WO1998019065A1

WO1998019065A1 - Internal combustion engine gas flow control system

Info

Publication number: WO1998019065A1
Application number: PCT/DE1997/002161
Authority: WO
Inventors: Karl Gmelin; Thomas Bursitzky; Johannes Meiwes
Original assignee: Robert Bosch Gmbh
Priority date: 1996-10-28
Filing date: 1997-09-24
Publication date: 1998-05-07
Also published as: DE19644687A1

Abstract

Air is fed through an auxiliary port of an internal combustion chamber at a high velocity of flow in a turbulence system. This enables mixture formation to be improved. Air flowing through the auxiliary port must be controlled. In the inventive gas flow control system, the main port gas flow (31) which circulates through the gas throttle port (34c) and the auxiliary port gas flow (12) are jointly regulated by the gas throttle (40). The gas flow control system is especially designed for automotive internal combustion engines.

Description

Gas guidance system of an internal combustion engine

State of the art

The invention relates to a gas routing system of an internal combustion engine according to the preamble of claim 1.

In internal combustion engines, a gas stream is usually supplied to the combustion chamber or combustion chambers via a channel. The channel has a relatively large cross-section, so that a large gas flow can be supplied to the combustion chamber or combustion chambers without excessive flow losses if required. In the course of the channel there is an adjustable throttling device with which the gas flow is controlled. The throttle element is adjusted using an actuator. The throttle element is usually a throttle valve. The gas stream is flowing air, which, depending on the type of internal combustion engine, is supplied with fuel in the course of the channel or the fuel is injected directly into the combustion chamber or into the combustion chambers.

Because the cross section of the channel is relatively large, the flow velocity is into the combustion chamber or into the

Combustion chamber inflowing gas flow is quite small. Because this is particularly true in the idle range of the internal combustion engine Problems with the mixture formation and thus with the course of combustion in the combustion chamber can lead to a secondary gas flow into the combustion chamber or into the combustion chambers via a secondary duct. Because the cross section of the secondary duct is quite small, the secondary gas flow in the secondary duct has a high flow velocity in the region of the inlet duct into the combustion chamber even with a relatively small secondary gas flow, which improves the mixture formation and thus the combustion process in the combustion chamber or in the combustion chambers.

In order to control the secondary gas flow in the secondary channel, a further throttle element has hitherto been provided in the course of the secondary channel. Both throttle bodies are adjusted with the help of one actuator each. The further throttle element and the further actuator require considerable effort overall, and the resulting additional costs in the manufacture of the gas routing system are of considerable disadvantage.

Advantages of the invention

The gas routing system of an internal combustion engine designed according to the invention with the characterizing features of claim 1 has the advantage that the manufacturing effort is significantly reduced.

Advantageous further developments and improvements of the gas routing system of an internal combustion engine specified in the main claim are possible through the measures listed in the subclaims.

If the throttle element is designed in the form of a throttle valve and the secondary duct inlet of the secondary duct is additionally controlled by a flat side of the throttle valve, this offers the advantage that the free cross-section in the secondary duct is evident or closable even with a slight adjustment of the throttle valve.

If the secondary duct inlet is used as a stop for the throttle valve, then the manufacturing outlay is advantageously also reduced, and the assignment of the throttle valve to the secondary duct inlet is easily possible.

Is the throttle body designed so that when the

Throttle valve closes the channel, the free cross-section of the channel is changed only slightly by slightly adjusting the throttle valve, then this has considerable advantages in assigning the throttle valve to the secondary channel inlet.

If the secondary duct inlet is deformable during manufacture, this advantageously also facilitates the manufacture of the gas routing system.

drawing

Preferred, particularly advantageous exemplary embodiments of the invention are shown in simplified form in the drawing and explained in more detail in the following description. 1 shows a schematic representation of a gas routing system designed according to the invention and FIGS. 2, 3 and 4 show details of differently designed exemplary embodiments.

