DE10342215B4 - Variable throttle device for an intake control in the intake tract of a gasoline engine - Google Patents

Abstract

Variable throttle device (1) for intake control in an intake pipe (10) of a port fuel injection engine, which regulates the inflow of a fuel air mixture to an intake valve (7) of a combustion chamber of a cylinder connected to the intake pipe (10) ) comprises a first throttle element (2a) and thus forms a throttle region having a throttle input port and a throttle output port defining a volume (6) between throttle output port and intake valve (7), wherein a second switchable throttle element (2b) is provided in the throttle region for changing the volume (6) between throttle region and inlet valve (7), through which flows the throttled fuel-air mixture, characterized in that in the throttle region at least one further throttle element (2c) is present, the change of the volume (6) depending on the load case is switchable, wherein in other load cases the Throttling elements (2a, 2b, 2c) are opened without any noticeable effect on the throttle function.

Description

The The present invention relates to a Otto multi-cylinder engine, a variable intake control and a variable throttle device for intake control in an intake manifold of a gasoline engine with intake manifold injection for load-controlled Inflow of a fuel air mixture to one with the intake manifold connected inlet valve of a combustion chamber of a cylinder, wherein the throttle device comprises a throttle element and so a throttle area with a throttle inlet opening and a throttle output opening forms to a volume between throttle output port and intake valve define.

such Otto multi-cylinder engines usually come in motor vehicles, in particular in passenger vehicles for Commitment. To an optimal degree of utilization of such a gasoline multi-cylinder engine to effect, a variable intake control is necessary, which a variable throttle device depending on the load case of the engine regulates. In particular, in a gasoline multi-cylinder engine, the load cases are full load, Part load and idle distinguished. To get the most out of the To achieve Otto multi-cylinder engine according to different load cases must be the cylinder filling the Otto engine, in particular the throttle device in the intake tract, which the supply of the cylinder or cylinders of the gasoline engine regulates, over one appropriate inlet control can be controlled.

Generally the use of a throttle body in an inlet channel is known for load control of the flow a fuel-air mixture to an intake valve of a cylinder from the formula 1. This area is the use of flat slides Known as a throttle body. Here is a flat slide per cylinder inlet flange close to the installed, the flat slide at full opening, this means at full load no flow resistance for the Represent fuel mixture. The opening direction of this flat slide is always formed parallel to the crankshaft of the gasoline engine.

at the known solution occurs the disadvantage that this throttle device and the so connected intake control and the entire Otto engine on one Full load operation are designed and the engine with the intake control and the throttle device in the daily Use for the normal consumer is not usable. In addition, this gasoline engine, and the intake control and the throttle device exclusively with respect to the response of the engine designed. A consideration the amount of fuel to be consumed is not.

Also is generally the use of throttle valves for load control known. For example, the BMW M3 engine becomes a cylinder-individual Single throttle valve device executed, which differs from the previously mentioned known solution essentially through the use of throttle valves instead of flat slides different.

at this known solution similar problems occur as in the aforementioned solution with flat slides on. This engine is predominantly for one good engine running at low load and is in daily use Use also not useable under fuel economy aspects.

Out JP 57088245 A a generic throttle device is known in which, depending on the load case, a displacement piston in the radial direction can be moved into a part of the intake pipe to change the volume between a throttle valve and an intake valve.

It Therefore, the object of the present invention is a gasoline engine, a variable intake control and a variable throttle device to create, in which the fuel consumption according to all occurring load cases is optimized and which is for the daily Use is suitable without any restrictions for the driver.

These The object is based on a variable throttle device according to the preamble of Claim 1, a variable intake control according to the preamble of claim 15 and an Otto multi-cylinder engine according to the claim 18 solved in conjunction with its characterizing features. advantageous Further developments of the invention are specified in the dependent claims.

The Invention includes the technical teaching that at least a second, switchable Throttling element is present in the throttle area to the volume between throttle area and intake valve, through which the throttled Fuel air mixture flows, to change. According to the invention is in at least one additional throttle element is present in the throttle region, that for change of the volume is switchable depending on the load case, where in others load cases the throttle elements without noticeable effect opened to the throttle function are.

These solution offers the advantage that, depending on the load case further throttle elements are switchable to the volume and thus the fuel air mixture supply to influence.

