EP1388660B1 - Device and method for increasing power of an internal combustion engine - Google Patents

Description

The invention relates to a method for increasing the performance of an internal combustion engine of a motor vehicle with a motor controller which receives input signals and generates control commands for normal operation of the internal combustion engine, wherein the input signals and / or the control commands are amplified in the sense of an increase in performance. Furthermore, the invention relates to an apparatus for carrying out such a method.

From the US 6 220 223 B1 For example, an engine control unit is known which calculates a virtual gear ratio from the vehicle speed and the engine speed, compares it with a predetermined threshold value, and limits the torque output by the internal combustion engine as a function of this comparison. In this way, in particular an overload of the transmission in the low gear range should be avoided.

In the US Pat. No. 6,377,884 B1 describes the internal design of a motor control, in which an optimal implementation of the predetermined by the operation of an accelerator pedal power requirement is in the foreground.

It is known that internal combustion engines can show different performances depending on the nature of their control. For example, a typical 2.0 l in-line four-cylinder CommonRail diesel engine is offered as standard in various power levels from approx. 85 kW (116 hp) / 265 Nm to 110 kW (150 hp) / 330 Nm. The different performance of otherwise identical engines is achieved only by the vote of the engine control or calibration.

Measures to increase the performance of an internal combustion engine are also made by tuners, which subsequently change a motor vehicle delivered by the manufacturer according to customer requirements. Since there is usually no access to the manufacturer calibration of the engine control in this case, simpler measures to increase performance must be applied. Such measures are particularly easy to perform in a common rail diesel, although in other types of diesel (such as distributor injection pump, pump nozzle and the like) or in gasoline engines with charging basically similar procedure can be followed. During the period before and during mixture ignition, fuel is injected into the combustion chamber of the diesel engine two to six times. Since the output of diesel engines not on the amount of fuel-air mixture supplied, but on the Amount of supplied fuel, which is supplied to the intake air is controlled, and since the soot limit is maintained in the range of an air-fuel ratio λ of 1.1 to 1.3 from the manufacturer-programmed engine controls usually with a considerable distance , An increase in performance of the diesel engine can be achieved by increasing the amount of fuel injected.

Furthermore, the boost pressure of the turbocharger usual in modern diesel engines can also be increased. This increases the amount of fuel-air mixture available in the engine for combustion. This also results in a larger power and torque output. The increase of the boost pressure may e.g. be achieved in that the signals supplied by the engine to the engine control are changed.

In the implementation of the above principles, a so-called black box is interposed between the engine control system and the individual engine components (eg injection valves, turbocharger including overpressure control unit) by "amplification" of the normal input signals and / or engine control commands for extended and enlarged injection strokes and / or increased charge pressure and thus causes the desired increase in the available for combustion fuel-air mixture. The advantage of such a black box is that the function of the motor control specified by the manufacturer need not be known and that in principle all the characteristics of the manufacturer programming as well as the vehicle / engine behavior are completely preserved. As a result, the exhaust gas behavior usually remains unchanged and expensive exhaust gas measurements can be dispensed with. The engine behaves only as if the series engine with its performance would spread very far up. The power and torque curve is shifted by such measures approximately by a constant multiplication factor up, with typically torque increases from 260 Nm to 320 Nm can be achieved.

A disadvantage of the described subsequent increase in performance is an increased load on the drive train of the motor vehicle, which is particularly noticeable in first gear and / or in reverse. Typically, the forces in the first gear are increased by more than 20%, so that after a short gear service life can lead to violent breakages.

Against this background, it was an object of the present invention to provide a method and a device for increasing the performance of an internal combustion engine, which allow an improved utilization of the potential for performance increase while sparing the drive train.

This object is achieved by a method having the features of claim 1 and by an apparatus having the features of claim 7.

Advantageous embodiments are contained in the subclaims.

