DE3244927A1 - Supercharged internal combustion engine - Google Patents

Abstract

In the case of an internal combustion engine supercharged by an exhaust gas turbo-charger, a bypass line is laid between the charge air manifold and the exhaust gas manifold. A bypass valve is connected into the said bypass line, which valve comprises two valve elements connected to one another by way of a spacer. In the bypass line a partition wall arranged at right angles to the axis of the latter and with openable and closable passage bore is assigned to this bypass valve. The bypass valve is mechanically pivoted on operating means arranged outside the bypass line, to which control means are assigned, which operate as a function of the charge air pressure or another actual value and are capable by way of the operating means of acting on the bypass valve in such a way that when the engine is in operation the bypass line   a) is shut off when idling,   b) from idling up to approximately 25% of the full load is increasingly opened to full admission and remains open up to approximately 50% of the full load, and thereafter   c) is increasingly closed up to approximately 60% of the full load, and then   d) is closed in the upper load range up to full load.

Description

PB 3193/1601 - X -

Supercharged internal combustion engine

The present invention relates to an internal combustion engine charged by means of an exhaust gas turbocharger a device for the targeted opening and closing of a blow-by line and other features accordingly the preamble of claim 1.

From EU-A1 00 22 584 an internal combustion engine charged by means of an exhaust gas turbocharger is known which has a device for the targeted opening and closing of a blow-in line. The latter branches off from the Charge air manifold and opens into the exhaust manifold in front of the Trubine. The opening and closing the blow-by line is controlled by a blow-by valve, which crosses the axial direction of the charge air collecting line works and cooperates with a valve seat incorporated in the wall. The blow-by valve carries a control piston, on the front side of which a compression spring is effective in the valve opening direction · On its rear side, the pressure piston is inside an associated pressure housing acted upon by a pressure medium effective in the valve closing direction, which is in its own control circuit provided. The latter comprises control means by which the pressure acting on said pressure piston

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is changeable. As such control means, several throttle valves are specified, which depending on the Working charge air pressure. According to a variant (FIG. 3), two throttle valves form a double cone valve summarized, the shaft of which is rigidly connected to a piston. This piston in turn is on its front side by the force of a compression spring and on its rear side in a pressure chamber by the Pressure supplied charge air is pressurized. As a mode of action this device is now given the following. If the charge air pressure is low, one valve cone should be used shut off the mass flow of the fluid used as the working medium, so that the blow-through valve is then closed and can prevent exhaust gas recirculation. With increasing load, said one valve cone should be lifted from its seat against the force of the compression spring, which then causes the blow-by valve is opened; the latter because the pressure acting on its pressure piston is then lower than before is. As the load continues to increase, the other, opposite valve cone narrows the flow cross-section until it closes completely before reaching full load, so that accordingly the blown air flow is to be continuously throttled and finally stopped completely.

This known solution requires, on the one hand, a control medium with a relatively high pressure constancy, which is appropriate Means of readiness required. On the other hand, the known solution requires in addition to the actual one Umblaseventil a considerable effort to control it.

In contrast, it is the object of the invention to provide an internal combustion engine charged by means of an exhaust gas turbocharger

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machine of the type defined at the outset to assign a device that enables a targeted opening and closing of the Umblaseleitung allows for an optimal operating behavior of the internal combustion engine in all load ranges and also manages with a comparatively low component cost.

This task is carried out with an internal combustion engine the means specified in claim 1 solved. Advantageous further developments and refinements of this solution are characterized in the subclaims.

Details of the invention and advantages thereof emerge from the following description of several Exemplary embodiments shown in the drawing. In the drawing show:

1 is a schematic representation of a supercharged internal combustion engine according to the _o invention,

Fig. 2 is a diagram showing the different passage cross-sections of the blow-by line are visible over the entire load range of the machine,

3 shows a first exemplary embodiment in a highly schematic manner a device for the targeted opening and closing of a blow-in line,

4 shows a second exemplary embodiment in a highly schematic manner a device for the targeted opening and closing of a blow-in line,

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FIG. 5 shows, in a highly schematic manner, a third exemplary embodiment of a device for the targeted opening and closing of a blow-in line.
5

For the sake of clarity, parts that are the same or that correspond to one another are also shown in the various figures the same reference numerals are drawn.