Description of the embodiments

The gas routing system of an internal combustion engine designed according to the invention can be used in any internal combustion engine in which a combustion chamber is provided via a channel a main channel gas stream and a secondary gas stream is to be supplied via a secondary channel. For example, the internal combustion engine can have only one combustion chamber. However, the internal combustion engine can also comprise several combustion chambers. For example, the channel can be divided into several individual channels before reaching the combustion chambers. The channel with the adjustable throttle element can be designed such that the adjustable throttle element controls the gas flow for all combustion chambers of the internal combustion engine. However, the gas routing system can also be designed such that, for example, each combustion chamber of the internal combustion engine is assigned a separate channel with a separate throttle element. At least one of these throttling elements then also serves to adjust the secondary gas flow in the secondary duct. However, it can also be provided that each of the adjustable throttle elements serves to control the main duct gas flow in the duct and also to control the secondary gas flow in the secondary duct.

In the following description of the exemplary embodiments, it is assumed, for reasons of simplification, that the internal combustion engine has four combustion chambers and the throttle element controls the gas flow, the main channel gas flow and the secondary gas flow for the four combustion chambers.

FIG. 1 shows a preferred selected embodiment in symbolic form.

1 schematically shows an internal combustion engine 2 and a gas routing system 4 belonging to the internal combustion engine 2. Inside the internal combustion engine 2 there are a first combustion chamber 6, a second combustion chamber 6 ', a third combustion chamber 6''and a fourth combustion chamber 6''' . The gas routing system 4 comprises a channel 8, a throttle element 10 and a secondary duct 12. The duct 8 comprises a duct inlet side 14, the throttle element 10, a connection 15 and a collector 16. Viewed in the direction of flow, the parts of the duct 8 mentioned come in the order in which they were named. A first individual channel 18, a second individual channel 18 ', a third individual channel 18''and a fourth individual channel 18''' branch off from the collector 16 in parallel. The individual channels 18, 18 ′, 18 ″, 18 ″ ″ are designed, for example, as oscillating tubes in order to be able to achieve the greatest possible full load output in the internal combustion engine 2.

At the transitions of the individual channels 18, 18 ', 18' ', 18' '' into the combustion chambers 6, 6 ', 6' ', 6' '' there are inlet valves which are not shown in the drawing for the sake of clarity. In the course of the channel 8 of the gas routing system 4, there is, for example, one injection valve or several injection valves. In the drawing, also for the sake of clarity, no injection valve is shown. The

Internal combustion engine 2 can, for example, be designed such that a fuel injection valve is located in the area of the channel inlet side 14 in front of the throttle element 10, or the internal combustion engine 2 can be constructed such that at the end of each of the individual channels 18, 18 ', 18' ', 18' ' 'one each

Fuel injection valve is arranged, which injects the fuel either upstream of the inlet valve into the individual channels 18, 18 ', 18' ', 18' '' or behind the inlet valves directly into the combustion chambers 6, 6 ', 6' ', 6' ''.

In the preferred embodiment selected, the secondary duct 12 comprises a secondary duct inlet 20, a secondary duct guide 22, a so-called turbulence collector 24, a first turbulence air supply 26, a second Turbulence air supply 26 ', a third turbulence air supply 26''and a fourth turbulence air supply 26'''. The secondary duct 12 branches off from the duct 8 in the region of the throttle element 10. The secondary duct 12 begins with the secondary duct inlet 20.

A gas stream 30 flows through the gas routing system 4. The gas stream 30 is shown symbolically in the drawing with an arrow provided with the reference symbol 30. Gas stream 30 is typically flowing air. The gas stream 30 can also be a fuel-air mixture, depending on whether one looks at the gas stream upstream or downstream of the fuel injection valve, where fuel is added to the flowing air. In the area of the throttle element 10, the

Gas stream 30 into a main channel gas stream 31 and into a secondary gas stream 32. The main channel gas stream 31 flows through the connection 15, through the collector 16 and through the individual channels 18, 18 ', 18' ', 18' '' into the combustion chambers 6, 6 ', 6 '', 6 '' '. The secondary gas stream 32 flows through the

Secondary duct inlet 20, then through the secondary duct guide 22, through the turbulence collector 24 and through the turbulence air supply lines 26, 26 ', 26' ', 26' '', where the secondary gas flow 32 is preferably directed directly onto the inlet valve or the inlet valves of the combustion chambers 6, 6 ', 6' ', 6' '' is directed. Because, apart from the relatively small gas flow 30 in the idling area of the internal combustion engine 2, the secondary gas flow 32 is significantly smaller than the main duct gas flow 31, the arrow 32 is shown thinner than the arrow 31.