The inventive method is used to increase the performance of the internal combustion engine (preferably a diesel engine and / or a gasoline engine with charging) of a motor vehicle with a motor control, which is manufacturer-side designed such that these input signals i receives and generates control commands s for normal operation of the internal combustion engine. In order to achieve an increase in performance compared with normal operation, in the method the input signals i are "amplified" on their way to the motor control and / or the control commands s on their way from the engine control to the internal combustion engine in the sense of an increase in output. This means that from a given input signal i an "amplified" input signal i ^{* is} calculated and forwarded to the motor controller, which there (in normal further processing) leads to a control command which causes a higher power generation of the internal combustion engine than the original input signal i belonging control command , In a similar manner, a "boosted" control command s * is calculated from a given control command s and forwarded to the internal combustion engine, which generates a higher power there than the original control command s. In this sense, in the context of the present application, the term To understand "amplification" of input signals or control commands, even if in individual cases such a "gain" should consist concretely in the reduction of a numerical value or a signal size. The inventive method is characterized in that the gain of the input signals and / or the control commands s is reduced in dependence on the operating condition of the motor vehicle, so that an overload of the drive train of the motor vehicle is avoided. In this case, a reduction of the gain includes in particular that the reduced-amplified control command s ** is closer to the original control command s than the amplified control command s *.

An amplification of the input signals i and / or the control commands s can be achieved in particular by the multiplication by a constant factor k , this factor having a value greater than or equal to one, if the input signal i and / or the control command s is a positive quantity and the power of the internal combustion engine monotonically increasing depends on this. In this case, the reduction of the gain can be done by reducing the said factor k.

With the method according to the invention, the available power potential in the control of an internal combustion engine can be better utilized by increasing the basic gain, at the same time maintaining the load limits of the motor vehicle by the situation-dependent reduction of the gain and thus normal life of the drive train can be achieved. It turns out that the load limits of the drive train can be very different depending on the operating condition. In the hitherto customary orientation on a single, lump-sum load limit, therefore, in many operating states of the motor vehicle an increase in power potential remained unused and / or the respective load limit was exceeded in other operating states and the service life of the drive train was thus reduced. In contrast, the method according to the invention, as a result, effects an improved adaptation of the power increase to the operating state of the motor vehicle.

The type of control commands s or the amplified control commands s ^* or the reduced-amplified control commands s ^** may vary depending on the underlying motor type. In particular, these may be signals which predetermine the fuel quantity to be injected and / or the charge pressure, the boosted control commands s ^* or s ^** leading to the injection of a larger fuel quantity or to a higher charge pressure than the unamplified control commands s.

The input signals i, the amplified input signals i * and the reduced-amplified input signals i ** may, for. B. to the measured boost pressure of the engine, the amplified input signals i ^* or i ^** lead to a higher boost pressure than the unamplified input signals i .

According to a preferred embodiment of the method, the gain of the input signals i and / or the control commands s is reduced as a function of the engaged gear of a transmission gearbox of the motor vehicle. In particular, the amplification of the input signals i and / or the control commands s can be maximally reduced when the first gear is engaged and / or the reverse gear is engaged. In extreme cases, the gain of the input signals and / or the control commands in these cases can also be completely suppressed, so that the original input signals i and / or control commands s are forwarded to the engine control or internal combustion engine. With the consideration of the engaged gear and in particular the small gears can be ensured that in these critical cases, the permissible force and torque loads are not exceeded. The transmission gear is thereby spared and its normal life is maintained.

The gear currently engaged in the gearbox is immediately displayed by corresponding signals in many motor vehicles. If such signals are not available, the gear can also be calculated from the driving speed of the motor vehicle and the engine speed, if the adjustable gear ratios in the transmission are known.

According to another embodiment of the method, the gain of the input signals i and / or the control commands s in certain speed ranges of the internal combustion engine can be reduced. Advantageously, this reduction is combined with the above-mentioned, dependent on the engaged gear reduction. Due to the additional consideration of the speed, it is possible to make finer distinctions within an engaged gear, since the load limit is usually speed-dependent. In this way, the performance enhancement potential can be exploited even better.

According to a development of the method, the amplification of the input signals i and / or of the control commands s is not reduced when the motor vehicle accelerates. An acceleration state of the motor vehicle can be detected in particular by observing the change in rotational speed of the internal combustion engine and / or the change in the vehicle speed. It has been found that in an acceleration state, the forces generated by the internal combustion engine are consumed mainly for accelerating the components of the internal combustion engine and therefore are not effective as loads on the subsequent drive train and the transmission gear. For this reason, the power increase in acceleration states can take on greater values without disadvantages, which is achieved by the suspension of the drive train's gentle reduction of the gain.

The method described above can be implemented in a particularly simple manner without changes to the hardware of the motor vehicle by a corresponding adaptation of the programming of the engine control. The amplification of the input signals and / or the control commands takes place here by conversions within the engine control.