In FIG. 1, a turbocharger 1 is charged by means of an exhaust gas turbocharger Internal combustion engine 2 shown. An exhaust manifold is connected to the turbine 3 of the exhaust gas turbocharger 1 4 connected, into which the exhaust gas outlets coming from the individual cylinders open. To the compressor 5 of the exhaust gas turbocharger 1 is a charge air manifold 6 connected, in which a charge air cooler 7 is switched on and from which to the individual Branch inlet lines leading to cylinders. With a total of 8 a blow-by line is designated, which branches off from the charge air manifold 6 in the area between compressor 5 and charge air cooler 7 and is short opens into the exhaust manifold 4 in front of the turbine 3. The blow-by line 8 enables, controlled by an in they switched on blow-by valve 9 - see Figures 3 to 5 - a blow-around of compressed air to increase of the mass flow passing through the turbine 3.

According to the invention, the blow-through valve 9 consists of two axially spaced apart valve bodies 10 and 11, which are connected to one another via a spacer with a smaller diameter. The latter has a cylindrical one Middle part 12 and goes at its ends with a concavely curved contour 13, 14 in each case conical valve seat ring surface 15 and 16 over. The two Valve seat ring surfaces 15, 16 are inclined towards one another and preferably each at an angle of

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45 ° to the bypass valve axis. Each valve body 10
or 11 advantageously has a dome 17, 18 designed to promote flow on its respective outer side.

According to a further feature of the invention

This blow-by valve 9 designed in this way in the blow-through line 8 is a transverse to the axis thereof
Partition wall 19 with a through hole 20 is assigned, at the respective end of which a correspondingly adapted conical valve seat 21 or 22 is connected to a valve seat ring surface 15, 16 of the blow-by valve 9.

According to a further feature of the invention, the blow-by valve 9 is mechanically articulated to actuating means arranged outside the blow-by line 8 and can be axially pushed back and forth by this. the
said actuating means are referred to further below

3 to 5 explained in more detail.

The said actuating means are, accordingly
a further feature of the invention, also explained in more detail below with reference to FIGS. 3 to 5

Assigned control means that work as a function of the charge air pressure or another manipulated variable derived. These tax funds are able to use the
Actuating means to act on the Umblaseventil 9 that the Umblaseleitung 8 - as from the

Diagram of Fig.2 can be seen - when operating the
Internal combustion engine 2

a) is locked when idling,

b) increasing from idling to around 25% of full load
can be opened up to full passage and up to

about 50% of the full load remains open,

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c) to the upper limit of the middle load range -

about 60% of the full load - is increasingly controllable,

d) is closed in the upper load range and remains closed until full load.

These variable cross-sectional ratios to be controlled are shown in FIG. 2 by the solid line 23. The passage cross-section of the blow-by line 8 is given by an annular surface which on the one hand by the spacer of the Umblaseventiles with its cylindrical central part 12 and its curved Contours 13, 14 and the conical valve seat ring surfaces 15, 16 and on the other hand through the passage bore 20 and the two valve seats 21, 22 in the partition 19 is limited. The maximum flow area the blow-by line 8 is given when the blow-by valve 9 is approximately symmetrical to the partition 19 stands, i.e. the two valve seat ring surfaces 15 and 16 each equidistant from the associated valve seat 21 and 22 are removed. This circular ring area becomes smaller, the further the spacer with one of its curved contours 13 or 14 into the Passage hole 20 is immersed.

In internal combustion engines that, at least for a short time, must be operable in the overload range - like ship propulsion machines - it proves to be advantageous to train the control means or to provide such additional control means that the blow-by line 8 when the machine is operated in the overload range (up to around 120% of full load) from the closed State can be opened again in such a way that the pressure of the machine in this power range supplied charge air at least approximately constant

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hold remains. This function is marked in FIG. 2 by the dash-dotted line 24.

That area is advantageously the blow-by line 8, in which the blow-by valve 9 is arranged, formed by two pipe bends 25 and 26 which are attached to the further parts 27, 28 (Fig.1) of the blow-in line are flanged, composed of a U-shaped pipe bend of at least 120 °, preferably 180 ° and each have a flange 29 and 30 for their connection, between which flanges 29, 30 the Partition 19 is clamped. Both pipe bends 25, 26 each wear slide bearings 31, 32 with one another aligned through bores 33, 34, in which a rod 35 is mounted axially displaceably. These Rod 35 carries the blow-through valve 9 already described in its details, is perpendicular to Partition 19 and coaxial with the through hole 20 and is coupled to the above-mentioned actuating means outside of the blow-in line 8, to which further has been received at the back. The rod 35 is within the blow-by line 8 to avoid Corrosion effects of flexible corrugated tubes 36, 37 surrounded. The blow-by valve 9 and the rod 35 form an assembly that is composed of several individual parts screwed together.

