DE102009058131B4 - contraption - Google Patents

Abstract

Device, in particular mobile or stationary work machine, utility vehicle, motor vehicle, land, water, rail or road vehicle, - with at least one internal combustion engine (2), - with an exhaust system (3), - with a burner (4) for introducing Heat in the exhaust system (3), characterized by - a conveyor device (5) for supplying the burner (4) with air, - a hydraulic motor (6) for driving the conveyor device (5), - a hydraulic pump (7) for driving the hydraulic motor (6).

Description

The present invention relates to a motorized device, such. As mobile or stationary machines, commercial vehicles, motor vehicles, land, water, rail and road vehicles, with the features of the preamble of claim 1.

Typically, such a device comprises at least one internal combustion engine, in particular a piston engine, and an exhaust system for discharging combustion exhaust gases of the internal combustion engine.

Modern exhaust systems are equipped with different exhaust gas treatment facilities, such. Eg catalysts and particle filters. Certain facilities of this kind, such. Ex. Oxydationskatalysatoren, NO _x storage catalysts and SCR catalysts require for proper operation a certain operating temperature, Other exhaust treatment facilities, such. For example, a particulate filter, require a certain regeneration temperature in order to perform a regeneration of the respective device can. Depending on the arrangement of the respective device along the exhaust system, it may take a comparatively long time until the respective device reaches the desired temperature. Furthermore, operating states may occur, in particular in diesel engines, during which only relatively little heat is obtained for a relatively long time, so that it is also possible for individual exhaust gas treatment devices not to reach the required operating temperature or regeneration temperature or very late. To remedy this problem, it is in principle possible to equip the device with an additional burner, with the aid of heat in the exhaust system can be initiated. For example, the burner converts fuel with air, which produces hot exhaust gases which can then be introduced into the exhaust system. As a result, the temperature in the exhaust gas of the exhaust system can be significantly increased, which ultimately leads to the desired increase in temperature in the respective facilities of the exhaust system.

From the DE 197 20 381 A1 a generic motor vehicle is known which has an internal combustion engine, an exhaust system and a fuel-powered burner for introducing heat into the exhaust system. In the known motor vehicle, a hydraulic motor for driving a driven by the internal combustion engine drive train is also provided, which in turn is driven by means of a pressure accumulator.

From the US 2005/0172547 A1 For example, a mixing apparatus for mixing a fuel gas with air for an internal combustion engine is known, which is equipped with a blower for driving the air and a static mixer for mixing the air flow with a fuel gas flow. To drive the fan, among other things, a hydraulic motor can be used.

From the DE 27 51 524 A1 a blue-burning oil burner is known, the air supply has a blower and a blower downstream throttle valve. The throttle valve has an air damper for controlling the druchströmbaren cross-section. A drive for driving the air damper can be designed as a hydraulic motor.

However, the use of such a burner for introducing heat into the exhaust system is problematic because in the exhaust system depending on the position of the discharge of the burner exhaust gas compared to the environment increased pressure prevails, for example. Depending on the current operating condition of the engine can be up to 1 bar. Against this pressure difference must promote a conveyor for supplying the burner with air. Depending on the application and the operating status of the burner requires comparatively much air, for example. A combustion air requirement of 60 kg / h is conceivable. This results in a conveying capacity of at least 1 kW for the conveyor. In principle, such a conveyor device can be driven by means of an electric motor. However, it can come in the usual on-board networks of the device to overloading, if over such a long time such high performance must be provided.

The present invention is concerned with the problem of providing for an apparatus of the type mentioned in an improved embodiment, which is characterized in particular by an improved drive of the conveyor, which leads in particular to a reduced load on the electrical system of the device.

This problem is solved according to the invention by the subject matter of the independent claim. Advantageous embodiments are the subject of the dependent claims.

The invention is based on the general idea to use for driving the conveyor a hydraulic motor, which is for this purpose connected to a hydraulic pump having a hydraulic system of the device, which is expediently present in the device anyway. Such a hydraulic motor can realize very high powers, without causing the risk of overheating or the like. The hydraulic pump, which ultimately drives the hydraulic motor, is suitably mechanically coupled to the internal combustion engine, that is to say mechanically driven by it, so that there is no load on the engine at this point either electric vehicle network takes place. If the device is already equipped with a hydraulic system, which should be the case regularly, also a correspondingly powerful hydraulic pump is present, which is mechanically driven in particular by the internal combustion engine and accordingly does not burden the electrical system.

