Charging device for an internal combustion engine and system consisting of an internal combustion engine and the charging device

Abstract

Charging device (1) for an internal combustion engine (10) with a variable power curve comprising a compressor (V) electrically driven by an electric motor (M) for charging the internal combustion engine with air via an air supply channel (L) and an electrical energy storage device (20) which is supplied with electrical energy via a first generator (30) driven by the internal combustion engine (10), wherein the electric motor (M) is connected to the electrical energy storage device (20) for the purpose of supplying energy with electrical energy stored in the energy storage device in order to drive the compressor (V) independently of the current load or operating point on the power curve of the internal combustion engine (10), wherein a second generator (40) is further provided which is indirectly connected via a mechanical coupling to a mechanical device driven by the exhaust gas flow (A) for the purpose of generating energy by means of an exhaust gas flow (A) of the internal combustion engine (10),wherein the device driven by the exhaust gas flow (A) of the internal combustion engine (10) is a turbine (T) which is effectively connected to the second power generator (40) in such a way that when the turbine (T) rotates, the second power generator (40) is mechanically driven to generate electrical energy, characterized in that the turbine (T) can also be effectively connected to or is connected to the first generator (30) in such a way.

Description

[0001] The invention relates to a charging device for an internal combustion engine and a system comprising an internal combustion engine and a charging device. A wide variety of designs of charging systems are known from the prior art.

[0002] From DE 10 2016 107 870 A1, for example, a method for operating an internal combustion engine with at least one high-pressure exhaust gas turbocharger having a high-pressure exhaust gas turbine with variable turbine geometry and a high-pressure compressor and at least one low-pressure exhaust gas turbocharger having a low-pressure exhaust gas turbine with variable turbine geometry and a low-pressure compressor is known.

[0003] WO 2016 / 074752 A relates to a charging device for an internal combustion engine, comprising a compressor that conveys fluid from a suction side toward a pressure side and thereby compresses it from a first pressure present on the suction side to a second pressure present on the pressure side. A bypass line is provided in a housing of the charging device between the pressure side and the suction side, in which bypass line a suction jet pump with a vacuum connection is located.

[0004] Such internal combustion engines, which are each charged via an exhaust gas turbocharger or exhaust gas compressor, generally have the disadvantage that, due to the exhaust gas turbocharger, there is a more or less pronounced power offset or power gap at the beginning when the power of the internal combustion engine is increased (e.g. when accelerating a drive motor).

[0005] US 2010 / 0 018 203 A1 discloses a charging device for an internal combustion engine according to the preamble of claim 1.

[0006] WO 2016 / 171 955 A1, DE 10 2012 004 394 A1, US 2018 / 0 202 353 A1, US 2013 / 0 124 025 A1, US 2015 / 0 069 832 A1 and US 6 054 776 A disclose further prior art.

[0007] However, a desirable condition is one in which the compressor immediately supercharges the internal combustion engine upon acceleration in order to avoid this initial power gap or power offset. The present invention is therefore based on the object of overcoming the aforementioned disadvantages and creating a supercharging device for an internal combustion engine that exhibits improved operating behavior, particularly during load transfer, and also ensures efficient air supply and thus immediate supercharging of the internal combustion engine at different operating points of the engine.

[0008] The object is achieved by a charging device for an internal combustion engine according to claim 1.

[0009] A first basic idea of ​​the invention is to ensure a faster supply of air during load increase by ensuring that the required charging is carried out via an electrically driven compressor, independent of the operating point of the internal combustion engine and its current load state, thus independent of the exhaust gas flow currently being generated. A second aspect of the invention relates to the power supply of the compressor's electric drive, which is also independent of the load and the current operating state, by providing an energy buffer from which the required electrical energy for the electric motor is obtained, even when the internal combustion engine is accelerated from a standstill.