In gasoline engines, there is a force between the throttle device and the intake valve substance air mixture volume, which is greater than the stroke volume of the subsequent cylinder. In the load case low part load, this leads to significant charge cycle losses and thus to increased fuel consumption. If the throttle device is positioned closer to the intake valve, the charge cycle losses due to the initially higher pressure in the volume between throttle device and intake valve during the intake stroke can be reduced. The position of the throttle device for the smallest possible charge cycle losses is therefore load-dependent. As a rule, the following statement can be made: the smaller the load, the smaller the volume in the flow direction behind the throttle device must be in order to achieve optimum efficiency. This means that the position of the throttle device is ideally variable depending on the load continuously.

By Complete the throttle device by at least one further throttle element can the Throttle opening output and / or the throttle input port further toward or away from the inlet valve Move so that the volume between throttle device and intake valve variable is. Naturally can be more additional Add throttle elements, so that ideally the volume is arbitrary in terms of the original Change volume leaves. By appropriate variation of the size and type of Throttle elements leaves also the grading of the variation within technical limits change as you like. That way the throttle device optimally to the corresponding load case to adjust.

Preferably is the second throttle element between the first throttle element and the inlet valve arranged to the volume between the in flow direction reduce last throttle element and intake valve.

There the main area of application - at least measured by the number - in the standard motor vehicle area, it is advantageous, the second Throttle element and all other throttle element between each to arrange the intake valve and the previous last throttle element. By this arrangement is starting from a maximum volume one Staging in terms of smaller volumes possible, leaving a variation volume from 0% to 100% of the original volume. That way the throttle device graduate more accurately than if additional Throttling elements further upstream be arranged, which is mostly for technical reasons too not easily possible is.

A sees the invention improving measure in that the second throttle element is designed as a displacement body to the Volume between the flow direction last throttle element and intake valve to change. Of course the education is as Displacer not limited to the second throttle element, as ever the limitation two throttle elements is not to be understood as an absolute maximum limit. Rather, you can in addition to a second throttle element, a third and many more Throttling elements are used. For this applies transferred the same as for the second throttle element.

By training as a displacement can be a change in a simple way of the volume, which is an alternative possibility to implement the rule: "Je the smaller the load, the smaller the volume in the flow direction behind the throttle device, for optimal efficiency to achieve "is. Thus, this rule can be used as an alternative to changing the position of the throttle device through change the volume realized by introducing a displacement in the volume become. As a displacement body is every body suitable, which displaces a sufficient volume, that is a sufficient displacement volume having.

Preferably is the displacer in the Inlet channel formed movable to change the volume. So let yourself the displacer complete remove from the inlet channel and insert into the inlet channel, so that a stepless change of the volume possible is.

A Further improvement of the invention provides that the displacement body a changeable displacement volume has to change by the displacer volume to change the volume. That way as well as with a displaceable in the inlet channel displacer a change the volume by change the displacer volume cause. This improvement eliminates the mechanism to move of the displacer, thereby the construction is easier.

A optimal change of the volume through a combination of the two previous improvements cause. This is how to achieve the optimum change in volume a displacement body, the a changeable one displacement volume has and which is designed to be movable in the inlet channel.

A Another measure improving the invention provides that the first throttle element and / or the second throttle element as a flat slide is designed to be a changeable Flow cross section to produce.

These Improvement offers the advantage that the throttle element when open Position has no effect on the flowing fuel air mixture and thus no flow losses may occur. When partially open Flat slide also results in an optimal for fuel consumption asymmetric flow distribution, so that when using flat slides as throttle elements a optimum efficiency is achieved.

Especially it is advantageous that the throttle element formed as a flat slide in non-parallel direction to a crankshaft of the gasoline engine is designed to be movable, to a variable flow area to create.

not parallel To crankshaft means that the flat slide in almost every any position and / or orientation and therefore also close to the Inlet valve can be arranged. Preferably, the opening direction designed perpendicular to the crankshaft. Connected to occur at the outer radius the inlet channel higher flow rates of the fuel air mixture, at the inner radius of the intake passage occur lower flow rates on. As a result, a strong Tumbleförmige charge movement is achieved, the in other such throttle devices only with additional Devices such as tumble flaps or tumble plates are achieved. Through this opening direction of the flat slide leaves thus cause an internal and external Abgasrückführverträglichkeit in the partial load, whereby the fuel consumption is further improved.

One another advantage be achieved in that the first throttle element and / or the second Throttle element designed as a pivotable about an axis throttle is. That way the throttle element saves space within the inlet channel Arrange and easily adjust, so that the throttle device is set optimally according to the respective load case. moreover is a simple series connection of multiple throttle valves to simple Way to realize.

