EP1347157B1 - Gas-dynamic pressure wave supercharger - Google Patents

Abstract

Gas dynamic pressure wave machine has a line (54, 57) leading from a high pressure exhaust gas channel (31) to a low pressure exhaust gas channel (35). The line is regulated via a suitable device to maintain the pressure wave process. A part of the exhaust gas stream from the high pressure exhaust gas stream is led from the high pressure channel into an enlarged section (53) before further exhaust gas is led from the high pressure exhaust gas channel to the low pressure exhaust gas channel. Preferred Features: The enlarged section consists of a recess or extension having a device for changing the enlargement without forming bar. The width of the opening of the line can be changed using an adjusting part. The adjusting part is regulated using a microprocessor.

Description

The invention relates to a gas-dynamic Pressure wave machine according to the preamble of claim 1.

Such a gas-dynamic pressure wave machine is in WO 99/11914 of the same applicant described in detail and it is referred to.

In a gas-dynamic pressure wave machine for charging of internal combustion engines, which with four channels without used additional control devices in the form of pockets is, the process vote is only on one operating point tuned to the internal combustion engine. One speaks in this Connection from the design point of the pressure wave machine. By Application of so-called pockets in the housing walls, the Pressure wave machine tuned insensitive and the load-speed and volume range are greatly expanded. Of the Disadvantage of this method is an increase in losses due to the secondary processes taking place in the pockets, such as Inflow and outflow of the gases and the generation of Pressure and expansion waves through the pockets.

The transition from the so-called primary process to the Main process, coordinated process, causes disturbances in the Pressure wave process, which rinse dips and thus Areas of high recirculation of exhaust gas in the charge air cause. To be able to work in these areas, as well as in To avoid increased recirculation, must be an inflow to the Gas pocket, either as milled threshold or as controlled inflow e.g. according to CH-A-681 738 become.

Made of e.g. EP-B-885 352 discloses a method which it in a standard pressure wave machine with a so-called Waste gate allows excess high pressure exhaust gas, e.g. in the partial load range of the internal combustion engine, from Redirect high-pressure exhaust gas channel in the low-pressure exhaust duct and thus to lower the pressure in front of the pressure wave machine. Then the pressure drops after the pressure wave machine and thus the pressure in the intake passage of the internal combustion engine. However, opening the waste gate does not existing inflow to the gas pocket, in addition to blowing off Excess high pressure exhaust gas a collapse of the Flushing the rotor of the pressure wave machine. This causes in the worst case even a recirculation of the exhaust gas in the intake duct of the internal combustion engine and in any case a significant deterioration of the Compression efficiency of the pressure wave machine.

Made of e.g. the aforementioned CH-A-681 738 and EP-A-0 210 328, a method is known from which the of Internal combustion engine exhausted exhaust via a branching inflow to the gas pocket of the pressure wave machine a blow-off of the excess high-pressure gas in the Gastaschen allows and thus improve the Compression efficiency through the improved flushing of the Rotor is achieved.

The aforementioned WO 99/11914 again prevents the continuous use of a gas pocket with their losses, and eliminates the web disturbing the pressure wave process between the exhaust duct and the gas pocket when open Inflow, as well as through the wiring to the gas pocket occurring energy losses in the form of flow and Temperature losses and limitations in the Design of the other channels.

In all these methods, however, is disadvantageous that in Part load range of the internal combustion engine by blowing off the excess high-pressure gas in the gas pockets or the Enlargement of the high-pressure exhaust gas duct, the pressure in the High-pressure exhaust duct still remains too high, that is, the thus adjusting negative pressure difference Charge air outlet from the pressure wave machine opposite High-pressure exhaust gas inlet into the pressure wave machine causes increased output losses of the internal combustion engine and thus worse consumption values in the partial load range of Combustion engine. At the same time, however, remains through the insufficient lowering of the exhaust gas pressure over the Pressure wave process an unwanted boost pressure after the Pressure wave machine exist. When gasoline engine with his Load control via the throttle now has this higher Pressure in the intake still by the partially closing the throttle to be reduced, which causes further losses in the form of throttle losses.

The methods of CH-A-681 738, EP-A-0 210 328 and WO 99/11194 for blowing off the excess high-pressure gas have the disadvantage that over a wide range of Internal combustion engine characteristic field, but mainly in the Part load report of the internal combustion engine, not enough can be blown off, that is, the pressure before the Pressure wave machine is at a higher level than the Pressure after the pressure wave machine. This gives a negative pressure difference also over the internal combustion engine and thus increased output of the piston of the Combustion engine. When gasoline engine must by the Quality control even the throttle partially closed to the over the pressure wave process resulting pressure in the intake port of the engine too to reduce. This has further losses in the form of Throttle losses result. Both loss factors affect each other negative on the partial load consumption of the internal combustion engine out.