The invention further relates to a device for increasing the performance of the internal combustion engine of a motor vehicle, preferably a diesel engine and / or a gasoline engine with charging, said device being arranged functionally between the engine control of the motor vehicle and the internal combustion engine. The device receives there to the engine control directed input signals i and / or coming from the engine control commands s, which are designed for normal operation of the internal combustion engine, and passes these input / control commands as amplified input / control commands to the engine control / internal combustion engine, as explained above with respect to the method "Gain" of the input signals / control commands in terms of a resulting increase in performance of the internal combustion engine is to be understood. The device is characterized in that it is designed to carry out a method of the kind explained above. That is, the device is designed in particular to reduce the gain of the input signals i and / or the control commands s depending on the operating state of the motor vehicle so that an overload of the drive train of the motor vehicle is avoided and corresponding load limits are met.

The device may in particular have signal inputs for the engine speed, the vehicle speed and / or the currently engaged gear of a transmission of the motor vehicle. The presence of such signal inputs makes it possible to reduce the amplification of the input signals and / or the control commands as a function of the values mentioned or the values calculated therefrom. In particular, the reduction can be designed maximum when engaged first gear or reverse gear.

In the following, the invention will be explained in more detail with reference to the figure by way of example. The single FIGURE shows schematically the components of a motor vehicle with a performance increase of the engine according to the invention.

In the provided with the reference numeral 3 internal combustion engine may be in particular a diesel engine whose power is controlled by the injected fuel quantity. The torque generated by the diesel engine 3 is transmitted in the following drive train via a transmission gear 4 to the wheels 5 of the motor vehicle.

A motor controller 1 configured in a conventional manner by the manufacturer of the motor vehicle generates (among other things) control commands s for the internal combustion engine 3, the value of which determines, for example, the length and size of the injection strokes and thus the quantity of fuel to be injected. In an unchanged after its production motor vehicle, the control commands s are forwarded directly to the internal combustion engine 3.

To increase the performance of the motor vehicle as part of a tuning, it is known to set a device 2 ("black box") in the signal transmission path between the engine controller 1 and the engine 3, said device 2 receives the normal control commands s of the engine controller 1 and amplified therefrom control signals s ^* calculated and forwarded to the internal combustion engine 3. The amplified control signals s ^* lead to the internal combustion engine to generate a higher power. For example, the injection strokes predetermined by the engine controller 1 may be lengthened and / or increased. The calculation of the amplified control signal s ^* takes place in the simplest case by the multiplication by a constant factor k according to FIG $$s^{*}=k\cdot s\left(\mathit{k}\mathit{\ge }\mathit{1}\right)\mathrm{,}$$

Additionally or alternatively, the apparatus 2 may also determined for the engine controller 1 inputs i from the engine, for example, as "reinforce" the measured boost pressure that their (normal) further processing in the engine controller 1 leads to an increased power of the internal combustion engine. 3 The calculation of the amplified input signal i ^* can also be done by multiplication by a factor k .

bzw. $$s^{**}=r\cdot s^{*}=r\cdot k\cdot s\left(\mathit{k}\mathit{\ge }\mathit{1}\right)\mathrm{.}$$

The performance increase described so far by the device 2 has the disadvantage that in certain operating conditions, the load limit of the drive train may be exceeded by the increased forces and torques or that in other operating conditions, the performance increase potential may not be exploited to the maximum. In order to avoid these disadvantages, the device 2 according to the invention is designed such that this depending on the operating condition of the internal combustion engine, the gain the input signals i and the control signal s reduced. That is to say that a "reduced-amplified" input signal i ^{** is determined} from the input signal i and a "reduced-amplified" control signal s ^{** is} determined from the control signal s of the motor controller 1. This can be achieved, for example, by multiplying the above-mentioned amplified input signal i ^* or control signal s ^* by a reduction factor r ≦ 1 according to FIG $$i^{**}=r\cdot j^{*}=r\cdot k\cdot i\left(\mathit{k}\mathit{\ge }\mathit{1}\right)$$

respectively. $$s^{**}=r\cdot s^{*}=r\cdot k\cdot s\left(\mathit{k}\mathit{\ge }\mathit{1}\right)\mathrm{,}$$

Since the introduced reduction factor r ensures compliance with the load limits of the drive train, the factor k can be chosen to be greater from the outset in order to exploit the maximum increase in performance in all conceivable operating states. Furthermore, the device 2 will generally calculate the input signal i ^** or the control signal s ^** directly (without the intermediate step via i ^* or s ^* ) from the signal i or s .