Preferably is formed as a throttle valve first and / or second throttle element in the inlet channel arranged so that it is open Position virtually no throttle function causes to open in Position no change to effect the volume. This also allows multiple throttle element arrange in the same way in the inlet duct without a Effect on the throttle function or the volume is noticeable.

A simple and inexpensive Solution sees in that the first and / or the second throttle element as a cross-sectional constriction is designed to effect a throttling of the fluid flowing through. This design of the throttle element requires no further components, so that a simple and inexpensive construction is realized.

Around a variable adjustment of the throttle element according to the respective To cause load case, it is advantageous that the second throttle element as a partition within the inlet channel with at least one lockable opening and one not closable opening formed is to change the volume. By opening or close the closable opening can be so the flow of the fuel air mixture and it is on easy Way a volume change realized. When the opening of the Partition wall is effected practically no volume change; the fuel-air mixture flows around the separation wall both sides. With closed opening the separation wall is a flow around only possible on one side, so that the separated by the partition wall volume part of the fuel air mixture can be flowed through.

Advantageous it is therefore that the partition wall has a closable inlet opening and a plurality Through openings having. That way The separated from the partition wall volume part in increments subdivide, so that optimization in terms of different Load cases is possible.

Around a change to effect the throttle device according to the respective load case It is advantageous that the through holes except for one in the flow direction last passage opening, closest to the inlet valve is, lockable are, with the closing order at the opening located farther from the inlet valve, a change to effect the volume. This order can be a simple one closing mechanism be used. In addition, the volume is gradually continuous variable, so that according to the load case change also a corresponding Setting the throttle device is feasible and not accidentally the throttle device on other than the actual Load case is set. The locking mechanism is due to the Closing order directly coupled with other components such as the gas pedal.

This can be realized in particular advantageous in that the openings of the partition can be closed with a displacer. The displacement body is arranged so that it successively, ie in series, the different opening closes or opens, starting at the most remote opening near the one Lassventil up to the entrance opening. This sequence corresponds approximately to the movement of the accelerator pedal, which controls the fuel supply in an analogous manner.

Farther includes the invention the technical teaching that at least one variable Throttle device according to one of the preceding claims and at least one control unit is present.

Thereby in that the variable intake control is a variable throttle device and at least one control unit, a gasoline engine can be optimally on the respective load cases to adjust. The control unit is required to handle the respective Signal to produce the throttle elements in the desired position to bring and so optimally adjust the throttle device.

Out For this reason, it is advantageous that the control unit has a drive for adjusting the throttle elements comprises for load-controlled adjustment the variable throttle device.

Around to realize an exhaust gas controlled intake control it is advantageous that the control unit cooperates with a lambda control. On that way To realize a control loop, which includes the exhaust gas values as a size and so a safe and reliable Regulation effected.

moreover includes the invention the technical teaching that each cylinder of the Otto multi-cylinder engine one by means of a variable intake control according to one of the claims 15 to 17 regulated variable throttle device according to one of claims 1 to 14 is assigned. In this way is a cylinder-individual Control possible, according to the conditions prevailing on each cylinder optimal operation of the engine.

Further the invention improving measures are in the subclaims or together with the description below a preferred embodiment of the Invention with reference to the figures shown. It shows:

1 a schematic cross-sectional view of a section of a variable throttle device by means of partition wall at idle,

2 a schematic cross-sectional view of a section of a variable throttle device at full load,

3 a schematic cross-sectional view of a variable throttle device with displacer,

four a schematic cross-sectional view of a variable throttle device with a plurality of throttle valves in different load cases 4a to 4d .

5 a schematic cross-sectional view of a section of a variable throttle device with flat slide at partial load and

6 a schematic cross-sectional view of a section of a variable throttle device with flat slide at full load.

1 shows a schematic cross-sectional view of a section of a variable throttle device 1 with throttle elements 2 , a first throttle element 2a , which is designed as a cross-sectional constriction and a second throttle element 2 B , wherein the second Drosselele element 2 B as a partition 3 is trained. The partition wall has a plurality of through openings four on, more precisely five through holes 4a . 4b . 4c . 4d and 4e , The dividing wall 3 is in an intake pipe 10 arranged, which is flowed through by a fuel-air mixture. Furthermore, the variable throttle device 1 a displacer 5 on, which has a variable displacement volume. The displacer 5 is therefore made of a stretchable, elastically deformable material, so that the displacer 5 always traceable to its original form. Between dividing wall 3 and displacer 5 is a volume 6 defining a space for the fuel-air mixture after passing through one or more, at least one throttle element 2 forms comprehensive throttle bodies. The throttle elements 2 are formed as flow cross-sectional constriction, which in the present figure as through holes four are formed. At idle load, the volume should 6 be as low as possible, that is, the volume of the displacer 5 - The Vedrängervolumen or displacer volume - should be correspondingly large or the throttle outlet should be located as close to the inlet valve. For this reason, takes at idle load the displacer 5 its maximum volume. The displacer 5 is arranged so that it depending on the displacer volume, the through holes 4a to 4d can close and only one through hole 4e is open to supply the cylinder. That's the volume 6 minimized.