For example, a motorized device of interest here can have a hydraulic tool, a hydraulic drive, a hydraulic brake system, a hydraulic level control or other hydraulic devices. In principle, such hydraulic systems are preferably used which work with oil as the hydraulic medium. Theoretically, however, a use of a hydraulic system is conceivable that works with water or coolant as the hydraulic medium. Because basically, the hydraulic motor z. B. also be connected to the cooling circuit of the internal combustion engine, which also basically represents a hydraulic system with mechanically driven hydraulic pump. Within the hydraulic system, the hydraulic pump and the hydraulic motor are appropriately coupled to each other via a hydraulic circuit, so that the hydraulic pump can hydraulically drive the hydraulic motor. The hydraulic motor itself drives the conveyor preferably mechanically. A corresponding mechanical drive connection can take place, for example, via a belt, a chain or a toothing or the like.

The conveyor may be configured according to an advantageous embodiment as a compressor. In this case, a configuration may be preferred as a so-called "hard" compressor. Such a hard compressor differs from a so-called "soft" compressor by different dependencies of the capacity of the back pressure against which promotes the compressor. A hard compressor has a hard characteristic, according to which the delivery depends only slightly on the applied counter pressure, while in a soft compressor, the corresponding soft characteristic shows a relatively large decrease in the flow rate with increasing back pressure. By using a hard compressor as a conveyor, a change in the speed of the hydraulic motor leads comparatively directly to a change in the flow rate. In addition, pressure fluctuations in the exhaust system affect less on the flow rate of the conveyor.

If the hydraulic system already present in the device has a hydraulic pump with comparatively low delivery rate, a pressure accumulator can also be provided in the hydraulic system, which is also connected to the hydraulic circuit to charge the memory at low power requirement of the hydraulic motor and compensate load peaks with increased engine power to be able to.

For operating the burner, a control device may be provided with the aid of which the delivery rate of the delivery device can be adjusted. For this purpose, the control device z. B. control at least one control valve, which is arranged in a return of the hydraulic motor or in a flow of the hydraulic motor and controls the flow of the hydraulic medium through the return or by the flow. The speed of the hydraulic motor can be adjusted by actuating the respective control valve virtually independent of the current speed or capacity of the hydraulic pump. Thus, there is no significant effect on the hydraulic system by operating the hydraulic motor. In that regard, the hydraulic system can still fulfill its previous function.

Alternatively, it is fundamentally possible for the control device to interact directly with the hydraulic motor for setting the delivery rate, provided that this is configured as a so-called variable displacement motor in which the rotational speed can be varied at constant delivery rate by adjusting a corresponding actuator.

The control device expediently communicates with a control device of the internal combustion engine, which is usually referred to as a control device. In principle, the control device of the burner can be implemented by software in the control unit of the internal combustion engine and / or integrated in hardware. As a result, the control device can adjust the rotational speed of the hydraulic pump and thus the delivery rate of the conveyor particularly easily depending on the current operating state of the internal combustion engine and in accordance with the current requirement for fresh air.

If only one control valve is to be used, this is preferably arranged in the return; However, it can in principle also be arranged in the flow. However, if two control valves are to be used, one is arranged in the return and the other in the flow. Likewise, a double-acting control valve can be used, which interacts with both the return and the flow. In the case of control valves or in the case of a double-acting control valve, it is possible, in particular, to brake the hydraulic motor for a short time. In this way, the operation of the burner, in particular with regard to its fresh air requirement, with relatively high dynamics are adapted to changing operating conditions of the internal combustion engine.

An embodiment is preferred in which the device has an electrical on-board network which operates on a 12 V basis. Here, the invention has a particularly advantageous effect, since at this comparatively low voltage level, the currents become correspondingly large when high powers are required for operating a conventional electric motor.

Other important features and advantages of the invention will become apparent from the dependent claims, from the drawing and from the associated description of the figures with reference to the drawing.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Preferred embodiments of the invention are illustrated in the drawings and will be explained in more detail in the following description.

