive control signal at the input, the electric motor is put into operation until the nose 57 the screw sleeve 42 actuates the limit switch 48 and the connection between the electric motor 45 and the inverter 64 interrupts. At this point in time, the by-pass throttle valve is independent of the position of the main throttle valve l8 closed so that no additional air is supplied to the fuel-air mixture. Receives the input of the engine control unit thereupon a zero signal from the control device 37, so the motor wii'd via the inverting stage in the opposite direction controlled until the screw sleeve 42 actuates the limit switch 47 and the supply of the electric motor interrupts. In this position, the by-pass throttle valve 32 is simultaneously with the main throttle valve by equal degrees emotional.

In the embodiment of FIG. 6, the same parts are with the same item numbers. As in the previous Embodiments are also the internal combustion engine 10 via the intake pipe from the vegetable generator 13 with a fuel-air mixture provided. In the by-pass air line 17 between the air suction pipe 14 and suction pipe 11, however, is in this embodiment a proportional valve 68 is provided as a throttle element. The closing member 69 of the proportional valve is

- 11 -

609885/0021

operated by a solenoid. The transmission of the rotary movement of the main throttle valve 18 in the intake manifold 11 takes place in this exemplary embodiment via the tap on a potentiometer 71, which takes place by means of a wiper 72 connected to the main throttle valve shaft 23. The potentiometer 71 is supplied with voltage from the control device 37 and is grounded at its other end. A line 7 ^ leads from the wiper 72 to a differential amplifier 75, which compares the voltage signal supplied to it via the line TH with a reference signal present at its other input 76. In the output stage of the power amplifier is the magnet winding 78 of the control magnet 70, which is now excited according to the voltage tap on the potentiometer "1 and" changes the opening cross-section of the proportional valve.

About the opening characteristics of the valve in the by-pass air line To correct, as shown in this exemplary embodiment according to FIG. 6, the potentiometer 71 can be activated various parallel resistors 79 be wired.

In this example Lel, too, a Coarse adjustment of the valve 68 according to the position of the main throttle valve 18 and, in addition, a corrective adjustment Control intervention from the control device 37, which sets the voltage level on the potentiometer between a minimum and changed to a maximum value. As in the examples described above, this takes place as a function of parameters the Bennkraftmaschine. The valve 68 is likewise used here by the control intervention either independently of the position the throttle valve 18 is held in the closed position or it becomes the free average cross-section according to control intervention 1 of the valve is set proportionally to the change in the cross-section of the durometer at the throttle valve. By wiring of the potentiometer with load points can also be used when using a throttle element other than a throttle valve, such as

£ 09885/0021 -12-

described in the preceding examples, on this throttle element the opening characteristic 1 - cos oC of a throttle valve be achieved. Of course, in this context, other closing organs can also have their closing movements continuously controllable can be used. Instead of the actuators described, other continuously operating actuators can also be used Actuators are used such as a heated bi-metallic spring, their ability to work with a suitable design, e.g. as a hairpin spring, adapted to the prevailing conditions can be.

In the exemplary embodiment according to FIG. 1, instead of the actuating magnet, the actuating drive, as shown in FIG. 2 and FIG. >', Can also be used. The actuating magnet is replaced by a threaded shaft with a screw socket, driven by a stationary electric motor, which is connected in an articulated manner to the intermediate link lever 27 at the pivot point J> k. The electric motor is controlled in the same way as in the exemplary embodiment according to FIGS. 2 and U by a motor control device 50 and the travel range is limited by limit switches. This design has the advantage that the desired travel can be maintained exactly regardless of any frictional forces. In addition, the electric motor also has an integrating effect in relation to the control device.

- 13 -

609885/0021

Claims (15)

Expectations 1.! Method for regulating the fuel supplied to an internal combustion engine Mixture in which a fuel-air mixture is certain Composition of additional air is supplied, characterized in that the metering of the amount of additional air as a function on the position of the mixture control device takes place and this dependency on a control device detecting parameters of the internal combustion engine is multiplicative between the value 0 and 1 can be influenced. 2. Arrangement for performing the method according to claim 1 with one depending on a main throttle valve for the mixture quantity control in the intake manifold of an internal combustion engine adjustable throttle element in a By-Pa £> air line opening into the intake manifold downstream of the main throttle valve, thereby characterized in that the adjustment of the throttle member (32, 69) by means of a transmission device from the main throttle valve (l8) and the transmission factor of the device can be changed multiplicatively by a control device (37) which detects certain parameters of the internal combustion engine. 3 · Arrangement according to claim 2, characterized in that as Throttle body a by-pass throttle valve (32) is used with the main throttle valve (18) coupled via a linkage is-3, which consists of a link intermediate lever (27), one of which S09885 / 0021 End can be pivoted around a pivot point (3 * 0, which is supported by a the control device (37) connected actuator (36) is adjustable and of which the other end with an operating lever (30) of the by-pass throttle valve (32) is connected and in its Link (26) a sliding block (25) of an actuating lever (24) of the main throttle valve (l8) is displaceable. 4. Arrangement according to claim 3, characterized in that the The actuator is a solenoid (36). 5. Arrangement according to claim 3, characterized in that the The actuator is a heatable bimetal spring. 6. Arrangement according to claim 3, characterized in that the actuator is a threaded shaft driven by an electric motor is with a screw sleeve which is articulated to the pivot point of the intermediate lever (27). 7. Arrangement according to claim 2, characterized in that as Throttle body a by-pass throttle valve (32) is used, which is connected to the main throttle valve (l8) via a parallelogram linkage is coupled, which consists of a stationary articulated lever (39)> the actuating lever (3O) of the by-pass throttle valve (32) and an intermediate rod (40) connecting the two levers, on which a sliding sleeve (4l) is arranged, which is connected to a Adjusting piece (42) is articulated on a lever (43) connected to the main throttle valve shaft (23), on which the adjustment piece (42) by means of a 009885/0021 - 15 - device (37) controlled actuator (45) between two
End points is adjustable. 8. Arrangement according to claim J _3, characterized in that the adjusting piece is a screw sleeve (42), and the lever is designed as a threaded shaft (43) which is driven by an electric motor (45). 9 · Arrangement according to claim 8, characterized in that the Electric motor shaft (46) is stationary and coaxial with the main throttle valve shaft (23) and via a bevel gear (55s 56} is connected to the threaded shaft (43 '). 10. The arrangement according to claim 9, characterized in that the electric motor (45) by the screw sleeve (42) actuated limit switches (47, 48) via a motor control unit (50)
can be switched off. 11. The arrangement according to claim J _3, characterized in that the adjusting piece is displaceable by means of a heatable bimetal spring. 12. The arrangement according to claim J _3, characterized in that the adjusting piece can be displaced by an actuating magnet on the lever. 13. The arrangement according to claim 2, characterized in that as transmission device of the main throttle position 609885/002 1 Potentiometer (71) is used and the difference between the voltage tap on the potentiometer and a reference voltage via a differential amplifier (75) and a power amplifier (77) is fed to an electrical adjusting device (70) of the throttle element (68) and the voltage level on the potentiometer is controlled by a control device (37). 14. The arrangement according to claim 13, characterized in that as Throttle element is a proportional valve that can be actuated by a solenoid (70) (68) is used. 15. The arrangement according to claim 14, characterized in that the The travel of the proportional valve is corrected by the connected load points (79) on the potentiometer (71). 609885/0021