2 shows a section of the variable throttle device 1 to 1 at full load. At full load becomes as large or as large a volume as possible 6 needed. For this reason, the displacement body 5 reduced to a minimum displacer volume, so that the fuel-air mixture can flow through all openings of the throttle, wherein the resistance, which counteracts the flow due to the large openings and the multiplicity of openings is minimal.

3 shows a schematic cross-sectional view of another embodiment of a variable throttle device 1 , The variable throttle device 1 has a first throttle element 2a and a second throttle element 2 B on. The second throttle element 2 B is as a displacement body 5 trained in the volume 6 is formed infinitely retractable and so the volume 6 to reduce the displacement volume. Furthermore, in 3 the inlet valve 7 shown schematically, which is the volume 6 limited to one side. The first throttle element 2a is as a throttle 8th formed, which rotatable about a central axis centrally in the inlet channel 9 the intake pipe 10 is trained. At full load is the displacer 5 completely retracted, that is the volume 6 is not reduced and the displacer 5 forms no resistance to the incoming fuel air mixture. On idling load, on the other hand, is the displacer 5 completely in the volume 6 extended, leaving the volume 6 is minimized and the throttle exit opening close to the inlet valve 7 is arranged.

four shows a schematic cross-sectional view of another embodiment of a variable throttle device 1 with several throttle elements 2 in different load cases a to d. In four are in the inlet channel 9 three throttle elements 2 arranged approximately in the middle. The volume 6 is located between the inlet valve 7 and in the flow direction last acting throttle element 2c , The three throttle elements 2a . 2 B . 2c are as throttle valves 8th formed, which pivotable about a central axis approximately centrally in the inlet channel 9 are arranged. When open, these form throttle valves 8th virtually no resistance to that through the inlet duct 9 flowing fuel-air mixture.

In 4a ) are the first two throttle elements 2a . 2 B opened and the third throttle element 2c almost closed. This setting of the throttle elements 2 represents the idle load case. The volume 6 is set so minimal.

In 4b ) is the second throttle element 2 B closed and the first and the third throttle element 2a . 2c open. The volume 6 is opposite to in 4a ) volume shown 6 slightly enlarged. This setting of the throttle elements 2 represents a partial load case at low load.

In. 4c ) is the first throttle element 2a closed and the second and the third throttle element 2 B . 2c open, leaving the volume 6 opposite to the volume 6 in 4b ) is further enlarged. This setting of the throttle elements 2 corresponds to a partial load case at high load.

In 4d ) are all throttle elements 2 open, leaving the volume 6 its maximum size. This setting corresponds to the full load case.

5 shows a schematic cross-sectional view of a section of another embodiment of a variable throttle device 1 with flat slide 11 at partial load. For better representability is only a throttle element 2 shown. The illustrated throttle element 2 is as a flat slide 11 educated. At partial load the flat slide forms 11 a resistance to the fuel-air mixture, this passes through the throttle at the outer edge of the intake pipe, whereby an asymmetric flow profile - as shown schematically - is generated.

6 Finally, shows a schematic cross-sectional view of a section of a variable throttle device 1 to 5 with flat slide 11 at full load. At full load is the flat slide 11 , Which is arranged in a flat slide housing, so retracted that the flow cross-section of the fuel-air mixture is not affected, that can flow freely through the throttle point.