The only 1 shows a greatly simplified schematic diagram of a device.

Corresponding 1 includes a symbolized by a drawn with a broken line frame device 1 , which is preferably a stationary or mobile machine, such. As an excavator, a crane or a lifting device, or a commercial vehicle such. As a truck or a tractor, or to a motor vehicle, such. As a land, a water, a rail or a road vehicle is, at least one internal combustion engine 2 , an exhaust system 3 , a burner 4 , a conveyor 5 , a hydraulic motor 6 and a hydraulic pump 7 , The internal combustion engine 2 is designed, for example, as a piston engine. In the example, a 4-cylinder in-line engine is shown without limiting the generality. It is clear that other numbers of cylinders and other cylinder arrangements are possible. The internal combustion engine 2 is via a fresh air system 8th Fresh air supplied. This fresh air system 8th has at least one air filter 9 on, in which a filter element 10 a raw page 11 from a clean side 12 separates. In operation, the internal combustion engine drives 2 a crankshaft 13 on, via a drive connection 14 a drive shaft 15 the hydraulic pump 7 drives. The drive connection 14 works mechanically and can, for example. Via a chain, a belt or a toothing or by a direct coupling of the crankshaft 13 with the drive shaft 15 be realized.

The exhaust system 3 promotes the operation of the internal combustion engine 2 generated exhaust gas away from the engine 2 , The exhaust system 3 can at least one exhaust treatment device 16 exhibit. In the example, by way of example only four exhaust gas treatment facilities 16 shown. This can be an oxidation catalyst 17 to a particle filter 18 to an SCR catalyst 19 and an NO _x storage catalyst 20 act. The aforementioned exhaust treatments 16 can be realized together in this order or in a different order or even individually and in any combination.

The burner 4 serves to introduce heat into the exhaust system 3 , This is the burner 4 in a suitable way to the exhaust system 3 connected. The burner must 4 even not from the exhaust of the internal combustion engine 2 be flowed through. Rather, the burner can 4 so to the exhaust system 3 be connected to that of the burner 4 generated exhaust gas in the exhaust system 3 entry. Downstream of the burner 4 thus mixes the exhaust gas of the burner 4 with the exhaust gas of the internal combustion engine 2 , The burner 4 produced exhaust gas is comparatively means, causing the in the exhaust system 3 downstream of the burner 4 transported exhaust flow contains comparatively much heat and thus the downstream of the burner 4 arranged exhaust treatment devices 16 can warm up.

The conveyor 5 serves to supply the burner 4 with air. For this purpose, the conveyor 5 on the pressure side to the burner 4 connected. In the example shown, the conveyor 5 suction side to the clean side 12 of the air filter 9 the fresh air system 8th connected. However, this is not mandatory. Basically, the conveyor 5 also suck in the air directly from the environment or suck it in from the environment through its own air filter.

The hydraulic motor 6 serves to drive the conveyor 5 , For this purpose, a drive shaft 21 of the hydraulic motor 6 with a drive shaft 22 the conveyor 5 drive-connected. A corresponding drive connection is herewith 23 designated. This drive connection 23 can be realized again by a suitable mechanical coupling, such. Eg a belt, a chain or a toothing or by a direct drive coupling of the two drive shafts 21 . 22 ,

The hydraulic pump 7 serves to drive the hydraulic motor 6 , For this are hydraulic pump 7 and hydraulic motor 6 via a hydraulic circuit 24 hydraulically coupled with each other. Thus, ultimately drives the internal combustion engine 2 the hydraulic pump 7 mechanically on, the hydraulic pump 7 drives the hydraulic motor 6 hydraulically on and the hydraulic motor 6 drives the conveyor 5 mechanically. Accordingly, the drive comes the Conveyor 5 ultimately without electrical energy, so that a rudimentary illustrated here electrical electrical system 37 the device 1 by the drive of the conveyor 5 not burdened.