From US-A1-4,488,532 (= EP 0 080 741 B1) is a Pressure wave machine according to the preamble of claim 1 known. This machine will be an adaptation of the Altitudes of the vehicle, for example when driving on pass roads or the like by means of a regulation of Flow of exhaust gas from the high pressure exhaust duct to Low pressure exhaust duct by means of a flap control causes, with a portion of this exhaust gas with open bypass line passed into a rotor side open gas pocket becomes. This will provide the required low pressure flush maintained of the rotor. Purpose and purpose of this Exhaust system is the compensation of a height correction means a bypass adjustment.

It is opposite this known and described state the technology object of the present invention, a Specify gas-dynamic pressure wave machine, which over the entire area of the map of an internal combustion engine and especially in the partial load range, improved fuel consumption and higher performance. This task is with the gas-dynamic pressure wave machine according to claim 1 solved.

Further advantages and embodiments are in the dependent claims defined.

Figur 1

zeigt schematisch einen abgewickelten zylindrischen Schnitt durch die Zellen eines Rotors einer Druckwellenmachine gemäss Stand der Technik,

Figur 2

zeigt schematisch ein Detail eines abgewickelten zylindrischen Schnittes durch die Zellen des Rotors der Figur 1,

Figuren 3, 3A

zeigen schematisch ein Detail eines abgewickelten zylindrischen Schnittes durch die Zellen eines Rotors gemäss Erfindung bei geschlossenem und offenem Schieber,

Figuren 4, 4A

zeigen eine Variante zur Ausführung nach den Figuren 3, 3A,

Figuren 5, 5A

zeigen eine Variante zur Ausführung nach den Figuren 3, 3A, und

Figuren 6, 6A

zeigen eine Variante zur Ausführung nach den Figuren 4, 4A.

The invention will be explained in more detail below with reference to drawings of exemplary embodiments.

FIG. 1

shows schematically a developed cylindrical section through the cells of a rotor of a pressure wave machine according to the prior art,

FIG. 2

1 schematically shows a detail of a developed cylindrical section through the cells of the rotor of FIG. 1, FIG.

FIGS. 3, 3A

show schematically a detail of a developed cylindrical section through the cells of a rotor according to the invention with the slide closed and open,

FIGS. 4, 4A

show a variant of the embodiment according to FIGS. 3, 3A,

FIGS. 5, 5A

show a variant of the embodiment of Figures 3, 3A, and

FIGS. 6, 6A

show a variant of the embodiment of Figures 4, 4A.

For the sake of simplicity, there is one in the settlements Pressure wave cycle shown and described. The Invention, however, is on the number of pressure wave cycles independently; It can be used for pressure wave machines with only one Cycle or with two or more cycles.

FIG. 1 shows a development of the rotor of FIG gas dynamic pressure wave machine 2 with the Combustion engine 1, the high pressure exhaust duct 3 and the Low-pressure exhaust duct 4 including the purge air S, the rotor 6 with the individual cells 18, the fresh air inlet 8, or low pressure fresh air supply channel 14, the high pressure charge air duct 10, which merges into the charge air duct 11 and leads to the internal combustion engine 1.

As already mentioned, is the Process tuning to the combustion engine at the Use of the four channels without additional Control devices only on one operating point of Combustion engine possible. This one speaks in this Connection from the design point of the pressure wave machine. By the use of pockets in the housing wall can be the Pressure wave machine made less sensitive to voting and thus the load, speed and volume range be greatly expanded. In the course of many years of development from such pressure wave machines have been milled various pockets in the housing wall 24, z. B. a compression pocket 19, an expansion pocket 20 and a gas pocket 21 with web 21A, whose applications the Skilled in the art. When using such Pockets it is a disadvantage that the pressure wave process in uncoordinated map area via ancillary processes which is never optimal efficiency result.

Normally, the pressure wave machine with known Methods, such as characteristics method and Design calculations, by the combustion engine manufacturer desired point, usually at nominal speed of the Motors, optimally designed, this being either without pockets or with one or two or all three pockets can happen.

In Figure 2, based on Figure 1, a high-pressure exhaust passage 3, which does not provide any means for Influencing the high-pressure exhaust gas stream has. The rotor 6 with its cells 18 is shown in unwound form and one also recognizes the gas housing 24, the high pressure exhaust passage 3 and the low pressure exhaust duct 4.

Further, in Figure 2, the gas pocket 21 located as For example, in the aforementioned CH-A-681 738 is available. This gas pocket and especially the there necessarily existing web 21 A between the high-pressure exhaust passage and gas pocket generates additional losses, especially if at low to medium speeds, Temperatures and flow rates usually blow off is unnecessary.