[0010] According to claim 1, a charging device for an internal combustion engine having a variable power curve is proposed, wherein the charging device has a compressor which is electrically driven by an electric motor for charging the internal combustion engine with air via an air supply duct, and an electrical energy store which is fed with electrical energy via a first power generator which is driven (or drivable) by the internal combustion engine, wherein the electric motor is connected to the electrical energy store for supplying energy with electrical energy stored in the energy store in order to drive the compressor independently of the current operating point on the power curve of the internal combustion engine.Additionally, a second power generator is provided, which is indirectly connected via a mechanical coupling to a mechanical device driven by the exhaust gas flow for generating energy using an exhaust gas flow from the internal combustion engine. The device driven by the exhaust gas flow from the internal combustion engine is a turbine (e.g., an exhaust gas turbine) that is drive-effectively connected to the second power generator such that, when the turbine rotates, the second power generator is mechanically driven to generate electrical energy. The turbine is also drive-effectively connectable or connected to the first generator. Thus, for example, when the internal combustion engine is running at low speed but an exhaust gas flow is present, this can be used to drive the generator.

[0011] It is preferred if the first power generator is a generator driven by a mechanical output from the combustion engine. This allows the energy extracted from the energy storage unit to be recharged, ensuring that the energy storage unit always has enough energy stored to power the compressor's electric motor.

[0012] It is particularly advantageous if the second power generator is also a generator.

[0013] In a preferred embodiment of the invention, it can be provided that the first generator is designed as a shaft generator which is connected directly or via a gear stage to the output of the internal combustion engine.

[0014] In a further advantageous embodiment of the invention, the second power generator provides the energy generated by it either to the energy storage device or, alternatively, to an electrical consumer. For this purpose, a corresponding control system can be provided that controls the flow of electrical energy to the components connected to the power generator.

[0015] It is particularly advantageous if a control and regulation device is also provided which controls the energy flow depending on the current operating point of the combustion engine, namely the extent to which the first and / or second power generator feeds the currently generated electrical energy to the electrical energy storage device, and the remaining amount of energy is thus available to an energy sink or a consumer for other purposes, depending on the engine load. With efficient control, for example, in an application in a vehicle or a means of transport, the conventional alternator for supplying energy to the consumers can be completely eliminated, and the required energy can be drawn from the generator of the charging device or the energy storage device.

[0016] A further aspect of the invention also relates to the system comprising an internal combustion engine and a charging device as described above, wherein the internal combustion engine is drivingly connected to at least the first power generator or generators and / or to the second power generator or generators indirectly via interposed drive components. It is particularly advantageous if the system is a hybrid drive system in which the internal combustion engine represents a drive component.

[0017] Other advantageous developments of the invention are characterized in the subclaims or are presented in more detail below together with the description of the preferred embodiment of the invention with reference to the figures.

[0018] They show: Fig. 1 a first embodiment of a charging device according to the invention and Fig. 2 a second alternative embodiment of a charging device according to the invention.

[0019] The invention is described below with reference to the Fig. 1 and Fig. 2 using exemplary embodiments. In the Fig. 1 and Fig. 2 shows two different embodiments of a charging device according to the invention, wherein the same reference numerals indicate the same structural or functional features.

[0020] In Fig. 1 shows a first embodiment of a charging device 1 according to the invention or a system comprising such a charging device 1 with an internal combustion engine 10.

[0021] As from the Fig. As can be seen in Figure 1, the charging device 1 is provided for an internal combustion engine 10. The internal combustion engine 10 here represents an internal combustion engine in a hybrid drive system, wherein the internal combustion engine 10 can be operated at different load points, so to speak, along its power curve. When the internal combustion engine 10 is in the load-free state, it generates only a small exhaust gas flow A. Fig. However, in the embodiment shown in Figure 1, the exhaust gas flow A is not used to drive a compressor. Rather, the compressor V shown is used to compress air drawn in at the inlet side via a supply channel L and to supply the air to the internal combustion engine 10 for charging.