The internal combustion engine 2 is via a fuel pump 25 with fuel from a fuel tank 26 provided. Appropriately, this is a liquid fuel such. For example, diesel, gasoline or a biofuel. The burner 4 serves to react a fuel with the air of the conveyor 5 , It is useful to supply the burner 4 with fuel also a fuel pump 27 intended. Particularly advantageous is the embodiment shown here, in which the burner 4 can be operated with the same fuel, including the internal combustion engine 2 receives. Accordingly, the fuel pump 27 of the burner 4 to the tank 26 connected. Basically, for conveying the fuel to the burner 4 also the already existing fuel pump 25 be used by z. B. a partial flow of the fuel to supply the burner 4 from a main flow of the fuel for supplying the internal combustion engine 2 is branched off.

The conveyor 5 is expediently designed as a compressor. Theoretically, it can also be realized as a blower or pump. However, preference is given to the design as a compressor due to the required delivery capacity here. Particularly useful is an embodiment in which the conveyor 5 designed as a hard compressor, which is characterized by a hard curve. Such a hard characteristic is present when the delivery rate of the conveyor 5 or of the respective compressor changes only slightly with changing counter-pressure. In contrast, in a soft compressor, which has a soft characteristic, the delivery rate drops significantly with increasing backpressure.

It is particularly advantageous, the conveyor 5 in the form of a compressor which is designed as a Roots compressor or as a claw compressor or as a rotary vane compressor or as a vane compressor or as a piston compressor.

The hydraulic motor 6 can be configured, for example, as a conventional oil engine. Preferably, it is the hydraulic motor 6 a vane motor or a gear motor or a rotary vane motor or an axial piston motor or a radial piston motor or an impeller flow motor or an orbital motor.

The hydraulic circuit 24 , the hydraulic pump 7 with the hydraulic motor 6 Couplings can be considered an open hydraulic circuit 24 or as a closed hydraulic circuit 24 be designed. With an open hydraulic circuit 24 The speed control for the hydraulic motor is simplified 6 ,

In the hydraulic circuit 24 may according to a preferred embodiment, a pressure accumulator 28 be arranged. With the help of such a pressure accumulator 28 It is possible to use hydraulic fluid under a comparatively high pressure during operating phases in which the hydraulic motor 6 Little power is needed to store and cover peak loads on the hydraulic motor 6 leave. This is particularly advantageous when the power requirement of the hydraulic motor 6 not with the power output of the hydraulic pump 7 correlated. The accumulator 28 is between the hydraulic pump 7 and the hydraulic motor 6 to the hydraulic circuit 24 connected.

The hydraulic pump 7 is with the hydraulic circuit 24 expediently a component of a hydraulic system 29 , this in 1 is symbolized by a drawn with a broken line frame. This hydraulic system 29 is in the device 1 anyway available. It is a device-side hydraulic system 29 or a hydraulic system 29 the device 1 , Accordingly, the hydraulic pump 7 in the device 1 Anyway available and serves to supply hydraulic components of the hydraulic system 29 with hydraulic medium or hydraulic pressure. This is preferably a hydraulic system 29 that works with oil as a hydraulic medium. The hydraulic circuit 24 is shown here greatly simplified. In particular, the hydraulic motor 6 only to a secondary branch of the hydraulic circuit 24 connected.

To operate the burner 4 is expedient a control device 30 intended. With the help of the control device 30 can be a capacity of the conveyor 5 be set. The control device 30 can connect to the electrical system 37 be connected. For adjusting the delivery rate of the conveyor 5 can the controller 30 z. B. at least one control valve 31 respectively. 32 drive. In the example shown are two control valves 31 . 32 intended. The one control valve 31 is in a lead 33 of the hydraulic motor 6 arranged while the other control valve 33 in a return 34 of the hydraulic motor 6 is arranged. If only a single control valve 31 . 32 should be present, an embodiment is preferred in which the one control valve 32 then in the return 34 is arranged. Basically, it can also be in the lead 33 be arranged. The respective control valve 31 . 32 is preferably configured as a proportional valve, so that basically any intermediate positions between a complete locked closed position and a fully open open position are adjustable.

Alternatively, a double-acting control valve can be used, which then both with the flow 33 as well as with the return 34 interacts.