In Figures 4, 4A and 5, 5A of WO 99/11914, to the is expressly referred to, is an influence of the High-pressure exhaust gas ducts by means of a slide schematically shown.

Figures 3 to 6a of the present invention relate also on the influence of the high pressure exhaust stream. In Figures 3 and 3A of the present Invention is the unwound rotor 40 with the cells 41st and, in contrast to the gas pocket 21 in FIG. 2, a serving as a gas pocket recess 48 in the gas housing 34th provided, which are changed by a slider 49 can, as indicated by the arrow 50. In FIG 3A, the slider 49 is fully engaged in the arrow direction, so that the high-pressure exhaust duct is widened without a Footbridge has emerged. By a suitable and for a Professional calculable control, the slider so be moved, that the high-pressure exhaust duct masses widened until the pressure in it has dropped so far is that generated by the pressure wave process Boost pressure drops to the desired level.

In Figures 4 and 4A is a variant of the slider shown, which is a pivotable part 51st act, which is hinged to a hinge 52 and through a similar control electronics can be moved as above, which causes a widening 53 of the exhaust high-pressure channel.

As shown in WO 99/11914 magnification of High-pressure exhaust passage by means of the recesses 48 or Broadening 53 is insufficient to the pressure level Lower the high-pressure exhaust gas so far that the pressure in This high-pressure exhaust part near the desired level Ambient pressure achieved, will be additional funds to Pressure reduction needed.

These pressure reduction means include those in the figures 3, 3A-6, 6A show additional line 54-57. In In FIGS. 3, 3A, this is the connecting channel 54, which is the Line between the recess 48 and the high-pressure exhaust passage 35 produces. In FIG. 3, the slide 49 closed and thus both the recess and the Connection channel 54 closed. In FIG. 4A, both the Recess as well as the connecting channel 54 open.

Through this liberated line 54 can now be a additional exhaust gas directly into the practically under Ambient pressure low pressure exhaust passage 35th be blown off. This reduces the pressure in the high pressure exhaust duct 31 to the desired lower level. Important is that the shared additional connection channel 54 only opens when a sufficiently large amount of exhaust gas first by the enlargement of the high pressure exhaust passage 31 directly is blown off into the rotor, otherwise the pressure wave process is disturbed and thus the flushing of the rotor collapses and unwanted exhaust passed to the engine becomes.

Analogous to the figures 3, 3A is in the figures 4, 4A a Connection channel 55 located between the line serving as a gas pocket widening 53 and the Low-pressure exhaust passage 35 produces, with the broadening 53 and the connecting channel 55 through the pivotable part 51st can be closed and opened.

In a variant of the embodiment according to FIGS. 3, 3A is a valve 58 schematically in Figure 5, 5A represented as e.g. in CH-A-681 738 for control the gas pocket inflow is used. Again, the Control that the valve 58 is moved so far that a sufficiently large proportion of high pressure exhaust gas 31 to Maintaining the rotor rinse in the recess 48th is redirected. The valve 58 is then opened further and a line 56 is released. This line 56 is over a suitable connection channel with the low pressure exhaust duct 35 connected. About this line 56 can now be a additional exhaust gas directly into the practically under Ambient pressure low pressure exhaust passage 35th be blown off. This reduces the pressure in the high pressure exhaust duct 31 to the desired lower level.

FIGS. 6 and 6A schematically show a roller 59 as shown in similar form in EP-A-0 210 328 is used to control the gas pocket inflow. Also Here, the roller 59 is only moved so far that a sufficient large proportion of high-pressure exhaust 31 to maintain the Rotor purge is diverted in the broadening 53.

The roller 59 is then rotated further and gives the Connecting channel 57 free. The connecting channel 57 is with connected to the low pressure exhaust passage 35. About this line Now an additional amount of exhaust gas can be used directly in the practical under ambient pressure low pressure exhaust duct 35th be blown off. This reduces the pressure in the high pressure exhaust duct 31 to the desired lower level.

Of course, the same measures can be applied to previously known other methods for controlling the high pressure exhaust stream be made in the gas pockets. In a Further development of the invention can be used in all possible ways Applications, either as previously described or at Use of known gas pockets, the additional, directly from the high-pressure exhaust passage 31 in the Low-pressure exhaust passage 35 led exhaust gas flow over a additional actuator done, for example, by a microprocessor is controlled. That's it irrelevant whether this additional actuator has a flap, a valve, a roller or a similar control organ to additional blow-off from the high pressure exhaust duct 31 in the Low-pressure exhaust passage 35 has. However, it is important that control technology ensures that the first Exhaust gas flow from the high pressure exhaust duct either through a Broadening of the high-pressure exhaust passage 31 as in the Figures 4A and 5A shown, or by a partial Redirecting the exhaust gas flow is conducted into the gas pocket, before the additional control organ the further opening directly from the high pressure exhaust passage 31 into the low pressure exhaust passage 35 releases. This control technique becomes the Maintaining the rotor flush needed.