1

variable throttling device

2

throttle element

2a

first throttle element

2 B

second throttle element

3

separation wall

4

Through opening

4a

First Through opening

4b

Second Through opening

4c

third Through opening

4d

Fourth Through opening

4e

Fifth passage opening

5

displacement

6

volume

7

intake valve

8th

throttle

9

inlet channel

10

intake

11

flat slide

Claims (18)

Variable throttle device ( 1 ) for an intake control in an intake pipe ( 10 ) of a gasoline engine with intake manifold injection, which the inflow of a fuel-air mixture to one with the intake pipe ( 10 ) connected inlet valve ( 7 ) Lastregelt a combustion chamber of a cylinder, wherein the throttling device ( 1 ) a first throttle element ( 2a ) and thus forms a throttle region with a throttle inlet opening and a throttle outlet opening, which has a volume ( 6 ) between throttle output port and intake valve ( 7 ), wherein, a second, switchable throttle element ( 2 B ) is present in the throttle area for changing the volume ( 6 ) between throttle area and inlet valve ( 7 ), through which flows the throttled fuel-air mixture, characterized in that in the throttle region at least one further throttle element ( 2c ), which is used to change the volume ( 6 ) is switchable depending on the load case, wherein in other load cases, the throttle elements ( 2a . 2 B . 2c ) are opened without any noticeable effect on the throttling function. Variable throttle device ( 1 ) according to claim 1, characterized in that the second throttle element ( 2 B ) between the first throttle element ( 2a ) and the inlet valve ( 7 ) and the volume ( 6 ) between the last in the flow direction throttle element ( 2 ) and the inlet valve ( 7 ) reduced. Variable throttle device ( 1 ) according to claim 1 or 2, characterized in that the second throttle element ( 2 B ) as a displacement body ( 5 ) and the volume ( 6 ) between the last in the flow direction throttle element ( 2 ) and the inlet valve ( 7 ) changed. Variable throttle device ( 1 ) according to claim 3, characterized in that the displacement body ( 5 ) in the inlet channel ( 9 ) is movable and the volume ( 6 ) changed. Variable throttle device ( 1 ) according to claim 3 or 4, characterized in that the displacement body ( 5 ) has a variable displacement volume and the volume ( 6 ) changed by changing the displacer volume. Variable throttle device ( 1 ) according to one of the preceding claims 1 to 5, characterized in that the first throttle element ( 2a ) and / or the second throttle element ( 2 B ) as a flat slide ( 11 ) is / are formed and generate / generate a variable flow area. Variable throttle device ( 1 ) according to claim 6, characterized in that the flat slide ( 11 ) formed throttle element ( 2 ) is designed to be movable in non-parallel direction to a crankshaft of the gasoline engine and generates a variable flow cross-section. Variable throttle device ( 1 ) according to claim 7, characterized in that the first throttle element ( 2a ) and / or the second throttle element ( 2 B ) as a pivotable about an axis throttle valve ( 8th ) is / are formed. Variable throttle device ( 1 ) according to claim 8, characterized in that the throttle valve ( 8th ) formed first and / or second throttle element ( 2 ) in the inlet channel ( 9 ) is arranged and in the open position practically no throttling function causes / effect and in the open position no change in the volume ( 6 ) causes / effect. Variable throttle device ( 1 ) according to one of claims 1 to 9, characterized in that the first and / or the second throttle element ( 2 ) is designed as a cross-sectional constriction and causes a throttling of the fluid flowing through / cause. Variable throttle device ( 1 ) according to one of claims 1 to 10, characterized in that the second throttle element ( 2 B ) as a partition ( 3 ) within the inlet channel ( 9 ) is formed with at least one closable opening and a non-closable opening and the volume ( 6 ) changed. Variable throttle device ( 1 ) according to claim 11, characterized in that the dividing wall ( 3 ) a closable inlet opening and a plurality of through openings ( four ) having. Variable throttle device ( 1 ) according to claim 12, characterized in that the passage openings ( four ) except for a flow passage last passage ( 4e ), the intake valve ( 7 ) are closable, wherein the closing order at the farthest from the inlet valve ( 7 ) arranged opening and a change in the volume ( 6 ) causes. Variable throttle device ( 1 ) according to one of claims 11 to 13, characterized in that the openings of the partition ( 3 ) with a displacement body ( 5 ) are closable. Variable intake control for an Otto multi-cylinder engine, characterized in that at least one variable throttle device ( 1 ) according to one of the preceding claims and at least one control unit is present. Variable inlet control according to claim 15, characterized in that the control unit has a drive for adjusting the throttle elements ( 2 ), and the variable throttle device ( 1 ) adjusted load-controlled. Variable inlet control according to claim 15 or 16, characterized in that the control unit cooperates with a lambda control and realizes an exhaust gas controlled intake control. Optimized Otto multi-cylinder engine, characterized in that each cylinder is controlled by a variable intake control according to one of claims 15 to 17 variable throttle device ( 1 ) is assigned according to one of claims 1 to 14.