With the help of at least one control valve 31 . 32 is the volume flow of the hydraulic medium in the hydraulic circuit 24 controllable, namely in the flow 33 or in the return 34 , So the hydraulic fluid flow through the hydraulic motor 6 controllable. By controlling the flow of hydraulic fluid through the hydraulic motor 6 can the speed of the hydraulic motor 6 be set. The speed of the hydraulic motor 6 However, it correlates directly with the speed of the conveyor 5 , The capacity of the conveyor 5 depends on their speed. Accordingly, the control device 3 by driving the control valves 31 . 32 ultimately the capacity of the conveyor 5 to adjust.

In an alternative embodiment, the hydraulic motor 6 be configured as an adjusting motor, in which there is a constant hydraulic fluid flow through the hydraulic motor 6 is possible, the speed at the corresponding drive shaft 21 to vary. For example, the hydraulic motor contains 6 For this purpose, an actuator that changes the speed when it is adjusted. In this case, the control device 30 directly with the hydraulic motor 6 be connected to make the desired setting of the speed.

The control device 30 can, for example, with a temperature probe 35 be connected, which is the temperature in the exhaust gas of the internal combustion engine 2 determined. The control device 30 can with the help of the respective temperature probe 35 a regulation of the burner 4 carry out. For this purpose, the control device uses 30 the measured exhaust gas temperature and the current exhaust gas volume flow. The latter receives the control device 30 z. B. via a corresponding, not shown here volume flow sensor or the engine control unit. Based on these values, the control device 30 determine a burner output depending on the target temperature to be set. Depending on the required burner output, that is dependent on the required amount of heat, the amount of fuel required for this purpose can be determined via the fuel delivery device 27 of the burner 4 the burner 4 must be supplied. Depending on the determined amount of fuel then the required amount of air can be determined, via the conveyor 5 must be supplied. By means of a lambda probe, not shown here, the residual oxygen contained in the exhaust gas can be taken into account in such a way that correspondingly less secondary air has to be delivered depending on the oxygen content in the exhaust gas. Subsequently, depending on the amount of air to be adjusted, the required speed of the conveyor 5 and the required speed of the hydraulic motor 6 determined. Finally, the required speed of the hydraulic motor leads 6 then to corresponding actuating signals for the respective control valve 31 . 32 or in a designed as a variable displacement hydraulic motor 6 to corresponding actuating signals for the hydraulic motor 6 or for its actuator.

To adverse effects on the rest of the hydraulic circuit 24 by the connection of the hydraulic motor 6 To reduce or avoid, with the help of the conveyor 5 actually promoted actual air quantity by means of an air quantity sensor 36 determined and compared with the previously determined set air quantity, in order then to readjust the speed accordingly. This ensures that the amount of air delivered also matches the required. Furthermore, it is achieved that the hydraulic system 29 by the secondary air injection just as much oil is taken out as is required, so that the impact on the other components of the hydraulic system 29 are as low as possible.

The airflow sensor 36 is in the example of 1 between the conveyor and the burner 4 arranged. However, he can also upstream of the conveyor 5 be arranged, for. B. between the air filter 9 and the conveyor 5 ,

In order to further reduce these adverse interactions, in a hydraulic system 29 that has several hydraulic circuits 24 has, the hydraulic motor 6 specifically in such a hydraulic circuit 24 be integrated, which is particularly robust against fluctuations in the oil flow and in particular is not relevant to safety. The same applies to the integration in the hydraulic circuit 24 if this is several hydraulic pumps 7 or a tandem pump or the like.

The burner 4 is expediently designed as a fuel converter ("fuel processor"). This fuel converter or burner 4 converts the fuel with the supplied air, generating the hot exhaust gases. These hot exhaust gases then enter the exhaust system 3 and mix with the exhaust gases of the internal combustion engine 2 and thereby lead to the desired heating in the exhaust system 3 or in the components incorporated therein, here the exhaust gas treatment devices 16 , downstream of the burner 4 , The burner 4 can be used, for example, to the SCR catalyst 19 and / or the oxidation catalyst 17 and / or the NO _x storage catalyst 20 bring to the respective operating temperature, which is especially at a cold start of Bennkraftmaschine 2 can be beneficial. Furthermore, the burner 4 Be used to the diesel particulate filter 18 to bring to a regeneration temperature.