The throttle body 10 shown symbolically preferably comprises a throttle valve connector 34. The throttle valve connector 34 has a tubular wall 36 and a throttle valve channel on the inside of the wall 36 34c. In the throttle valve channel 34c there is a throttle valve 40, which is symbolically shown in FIG. 1 and is pivotably mounted with the aid of a throttle valve shaft 38. The

Throttle valve 40 can be adjusted with a mechanically and / or electrically operating actuator 42, which is also shown symbolically. The actuator 42 comprises, for example, an electric motor with which the throttle valve shaft 38 and the throttle valve 40 fastened to the throttle valve shaft 38 can be adjusted via a gear, not shown.

The actuator 42 can adjust the throttle valve 40 so that the free cross section for the main channel gas flow 31 is completely or almost completely closed. The throttle valve 40 can also be adjusted so that the air or the fuel-air mixture can flow largely unthrottled through the throttle valve duct 34c of the throttle valve connector 34 into the collector 16. By adjusting the throttle valve 40, the main duct gas flow 31 flowing through the duct 8 can be controlled.

In the embodiment shown in FIG. 1, the secondary duct inlet 20 is formed, for example, by a plurality of cross bores leading through the wall 36 of the throttle valve connector 34 into the throttle valve duct 34c. The transverse bores are arranged, for example, such that when the throttle valve duct 34c of the duct 8 is closed by the throttle valve 40, the transverse bores of the secondary duct inlet 20 are also closed. The transverse bores of the secondary duct inlet 20 can be closed by the peripheral surface of the disk-like throttle valve 40. If the throttle valve 40 has opened the free cross section through the channel 8, then the transverse bores of the Secondary channel inlet 20 is opened, and the secondary gas flow 32 can flow through the secondary channel 12 into the combustion chambers 6, 6 ', 6'',6'''. In the exemplary embodiment shown symbolically in FIG. 1 and embodied according to the invention, by adjusting one

Throttle valve 40 both the main channel gas flow 31 flowing through the channel 8 and the secondary gas flow 32 flowing through the secondary channel 12 can be controlled. The control of the gas flow 30 or the main channel gas flow 31 and the secondary gas flow 32 is possible together with the adjustable throttle element 10.

Because the transverse bores of the secondary duct inlet 20 leading through the wall 36 cannot be made arbitrarily large in the exemplary embodiment shown symbolically in FIG. 1, in particular because the throttle valve 40 is not arbitrarily thick, and because these transverse bores are not arranged over the entire circumference of the throttle valve duct 34c In the exemplary embodiment shown in FIG. 1, only a relatively small secondary gas flow 32 can be led through the secondary channel 12. Because the secondary gas stream 32 is often intended to be larger than is possible in the exemplary embodiment shown in FIG. 1, exemplary embodiments are shown in the following figures in which the control of a larger secondary gas stream 32 is also possible.

FIG. 2 shows, with a changed scale, a modified, particularly advantageous, preferably selected one

Embodiment, for the sake of clarity only the area of the throttle valve connector 34 is shown. In all figures, parts that are the same or have the same effect are provided with the same reference symbols. Unless otherwise stated or shown in the drawing, that which is mentioned and illustrated with reference to one of the figures also applies to the other exemplary embodiments. Unless otherwise stated, the details of the various exemplary embodiments can be combined with one another.

Roughly speaking, the throttle valve 40 has the shape of a flat, flat, approximately round disk. The throttle valve 40 has a first side surface 40a facing the channel inlet side 14 and a second second surface 40b facing the connection 15 or the combustion chambers 6, 6 ', 6' ', 6' ''. The throttle valve 40 has a circumferential surface 40c between the two side surfaces 40a, 40b.

In the embodiment shown in Figure 2, the secondary channel inlet 20 is essentially one

Bypass tube 44 formed. The throttle valve connector 34 with the wall 36 is an injection molded part. The secondary channel guide 22 of the secondary channel 12 or a first part of the

Auxiliary duct guide 22 is cast as a cavity in wall 36 of throttle valve connector 34. in the

Throttle valve connector 34 is provided with a transverse mounting hole 46 leading from the outside through the wall 36 into the channel inlet side 14. To the outside, the mounting hole 46 is closed with a plug 46a. The mounting hole 46 connects the

