DE4224426A1 - Method to limit output of IC engine in motor vehicle - uses control arrangement of intake to adjust intake tube length groups - Google Patents

Abstract

The engine output is limited via the control member arrangement of an intake system. This is used to adjust the various intake tube length and/or intake tube groups. The output is limited when a max. permissible RPM value of the engine and/or a max. high speed value of the vehicle is reached. The output limitation by control member arrangement is overlaid additionally by further output-reducing methods. This takes place, when the process only is not sufficient to prevent exceeding the max. permissible RPM value and/or max. permissible high speed. USE/ADVANTAGE - Simple and economical output reduction while maintaining optimum combustion and minimum exhaust gas emission.

Description

The invention relates to a method for loading Limiting the performance of an internal combustion engine in one Motor vehicle.

With the late adjustment of the ignition angle, the scarf the injection valves and the reduction of the throttle Selklappenöffnungswinkel are such procedures widely known.

However, these known methods either deteriorate the combustion and thus increase the exhaust emissions NEN or you need complex control systems with own actuators and are therefore expensive.

It is an object of the invention to be simple and cost-effective favorable performance reduction while maintaining optimal combustion and minimal exhaust emissions create.  

The invention solves the problem according to claim 1 using an existing one in the vehicle Intake system for speed-dependent improvement the combustion chamber filling between different suction pipe lengths and / or suction pipe groups using a Actuator arrangement switches to in connection with fuel metering primarily an efficient and pollutant-free operation of the internal combustion engine to reach.

According to the direct impact of one of the like intake manifold switching on the performance of the focal exploited for additional functions in the engine Motor vehicle that is not with the primary function of the Intake system, but with the power of the internal combustion engine machine are directly related.

DE 40 28 443 A1, for example, describes a convention Lich intake system known in the case of a pre pipe arrangement to the combustion chambers of each cylinder because both a long and a short suction pipe lead, the short suction pipes by means of flaps in be closed in a low speed range and are open in a high speed range.

To reduce the power according to the invention Flaps are closed in the high speed range, if, for example, a higher priority is exceeded preventive performance-related limits shall be.

An advantageous development of the invention The method is claimed in claim 2.

For example, the internal combustion engine is a force Protected vehicle from overturning by Errei  the maximum permissible speed order of the known intake system in one performance-reducing position is brought, d. H. e.g. B. applied to the known from DE 40 28 443 A1 suction system by closing the flaps.

Here, for example, is the protection of the internal combustion engine Priority of the machine is given higher priority than the Opti performance, which means that the same system can be used stem two different functions at different times be met without worsening the exhaust gas emissions tern.

Furthermore, the vehicle speed is reduced to one maximum permissible value is limited by the Performance by hiring an appropriate bottom sition of the actuator arrangement of the intake system redu is decorated.

Another advantageous embodiment of the invention According to the method is the subject of claim 3.

Reaches that through the actuator arrangement of the intake system stems existing possibility of influencing the performance not out to counter the primary function of an An suction system to achieve sufficient power limitation chen, an additional performance reduction by conventional methods, e.g. B. injection shutdown, be overlaid. Through this overlay the Degree of performance reduction by the conventional Procedures and their adverse effects at least diminished. For example with a lei Power reduction simply by switching off the On spray valves creates an uncomfortable jerking of the  Vehicle because z. B. with group shutdown of Injectors a sudden drop in performance by about 60%. In addition, the ent standing excess air the catalytic exhaust gas action disturbed. With a combination of conventional Chen and the inventive method is a lei Stungsredierung better dosed, which means a com loss of forest is largely prevented.

In the drawing is an embodiment of the Erfin shown. It shows

Fig. 1 is a schematic diagram of a known group suction system with an actuator for switching dynamically different suction pipe groups and

Fig. 2 shows the torque curves of the internal combustion engine depending on the position of the actuator of this group pensauganlage in connection with a power reduction when reaching a maximum permissible maximum vehicle speed.

In Fig. 1 at the input of a Frischluftansaugleitung is shown a according to the accelerator setting adjustable throttle valve (1). The fresh air intake leads after the throttle valve ( 1 ) to a collector ( 2 ) which branches into two front pipes ( 3 , 4 ). At the end of the front pipes ( 3 , 4 ) opposite the collector ( 2 ), an adjustable connecting flap ( 5 ) is arranged between these front pipes ( 3 , 4 ). The front pipe ( 3 ) and the front pipe ( 4 ) each branch into two individual pipes ( 8 , 9 and 6 , 7 ) after the connecting flap ( 5 ).