Furthermore, the burner 4 be used by an appropriate temperature setting also to oxidize the fuel only partially, creating a hydrogen-containing and / or hydrocarbon-containing exhaust gas, which is implemented in particular in the respective downstream catalytic device and z. B. can be used for rapid heating to the respective operating temperature.

Claims (11)

Device, in particular mobile or stationary work machine, commercial vehicle, motor vehicle, land, water, rail or road vehicle, - with at least one internal combustion engine ( 2 ), - with an exhaust system ( 3 ), - with a burner ( 4 ) for introducing heat into the exhaust system ( 3 ), characterized by - a conveyor ( 5 ) for supplying the burner ( 4 ) with air, - a hydraulic motor ( 6 ) for driving the conveyor ( 5 ), - a hydraulic pump ( 7 ) for driving the hydraulic motor ( 6 ). Device according to claim 1, characterized in that - the internal combustion engine ( 2 ) the hydraulic pump ( 7 ), in particular mechanically, drives, and / or - that the hydraulic motor ( 6 ) the conveyor ( 5 ) drives mechanically. Apparatus according to claim 1 or 2, characterized in that - the conveyor ( 5 ) is designed as a compressor, - in particular it can be provided that the conveyor ( 5 ) is designed as a hard compressor, - in particular it can be provided that the compressor is a Roots compressor or a claw compressor or a rotary vane compressor or a vane compressor or a reciprocating compressor. Device according to one of claims 1 to 3, characterized in that the hydraulic motor ( 6 ) is designed as a vane motor or as a gear motor or as a rotary valve motor or as an axial piston motor or as a radial piston motor or as Flügelradströmungsmotor or orbital motor. Device according to one of claims 1 to 4, characterized in that - the hydraulic pump ( 7 ) via a hydraulic circuit ( 24 ) with the hydraulic motor ( 6 ), wherein - in particular it can be provided that the hydraulic circuit ( 24 ) as an open or closed hydraulic circuit ( 24 ) is configured. Apparatus according to claim 5, characterized in that in the hydraulic circuit ( 24 ) an accumulator ( 28 ) is arranged. Device according to one of claims 1 to 6, characterized in that the hydraulic pump ( 7 ) a component of a hydraulic system ( 29 ) of the device ( 1 ) to which the hydraulic motor ( 6 ) is additionally connected. Device according to one of claims 1 to 7, characterized in that a control device ( 30 ) for adjusting a delivery rate of the conveyor ( 5 ) is provided. Device according to claim 8, characterized in that - the control device ( 30 ) for adjusting the conveying capacity of the conveyor ( 5 ) at least one control valve ( 31 . 32 ), which in a return ( 34 ) of the hydraulic motor ( 6 ) or in a forerun ( 33 ) of the hydraulic motor ( 6 ) and with which the flow of hydraulic medium through the hydraulic motor ( 6 ) is controllable, - in particular, it may be provided that only one control valve ( 32 ) provided in the return ( 34 ) or in the flow ( 33 ), or that both in the return ( 34 ) as well as in the flow ( 33 ) one control valve each ( 31 . 32 ) is arranged or that a double-acting control valve is provided, both with the flow ( 33 ) as well as with the return ( 34 ) - it being possible in particular to provide that at least one such control valve ( 31 . 32 ) is designed as a proportional valve. Device according to claim 8, characterized in that - the hydraulic motor ( 6 ) is designed as an adjusting motor, in which at constant hydraulic fluid flow, the speed is variable, - that the control device ( 30 ) for adjusting the conveying capacity of the conveyor ( 5 ) the hydraulic motor ( 6 ) for setting a matching speed. Device according to one of claims 1 to 10, characterized - that the burner ( 4 ) is designed as a fuel converter, which converts a fuel with the supplied air and thereby generates hot exhaust gas, - that the burner ( 4 ) on the exhaust side to the exhaust system ( 3 ) is connected, so that the exhaust gas of the burner ( 4 ) into the exhaust system ( 3 ), - in particular it may be provided that the exhaust system ( 3 ) downstream of the burner ( 4 ) contains at least one of the following components: SCR catalyst ( 19 ), Particle filter ( 18 ), Oxidation catalyst ( 17 ), NO _x storage catalyst ( 20 ).

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