In the embodiment according to Figure 3 is the blow-by valve 9 is assigned a pressure cell 38, which is primarily fastened to the slide bearing 31, as the actuating means.

The latter comprises in its two-part housing 39 a rolling membrane 40, which at its edge area between clamped in both housing parts and - supported by a pressure plate 41 - at one end of the inside the pressure cell 38 is attached to the elongated rod 35 and together with wall parts of the device

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housing 39 limits a control pressure chamber 42. This pressure cell 38 are a control means beyond the ümblaseventiles 9 at the other end of the rod 35 attacking Assigned to the spring system 43 and a control line, which is a connection from a flow-wise located in front of the partition 19 part of the blow-by line 8 to the control pressure chamber 42 and so the latter constantly with the prevailing charge air pressure applied. The spring system 43 is in a housing, preferably fastened to the slide bearing 32 capsuled; it consists of several - here two - tailored to the charge air pressures to be controlled Helical compression springs 46, 47 which are coupled to one another via specially designed guide and connecting sleeves 48, 4 9 are as well as a pressure plate 50 attached to the end of the rod 35 on the latter act. The spring system 43 is in its compressive force via a protruding from the housing 45 Adjusting screw 51 adjustable. With these control means and the charge air pressure as a reference variable opening and closing of the blow-in line 8 corresponding to that entered in FIG Controllable curve. In addition, the function according to the dash-dotted line To be able to control line 24 of Figure 2, a compressed air source 52, for example a starting air bottle, one leading from this compressed air source 52 to the pressure cell 38 and there, with a second pressure chamber 53 on the other side of the control pressure chamber delimited by the rolling diaphragm 40 42 connected compressed air line 54, furthermore a switched on in the latter Control valve 55 and a control device 56 assigned to it are provided, the latter being an as required Open the compressed air line 54 is able to control.

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The device shown in Figure 3 operates as follows. When the internal combustion engine 2 is idling, the Umblaseleitung 8 closed, the Umblaseventil 9 with its valve seat ring surface 16 on the associated The valve seat 22 rests against the partition 19 and is held in this position by the spring system 43 remain; the latter until the machine is to be accelerated. As soon as the machine is out of the If the idle speed is to be accelerated out, the fuel supply is increased. This enlarged the exhaust gas mass flow that can be fed to the turbine 3 and flowing through it, with the result that more charge air is conveyed by the compressor and it is also compressed more highly. This charge air 5 The pressure increase acts via the control line 44 and in the pressure chamber 42 in the pressure cell 38 via the rolling diaphragm 40 as well as the pressure plate 41 directly on the rod 35, whereby then at about 10% boost pressure, based on the boost pressure prevailing at full load, the counterforce of the spring system 4 3 overcome and the bypass valve 9 is moved (to the right in the plane of the drawing). The latter causes the blow-by line 8 after lifting the valve seat ring surface and its associated valve seat 22 for a small one Cross-section is released and thus already a certain proportion of compressed charge air over the blow-by line 8 can be blown to the exhaust manifold 4, which in turn results in the the turbine penetrating mass flow increased.

The latter, in turn, causes the pressure of the compressed charge air to increase, so that too Umblaseventil 9 moved further and further and the Umblaseleitung up to the full passage area is turned on. This process takes place in a range from idling to around 25% of full load, at which operating point then approximately the full

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PB 3193/1601

lass cross-section is given and thus also the largest amount of compressed air from the charge air manifold 6 can be blown to the exhaust manifold 4. This full passage cross-section remains due to of the cylindrical central part 12 received on the spacer of the blow-by valve up to about 50% of the full load; only towards the upper limit of the middle load range - around 60% of full load - does the passage cross-section become and thus the amount of air to be blown is smaller again; the latter because of the further increasing charge air pressure the blow-by line through the curved contour 13 of the spacer and the conical valve seat ring surface 15 is increasingly closed again will. From a certain charge air pressure, which is around 30 to 40% of that prevailing at full load Charge air pressure is and is given at an output of about 60% of full load, is the bypass line blocked again, in this case by the valve seat ring surface 15 of the valve seat 21 Umblaseventiles 9. In the upper load range up to full load, the recirculation line 8 remains blocked. For the case that the internal combustion engine has said additional control means 52, 54, 55, 56 has, the blown line 8 can when operating the Machine can be opened again in the overload range, in that compressed air in the second pressure chamber 53 is initiated in the pressure cell 38. This results in a counter pressure in this pressure chamber 53, by which the blow-by valve 8 is again shifted somewhat to the left in the plane of the drawing and thus the valve seat ring surface 15 from the associated valve seat 21 is lifted off a little again and compressed charge air then flows back to the exhaust manifold 4 can. The compressed air supply to the pressure chamber 5 3 is