Secondary duct guide 22 with the duct inlet side 14. The bypass tube 44 is inserted into the mounting hole 46 on the side of the wall 36 facing the duct inlet side 14, and is fixed and sealed therein. The bypass tube 44 has one of the side surfaces 40a of the throttle valve 40 facing end 48. The bypass tube 44 is bent so that the end 48 extends approximately parallel to the longitudinal axis of the throttle valve connector 34 in the direction of the throttle valve 40. An end piece 50 is fitted into the end 48 of the bypass tube 44, sealed and fixed with respect to the bypass tube 44. The end piece 50 of the secondary duct inlet 20 of the secondary duct 12 is tubular and has an end face 20a facing the first side surface 40a of the throttle valve 40. Depending on the position of the, there is between the end face 20a and the side face 40a

Throttle valve 40, a more or less controllable secondary duct throttle cross section 52. Der

Auxiliary duct throttle cross section 52 depends on the position of throttle valve 40. Roughly considered, the secondary duct throttle cross section 52 is determined by the scope of the

End face 20a and from the distance from the end face 20a to the side face 40a of the throttle valve 40.

By providing the secondary channel guide 22 of the secondary channel 12 or the first part of the secondary channel guide 22 as

Cavity in the wall 36 of the throttle valve connector 34 results in considerable advantages in terms of production costs, weight or material requirements and the space requirements of the gas routing system 4.

The tubular throttle valve connector 34 has an inner lateral surface. This lateral surface forms the throttle valve channel 34c. Depending on the position of the throttle valve 40, there is a more or less large throttle cross-section 55 between the throttle valve channel 34c and the peripheral surface 40c of the throttle valve 40. The throttle valve 40 can be adjusted in the opening direction until the throttle valve 40 is parallel to the longitudinal direction of the throttle valve body 34. In the exemplary embodiment shown in FIG. 2, this is a rotation counter clockwise. In this position of the throttle valve 40, the throttle cross section 55 is opened to the maximum. By turning the throttle valve 40 in the closing direction, ie in FIG. 2 by turning the throttle valve 40 clockwise, the

Throttle cross section 55 in the end position of the throttle valve 40, its minimum or the throttle cross section 55 is completely closed. On the outside of the throttle valve connector 34, a closed position stop (not shown) is provided, against which the throttle valve shaft 38 comes to rest in the closed position. However, it can also be provided that the throttle valve 40 strikes the throttle valve duct 34c in the closed position; d. H. the throttle valve channel 34c serves as a closed position stop. So that the throttle valve 40 does not become jammed with the throttle valve duct 34c, the throttle valve 40 is set in the closed position, i. H. The throttle valve 40 is not adjustable in the closed position until the throttle valve 40 is transverse to the longitudinal axis of the throttle valve connector 34, but the throttle valve 40 comes into contact with the closed position stop at an angle of less than 90 ° relative to the longitudinal axis of the throttle valve connector 34 .

In the drawing, the throttle valve 40 is shown in a position in which the throttle valve 40 is slightly adjusted in the opening direction, i. H. The throttle valve 40 is shown in a position in which the secondary duct throttle cross section 52 and the throttle cross section 55 are slightly open.

If the throttle valve 40 is in the closed position, ie if the throttle valve 40 or the throttle valve shaft 38 abuts the closed position stop, then the throttle cross section 55 is complete or Nearly completely closed, and also the secondary duct throttle cross section 52 is at least almost completely closed. If the throttle valve 40 is adjusted in the opening direction by the actuator 42 (FIG. 1), starting from the closed position, that is to say in the exemplary embodiment shown in FIG. 2, rotation counterclockwise, then the secondary duct throttle cross section 52 is already at a slight rotation of the throttle valve 40 opened relatively wide, whereas the throttle cross section 55 is initially only opened relatively little. When the throttle valve 40 is rotated further in the opening direction, the secondary duct throttle cross section 52 is opened further, to such an extent that the throttling of the secondary gas flow 32 flowing through the secondary duct 12 essentially no longer takes place at the secondary duct throttle cross section 52, but within the secondary duct guide 22; at the same time, the throttle cross section 55 is increasingly opened.