It is advantageous, although not a condition that the Line from the high-pressure exhaust duct into the low-pressure exhaust duct from the gas pocket, or recess or Broadening goes out.

From the above description it is apparent that with it Method for partial load reduction of Reciprocating engines by means of an efficiency improvement a gas-dynamic pressure wave machine is made possible. The method can be combined with other methods, or also individually by means of thermodynamic Improvement of a pressure wave machine according to the Claims are used.

It also shows that the pressure in the Hochdruckabgaskanal and thus also the boost pressure and the negative pressure difference across the loader significantly reduced become. As a result, this also the negative pressure difference reduced by the internal combustion engine, can with this i Procedure also the partial load fuel consumption of Internal combustion engine can be reduced. In addition, at Gasoline engines in the partial load range largely throttling by throttle, since the boost pressure by the almost complete reduction of the exhaust gas pressure to the ambient pressure largely corresponds. This causes a further reduction of partial load consumption.

The pressure wave machine according to the invention makes it possible over the entire area of the map of a Internal combustion engine both the negative pressure difference and thus the increased expulsion work of the internal combustion engine so to keep low as possible, as well as the Abblasemenge so far as to increase the pressure in the high-pressure exhaust duct as far as can be lowered, that the pressure in the Charge air duct can be reduced so far that a partial closure of the throttle valve Internal combustion engine can be omitted in the partial load range. The Effectiveness of the invention is given in particular when can be guaranteed that a sufficiently large Exhaust gas quantity first by increasing the high-pressure exhaust gas duct 31, or through the gas pockets, directly into the Rotor is blown off, otherwise the pressure wave process is disturbed and thus the flushing of the rotor collapses and unwanted exhaust gas is passed to the engine. This is by suitable control technical design of the invention sure.

Claims (6)

1. Gas dynamic pressure wave machine, which is designed to supply charge air to a internal combustion engine, with a rotor (6, 40) comprising a cell (18, 41), a low-pressure fresh air inlet channel (14), a high-pressure charge air channel (10) leading to the internal combustion engine (1), a high-pressure exhaust channel (3, 31) coming from the internal combustion engine and a low-pressure exhaust channel (4, 35), wherein the high-pressure exhaust channel (3, 31) and the low-pressure exhaust channel (4, 35) are arranged in a gas enclosure (24, 34) and the low-pressure fresh air inlet channel (14) and the high-pressure charge air channel (10) are arranged in an air enclosure, and the high-pressure exhaust channel (3, 31) on the rotor side has an enlarged section (21, 48, 53) from which a bypass duct (54 -57) leads to the low-pressure exhaust channel (4, 35), characterised in that the bypass duct (54-57) is regulated for maintaining the pressure wave process by suitable means such that firstly a portion of the exhaust flow is always conducted from the high-pressure exhaust channel (3, 31) into the enlarged section (21; 48; 53) before additional exhaust is conducted from the high-pressure exhaust channel (3; 31) to the low-pressure exhaust channel (4, 35) along the duct (54-57), whereby the enlarged section (21; 48; 53) comprises a cut-out (48) or widening (53) on the rotor side, which comprises means (49, 51, 58, 59) for varying the enlarged section (21; 48; 53) without forming a web, and whereby the means for varying the enlarged section (21, 48, 53) are designed in such a way that the aperture of the bypass duct (54-57) can also be changed.
2. Gas dynamic pressure wave machine according to claim 1, characterised in that the aperture of the duct (54-57) can be varied by an actuating member.
3. Gas dynamic pressure wave machine according to claim 2, characterised in that the actuating member is controlled by means of a microprocessor.
4. Gas dynamic pressure wave machine according to one of claims 1 to 3, characterised in that the means for varying the cut out (48) and the aperture of the duct (56) comprise a valve (58), whereby in a displacement of the valve firstly a sufficient amount of the exhaust flow is conducted into the cut out (48), and with a further displacement of the valve the duct (56) is also opened into the low-pressure exhaust channel.
5. Gas dynamic pressure wave machine according to one of claims 1 to 4, characterised in that the means for varying the widened section (53) of the high-pressure exhaust channel and the aperture of the duct (57) comprise a roller (59), which is controlled so that firstly a sufficiently large amount of the exhaust flow is conducted into the widened section (53) and with a further rotation the duct (57) is also opened in the low-pressure exhaust channel.
6. Gas dynamic pressure wave machine according to one of claims 1 to 5, characterised in that it comprises a device for controlling a branching from the high-pressure exhaust channel to the enlarged section or to the gas pocket channel.

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