Each of the individual tubes ( 6 , 7 , 8 , 9 ) ends in a combustion chamber of a four-cylinder internal combustion engine ( 10 ), each of which is not visible here and is assigned to a cylinder.

In the following, in connection with FIG. 2, functionally in particular the effects on the performance of the internal combustion engine ( 10 ) related to the position of the connecting flap ( 5 ) will be discussed.

In the suction system known from FIG. 1, two settings of the connecting flap ( 5 ) are set. In a lower defined speed range, the connec tion flap ( 5 ) is closed, ie the front pipes ( 3 , 4 ) are separated. As a result, the cylinders belonging to the individual tubes ( 8 , 9 ) or to the individual tubes ( 6 , 7 ) suck in groups from a front tube ( 3 ) or ( 4 ). When the front pipes ( 3 , 4 ) are separated by the connection flap ( 5 ), each front pipe in connection with a single pipe acts like a long oscillating pipe with a low natural frequency. The closed connection flap ( 5 ) improves the cylinder filling in a lower speed range.

In a defined upper speed range, a long vibrating tube is dynamically too slow. Therefore, the connecting flap ( 5 ) is opened in this speed range, ie the front pipes ( 3 , 4 ) are connected to each other. As a result, the individual tubes ( 6 , 7 , 8 , 9 ) now act dynamically as short oscillating tubes. Short vibrating tubes with a high natural frequency improve the cylinder filling at high speeds.

The described effects of the two positions of the connecting flap ( 5 ) are shown in FIG. 2 with characteristic motor characteristic curves, ie with courses of the torque M _{Mot of} the internal combustion engine depending on the speed n and the position of the connecting flap ( 5 ).

The maximum possible engine torque M _Mot of the engine torque characteristic curve associated with the closed state of the connecting flap ( 5 ) occurs at a significantly lower speed n than the maximum possible engine torque M _Mot of the engine torque characteristic curve associated with the open state of the connecting flap ( 5 ).

Primarily, such a suction system should provide the maximum possible power or the maximum possible engine torque M _Mot ; ie the control of the connection flap ( 5 ) must generate the envelope of the two Darge engine torque characteristics.

For example, as in this exemplary embodiment, as a performance-limiting function, a maximum permissible vehicle speed v _{max is} not to be exceeded, the connecting flap ( 5 ) is closed, provided that it is currently open. In a first example, the maximum permissible vehicle speed v _{max is to be} reached at a speed n ₂ . Thereupon the connecting flap ( 5 ) originally opened at the speed n _{2 is} closed. The engine torque M _{Mot is} reduced, as shown in Fig. 2 with an arrow, by the difference between the engine torque M _Mot , which is in accordance with the effective engine torque characteristic curve for the speed n ₂ when the connection is open, and the engine torque M _Mot that emerges for the same speed n ₂ from the effective engine torque characteristic curve when the connection flap is closed.

In Fig. 2, a driving resistance torque curve is also drawn, which represents the engine torque M _Mot depending on the speed n, which is at least required in each case in order to maintain sufficient traction for maintaining a vehicle speed.

If, for example, the maximum permissible vehicle speed v _max already occurred at a speed n ₁ , closing the connecting flap ( 5 ) would not reduce the power sufficiently to prevent the maximum permissible vehicle speed v _max from being exceeded, since there is still a tractive force shot is present. The remaining excess traction is determined by the difference between the running resistance torque from the road load torque characteristic at the rotational speed N ₁ and the motor torque M _Mot formed which for the rotational speed n is ₁ from the effective to the closed connection flap (5) engine torque characteristic is obtained. In this case, the reduction in performance is, depending on the need, exclusively or in addition by another performance-reducing method, such as. B. retarding ignition timing or switching off a spray valves performed.

In addition, it should be noted that the invention also includes continuous power reduction, if the intake system has one or more actuators contains that not only stepwise in two positions, but continuously in any number of positions are adjustable.

Claims (3)

1. A method for limiting the power of an internal combustion engine in a motor vehicle, characterized in that the limitation of the power is carried out by means of an actuator arrangement of an intake system, through which different suction pipe lengths and / or intake pipe groups are set. 2. The method according to claim 1, characterized records that the limitation of performance at Er range of a maximum permissible speed value the internal combustion engine and / or one maximum casual maximum speed value of the force vehicle is made. 3. The method according to claim 2, characterized records that the limitation of performance by means of the actuator arrangement of the intake system through other performance-reducing processes is superimposed if the power limitation with means of the actuator arrangement of the intake system al line is not sufficient to exceed the ma maximum permissible speed value and / or the maxi times permissible maximum speed value prevent.