When the throttle valve 40 rotates relatively slightly from the closed position, the secondary duct throttle cross section 52 is first opened relatively strongly, and the throttle cross section 55 is opened relatively weakly in the process. A relatively wide rotation of the throttle valve 40 in the opening direction then has virtually no influence on the secondary duct throttle cross section 52 and thus on the size of the secondary gas flow 32 flowing through the secondary duct 12, but by turning the throttle valve 40 then essentially only the through the main channel gas flow 31, which flows relatively broadly opening throttle cross section 55, is controlled.

So that the throttle valve 40 can properly reach its closed position stop, and in order to ensure that the end face 20a of the secondary duct inlet 20 is opposite the side face 40a, in particular in FIG The closed position of the throttle valve 40 is correctly aligned, wherein it is preferably provided that the throttle valve 40 in its closed position rests on the end face 20a of the secondary duct inlet 20 and thus also the secondary duct throttle cross section 52 is closed in the closed position, it can be provided that the end piece 50 is elastic is a resilient molded elastomer part on which the throttle valve 40 comes to rest shortly before reaching its closed position and then presses this elastomer part back until the throttle valve 40 reaches its closed position.

In a modification of the embodiment just described, the end piece 50 can also be a molded part which is plastically deformable during the assembly of the throttle valve connector 34. The end piece 50 is, for example

Thermoplastic that can be deformed by heating. The end piece 50 is installed in the longitudinal direction with oversize in the throttle valve connector 34. After installation, the end piece 50 is heated and the throttle valve 40 is simultaneously in the closing direction up to

Closed position stop pressed. Because the end piece 50 is deformed by the supply of heat, the end face 20a is pushed back somewhat, so that the end face 20a lies exactly against the side face 40a of the throttle valve 40 when the throttle valve 40 is in the

Closed position. The plastic reshaping of the end piece 50 also makes it easy to ensure that the end face 20a extends somewhat obliquely and thus the angle of attack of the throttle valve 40 is also optimally adapted in terms of angle. After the shaped part 50 has cooled down again, the position of the end face 20a is such that when the throttle valve 40 is in its closed position, the side face 40a of the throttle valve 40 lies just against the end face 20a. The embodiment just described can also be modified so that the end piece 50 is dispensed with, so that the end face 20a is located directly on the bypass tube 44. For the purpose of adapting the bypass tube 44 to the throttle valve 40, the entire bypass tube 44 can be produced from a thermoplastic material which can be deformed by the supply of heat. By heating the bypass tube 44 while simultaneously pressing the throttle valve 40, the bypass tube 44 is deformed somewhat, so that after the bypass tube 44 has cooled, the bypass tube 44 assumes the intended shape and length.

In order to be able to produce a relatively large secondary duct throttle cross section 52 with a moderate circumference of the end face 20a of the secondary duct inlet 20, the end 48 of the bypass tube 44 facing the throttle valve 40, viewed in the radial direction, preferably has a slight distance from the wall 36 of the throttle valve connector 34, so that the entire circumference the end face 20a can be available for the secondary duct throttle cross section 52. The bypass tube 44 projecting inward in the throttle valve connector 34 can be connected to the wall 36 of the throttle valve connector 34 via a narrow web 58 for reasons of stability.

FIG. 3 shows a further, preferably selected, particularly advantageous exemplary embodiment.

In the exemplary embodiment shown in FIG. 3, the throttle valve 40 is installed in the throttle valve connector 34 such that the throttle valve 40 is not in its closed position, as shown in FIG. 2, but is located transversely to the longitudinal axis of the throttle valve connector 34. In this closed position of the throttle valve 40 there is over the circumference the throttle valve 40 has a narrow gap between the circumferential pool 40c of the throttle valve 40 and the throttle valve channel 34c of the throttle valve connector 34. It is preferably provided that the end face 20a on the bypass tube 44 also serves as a closed position stop for the throttle valve 40. In this embodiment, the throttle valve 40 comes to rest on the end face 20a in its closed position. The end face 20a determines the closed position of the throttle valve 40.

When the throttle valve 40 is adjusted in the opening direction, as explained with reference to FIG. 2, the secondary duct throttle cross section 52 also opens relatively strongly in the exemplary embodiment according to FIG. 3. Because the throttle valve 40 is in its closed position substantially perpendicular to the longitudinal axis of the throttle valve connector 34 in FIG. 3, when the throttle valve 40 is actuated in the opening direction, the throttle cross section 55 initially opens less strongly than in the exemplary embodiment shown in FIG. 2 with a small adjustment angle.