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PB 3193/1601 - y (- *,

controlled in such a way that the pressure of the charge air supplied to the machine in this power range remains at least approximately constant.

In the event of a decline in performance, the control and functional processes described above run in opposite directions Direction off.

In the embodiment according to Figure 4 is the Umbase-ο valve 9 as actuating means assigned to an electric servomotor 5 7, which with its pinion 58 in a Toothing 59 engages the correspondingly elongated rod 35. The servomotor 57 sits on a bracket 60 which is attached to the outside of the sliding bearing 31 and also carries a bearing bush 61 which forms an abutment for the extended part of the rod. The servomotor 57 is used as a control means, for example associated with an electronic control unit 62 comprising a microprocessor, which is shown in FIG Depending on the charge air pressure and / or another manipulated variable derived works and corresponding Able to output control signals to the servomotor 57. These control signals result from the processing of signaled actual values in a processor-internal program that is designed in this way is that by appropriate control of the servomotor 5 7 practically the same influence the bypass valve 9 is possible as in the embodiment according to Figure 3 by the control given there and actuating means.

Similar relationships as in Figure 4 are also in the Solution given according to Fig.5. Here, the bypass valve 9 is a hydraulic actuating means Servomotor 63 assigned. The latter includes one

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Control piston 64 on the correspondingly elongated rod 35 and a housing 65 with two on both sides of the control piston 64 arranged pressure chambers 66 and 67. The housing 65 is preferably on the sliding bearing 31 attached outside. The two pressure chambers 66 and 67 are via hydraulic control lines 68, connected to a hydraulic control circuit 70, which also here as a control means, for example, an electronic control unit 71 comprising a microprocessor is assigned. This control unit 71 works in the same way as that control unit 62, which is assigned to the electric servomotor 5 7 of the embodiment of Figure 4, on the basis signaled actual values by processing them in a processor-internal program. The latter is also designed here so that by appropriate influence on the hydraulic control circuit 70 and thus the hydraulic servomotor 63 practically the same influence on the blow-by valve 9 is possible, as in the embodiment according to FIG. 3 by the control and actuation means given there. Since the The manner in which the blow-by line 8 is opened and closed by the blow-through valve 9 in the exemplary embodiments 4 and 5 is the same as in the embodiment of FIG Reference is made to the relevant functional explanations, which also apply accordingly to the exemplary embodiments according to Fig. 4 and 5 apply. In the exemplary embodiments according to FIG. 4 and: 5, only the Control forces required to move the blow-by valve from other components upset.

Claims (1)