[0022] The compressor V is not designed here as an exhaust gas turbocharger, but as a compressor V electrically driven by an electric motor M. The electric motor M is connected to an electrical energy storage device 20 in order to be supplied with electrical energy by the latter.

[0023] Furthermore, a first power generator 30 driven by the combustion engine 10 is provided to charge the energy storage device 20.

[0024] Since the electric motor M receives the energy it requires for propulsion directly from the electrical energy storage device 20, it is possible to drive the compressor V independently of the current load or operating point of the combustion engine 10 and thus independently of the exhaust gas flow A of the combustion engine 10. Thus, even in the lower power range of the combustion engine 10 and immediately upon acceleration, the compressor V can develop its full air power, which is only possible with a certain power offset using an exhaust gas turbocharger.

[0025] In this embodiment, the first power generator 30 is a shaft generator which is driven via a mechanical output 11, namely via a drive shaft of the internal combustion engine 10.

[0026] In the alternative embodiment of the Fig. 2, a second power generator 40, in this case also a power generator, is provided, which is driven by a mechanical coupling to generate energy by means of an exhaust gas flow A from the internal combustion engine 10 indirectly via an exhaust turbine T. The generator 40 supplies electrical energy to the energy storage device 20.

[0027] In the embodiment according to Fig. 2, energy can therefore be obtained via the first and both the second generator 30, 40 for the energy storage 20 to operate the compressor V.

[0028] In this variant, a control and regulation device 50 can also be provided, which controls the energy flow of the generators 30, 40 depending on the respective current operating point of the internal combustion engine 10. The control operates in such a way that it is determined to what extent the first and / or the second generator 30, 40 feed the currently generated electrical energy to the electrical energy storage device 20 and the remaining amount of energy is thus available to an energy sink or an external consumer depending on the engine load.

Claims

[1] Charging device (1) for an internal combustion engine (10) with a variable power curve, comprising a compressor (V) electrically driven by an electric motor (M) for charging the internal combustion engine with air via an air supply duct (L), and an electrical energy store (20) which is fed with electrical energy via a first power generator (30) driven by the internal combustion engine (10), wherein the electric motor (M) is connected to the electrical energy store (20) for supplying power with electrical energy stored in the energy store in order to drive the compressor (V) independently of the current load or operating point on the power curve of the internal combustion engine (10), wherein a second power generator (40) is also provided,which is connected indirectly via a mechanical coupling to a mechanical device drivable by the exhaust gas flow (A) for energy generation by means of an exhaust gas flow (A) of the internal combustion engine (10), wherein the device drivable by the exhaust gas flow (A) of the internal combustion engine (10) is a turbine (T) which is drive-effectively connected to the second power generator (40) such that when the turbine (T) rotates, the second power generator (40) is mechanically driven to generate electrical energy, characterized by that the turbine (T) is or can be connected to the first generator (30) in a drive-effective manner. [2] Charging device (1) according to claim 1, characterized by that the first power generator (30) is a generator which is driven via a mechanical output (11) of the internal combustion engine (10). [3] Charging device (1) according to claim 1 or 2, characterized by that the second power generator (40) is a generator. [4] Charging device (1) according to claim 2, characterized by that the first generator (30) is designed as a shaft generator which is connected directly or via a gear stage to the output of the internal combustion engine (10). [5] Charging device (1) according to claim 2, characterized by that a control and regulating device (50) is provided which, depending on the respective current operating point of the internal combustion engine (10), controls the extent to which the first and / or the second power generator (30, 40) feeds the respective currently generated electrical energy to the electrical energy store (20) and the respective remaining amount of energy is thus available to an energy sink or a consumer depending on the engine load. [6] System comprising an internal combustion engine (10) and a charging device (1) according to one of claims 1 to 5, wherein the internal combustion engine (10) is drivingly connected to at least the first or a first power generator (30) and / or to the second or a second power generator (40) indirectly via intermediate drive components. [7] System according to claim 6, wherein the system is a hybrid drive system in which the internal combustion engine (20) is one of the drive components.

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