The reduction of the gain may depend, in particular, on the gear engaged in the transmission 4, in the simplest case the amplification in the first gear and / or in the reverse gear being omitted altogether, so that in this case r = 1 / k and * i ^** = i or s ^** = s is. In order to make a gear-dependent reduction, the device 2 must receive corresponding information about the currently engaged gear. This can for example be done via a directly from the transmission gear 4 (or another source of engine / vehicle management) coming gear signal g . For the generation of the signal g , for example, a contact switch for the reversing spotlight can be accessed, since the illumination of the return lights indicates an engaged reverse gear. If further only the first gear is of interest, an additional contact switch in the gear 4 can be provided for this. Further For example , it is possible to calculate the currently engaged gear from a signal indicating the vehicle speed v and the engine speed n, wherein the transmission ratios available in the transmission 4 are to be assumed to be known.

A further improvement of the power increase is achieved by reducing the gain in first gear only over a certain speed range. The maximum value of the torque is then available over a wider speed range.

Furthermore, the device 2 may be designed so that in the case of a high acceleration of the motor vehicle no or only a very small reduction in the gain takes place. In the acceleration case, namely a large part of the energy and forces to accelerate the parts of the internal combustion engine 3 is consumed, so that arrive despite unimpeded accelerator pedal only uncritical torque values in the transmission 4. Therefore, a reduction of the power increase can be dispensed with. The acceleration case can be detected by the device 2, for example by a large rate of change of the engine speed n.

The dependencies of the gain reduction of various operating parameters enumerated above and only to be understood as examples can be expressed by a corresponding functional dependency of the reduction factor r, ie r = r (n, g, v,...).

Furthermore, it is possible that the function of the device 2 is achieved by a corresponding programming of the engine control 1, so that no interference in the hardware of the motor vehicle are required.

Claims (9)

1. Method for subsequently increasing the power ('tuning') of an internal combustion engine (3) of a motor vehicle having an engine controller (1) which receives input signals (i) and generates control commands (s) for a normal operating mode of the internal combustion engine, and having a device arranged functionally between the engine controller (1) and the internal combustion engine (3), in which the input signals and/or the control commands are amplified in order to subsequently increase the power, and which is not necessary for the normal operating mode of the internal combustion engine, characterized in that in the said device the amplification is reduced as a function of the operating state of the motor vehicle in such a way that overloading of the drive train of the motor vehicle is avoided, and that the amplification of the control command(s) is not reduced when the motor vehicle accelerates.
2. Method according to Claim 1, characterized in that the control commands (s) define the quantity of fuel to be injected and/or the charge pressure, and characterized in that the amplified control commands give rise to the injection of a relatively large quantity of fuel or to a higher charge pressure.
3. Method according to Claim 1 or 2, characterized in that the amplification is reduced as a function of the selected gear of a speed transforming transmission (4) of the motor vehicle.
4. Method according to Claim 3, characterized in that the amplification is reduced in the first gear and/or in the reverse gear to a maximum degree and/or suppressed entirely.
5. Method according to Claim 3 or 4, characterized in that the selected gear is calculated from the velocity (v) of the vehicle and the engine speed (n).
6. Method according to at least one of Claims 1 to 5, characterized in that the amplification is reduced in specific speed ranges of the internal combustion engine (3).
7. Device (2) for subsequently increasing the power ('tuning') of the internal combustion engine (3) of a motor vehicle, the device being arranged functionally between the engine controller (1) and the internal combustion engine (3) and being embodied in such a way that it amplifies input signals (i) directed at the engine controller and/or control commands (s), intended for the normal operation of the internal combustion engine, of the engine controller in order to increase the power, before said input signals (i) and/or control commands (s) are passed on, and the device not being necessary for the normal operating mode of the internal combustion engine (3), characterized in that the device (2) is also embodied in such a way that it carries out a method according to at least one of Claims 1 to 6.
8. Device according to Claim 7, characterized in that it has signal inputs for the engine speed (n), the velocity (v) of the vehicle and/or the selected gear (g) of a speed transforming transmission (4) of the motor vehicle.
9. Device according to Claim 7 or 8, characterized in that the internal combustion engine is embodied as a diesel engine (3) and/or as a spark ignition engine with super charging.

Images