Because in the exemplary embodiment shown in FIG. 3 the closed position for the throttle valve 40 has to be set less precisely than in the exemplary embodiment shown in FIG. 2, the exact position of the end face 20a in the exemplary embodiment according to FIG. 3 must also be set less precisely than in the case of the exemplary embodiment according to FIG. 2. This simplifies the manufacture of the gas routing systems 4.

FIG. 4 shows a further, preferably selected, particularly advantageous exemplary embodiment. In order to achieve a smaller opening of the throttle cross-section 55 compared to FIG. 3 when adjusting the throttle valve 40 in the opening direction with a small adjustment angle, the throttle valve channel 34c in FIG. 4 is not cylindrical as in FIG. 3, but in FIG. 4 the throttle valve channel 34c is in approximately dome-shaped. As a result, the opening of the throttle cross-section 55 can be further delayed when the throttle valve 40 is adjusted in the opening direction, which facilitates the coordination of the throttle cross-section 55 and the secondary duct throttle cross-section 52 with one another and also the combustion process in the combustion chambers 6, 6 ', 6'',6'''' Favorably influenced in the lower idling range of the internal combustion engine 2, because due to the spherical shape of the throttle valve duct 34c with a small adjustment angle of the throttle valve 40 in the lower idling range, a relatively large amount of air with high flow velocity through the relatively small cross section of the secondary duct 12 into the combustion chambers 6, 6 ', 6'' , 6 '''flows, while no or almost no air flows in through the relatively large cross section of the channel 8. Because of the desired high flow velocity when the secondary gas flow 32 flows into the combustion chambers 6, 6 ', 6'',6''', the cross section of the secondary duct 12 is particularly at the transitions into the combustion chambers 6, 6 ', 6'', 6 ''', especially small.

The idling of the internal combustion engine 2 is regulated both by the opening or closing throttle cross section 55 between the throttle valve duct 34c and the throttle valve 40 and also by the opening or closing at the same time

Secondary throttle cross-section 52 between the end face 20a of the secondary duct 12 and the side surface 40a of the throttle valve 40. The throttle cross-section 55 and the secondary-channel throttle cross-section 52 contribute together Control of the performance of the internal combustion engine 2. The sum of the throttle cross section 55 and the

Auxiliary duct throttle cross section 52 together, but depending on the position of throttle valve 40 with different proportions, determine the performance of internal combustion engine 2.

Claims

claims

1. Gas routing system of an internal combustion engine with at least one combustion chamber, with a channel (8) for supplying a main channel gas flow into the combustion chamber, with an adjustable throttle element (10, 40) in the channel (8) for controlling the main channel gas flow and with a secondary channel (12) for supplying a secondary gas flow into the combustion chamber, characterized in that the adjustable throttle member (10, 40) is provided for controlling the secondary gas flow (32).

2. Gas routing system according to claim 1, characterized in that the secondary gas stream (32) is a secondary air stream.

3. Gas supply system according to one of the preceding claims, characterized in that the secondary duct (12, 26, 26 ', 26' ', 26' '') for supplying the secondary gas stream (32) into the combustion chamber (6, 6 ', 6' ', 6' '') with high flow velocity.

4. Gas supply system according to one of claims 1 to 3, characterized in that the throttle member (10, 40) in a throttle valve channel (34c) is pivotally mounted throttle valve (40).

5. Gas routing system according to claim 4, characterized in that the secondary duct (12) branches off from the throttle valve duct (34c).

6. Gas routing system according to claim 4 or 5, characterized in that the secondary channel (12) at one of the throttle valve (40) at least partially closable secondary channel inlet (20, 20a) begins.

7. Gas routing system according to claim 6, characterized in that the secondary duct inlet (20, 20a) from a side surface (40a) of the throttle valve (40) is at least partially closable.

8. Gas routing system according to claim 6 or 7, characterized in that the secondary duct inlet (20, 20a) forms a closed position stop (20a) for the throttle valve (40).

9. Gas routing system according to one of claims 4 to 8, characterized in that the throttle valve channel (34c) in the region of the throttle valve (40) is dome-shaped.

10. Gas routing system according to one of claims 6 to 8, characterized in that at least a portion of the secondary duct inlet (20, 44, 50) is plastically deformable for reasons of adjustment.