PB 3193/1601 Patent claims: Internal combustion engine charged by means of an exhaust gas turbocharger with a device for targeted charging and control of a branching off from the charge air manifold and into the exhaust manifold opening Umblaseleitung, which, controlled by a Umblaseventil switched into it, a Allows compressed air to be blown around to increase the mass flow passing through the turbine, characterized, - That the bypass valve (9) consists of two valve bodies (10, 11), which have a smaller diameter Spacer are connected to each other, which has a cylindrical central part (12) and at its ends in each case with a curved contour (13, 14) into a conical one Valve seat ring surface (15, 16) merges, - That this Umblaseventil (9) in the Umblaseleitung (8) is assigned a ⁵ transverse to the axis of the partition (19) which has a through hole (20) and at each end of the same one, a valve seat ring surface (15,16) of the Umblaseventiles (9) has associated conical valve seat (21, 22), - That this blow-by valve (9) is arranged mechanically on outside the blow-by line (8) Actuating means (38, 39, 40, 41, 42; 57, 58, 59; 63, 64, 65, 66, 67, 68, 69, 70) are articulated and can be moved axially back and forth through this, - that said actuating means control means (43, 44, 45, 46, 47, 48, 49, 50, 51) are assigned, depending on the charge air pressure or otherwise derived PB 3193/1601 - 2 - Working manipulated variable, and are able to act on the blow-by valve (9) via the actuating means in such a way that the blow-by line (8) during operation of the machine
a) is locked when idling, b) increasing from idling to around 25% of full load can be opened up to full passage and open up to about 50% of full load remain, c) to the upper limit of the mean load range ches - around 60/6 full load - is increasingly controllable, d) is closed in the upper load range and remains closed until full load. 2. Supercharged internal combustion engine according to claim 1, characterized in that the control means themselves are designed in this way or in addition such Control means (52, 53, 54, 55, 56) are provided that when the machine is operating in the overload range a renewed opening of the recirculation line (8) is possible in such a way that the printing is to be fed to the machine in this language area Charge air remains at least approximately constant. 3. Supercharged internal combustion engine according to the preceding Claims, characterized in that that area of the blow-in line (8) in which the bypass valve (9) is arranged by two pipe bends (25, 26) are formed, which are attached to the other parts (27, 28) of the blow-in line (8) are flanged, composed of a U-shaped pipe bend of at least 120 °, BAD ORfGINAL PB-3193/1601 - 3 - preferably 180 °, and each have a flange (29, 30) for their connection, between which flanges (29, 30) the partition (19) is clamped.
5 4. Supercharged internal combustion engine according to claim 3, characterized in that the two pipe bends (25, 26) carry plain bearings (31, 32) with through bores (33, 34) aligned with one another, in which one is arranged perpendicular to the partition (19) and coaxially to the through hole (20), the bypass valve (9) carrying rod (35) is axially displaceable, which rod (35) outside of the blow-in line (8) to said actuating means (38, 39, 40, 41, 42; 57, 58, 59; 63, 64, 65, 66, 67, 68, 69, 70) is coupled. 5. Supercharged internal combustion engine according to an or several of the preceding claims, characterized in that the blow-through valve (9) as Actuating means is associated with a pressure cell (38) which has one end in a housing (39) has a rolling membrane (40) fastened to the rod (35) and supported by a pressure plate (41), which, together with wall parts of the housing (39), delimits a control pressure chamber (42). 6. Supercharged internal combustion engine according to claim 5, characterized in that the pressure cell (38) a control means acting on the other side of the blow-through valve (9) at the other end of the rod (35) Spring system (43) with several, tailored to the charge air pressures to be controlled Helical compression springs (46, 47) and a control line (44) are assigned to establish a connection BATH ORIGINAL PB 31 93/1 601 - 4 - of one in front of the partition (19) in terms of flow located part of the blow-by line (8) to the control pressure chamber (42) of the pressure cell (38). 7. Supercharged internal combustion engine according to claim 6, characterized in that the spring system (43) encapsulated in a housing (45) and with respect to an adjusting screw (51) protruding from this its compressive force is adjustable. 8. Supercharged internal combustion engine according to the claims 2, 5, 6 and 7, characterized in that, as additional control means, a compressed air source (52), one leading from this to the pressure cell (38) and there with a second pressure chamber (53) beyond the control pressure chamber (42) bounded by the rolling diaphragm (40) Compressed air line (54), furthermore a control valve (15) connected to the latter and one of these associated control device (56) are provided, the latter opening as required the compressed air line (54) is able to control. 9. Supercharged internal combustion engine according to one or several of claims 1 to 4, characterized in that the blow-by valve (9) as an actuating means an electric servomotor (5 7) is assigned which with its pinion (78) in a toothing (59) engages on the correspondingly elongated rod (35). 10. Supercharged internal combustion engine according to one or several of claims 1 to 4, characterized in that the blow-by valve (9) as an actuating means a hydraulic servomotor (63) lWSÄL U "« iac · * · PB 3193/1601 - 5 - is assigned, which has a control piston (64) on the correspondingly elongated rod (35) and a Housing (65) with two pressure chambers (66, 67) arranged on both sides of the control piston (64), which the latter via hydraulic control lines (68, 69) to a hydraulic control circuit (70) are connected includes. 1 . Supercharged internal combustion engine according to the claims and 10, characterized in that the electrical or hydraulic servomotor (57 or 63) as control means, an electronic control unit (62 or 71) is assigned to a microprocessor by means of the signaled charge air pressure and / or another manipulated variable derived from the program, the desired opening and Closing characteristics of the blow-by valve (9) is controllable. 12. Supercharged internal combustion engine according to one or several of claims 1 to 4, characterized in that the blow-through valve (9) and the Rod (35) form an assembly which is composed of several individual parts screwed together is.